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Sample records for deep hess observations

  1. Deep H.E.S.S. Observations of the Supernova Remnant RX J0852.0-4622

    NASA Astrophysics Data System (ADS)

    Nukri, Komin; Schwanke, Ullrich; Arribas, Manuel Paz; Sushch, Iurii

    2016-07-01

    Shell-type supernova remnants (SNRs) are the prime candidates for being the accelerators of the Galactic Cosmic Rays. This hypothesis is supported by the observation of their non-thermal emission from radio up to TeV gamma-rays. The SNR RX J0852.0-4622 (also called Vela Junior) is one of the few supernova remnants where the shell is resolved in TeV gamma rays. It has been extensively observed with the High Energy Stereoscopic System (H.E.S.S.). This new data set allows for an unprecedented look at this supernova remnant. The energy spectrum obtained with H.E.S.S. is combined with the results at GeV energies obtained with the Fermi/LAT. This combined spectrum allows the investigation of the underlying particle population with gamma-ray data alone. The significant detection of a cut-off in the energy spectrum can be used to estimate the maximum energy of the particles accelerated in the SNR. The large angular extent of the SNR together with the good angular resolution of H.E.S.S. allows spatially resolved spectroscopy studies. These results will be presented at the conference. Even though no conclusion on a leptonic or hadronic origin of the emission can be drawn these new data allow a better understanding of particle acceleration in SNRs.

  2. Seismotectonics of mid-ocean ridge propagation in Hess Deep.

    PubMed

    Floyd, Jacqueline S; Tolstoy, Maya; Mutter, John C; Scholz, Christopher H

    2002-11-29

    Hydroacoustic data from the eastern equatorial Pacific reveal low-magnitude seismicity concentrated at the propagating tip of the Galapagos Rise in Hess Deep. The patterns of seismicity and faulting are similar to those observed in the process zone of laboratory-scale propagating tensile cracks. Because the fracture energy required for propagation scales with crack length and process zone size, it follows that ridges can propagate stably in the brittle crust without exceptional resisting forces as proposed by previous models based on linear elastic fracture mechanics.

  3. A Dual-Porosity, In Situ Crystallisation Model For Fast-Spreading Mid-Ocean Ridge Magma Chambers Based Upon Direct Observation From Hess Deep

    NASA Astrophysics Data System (ADS)

    MacLeod, C. J.; Lissenberg, C. J.

    2014-12-01

    We propose a revised magma chamber model for fast-spreading mid-ocean ridges based upon a synthesis of new data from a complete section of lower crust from the East Pacific Rise, reconstructed from samples collected from the Hess Deep rift valley during cruise JC21. Our investigation includes detailed sampling across critical transitions in the upper part of the plutonic section, including the inferred axial melt lens (AML) within the dyke-gabbro transition. We find that an overall petrological progression, from troctolite and primitive gabbro at the base up into evolved (oxide) gabbro and gabbronorite at the top of the lower crustal section, is mirrored by a progressive upward chemical fractionation as recorded in bulk rock and mineral compositions. Crystallographic preferred orientations measured using EBSD show that the downward increase in deformation of mush required in crystal subsidence models is not observed. Together these observations are consistent only with a model in which crystallisation of upward migrating evolving melts occurs in situ in the lower crust. Over-enrichment in incompatible trace element concentrations and ratios above that possible by fractional crystallisation is ubiquitous. This implies redistribution of incompatible trace elements in the lower crust by low porosity, near-pervasive reactive porous flow of interstitial melt moving continuously upward through the mush pile. Mass balance calculations reveal a significant proportion of this trace element enriched melt is trapped at mid-crustal levels. Mineral compositions in the upper third to half of the plutonic section are too evolved to represent the crystal residues of MORB. Erupted MORB therefore must be fed from melts sourced in the deeper part of the crystal mush pile, and which must ascend rapidly without significant modification in the upper plutonics or AML. From physical models of mush processes we posit that primitive melts are transported through transient, high porosity

  4. Exploring the plutonic crust at a fast-spreading ridge:new drilling at Hess Deep

    SciTech Connect

    Gillis, Kathryn M.; Snow, Jonathan E.; Klaus, Adam; Guerin, Gilles; Abe, Natsue; Akizawa, Norikatsu; Ceuleneer, Georges; Cheadle, Michael J.; Adriao, Alden de Brito; Faak, Kathrin; Falloon, Trevor J.; Friedman, Sarah A.; Godard, Marguerite M.; Harigane, Yumiko; Horst, Andrew J.; Hoshide, Takashi; Ildefonse, Benoit; Jean, Marlon M.; John, Barbara E.; Koepke, Juergen H.; Machi, Sumiaki; Maeda, Jinichiro; Marks, Naomi E.; McCaig, Andrew M.; Meyer, Romain; Morris, Antony; Nozaka, Toshio; Python, Marie; Saha, Abhishek; Wintsch, Robert P.

    2013-02-28

    Integrated Ocean Drilling Program (IODP) Hess Deep Expedition 345 was designed to sample lower crustal primitive gabbroic rocks that formed at the fast-spreading East Pacific Rise (EPR) in order to test models of magmatic accretion and the intensity of hydrothermal cooling at depth. The Hess Deep Rift was selected to exploit tectonic exposures of young EPR plutonic crust, building upon results from ODP Leg 147 as well as more recent submersible, remotely operated vehicle, and near-bottom surveys. The primary goal was to acquire the observations required to test end-member crustal accretion models that were in large part based on relationships from ophiolites, in combination with mid-ocean ridge geophysical studies. This goal was achieved with the recovery of primitive layered olivine gabbros and troctolites with many unexpected mineralogical and textural relationships, such as the abundance of orthopyroxene and the preservation of delicate skeletal olivine textures.

  5. Iodp Exp 345: Orthopyroxene Omnipresent in Layered Gabbros from the Hess Deep, EPR

    NASA Astrophysics Data System (ADS)

    Koepke, J.; Abe, N.; Akizawa, N.; Falloon, T.; Hoshide, T.; Jean, M. M.; Maeda, J.; Snow, J. E.

    2013-12-01

    Drilling studies of the lower oceanic crust in the framework of the IODP (Integrated Ocean Drilling Program) have the objective of understanding the construction processes of the ocean crust. Currently, much attention is focused on the relatively inaccessible fast spreading lower ocean crust (IODP Hole 1256D, ODP Hole 894G, this study). At the Hess Deep Rift, propagation of the Cocos Nazca Ridge into young, fast-spreading East Pacific Rise crust generates extensive exposures of the plutonic lower crust. IODP Exp. 345 drilled a dismembered section of lower crust at ~4850 m water depth under challenging borehole conditions. We drilled three main holes between 35-110 mbsf with ~30% recovery, returning cores relevant to the igneous evolution of the lower crust. The drilled cores show spectacular modal and/or grain size layering present in >50% of the recovered core. Typical rocks are primitive (Mg# 75-89) olivine gabbro, troctolitic gabbro and olivine gabbronorite. A very significant first-order observation from this expedition is that orthopyroxene was found as an abundant phase in many of the layered primitive gabbroic rocks. This was unexpected, since experiments on the liquid line of descent of MORB show that orthopyroxene always crystallizes late, at low melt fractions, and commonly interstitially. Recovered rocks at Site U1415, however, show that orthopyroxene crystallization is common: both as an interstitial phase in primitive troctolite (crystallization even before clinopyroxene), as a cumulus phase coexisting with clinopyroxene in primitive olivine gabbros and as monomineralic bands in primitive gabbros of the Multitextured Layered Gabbro series in Hole U1415P. None of these features are commonly observed in ocean floor gabbros. The discovery of orthopyroxene in primitive lithologies in high quantities in the lower crustal section at Hess Deep is a novel finding, although the presence of orthopyroxene in one primitive gabbro sample from Hess Deep was reported

  6. Pb-isotopic Features of Primitive Rocks from Hess Deep: Distinguishing between EPR and Cocos-Nazca Mantle Source(s)

    NASA Astrophysics Data System (ADS)

    Jean, M. M.; Falloon, T.; Gillis, K. M.

    2014-12-01

    We have acquired high-precision Pb-isotopic signatures of primitive lithologies (basalts/gabbros) recovered from IODP Expedition 345.The Hess Deep Rift, located in the vicinity of the Galapagos triple junction (Cocos, Nazca, and Pacific), is viewed as one the best-studied tectonic windows into fast-spreading crust because a relatively young (<1.5 Ma) cross section of oceanic crust. This allows for (1) characterization of the mantle source(s) at Hess Deep, (2) insight into the extent of isotopic homogeneity or heterogeneity in the area, and (3) constrain the relative contributions from the intruding Cocos-Nazca spreading center. The observed Pb-isotopic variation at Hess Deep covers almost the entire range of EPR MORB (10°N to -5°S). Hess Deep samples range from 208Pb (37.3-38.25), 207Pb (15.47-15.58), 206Pb (17.69-18.91). These compositions suggest that this part of Hess Deep mantle is no more isotopically homogeneous than EPR mantle. Two distinct arrays are also observed: 208Pb-enriched (r2=0.985; n=30) and 208Pb-depleted (r2=0.988; n=6). The 208Pb/204Pb isotopes indicates that the Pb-source for some of the samples at Hess Deep had very low Th/U ratios, whereas other areas around the Galapagos microplate seem to have more "normal" ratios. These trends are less apparent when viewed with 207Pb-isotopes. Instead, the majority of basalts and gabbros follow the NHRL, however, at the depleted-end of this array a negative excursion to more enriched compositions is observed. This negative but linear trend could signify an alteration trend or mixing with an EMI-type mantle source, yet this mixing is not observed with 208Pb. This trend is also observed at Pito Deep, which has similar origins to Hess Deep (Barker et al., 2008; Pollack et al., 2009). The Galapagos region has been considered a testing ground for mixing of HIMU, Enriched Mantle, and Depleted Mantle reservoirs (e.g., Schilling et al., 2002). According to our data, however, an EPR-component must also be

  7. Morphotectonics of Hess Deep: Preliminary Results of RRS James Cook Cruise JC21

    NASA Astrophysics Data System (ADS)

    MacLeod, C. J.; Teagle, D. A.; Gillis, K. M.; Shillington, D. J.; Scientific Party, R. J.

    2008-12-01

    Hess Deep (2° 15'N, 101° 30'W), a rifted depression formed by the westward propagation of the Cocos-Nazca plate boundary towards the East Pacific Rise, provides unique exposures of the deeper levels of ocean crust formed at a fast spreading mid-ocean ridge. In January-February 2008, during RRS James Cook cruise JC21, we conducted a site survey of Hess Deep in support of proposed Integrated Ocean Drilling Program operations there. Using the Isis remotely-operated vehicle we acquired microbathymetry and collected 145 samples from an 11 sq km area from the nadir of the Deep (5400m water depth) up and onto the intra-rift ridge (3000m), a horst block within the broader rift valley that had previously been drilled at ODP Sites 894 and 895. From previous investigations it was considered that a continuous section through the lower crust down to the Moho transition zone existed in this region, tilted northwards as a result of extension during opening of the rift. Detachment faulting, perhaps assisted by serpentinite diapirism, had been invoked to explain uplift of the intra-rift ridge (Francheteau et al., 1990; MacLeod et al., 1996). However, our detailed mapping and sampling indicates a significantly more complex distribution of rock types across Hess Deep than previously supposed, and that a re-examination of the existing models for the structure and tectonic evolution of the rift is required. We here present our new geological constraints and propose a revised model for the opening of Hess Deep and uplift of the intra-rift ridge, emphasising the role of previously unsuspected neotectonics in controlling the structure of the rift valley. Francheteau, J. et al., 1990. 1 Ma East Pacific Rise oceanic crust and uppermost mantle exposed by rifting in Hess Deep (equatorial Pacific Ocean). EPSL 101, 281-295. MacLeod, C.J. et al., 1996. Tectonics of Hess Deep: A synthesis of drilling results from Leg 147. Proc. ODP, Sci. Res. 147, College Station TX, 461-475.

  8. VERITAS and H.E.S.S. observations of the gamma-ray binary HESS J0632+057

    NASA Astrophysics Data System (ADS)

    Bordas, P.; H. E. S. S. Collaboration; Maier, G.; VERITAS Collaboration

    2012-12-01

    HESS J0632+057 has been recently identified as a new gamma-ray binary system. The source, located in the Monoceros region and associated with the massive Be star MWC 148, shows variability from radio to very high energy (VHE) gamma-rays, displaying a maximum of its non-thermal emission about 100 days after periastron passage (at orbital phases ~ 0.3). We present here the results obtained with the VERITAS and H.E.S.S Cherenkov telescopes spanning a wide time interval from 2004 to 2012. The source is detected at TeV gamma-rays at a high significance level at phases ~ 0.3. We also report for the first time TeV observations belonging to orbital phases never explored so far. The VHE gamma-ray results are discussed in a multiwavelength context, focusing on contemporaneous observations obtained with the Swift-XRT.

  9. Possible dark matter origin of the gamma ray emission from the Galactic Center observed by HESS

    NASA Astrophysics Data System (ADS)

    Cembranos, J. A. R.; Gammaldi, V.; Maroto, A. L.

    2012-11-01

    We show that the gamma ray spectrum observed with the HESS array of Cherenkov telescopes coming from the Galactic Center region and identified with the source HESS J1745-290 is well fitted by the secondary photons coming from dark matter (DM) annihilation over a diffuse power law background. The amount of photons and morphology of the signal localized within a region of few parsecs, require compressed DM profiles as those resulting from baryonic contraction, which offer ˜103 enhancements in the signal over DM alone simulations. The fitted background from HESS data is consistent with recent Fermi-LAT observations of the same region.

  10. Evidence for pervasive melt-rock reaction within the uppermost mantle at Hess Deep

    NASA Astrophysics Data System (ADS)

    Shejwalkar, A. S.; Coogan, L. A.

    2015-12-01

    A suite of spinel harzburgites from ODP Site 895 at Hess Deep have been analysed for the major and trace element compositions of the major mineral phases and of the bulk rock to investigate the effect of melt rock reaction on mineral and bulk rock geochemistry. The harzburgites are at the depleted end of the global array of abyssal peridotite compositions in terms of moderately incompatible elements such as Al2O3, CaO, V and Sc. The whole-rock HREE abundances can be modeled as the residues of 15-25% near fractional melting of DMM however the LREE have much higher concentrations than predicted by this model and the samples show a significant positive Eu anomaly. The data can be fit well by a model of near-fractional melting followed by 0.5 to 2% precipitation of plagioclase that has a trace element composition in equilibrium with MORB. Plagioclase impregnation is common in the mantle section drilled at Site 895 although plagioclase is not observed petrographically in the samples studied here. The rocks are 20-70% altered and we hypothesize that plagioclase was entirely replaced during this alteration. The LREE-enrichment, relative to a melting residue, observed in the bulk-rock is not observed in clinopyroxene compositions. One explanation for this could be that the rocks were relatively cool when plagioclase impregnation occurred meaning diffusion was inefficient at modifying the clinopyroxene compositions [e.g. 1]. Whether melt-rock reaction occurs on- or off-axis is currently being investigated. Refs: [1] Niu, 2004. Journal of Petrology. Volume 45 (12), 2423-2458.

  11. Rapidly-formed ferromanganese deposit from the eastern Pacific Hess Deep

    USGS Publications Warehouse

    Burnett, W.C.; Piper, D.Z.

    1977-01-01

    A thick ferromanganese deposit encrusting fresh basaltic glass has been dredged from the Hess Deep in the eastern Pacific. Contiguous layers within the Fe-Mn crust have been analysed for uranium-series isotopes and metal contents. The rate of accumulation of the deposit, based on the decline of uranium-unsupported 230Th, is calculated to be approximately 50 mm per 106 yr. Based on hydration-rind dating of the underlying glass and an 'exposure age' calculation, this rate is concluded to be too slow, and an accretion rate on the order of 1 mm per 103 yr is more consistent with our data. ?? 1977 Nature Publishing Group.

  12. Hydrothermal spinel, corundum and diaspore in lower oceanic crustal troctolites from the Hess Deep Rift

    NASA Astrophysics Data System (ADS)

    Nozaka, Toshio; Meyer, Romain; Wintsch, Robert P.; Wathen, Bryan

    2016-06-01

    Aluminous spinel, corundum and diaspore are reported from intensely altered parts of primitive troctolites recovered from IODP Site U1415 at the Hess Deep Rift. The spinel is green-colored, has an irregular shape, has low Cr concentrations, and is so distinct from primary igneous chromite. Corundum and diaspore occur mainly at the rims of green spinel grains with a texture suggesting a sequential replacement of spinel by corundum, and then corundum by diaspore. The green spinel is associated with anorthite and pargasite, which is overgrown by tremolite that forms coronitic aggregates with chlorite around olivine. These petrographic observations are supported by pressure-temperature pseudosections, which predict spinel + pargasite stability field, and tremolite/hornblende + chlorite field at lower temperature conditions. From these pseudosections and simplified system phase diagrams, estimated formation temperature conditions calculated at 2 kbar are 650-750 °C for spinel + pargasite, 410-690 °C for tremolite/hornblende + chlorite, 400-710 °C for corundum, and <400 °C for diaspore. Because the aluminous spinel occurs in the domains that were previously occupied by magmatic plagioclase, and because spinel-bearing rocks characteristically have high Al2O3/CaO and Al2O3/SiO2 ratios, it is likely that the stabilization of spinel was caused by the loss of Ca2+ and SiO2(aq) in high-temperature hydrothermal fluids. The results of this study suggest that (1) the concentrations of aluminous phases in the lower oceanic crust are presently underestimated, and (2) chemical modification of the lower oceanic crust due to high-temperature hydrothermal metasomatic reactions could be common near spreading axes.

  13. HESS J1640-465 and HESS J1641-463: Two Intriguing TeV Sources in Light of New Fermi-LAT Observations

    NASA Astrophysics Data System (ADS)

    Lemoine-Goumard, M.; Grondin, M.-H.; Acero, F.; Ballet, J.; Laffon, H.; Reposeur, T.

    2014-10-01

    We report on γ-ray analysis of the region containing the bright TeV source HESS J1640-465 and the close-by TeV source HESS J1641-463 using 64 months of observations with the Fermi Large Area Telescope (LAT). Previously only one GeV source was reported in this region and was associated with HESS J1640-465. With an increased data set and the improved sensitivity afforded by the reprocessed data (P7REP) of the LAT, we now report the detection, morphological study, and spectral analysis of two distinct sources above 100 MeV. The softest emission in this region comes from the TeV source HESS J1641-463 which is well fitted with a power law of index Γ = 2.47 ± 0.05 ± 0.06 and presents no significant γ-ray signal above 10 GeV, which contrasts with its hard spectrum at TeV energies. The Fermi-LAT spectrum of the second TeV source, HESS J1640-465 is well described by a power-law shape of index Γ = 1.99 ± 0.04 ± 0.07 that links up naturally with the spectral data points obtained by the High Energy Stereoscopic System (H.E.S.S.). These new results provide new constraints concerning the identification of these two puzzling γ-ray sources.

  14. HESS J1640–465 AND HESS J1641–463: TWO INTRIGUING TeV SOURCES IN LIGHT OF NEW FERMI-LAT OBSERVATIONS

    SciTech Connect

    Lemoine-Goumard, M.; Grondin, M.-H.; Laffon, H.; Reposeur, T.

    2014-10-10

    We report on γ-ray analysis of the region containing the bright TeV source HESS J1640–465 and the close-by TeV source HESS J1641–463 using 64 months of observations with the Fermi Large Area Telescope (LAT). Previously only one GeV source was reported in this region and was associated with HESS J1640–465. With an increased data set and the improved sensitivity afforded by the reprocessed data (P7REP) of the LAT, we now report the detection, morphological study, and spectral analysis of two distinct sources above 100 MeV. The softest emission in this region comes from the TeV source HESS J1641–463 which is well fitted with a power law of index Γ = 2.47 ± 0.05 ± 0.06 and presents no significant γ-ray signal above 10 GeV, which contrasts with its hard spectrum at TeV energies. The Fermi-LAT spectrum of the second TeV source, HESS J1640–465 is well described by a power-law shape of index Γ = 1.99 ± 0.04 ± 0.07 that links up naturally with the spectral data points obtained by the High Energy Stereoscopic System (H.E.S.S.). These new results provide new constraints concerning the identification of these two puzzling γ-ray sources.

  15. Characterization of the in situ magnetic architecture of oceanic crust (Hess Deep) using near-source vector magnetic data

    NASA Astrophysics Data System (ADS)

    Tominaga, Masako; Tivey, Maurice A.; MacLeod, Christopher J.; Morris, Antony; Lissenberg, C. Johan; Shillington, Donna J.; Ferrini, Vicki

    2016-06-01

    Marine magnetic anomalies are a powerful tool for detecting geomagnetic polarity reversals, lithological boundaries, topographic contrasts, and alteration fronts in the oceanic lithosphere. Our aim here is to detect lithological contacts in fast-spreading lower crust and shallow mantle by characterizing magnetic anomalies and investigating their origins. We conducted a high-resolution, near-bottom, vector magnetic survey of crust exposed in the Hess Deep "tectonic window" using the remotely operated vehicle (ROV) Isis during RRS James Cook cruise JC21 in 2008. Hess Deep is located at the western tip of the propagating rift of the Cocos-Nazca plate boundary near the East Pacific Rise (EPR) (2°15'N, 101°30'W). ROV Isis collected high-resolution bathymetry and near-bottom magnetic data as well as seafloor samples to determine the in situ lithostratigraphy and internal structure of a section of EPR lower crust and mantle exposed on the steep (~20°dipping) south facing slope just north of the Hess Deep nadir. Ten magnetic profiles were collected up the slope using a three-axis fluxgate magnetometer mounted on ROV Isis. We develop and extend the vertical magnetic profile (VMP) approach of Tivey (1996) by incorporating, for the first time, a three-dimensional vector analysis, leading to what we here termed as "vector vertical magnetic profiling" approach. We calculate the source magnetization distribution, the deviation from two dimensionality, and the strike of magnetic boundaries using both the total field Fourier-transform inversion approach and a modified differential vector magnetic analysis. Overall, coherent, long-wavelength total field anomalies are present with a strong magnetization contrast between the upper and lower parts of the slope. The total field anomalies indicate a coherently magnetized source at depth. The upper part of the slope is weakly magnetized and magnetic structure follows the underlying slope morphology, including a "bench" and lobe

  16. Suzaku observations of the old pulsar wind nebula candidate HESS J1356-645

    NASA Astrophysics Data System (ADS)

    Izawa, Masaharu; Dotani, Tadayasu; Fujinaga, Takahisa; Bamba, Aya; Ozaki, Masanobu; Hiraga, Junko S.

    2015-06-01

    A largely extended X-ray emission was discovered around the pulsar PSR J1357-6429 with the Suzaku deep observations. The pulsar, whose characteristic age is 7.3 kyr, is located within the TeV γ-ray source HESS J1356-645. The extended emission is found to have a 1 σ X-ray size of ˜ 4', or ˜ 3 pc at 2.4 kpc, with a small offset from the pulsar. Its X-ray spectrum is well reproduced by a simple power-law model with a photon index of 1.70_{-0.06}^{+0.07}. No significant spatial variation was found for the X-ray photon index as a function of distance from the pulsar. We conclude that the extended emission is associated to the pulsar wind nebula (PWN) of PSR J1357-6429. This is a new sample of largely extended nebulae around middle-aged pulsars. We discuss the evolution of this PWN according to the relic PWN scenario.

  17. Search for dark matter annihilation signatures in H.E.S.S. observations of dwarf spheroidal galaxies

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Backes, M.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carrigan, S.; Casanova, S.; Chadwick, P. M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goudelis, A.; Grondin, M.-H.; Grudzińska, M.; Hadsch, D.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morâ, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Serpico, P.; Sol, H.; Spanier, F.; Spengler, G.; Spieß, F.; Stawarz, L.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; H. E. S. S. Collaboration

    2014-12-01

    Dwarf spheroidal galaxies of the Local Group are close satellites of the Milky Way characterized by a large mass-to-light ratio and are not expected to be the site of nonthermal high-energy gamma-ray emission or intense star formation. Therefore they are among the most promising candidates for indirect dark matter searches. During the last years the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes observed five of these dwarf galaxies for more than 140 hours in total, searching for TeV gamma-ray emission from annihilation of dark matter particles. The new results of the deep exposure of the Sagittarius dwarf spheroidal galaxy, the first observations of the Coma Berenices and Fornax dwarves and the reanalysis of two more dwarf spheroidal galaxies already published by the H.E.S.S. Collaboration, Carina and Sculptor, are presented. In the absence of a significant signal new constraints on the annihilation cross section applicable to weakly interacting massive particles (WIMPs) are derived by combining the observations of the five dwarf galaxies. The combined exclusion limit depends on the WIMP mass and the best constraint is reached at 1-2 TeV masses with a cross-section upper bound of ˜ 3.9 ×10-24 cm3 s-1 at a 95% confidence level.

  18. Characterization of the in situ magnetic and lithologic architecture of Hess Deep using near-bottom vector magnetic data

    NASA Astrophysics Data System (ADS)

    MacLeod, C. J.; Tominaga, M.; Tivey, M.; Morris, A.; Shillington, D. J.

    2010-12-01

    Marine magnetic anomalies are a powerful tool in detecting not only geomagnetic polarity reversals but also lithological boundaries, topographic contrasts, and alteration fronts in the oceanic lithosphere. Recent progress in marine magnetic studies shows that the lower oceanic crust is an integral part of the magnetic source layer and a complete understanding of oceanic crustal magnetization must incorporate knowledge of this lower crust as well as the extrusive upper crust. To fully investigate the possible origins of magnetic anomalies in fast-spreading lower crust, we analyzed high-resolution, near-bottom, 3-component magnetic data acquired at the Hess Deep “tectonic window” by RRS James Cook cruise JC-21. Hess Deep is located at the western tip of the propagation rift of the Cocos-Nazca plate boundary near the East Pacific Rise (2° 15’N, 101° 30’W). Remotely Operated Vehicle (ROV) ISIS collected high-resolution bathymetry and magnetic data as well as seafloor samples to determine the in situ lithology of the Hess Deep crust. Magnetic study is focused on a south-facing slope with the total area of 3 x 1.6 km2. Rock samples indicate that the western part of the slope is primarily composed of gabbros while the eastern part is mainly dikes, although the location of the lithological boundary is ambiguous from the sampling and observations alone. A total of 10 magnetic profiles along the slope were collected by a magnetometer mounted on ISIS. The raw magnetic data were corrected for the ROV motion and external field variations, and then merged with navigation data. We used a geometrical transformation to project the magnetic data into a rotated horizotal scarp face and then calculated the source magnetization distribution, 3D indices and strikes of possible magnetic boundaries using both the total-field Fourier-transform inversion approach and a modified differential vector magnetic analysis respectively. A strong magnetization contrast is found between the

  19. Suzaku Observation of the Unidentified Very High Energy Gamma-Ray Source HESS J1702-420

    NASA Astrophysics Data System (ADS)

    Fujinaga, Takahisa; Bamba, Aya; Dotani, Tadayasu; Ozaki, Masanobu; Pü:Hlhofer, Gerd; Wagner, Stefan; Reimer, Olaf; Funk, Stefan; Hinton, Jim

    2011-11-01

    A deep X-ray observation of the unidentified very high energy (VHE) gamma-ray source HESS J1702-420, for the first time, was carried out by Suzaku. No bright sources were detected in the XIS field of view (FOV), except for two faint point-like sources. The two sources, however, are considered not to be related to HESS J1702-420, because their fluxes in the 2-10 keV band (˜10-14 erg s-1 cm-2) are ˜3 orders of magnitude smaller than the VHE gamma-ray flux in the 1-10 TeV band (FTeV = 3.1 × 10-11 erg s-1 cm-2). We compared the energy spectrum of diffuse emission, extracted from the entire XIS FOV with those from nearby observations. If we consider the systematic error of background subtraction, no significant diffuse emission was detected with an upper limit of FX < 2.7 × 10-12 erg s-1 cm-2 in the 2-10 keV band for an assumed power-law spectrum of Γ = 2.1 and a source size same as that in the VHE band. The upper limit of the X-ray flux is twelve-times as small as the VHE gamma-ray flux. The large flux ratio (FTeV/FX) indicates that HESS J1702-420 is another example of a ``dark'' particle accelerator. If we use a simple one-zone leptonic model, in which VHE gamma-rays are produced through inverse Compton scattering of the cosmic microwave background and interstellar far-infrared emission, and the X-rays via the synchrotron mechanism, an upper limit of the magnetic field (1.7μG), is obtained from the flux ratio. Because the magnetic field is weaker than the typical value in the galactic plane (3-10 νG), the simple one-zone model may not work for HESS J1702-420 and a significant fraction of the VHE gamma-rays may originate from protons.

  20. IODP Expedition 345: Paleomagnetism and physical properties of primitive lower crustal rocks recovered from the Hess Deep Rift

    NASA Astrophysics Data System (ADS)

    Morris, A.; Ildefonse, B.; Horst, A. J.; Friedman, S. A.; Machi, S.; Adrião

    2013-12-01

    We report preliminary paleomagnetic and physical property results from Integrated Ocean Drilling Program (IODP) Expedition 345, which recovered primitive gabbroic rocks from the Hess Deep Rift, where propagation of the Cocos-Nazca Ridge into young, fast-spreading East Pacific Rise crust has exposed a dismembered, but nearly complete lower crustal section. Gabbros and troctolites hold stable magnetizations with a variety of remanence structures. In all samples, components that unblock close to the magnetite Curie temperature are considered to represent primary thermoremanent magnetizations acquired during crustal accretion. Downhole variations in the inclination of this stable, high temperature component indicate that at least two blocks have been sampled in each of the two deepest holes (U1415J and U1415P). The data provide evidence of relative displacements of individual, internally coherent blocks (10's metres in size), consistent with emplacement by mass-wasting on the southern slope of the Hess Deep intrarift ridge. In addition to high unblocking temperature components, thermal demagnetization experiments also identified more complex remanences in some core pieces sampled in Hole U1415J. These show nearly antipodal components of magnetization that unblock over different temperature ranges, indicating that magnetizations were acquired across a time interval spanning at least two geomagnetic polarity chrons. Such multicomponent remanences have been observed only rarely in oceanic crust, and post-cruise research aimed at understanding their origin may provide constraints on conditions and processes at the time of geomagnetic reversals. Grain density ranges from 2.77 g/cc in troctolites to 2.90 g/cc in gabbro-gabbronorites, on average. Density decreases with increasing olivine mode, because olivine is significantly more altered than other minerals. Porosity is relatively low (0.6 to 1.2% on average), does not depend on lithology, and is higher (>3%) in the

  1. Radio Observations of the Pulsar Wind Nebula HESS J1303-631 with ATCA

    NASA Astrophysics Data System (ADS)

    Sushch, Iurii; Oya, Igor; Schwanke, Ullrich; Johnston, Simon; Dalton, Matthew

    2016-04-01

    Based on its enregy-dependent morphology the initially unidentified very high energy (VHE; E > 100 GeV) gamma-ray source HESS J1303-631 was recently associated with the pulsar PSR J1301-6305. Subsequent detection of X-ray and GeV counterparts further supports the identification of the H.E.S.S. source as evolved pulsar wind nebula (PWN). Recent radio observations of the PSR J1301-6305 region with ATCA dedicated to search for the radio counterpart of HESS J1303-631 are reported here. Observations at 5.5 GHz and 7.5 GHz do not reveal any extended emission associated with the pulsar. The analysis of the archival 1.384 GHz and 2.368 GHz data also does not show any significant emission. The 1.384 GHz data reveal a hint of an extended shell-like emission in the same region which might be a supernova remnant. The implications of the non-detection at radio wavelengths on the nature and evolution of the PWN as well as the possibility of the SNR candidate being a birth place of PSR J1301-6305 are discussed.

  2. Static and fault-related alteration in the lower ocean crust, IODP Expedition 345, Hess Deep

    NASA Astrophysics Data System (ADS)

    McCaig, Andrew; Faak, Kathrin; Marks, Naomi; Nozaka, Toshio; Python, Marie; Wintsch, Robert; Harigane, Yumiko; Titarenko, Sofya

    2014-05-01

    IODP Expedition 345 drilled the first holes in the lower plutonic crust at a fast-spreading ridge, recovering primitive layered gabbros (Gillis et al 2014). Alteration can be subdivided into two series: 1) a largely static pseudomorphic alteration affecting predominantly olivine. This began in the amphibolite facies with minor secondary cinopyroxene and hornblendic amphibole replacing primary pyroxene, and sporadically developed corona textures with tremolite and chlorite replacing olivine and plagioclase respectively, but was predominantly in the greenschist and sub-greenschist facies with talc, serpentine, clay minerals,oxides andsulphides replacing olivine, and prehnite and locally other calcsilicates replacing plagioclase, commonly in micro-vein networks. Albitic plagioclase is sporadically developed, and locally zeolite and carbonate. 2) An overprinting metasomatic alteration under sub-greenschist or perhaps lowermost greenschist conditions(<350 °C) dominated by prehnite and chlorite, with subordinate epidote/clinozoisite, secondary clinopyroxene in veins, clays and zeolite. This alteration is spatially related to cataclastic fault zones and macroscopic veins. Comminuted plagioclase in cataclasites is commonly completely replaced by prehnite, while chlorite may completely pseudomorph olivine, locally with textures suggesting replacement of previous secondary minerals such as talc and serpentine. Chlorite also ubiquitously occurs as patches replacing plagioclase along grain boundaries, locally associated with carbonate and amphibole needles. Metamorphosed dykes show chilled margins within the cataclasites, and are affected by cataclastic deformation. Faults, dykes and overprinting alteration are all inferred to be related to the westward propagation of Cocos-Nazca spreading that formed Hess Deep. Samples of different alteration and cataclastic domains were cut out of this section chips for isotopic analysis. 87Sr/86Sr ratios of cataclasites and dyke rocks are

  3. Hydrothermal Spinel, Corundum and Diaspore in Gabbroic Rocks from the Hess Deep Rift, IODP Site U1415

    NASA Astrophysics Data System (ADS)

    Nozaka, T.; Meyer, R.; Wintsch, R. P.

    2014-12-01

    Hydrothermal alteration of oceanic lower crust has significant implications on geophysical properties of oceanic plates and global-scale geochemical cycles. A first order observation on the hydrothermal alteration at fast-spreading ridges is provided by the gabbroic rocks recovered from the Integrated Ocean Drilling Program (IODP) Site U1415 at the Hess Deep Rift near the East Pacific Rise. Shipboard observations of these rocks have revealed an alteration sequence formed under temperature conditions ranging from amphibolite to zeolite facies with mineral assemblages including amphibole, secondary clinopyroxene, chlorite, talc, serpentine, prehnite, zeolite and clay minerals (Gillis et al., 2014). Amphibolite-facies alteration is illustrated by the tremolite-chlorite corona textures between primary olivine and plagioclase in primitive olivine gabbro or troctolite lithologies (Nozaka and Fryer, 2011). The abundance of these alteration mineral assemblages within some sampled intervals suggests localized high-temperature fluid flow near the spreading axis. Our post-cruise studies prove that some of the coronitic amphiboles, particularly those of incipient-stage corona have hornblendic compositions, suggesting a somewhat higher-temperature formation condition than tremolite. We report here another set of alteration products from Site U1415: that is, Al-spinel, corundum and diaspore. They occur in intensely altered parts of the drilled troctolites. The Al-spinel is associated with An-rich plagioclase and pargasitic amphibole that points to even higher temperature conditions than the amphibole-chlorite corona formation. The Al-spinel is partly replaced by corundum, and the corundum, in turn, is pseudomorphically replaced by diaspore. From modes of occurrence and chemical compositions of minerals, and thermodynamic calculations of the stability conditions for these mineral assemblages, we conclude that the highly aluminous phases were formed by localized fluid flow at

  4. Transient Hydrothermal Alteration in Fault Zones Cutting the Lower Oceanic Crust, Hess Deep Rift

    NASA Astrophysics Data System (ADS)

    McCaig, Andrew; Titarenko, Sofya; Cliff, Robert; Ivan, Savov; Adrian, Boyce

    2015-04-01

    IODP Expedition 345 drilled the first holes in the lower plutonic crust at a fast-spreading ridge, recovering primitive layered gabbros [1]. Alteration occurred as: 1) a largely static pseudomorphic alteration, predominantly in the greenschist and sub-greenschist facies with mainly talc and serpentine replacing olivine, and prehnite replacing plagioclase. Talc sometimes overprints serpentine mesh texture. 2) an overprinting metasomatic alteration, spatially related to cataclastic fault zones and macroscopic veins, dominated by prehnite and chlorite. Secondary clinopyroxene and epidote locally overprint the prehnite-chlorite assemblage, but the last events are veins of prehnite and zeolite. Metamorphosed dykes show chilled margins within the cataclasites, and are themselves affected by cataclastic deformation. Faults, dykes and overprinting alteration are all inferred to be related to the westward propagation of Cocos-Nazca spreading forming Hess Deep. 87Sr/86Sr ratios of small whole rock samples of cataclasites and dyke rocks are in the range 0.7037 - 0.7048, indicating alteration by seawater at moderate integrated fluxes. The highest values were in cataclasites overprinted by prehnite. Sampling of individual minerals has been undertaken using a microscope mounted drill, and shows that alteration is mainly affecting secondary minerals, with late prehnite veins ranging up to Sr isotope ratios of 0.7054. δ18O values range from +1 to + 6 per mil. Combined with metamorphic data this indicates alteration at temperatures between 200 and 400 °C. Secondary clinopyroxene and talc replacing serpentine are interpreted to indicate transient prograde hydrothermal events. Preliminary modelling using Comsol Multiphysics suggests that the temperatures of the overprinting alteration, as well as transient prograde events, could be achieved in a permeable fault slot cutting through crust 0.5 to 1 m.y. old. The prehnite-chlorite assemblage is predicted to be important in off

  5. Transient Hydrothermal Alteration In Fault Zones Cutting The Lower Oceanic Crust, Hess Deep Rift

    NASA Astrophysics Data System (ADS)

    McCaig, A. M.; Titarenko, S.; Cliff, R. A.; Savov, I. P.; Boyce, A.; Dutt, R.

    2014-12-01

    IODP Expedition 345 drilled the first holes in the lower plutonic crust at a fast-spreading ridge, recovering primitive layered gabbros [1]. Alteration occurred as: 1) a largely static pseudomorphic alteration, predominantly in the greenschist and sub-greenschist facies with mainly talc and serpentine replacing olivine, and prehnite replacing plagioclase. Talc sometimes overprints serpentine mesh texture. 2) an overprinting metasomatic alteration, spatially related to cataclastic fault zones and macroscopic veins, dominated by prehnite and chlorite. Secondary clinopyroxene and epidote locally overprint the prehnite-chlorite assemblage, but the last events are veins of prehnite and zeolite. Metamorphosed dykes show chilled margins within the cataclasites, and are themselves affected by cataclastic deformation. Faults, dykes and overprinting alteration are inferred to be related to the westward propagation of Cocos-Nazca spreading forming Hess Deep. 87Sr/86Sr ratios of small whole rock samples of cataclasites and dyke rocks are in the range 0.7037 - 0.7048, indicating alteration by seawater at moderate integrated fluxes. The highest values were in cataclasites overprinted by prehnite. Sampling of individual minerals has been undertaken using a microscope mounted drill, and shows that alteration is mainly affecting secondary minerals, with late prehnite veins ranging up to 0.7054. δ18O values range from +1 to + 6 per mil. Combined with metamorphic data this indicates alteration at temperatures between 200 and 400 °C. Secondary clinopyroxene and talc replacing serpentine are interpreted to indicate transient prograde hydrothermal events. Preliminary modelling using Comsol Multiphysics suggests that the temperatures of the overprinting alteration, as well as transient prograde events, could be achieved in a permeable fault slot cutting through crust 0.5 to 1 m.y. old. The prehnite-chlorite assemblage is predicted to be important in off-axis alteration, common in any

  6. Suzaku Observation of the Unidentified Gamma-ray Source HESS J1841-055

    NASA Astrophysics Data System (ADS)

    Nobukawa, Kumiko

    HESS J1841-055 is an unidentified Gamma-ray source and spread across 1 degree. There is not yet a conclusive counterpart in any other wave length. We observed HESS J1841-055 with Suzaku. Several sources were found in the region. (1) High mass X-ray binary AX J1841.0-0536 exhibited many short flares with the time-scales of a few hundred seconds and a large flare with the peak flux (1.0-10 keV) of ≤2×10(-10) erg s(-1) cm(-2) . The source had a high dynamical range (ratio of the peak luminosity in the large flare to the quiescent emission), which spanned 3 orders of magnitudes. (2) Soft (0.5-2.0 keV) diffuse X-ray emission is a supernova remnant candidate, since its spectrum was fit by an optically thin thermal plasma model. (3) 2 arcminutes extended source in the hard band (2.0-8.0 keV) had a high column density of N_mathrm{H}˜10(23) cm(-2) and a red-shifted iron line. It can be a new candidate of a cluster of galaxy.

  7. Very-high-energy Gamma-ray Observations Of Synchrotron-dominated Supernova Remnants With H.E.S.S.

    NASA Astrophysics Data System (ADS)

    Chaves, Ryan C. G.; Sushch, I.; Paz Arribas, M.; Volpe, F.; Komin, N.; Kerschhaggl, M.; H.E.S.S. Collaboration

    2011-09-01

    Supernova remnants (SNRs) are expected to produce very-high-energy (VHE; E > 100 GeV) gamma rays through interactions of high-energy particles with the surrounding medium and photon fields. VHE gamma-ray emission has indeed been discovered, by ground-based imaging atmospheric Cherenkov telescopes such as the H.E.S.S. telescope array, from a number of SNRs, establishing them as a prominent source class in the VHE domain. Of particular interest are the handful of SNRs whose X-ray spectra are dominated by non-thermal synchrotron emission; of these, the H.E.S.S. array has detected VHE gamma-ray emission from RX J1713.7-3946, RX J0852.0-4622 (Vela Jr.), RCW 86, SN 1006 and HESS J1731-347. The shell-type SNRs G1.9+0.3 and G330.2+1.0 also belong to this subclass and are further notable for their young ages (< 1 kyr), especially G1.9+0.3, which was recently determined to be the youngest SNR in the Galaxy ( 100 yr). These unique characteristics motivated investigations with H.E.S.S. to search for VHE gamma rays. The results of the H.E.S.S. observations and analyses will be presented, along with implications for potential particle acceleration scenarios, and discussed in comparison with the previously detected VHE gamma-ray shells.

  8. IODP Expedition 345: Bulk Mineralogy From Lower Oceanic Crustal Rocks of the Hess Deep

    NASA Astrophysics Data System (ADS)

    Wintsch, R. P.; Bish, D. L.; Meyer, R.

    2013-12-01

    Young lower oceanic crustal rocks produced along the East Pacific Rise are exposed at the sea floor of the Hess Deep by rifting of the Cocos-Nazca ridge. Coring into these rocks (IODP Expedition 345) had the goal of understanding the petrologic processes that produce lower oceanic crust. Variable orientations of magmatic layering and foliation and magnetic remanance directions in the recovered gabbro and troctolite suggest that these samples were extracted from large blocks slumped into the rift. The overall poor recovery of core (~30%) and thick sections of broken rock disaggregated by cataclasis suggest that associated fractures produced the locally intense alteration of the magmatic mineralogy. We characterized this alteration by collecting the cuttings from the rock saw that divided the core into archive and working halves. The resultant ~1 mm wide slot should yield a calculated ~150 g/m of core, constituting the most representative sample of the entire core possible. A plastic housing surrounding the entire saw assembly captured all sedimented cuttings as well as distilled wash and lubricating water. All cuttings and a final wash water (holding suspended clay-size particles) were collected through the single drain at the base of the housing. We recovered 132 g/m of core, in close agreement with the calculations above. Our results show that the suspended material constitutes 10- 30 wt.% of the total sample, demonstrating the need for collection of the rinse water. Modal mineralogy of a few samples was measured by quantitative X-ray powder diffraction and Rietveld methods. These results revealed in descending order of abundance the magmatic plagioclase, augite, and Fe-forsterite identified optically. The higher-temperature alteration mineral actinolite was present at low concentrations. Alteration phyllosilicates included chlorite > prehnite > lizardite > talc. Chrysotile and antigorite were not identified. Rietveld refinements confirmed the presence of low

  9. CHANDRA OBSERVATION OF THE TeV SOURCE HESS J1834-087

    SciTech Connect

    Misanovic, Zdenka; Kargaltsev, Oleg; Pavlov, George G. E-mail: oyk100@astro.ufl.edu

    2011-07-01

    Chandra ACIS observed the field of the extended TeV source HESS J1834-087 for 47 ks. A previous XMM-Newton EPIC observation of the same field revealed a point-like source (XMMU J183435.3-084443) and an offset region of faint extended emission. In the low-resolution, binned EPIC images the two appear to be connected. However, the high-resolution Chandra ACIS images do not support the alleged connection. In these images, XMMU J183435.3-084443 is resolved into a point source, CXOU J183434.9-084443 (L{sub 0.5-8keV} {approx_equal} 2.3 x 10{sup 33} erg s{sup -1}, for a distance of 4 kpc; photon index {Gamma} {approx_equal} 1.1), and a compact ({approx}< 20'') nebula with an isotropic morphology and a softer spectrum (L{sub 0.5-8keV} {approx_equal} 4.1 x 10{sup 33} erg s{sup -1}, {Gamma} {approx_equal} 2.7). The nature of the nebula is uncertain. We discuss a dust scattering halo and a pulsar-wind nebula as possible interpretations. Based on our analysis of the X-ray data, we re-evaluate the previously suggested interpretations of HESS J1834-087 and discuss a possible connection to the Fermi Large Area Telescope source 1FGL J1834.3-0842c. We also obtained an upper limit of 3 x 10{sup -14} erg cm{sup -2} s{sup -1} on the unabsorbed flux of the SGR J1833-0832 (in quiescence), which happened to be in the ACIS field of view.

  10. Fermi Large Area Telescope observations of the supernova remnant HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Yang, Rui-zhi; Zhang, Xiao; Yuan, Qiang; Liu, Siming

    2014-07-01

    Context. HESS J1731-347 has been identified as one of the few TeV-bright shell-type supernova remnants (SNRs). These remnants are dominated by nonthermal emission, and the nature of TeV emission has been continuously debated for nearly a decade. Aims: We carry out the detailed modeling of the radio to γ-ray spectrum of HESS J1731-347 to constrain the magnetic field and energetic particles sources, which we compare with those of the other TeV-bright shell-type SNRs explored before. Methods: Four years of data from Fermi Large Area Telescope (LAT) observations for regions around this remnant are analyzed, leading to no detection correlated with the source discovered in the TeV band. The Markov chain Monte Carlo method is used to constrain parameters of one-zone models for the overall emission spectrum. Results: Based on the 99.9% upper limits of fluxes in the GeV range, one-zone hadronic models with an energetic proton spectral slope greater than 1.8 can be ruled out, which favors a leptonic origin for the γ-ray emission, making this remnant a sibling of the brightest TeV SNR RX J1713.7-3946, the Vela Junior SNR RX J0852.0-4622, and RCW 86. The best-fit leptonic model has an electron spectral slope of 1.8 and a magnetic field of ~30 μG, which is at least a factor of 2 higher than those of RX J1713.7-3946 and RX J0852.0-4622, posing a challenge to the distance estimate and/or the energy equipartition between energetic electrons and the magnetic field of this source. A measurement of the shock speed will address this challenge and has implications on the magnetic field evolution and electron acceleration driven by shocks of SNRs.

  11. Multipolarity remanences in lower oceanic crustal gabbros recovered by drilling at Hess Deep (Integrated Ocean Drilling Program Expedition 345)

    NASA Astrophysics Data System (ADS)

    Morris, Antony; Horst, Andrew; Friedman, Sarah; Nozaka, Toshio

    2015-04-01

    A long-term goal of the scientific ocean drilling community is to understand the processes by which the ocean crust is constructed through magmatism, deformation, metamorphism and hydrothermal cooling. Insights into the magnetic properties of the lower crust have come from drilling at oceanic core complexes and in tectonic windows. At the Hess Deep Rift, propagation of the Cocos-Nazca Ridge into young, fast-spreading East Pacific Rise crust exposes a dismembered, but nearly complete lower crustal section. Here, IODP Expedition 345 (Site U1415) recovered primitive plutonic lithologies including gabbro, troctolitic gabbro and olivine gabbronorite. These rocks exhibit cumulate textures similar to those found in layered basic intrusions and some ophiolite complexes. Metamorphism is dominated by background greenschist facies alteration associated with cataclastic deformation that likely results from Cocos-Nazca rifting. Some intervals display complex, multiple remanence components within individual samples. A high temperature component unblocks above 500°-520°C and an intermediate temperature component of nearly antipodal direction unblocks between 425°-450°C and 500°-520°C. In addition, a few samples display a third component that unblocks between 100-350°C that is nearly parallel to the highest temperature component. These multiple, nearly antipodal components suggest that remanence was acquired in different geomagnetic chrons, and represent the first multipolarity remanences seen in Pacific lower oceanic crust. Similar remanence structures, however, have been reported in lower crustal gabbros recovered from slow-spreading rate crust along the Mid-Atlantic Ridge, and have been interpreted to reflect protracted accretion or protracted cooling. In contrast, at Hess Deep unblocking temperatures appear consistent with temperatures inferred for successive phases of alteration, suggesting an alteration history spanning at least two polarity chrons.

  12. Multipolarity Remanences in Lower Oceanic Crustal Gabbros Recovered By Drilling at Hess Deep (Integrated Ocean Drilling Program Expedition 345)

    NASA Astrophysics Data System (ADS)

    Morris, A.; Horst, A. J.; Friedman, S. A.

    2014-12-01

    A long-term goal of the scientific ocean drilling community is to understand the processes by which the ocean crust is constructed through magmatism, deformation, metamorphism and hydrothermal cooling. Insights into the magnetic properties of the lower crust have come from drilling at oceanic core complexes and in tectonic windows. At the Hess Deep Rift, propagation of the Cocos-Nazca Ridge into young, fast-spreading East Pacific Rise crust exposes a dismembered, but nearly complete lower crustal section. Here, IODP Expedition 345 (Site U1415) recovered primitive plutonic lithologies including gabbro, troctolitic gabbro and olivine gabbronorite. These rocks exhibit cumulate textures similar to those found in layered basic intrusions and some ophiolite complexes. Metamorphism is dominated by background greenschist facies alteration associated with cataclastic deformation that likely results from Cocos-Nazca rifting. Some intervals display complex, multiple remanence components within individual samples. A high temperature component unblocks above 500°-520°C and an intermediate temperature component of nearly antipodal direction unblocks between 425°-450°C and 500°-520°C. In addition, a few samples display a third component that unblocks between 100-350°C that is nearly parallel to the highest temperature component. These multiple, nearly antipodal components suggest that remanence was acquired in different geomagnetic chrons, and represent the first multipolarity remanences seen in Pacific lower oceanic crust. Similar remanence structures, however, have been reported in lower crustal gabbros recovered from slow-spreading rate crust along the Mid-Atlantic Ridge, and have been interpreted to reflect protracted accretion or protracted cooling. In contrast, at Hess Deep unblocking temperatures appear consistent with temperatures inferred for successive phases of alteration, suggesting an alteration history spanning at least two polarity chrons.

  13. Probing the gamma-ray emission from HESS J1834-087 using H.E.S.S. and Fermi LAT observations

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Backes, M.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2015-02-01

    Aims: Previous observations with the High Energy Stereoscopic System (H.E.S.S.) have revealed an extended very-high-energy (VHE; E> 100 GeV) γ-ray source, HESS J1834-087, coincident with the supernova remnant (SNR) W41. The origin of the γ-ray emission was investigated in more detail with the H.E.S.S. array and the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. Methods: The γ-ray data provided by 61 h of observations with H.E.S.S., and four years with the Fermi LAT were analyzed, covering over five decades in energy from 1.8 GeV up to 30 TeV. The morphology and spectrum of the TeV and GeV sources were studied and multiwavelength data were used to investigate the origin of the γ-ray emission toward W41. Results: The TeV source can be modeled with a sum of two components: one point-like and one significantly extended (σTeV = 0.17° ± 0.01°), both centered on SNR W41 and exhibiting spectra described by a power law with index ΓTeV ≃ 2.6. The GeV source detected with Fermi LAT is extended (σGeV = 0.15° ± 0.03°) and morphologically matches the VHE emission. Its spectrum can be described by a power-law model with an index ΓGeV = 2.15 ± 0.12 and smoothly joins the spectrum of the whole TeV source. A break appears in the γ-ray spectra around 100 GeV. No pulsations were found in the GeV range. Conclusions: Two main scenarios are proposed to explain the observed emission: a pulsar wind nebula (PWN) or the interaction of SNR W41 with an associated molecular cloud. X-ray observations suggest the presence of a point-like source (a pulsar candidate) near the center of the remnant and nonthermal X-ray diffuse emission that could arise from the possibly associated PWN. The PWN scenario is supported by the compatible positions of the TeV and GeV sources with the putative pulsar. However, the spectral energy distribution from radio to γ-rays is reproduced by a one-zone leptonic model only if an excess of low-energy electrons is injected

  14. The Paradox of the Axial Melt Lens: Petrology and Geochemistry of the Upper Plutonics at Hess Deep

    NASA Astrophysics Data System (ADS)

    Lissenberg, C. J.; Loocke, M. P.; MacLeod, C. J.

    2014-12-01

    The axial melt lens (AML) is a steady-state magma-rich body located at the dyke-gabbro transition at intermediate- and fast-spreading ridges. It is widely believed to be the reservoir from which mid-ocean ridge basalt (MORB) is erupted. The paradox of the axial melt lens is that the plutonic rocks that occur at this level are far too evolved to be in equilibrium with MORB, which is basaltic by definition; hence, the plutonic and volcanic records do not match. We explore this paradox by study of the first comprehensive sample suite of the uppermost plutonics of a fast-spreading ridge, taken by remotely-operated vehicle from the Hess Deep rift during cruise JC21. 23 samples (8 dolerites, 14 gabbronorites, and 1 gabbro) were collected from a section containing the transition from the uppermost gabbroic section into sheeted dykes. We present the results of a detailed petrographic and microanalytical investigation of these samples. They are dominated by evolved, varitextured (both in hand sample and thin section) oxide gabbronorites; olivine occurs in only one sample. A preponderance of the samples have positive Eu/Eu* and Sr/Sr*, indicating a cumulate origin. However, the minerals have evolved compositions, and are in equilibrium with melts significantly more evolved than East Pacific Rise MORB. Furthermore, the trace element contents of clinopyroxene differ significantly from clinopyroxene in equilibrium with MORB, being more enriched in incompatible elements. To account for both the evidence of derivation of MORB from the AML and the evolved nature of its rock record, we posit that the AML must be fed by melts on two different timescales: continual low-volume feeding by evolved interstitial melt from the cumulus pile below is augmented episodically by delivery of high volumes of more primitive melt. The latter episodes may trigger eruptions; hence the primitive melts are held in the magma chamber for only short periods, and erupt on the seafloor before significant

  15. EVN Observations of HESS J1943+213: Evidence for an Extreme TeV BL Lac Object

    NASA Astrophysics Data System (ADS)

    Akiyama, Kazunori; Stawarz, Łukasz; Tanaka, Yasuyuki T.; Nagai, Hiroshi; Giroletti, Marcello; Honma, Mareki

    2016-06-01

    We report on the 1.6 GHz (18 cm) very long baseline interferometry (VLBI) observations of the unresolved, steady TeV source HESS J1943+213 located in the Galactic plane, performed with the European VLBI Network (EVN) in 2014. Our new observations with a nearly full EVN array provide the deepest image of HESS J1943+213 at the highest resolution ever achieved, enabling us to resolve the long-standing issues of the source identification. The milliarcsecond-scale structure of HESS J1943+213 has a clear asymmetric morphology consisting of a compact core and a diffuse jet-like tail. This is broadly consistent with the previous e-EVN observations of the source performed in 2011 and re-analyzed in this work. The core component is characterized by the brightness temperature of ≳ 1.8× {10}9 K, which is typical for low-luminosity blazars in general. Overall, the radio properties of HESS J1943+213 are consistent with the source classification as an “extreme high-frequency-peaked BL Lac object.” Remarkably, we note that because HESS J1943+213 does not reveal any optical or infrared signatures of the active galactic nucleus activity, it would never be recognized and identified as a BL Lac object if not for its location close to the Galactic plane where the High Energy Stereoscopic System surveyed for and the follow-up dedicated X-ray and radio studies triggered by the source detection in the TeV range. Our results suggest, therefore, a presence of an unrecognized, possibly very numerous population of particularly extreme HBLs and simultaneously demonstrate that the low-frequency VLBI observations with high angular resolution are indispensable for a proper identification of such objects.

  16. SUZAKU OBSERVATIONS OF THE NON-THERMAL SUPERNOVA REMNANT HESS J1731-347

    SciTech Connect

    Bamba, Aya; Yamazaki, Ryo; Puehlhofer, Gerd; Klochkov, Dmitry; Acero, Fabio; Li Zhiyuan; Horns, Dieter; Kosack, Karl

    2012-09-10

    A detailed analysis of the non-thermal X-ray emission from the northwestern and southern parts of the supernova remnant (SNR) HESS J1731-347 with Suzaku is presented. The shell portions covered by the observations emit hard and lineless X-rays. The spectrum can be reproduced by a simple absorbed power-law model with a photon index {Gamma} of 1.8-2.7 and an absorption column density N{sub H} of (1.0-2.1) Multiplication-Sign 10{sup 22} cm{sup -2}. These quantities change significantly from region to region; the northwestern part of the SNR has the hardest and most absorbed spectrum. The western part of the X-ray shell has a smaller curvature than the northwestern and southern shell segments. A comparison of the X-ray morphology to the very high energy gamma-ray and radio images was performed. The efficiency of the electron acceleration and the emission mechanism in each portion of the shell are discussed. Thermal X-ray emission from the SNR was searched for but could not be detected at a significant level.

  17. Suzaku Observations of the Non-thermal Supernova Remnant HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Bamba, Aya; Pühlhofer, Gerd; Acero, Fabio; Klochkov, Dmitry; Tian, Wenwu; Yamazaki, Ryo; Li, Zhiyuan; Horns, Dieter; Kosack, Karl; Komin, Nukri

    2012-09-01

    A detailed analysis of the non-thermal X-ray emission from the northwestern and southern parts of the supernova remnant (SNR) HESS J1731-347 with Suzaku is presented. The shell portions covered by the observations emit hard and lineless X-rays. The spectrum can be reproduced by a simple absorbed power-law model with a photon index Γ of 1.8-2.7 and an absorption column density N H of (1.0-2.1) × 1022 cm-2. These quantities change significantly from region to region; the northwestern part of the SNR has the hardest and most absorbed spectrum. The western part of the X-ray shell has a smaller curvature than the northwestern and southern shell segments. A comparison of the X-ray morphology to the very high energy gamma-ray and radio images was performed. The efficiency of the electron acceleration and the emission mechanism in each portion of the shell are discussed. Thermal X-ray emission from the SNR was searched for but could not be detected at a significant level.

  18. X-ray observations of Galactic H.E.S.S. sources: an update

    NASA Astrophysics Data System (ADS)

    Puehlhofer, G.; Eger, P.; Sasaki, M.; Gottschall, D.; Capasso, M.; H. E. S. S. Collaboration

    2016-06-01

    X-ray diagnostics of TeV sources continues to be an important tool to identify the nature of newly detected sources as well as to pinpoint the physics processes that are at work in these highly energetic objects. The contribution aims at giving a review of recent studies that we have performed on TeV sources with H.E.S.S. and XMM-Newton and also other X-ray facilities. Here, we will mainly focus on Galactic objects such as gamma-ray binaries, pulsar wind nebulae, and supernova remnants (SNRs). Particular emphasis will be given to SNR studies, including recently identified SNRs such as HESS J1731-347 and HESS J1534-571 as well as a revisit of RX J1713.7-3946.

  19. H.E.S.S. observations of the Crab during its March 2013 GeV gamma-ray flare

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-02-01

    Context. On March 4, 2013 the Fermi-LAT and AGILE reported a flare from the direction of the Crab nebula in which the high-energy (HE; E > 100 MeV) flux was six times above its quiescent level. Simultaneous observations in other energy bands give us hints about the emission processes during the flare episode and the physics of pulsar wind nebulae in general. Aims: We search for variability in the emission of the Crab nebula at very-high energies (VHE; E > 100 GeV), using contemporaneous data taken with the H.E.S.S. array of Cherenkov telescopes. Methods: Observational data taken with the H.E.S.S. instrument on five consecutive days during the flare were analysed for the flux and spectral shape of the emission from the Crab nebula. Night-wise light curves are presented with energy thresholds of 1 TeV and 5 TeV. Results: The observations conducted with H.E.S.S. on March 6 to March 10, 2013 show no significant changes in the flux. They limit the variation in the integral flux above 1 TeV to less than 63% and the integral flux above 5 TeV to less than 78% at a 95% confidence level.

  20. New constraints on the structure of Hess Deep from regional- and micro-bathymetry data acquired during RRS James Cook in Jan-Feb 2008 (JC021)

    NASA Astrophysics Data System (ADS)

    Shillington, D. J.; Ferrini, V. L.; MacLeod, C. J.; Teagle, D. A.; Gillis, K. M.; Cazenave, P. W.; Hurst, S. D.; Scientific Party, J.

    2008-12-01

    In January-February 2008, new geophysical and geological data were acquired in Hess Deep using the RRS James Cook and the British ROV Isis. Hess Deep provides a tectonic window into oceanic crust emplaced by fast seafloor spreading at the East Pacific Rise, thereby offering the opportunity to test competing hypotheses for oceanic crustal accretion. The goal of this cruise was to collect datasets that can constrain the structure and composition of the lower crustal section exposed in the south-facing slope of the Intrarift Ridge just north of the Deep, and thus provide insights into the emplacement of gabbroic lower crust at fast spreading rates. Additionally, the acquired datasets provide site survey data for IODP Proposal 551-Full. The following datasets were acquired during JC021: 1) regional multibeam bathymetry survey complemented with sub-bottom profiler (SBP) data (in selected areas), 2) two micro-bathymetry surveys, and 3) seafloor rock samples acquired with an ROV. Here we present grids of regional multibeam and microbathymetry data following post-cruise processing. Regional multibeam bathymetry were acquired using the hull-mounted Kongsberg Simrad EM120 system (12 kHz). These data provide new coverage of the northern flank of the rift as far east as 100°W, which show that it comprises of a series of 50- to 100-km-long en echelon segments. Both E-W and NE-SW striking features are observed in the immediate vicinity of the Deep, including in a newly covered region to the SW of the rift tip. Such features might arise due to the rotation of the Galapagos microplate(s), as proposed by other authors. The ROV Isis acquired micro-bathymetry data in two areas using a Simrad SM2000 (200 kHz) multibeam sonar. Data were acquired at a nominal altitude of ~100 m and speed of 0.3 kts to facilitate high-resolution mapping of seabed features and also permit coverage of two relatively large areas. Swath widths were ~200- 350 m depending on noise and seabed characteristics

  1. Flux upper limits for 47 AGN observed with H.E.S.S. in 2004-2011

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O.'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-04-01

    Context. About 40% of the observation time of the High Energy Stereoscopic System (H.E.S.S.) is dedicated to studying active galactic nuclei (AGN), with the aim of increasing the sample of known extragalactic very-high-energy (VHE, E > 100 GeV) sources and constraining the physical processes at play in potential emitters. Aims: H.E.S.S. observations of AGN, spanning a period from April 2004 to December 2011, are investigated to constrain their γ-ray fluxes. Only the 47 sources without significant excess detected at the position of the targets are presented. Methods: Upper limits on VHE fluxes of the targets were computed and a search for variability was performed on the nightly time scale. Results: For 41 objects, the flux upper limits we derived are the most constraining reported to date. These constraints at VHE are compared with the flux level expected from extrapolations of Fermi-LAT measurements in the two-year catalog of AGN. The H.E.S.S. upper limits are at least a factor of two lower than the extrapolated Fermi-LAT fluxes for 11 objects. Taking into account the attenuation by the extragalactic background light reduces the tension for all but two of them, suggesting intrinsic curvature in the high-energy spectra of these two AGN. Conclusions: Compilation efforts led by current VHE instruments are of critical importance for target-selection strategies before the advent of the Cherenkov Telescope Array (CTA).

  2. Wide-Range Multiwavelength Observations of Northern TeV Blazars With MAGIC / HESS, Suzaku And KVA

    SciTech Connect

    Hayashida, M.; Rugamer, S.; Mazin, D.; Firpo, R.; Mannheim, K.; Tavecchio, F.; Teshima, M.; Horns, D.; Costamante, L.; Schwarzburg, S.; Wagner, S.; Takahashi, T.; Kataoka, J.; Madejski, G.; Sato, R.; Ushio, M.; /JAXA, Sagamihara

    2007-11-14

    We have conducted multiwavelength observations of several northern TeV blazars employing the ground-based {gamma}-ray observatories MAGIC and HESS, the optical KVA telescope, and the Suzaku X-ray satellite. The data taken in 2006 establish measurements of the contemporaneous spectral energy distributions of the rapidly variable blazar emission over a wide range of frequencies. Results allow us to test leptonic and hadronic emission and particle acceleration models which predict different correlations between the optical, X-ray, and very high energy {gamma}-ray emissions. In this presentation, we report on the highlights of the results of these observations.

  3. PKS 2155-304 in July 2006: H.E.S.S. results and simultaneous multi-wavelength observations

    SciTech Connect

    Lenain, Jean-Philippe; Boisson, Catherine; Sol, Helne; Zech, Andreas; Benbow, Wystan; Buehler, Rolf; Costamante, Luigi; Raue, Martin; Giebels, Berrie; Superina, Giulia; Punch, Michael; Volpe, Francesca

    2008-12-24

    The high-frequency-peaked BL Lac PKS 2155-304 is one of the brightest and best-studied VHE {gamma}-ray sources in the southern hemisphere. The High Energy Stereoscopic System (H.E.S.S.) has monitored PKS 2155-304 in 2006 and a multi-wavelength campaign involving X-ray, optical and radio observatories was triggered by the detection of an active state in July 2006, followed by the detection of two extraordinary flares on July, 28th and 30th, with peak fluxes {approx}100 times the usual values. We present results from the spectral and flux variability analysis of the VHE and simultaneous X-ray observations with Chandra during the second flare, as well as the detailed evolution of the VHE flux of PKS 2155-304 observed by H.E.S.S. in 2006. A study of flux correlations in the different frequency ranges during the second flare and the adjacent nights is discussed. We also present an interpretation of the active state of PKS 2155-304 in the framework of synchrotron self-Compton emission.

  4. Observations of AGN at very-high energy gamma rays with the H.E.S.S. telescopes

    NASA Astrophysics Data System (ADS)

    Wagner, Robert

    2016-08-01

    At the high-energy end of their electromagnetic spectra, the emission of AGNs is based on non-thermal particle acceleration processes. Ground-based Imaging Atmospheric Cherenkov Telescopes, like the H.E.S.S. array of gamma-ray telescopes, offer excellent sensitivity at E>100 GeV, a superb time resolution, and in combination with multi-wavelength instruments, represent powerful tools for investigating the particle accelerators within AGN. In the past decade, non-thermal emission from relativistic jets in numerous blazars and radio galaxies could be investigated. The gamma-rays are likely due to Compton scattering of lower energy photons, either from within the jet or from the surrounding gas. The physical properties of the jet and the way in which it is produced are still largely a unknown, but are probably related in some way to accretion onto a central supermassive black hole. In the presentation, we will discuss H.E.S.S. results of observations of AGN, both highlighting substantial new lessons learned at the high energy end of the electromagnetic spectrum and in multi wavelength contexts.

  5. PKS 2005-489 at VHE: four years of monitoring with HESS and simultaneous multi-wavelength observations

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Becherini, Y.; Behera, B.; Benbow, W.; Bernlöhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Borrel, V.; Brucker, J.; Brun, F.; Brun, P.; Bühler, R.; Bulik, T.; Büsching, I.; Boutelier, T.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Costamante, L.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubois, F.; Dubus, G.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fiasson, A.; Förster, A.; Fontaine, G.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Göring, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Holleran, M.; Hoppe, S.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jung, I.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Kerschhaggl, M.; Khangulyan, D.; Khélifi, B.; Keogh, D.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Lamanna, G.; Lenain, J.-P.; Lohse, T.; Marandon, V.; Martineau-Huynh, O.; Marcowith, A.; Masbou, J.; Maurin, D.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; Olive, J.-F.; de Oña Wilhelmi, E.; Orford, K. J.; Ostrowski, M.; Panter, M.; Paz Arribas, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raubenheimer, B. C.; Raue, M.; Rayner, S. M.; Renaud, M.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sikora, M.; Skilton, J. L.; Sol, H.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Superina, G.; Szostek, A.; Tam, P. H.; Tavernet, J.-P.; Terrier, R.; Tibolla, O.; Tluczykont, M.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Venter, L.; Vialle, J. P.; Vincent, P.; Vivier, M.; Völk, H. J.; Volpe, F.; Wagner, S. J.; Ward, M.; Zdziarski, A. A.; Zech, A.

    2010-02-01

    Aims: Our aim is to study the very high energy (VHE; E>100 GeV) γ-ray emission from BL Lac objects and the evolution in time of their broad-band spectral energy distribution (SED). Methods: VHE observations of the high-frequency peaked BL Lac object PKS 2005-489 were made with the High Energy Stereoscopic System (HESS) from 2004 through 2007. Three simultaneous multi-wavelength campaigns at lower energies were performed during the HESS data taking, consisting of several individual pointings with the XMM-Newton and RXTE satellites. Results: A strong VHE signal, ~17σ total, from PKS 2005-489 was detected during the four years of HESS observations (90.3 h live time). The integral flux above the average analysis threshold of 400 GeV is ~3% of the flux observed from the Crab Nebula and varies weakly on time scales from days to years. The average VHE spectrum measured from ~300 GeV to ~5 TeV is characterized by a power law with a photon index, Γ = 3.20± 0.16_stat± 0.10_syst. At X-ray energies the flux is observed to vary by more than an order of magnitude between 2004 and 2005. Strong changes in the X-ray spectrum (ΔΓX ≈ 0.7) are also observed, which appear to be mirrored in the VHE band. Conclusions: The SED of PKS 2005-489, constructed for the first time with contemporaneous data on both humps, shows significant evolution. The large flux variations in the X-ray band, coupled with weak or no variations in the VHE band and a similar spectral behavior, suggest the emergence of a new, separate, harder emission component in September 2005. Supported by CAPES Foundation, Ministry of Education of Brazil.Now at Harvard-Smithsonian Center for Astrophysics, Cambridge, USA.Now at W.W. Hansen Experimental Physics Laboratory & Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, USA.

  6. Hess Deep Interactive Lab: Exploring the Structure and Formation of the Oceanic Crust through Hands-On Models and Online Tools

    NASA Astrophysics Data System (ADS)

    Kurtz, N.; Marks, N.; Cooper, S. K.

    2014-12-01

    Scientific ocean drilling through the International Ocean Discovery Program (IODP) has contributed extensively to our knowledge of Earth systems science. However, many of its methods and discoveries can seem abstract and complicated for students. Collaborations between scientists and educators/artists to create accurate yet engaging demonstrations and activities have been crucial to increasing understanding and stimulating interest in fascinating geological topics. One such collaboration, which came out of Expedition 345 to the Hess Deep Rift, resulted in an interactive lab to explore sampling rocks from the usually inacessible lower oceanic crust, offering an insight into the geological processes that form the structure of the Earth's crust. This Hess Deep Interactive Lab aims to explain several significant discoveries made by oceanic drilling utilizing images of actual thin sections and core samples recovered from IODP expeditions. . Participants can interact with a physical model to learn about the coring and drilling processes, and gain an understanding of seafloor structures. The collaboration of this lab developed as a need to explain fundamental notions of the ocean crust formed at fast-spreading ridges. A complementary interactive online lab can be accessed at www.joidesresolution.org for students to engage further with these concepts. This project explores the relationship between physical and on-line models to further understanding, including what we can learn from the pros and cons of each.

  7. Water in orthopyroxene from abyssal spinel peridotites of the East Pacific Rise (ODP Leg 147: Hess Deep)

    NASA Astrophysics Data System (ADS)

    Hesse, Kirsten T.; Gose, Jürgen; Stalder, Roland; Schmädicke, Esther

    2015-09-01

    Abyssal spinel peridotites from Hess Deep, East Pacific Rise (ODP Leg 147) were investigated concerning their major, minor, and trace element mineral chemistry and the incorporation of structural water in orthopyroxene. The rocks are partially serpentinized harzburgites containing primary minerals of olivine, orthopyroxene, clinopyroxene, and spinel. Orthopyroxene is enstatitic with Mg# (Mg/(Mg + Fe)) between 0.90 and 0.92 and Al2O3 from 0.5 to 2.9 wt.%. The residual harzburgite experienced high degrees of melt removal in the spinel peridotite stability field. The average degree of partial melting was calculated to be 17.5% (range: 16.4-17.8%). Trace element data of ortho- and clinopyroxenes reflect this strong depletion, characteristic for the restitic nature of abyssal peridotites. Mantle re-equilibration temperatures around 1000 °C indicate that, after melt extraction and before exhumation to the ocean floor, the rocks experienced significant cooling in the spinel peridotite facies. Water contents of orthopyroxene range from 86 to 233 wt. ppm H2O with an average concentration of 142 wt. ppm H2O. These results represent the first data on water contents in the sub-pacific mantle obtained by direct measurements of sub-oceanic peridotite. The water contents are not related to mineral chemistry, stratigraphy, melting degree, mantle equilibrium conditions or oxidation state. Calculated post-melt peridotite water contents vary between 40 and 100 wt. ppm H2O. Compared to Mid-Atlantic Ridge peridotites, the East Pacific Rise samples of Leg 147 contain somewhat lower water concentrations than samples from Leg 153 and considerably higher contents than those of Leg 209 (Gose et al., 2009; Schmädicke et al., 2011). In Leg 147, the strongest OH absorbtion band occurs at 3420 cm- 1, wheras orthopyroxene from MAR peridotite (Legs 153 and 209) has its strongest absorbtion band at 3566 and 3522 cm- 1. The mantle equilibrium temperature of Leg 147 peridotites is lower than that

  8. OBSERVATION OF TeV GAMMA RAYS FROM THE UNIDENTIFIED SOURCE HESS J1841-055 WITH THE ARGO-YBJ EXPERIMENT

    SciTech Connect

    Bartoli, B.; Catalanotti, S.; Bernardini, P.; D'Amone, A.; Bi, X. J.; Cao, Z.; Chen, S. Z.; Chen, Y.; Bolognino, I.; Branchini, P.; Budano, A.; Calabrese Melcarne, A. K.; Cardarelli, R.; Cattaneo, C.; Chen, T. L.; Creti, P.; Cui, S. W.; Dai, B. Z.; D'Ali Staiti, G.; Collaboration: ARGO-YBJ Collaboration; and others

    2013-04-20

    We report the observation of a very high energy {gamma}-ray source whose position is coincident with HESS J1841-055. This source has been observed for 4.5 years by the ARGO-YBJ experiment from 2007 November to 2012 July. Its emission is detected with a statistical significance of 5.3 standard deviations. Parameterizing the source shape with a two-dimensional Gaussian function, we estimate an extension {sigma}=(0.40{sup +0.32}{sub -0.22}){sup o}, which is consistent with the HESS measurement. The observed energy spectrum is dN/dE = (9.0 {+-} 1.6) Multiplication-Sign 10{sup -13}(E/5 TeV){sup -2.32{+-}0.23} photons cm{sup -2} s{sup -1} TeV{sup -1}, in the energy range 0.9-50 TeV. The integral {gamma}-ray flux above 1 TeV is 1.3 {+-} 0.4 Crab, which is 3.2 {+-} 1.0 times the flux derived by HESS. The differences in the flux determination between HESS and ARGO-YBJ and possible counterparts at other wavelengths are discussed.

  9. Insights into Oceanic Crust Accretion from a Comparison of Rock Magnetic and Silicate Fabrics from Lower Crustal Gabbros from Hess Deep Rift

    NASA Astrophysics Data System (ADS)

    Horst, A. J.; Morris, A.; Friedman, S. A.; Cheadle, M. J.

    2014-12-01

    The mechanisms of lower crustal accretion remain a long-standing question for those who study fast-spreading mid-ocean ridges. One of the goals of Integrated Ocean Drilling Program (IODP) Expedition 345 is to test accretionary models by investigating the structure of the lower oceanic crust exposed within the Hess Deep Rift. Located near the tip of the westward-propagating Cocos-Nazca spreading center, Hess Deep Rift exposes crust formed at the East Pacific Rise. During IODP Expedition 345, primitive gabbroic rocks were recovered from a dismembered lower crustal section at ~4850 meters below sealevel. Constraints on physical processes during magmatic accretion are provided by the relative orientation and strength of rock fabrics. We present anisotropy of magnetic susceptibility (AMS) fabric data from gabbros recovered from the two deepest holes (U1415J and U1415P). AMS measurements provide petrofabric data that may be used to constrain magma emplacement and subsequent magmatic flow. Bulk susceptibility ranges from 1.15 x 10-4 to 5.73 x 10-2 SI, with a majority of the samples having susceptibility greater than 10-3 SI, suggesting magnetite is the dominant contributor to the AMS signal. Low-temperature demagnetization data show Verwey transitions near 125K indicating the presence of nearly stoichiometric magnetite in most samples. AMS reveals dominantly oblate fabrics with a moderate degree of anisotropy (P') ranging from 1.01 to 1.38 (average P' = 1.13). Fabric strength varies within each of the petrologically-defined units recovered from different crustal blocks. Additional remanence anisotropy fabric analyses of a few specimens reveal nearly identical directions of principal axes compared to AMS, but with larger degrees of anisotropy. Electron backscatter diffraction (EBSD) data from one sample shows a moderate plagioclase crystallographic preferred orientation best defined by a b-axis maxima that is coincident with the AMS minimum principal axis. This comparison

  10. XMM-Newton Observations Reveal the X-ray Counterpart of the Very-high-energy gamma-ray Source HESS J1640-465

    SciTech Connect

    Funk, S.; Hinton, J.A.; Puhlhofer, G.; Aharonian, F.A.; Hofmann, W.; Reimer, O.; Wagner, S.; Funk, S.; Hinton, J.A.; Puehlhofer, G.; Aharonian, F.A.; Hofmann, W.; Reimer, O.; Wagner, S.

    2007-03-05

    We present X-ray observations of the as of yet unidentified very high-energy (VHE) {gamma}-ray source HESS J1640-465 with the aim of establishing a counterpart of this source in the keV energy range, and identifying the mechanism responsible for the VHE emission. The 21.8 ksec XMM-Newton observation of HESS J1640-465 in September 2005 represents a significant improvement in sensitivity and angular resolution over previous ASCA studies in this region. These new data show a hard-spectrum X-ray emitting object at the centroid of the H.E.S.S. source, within the shell of the radio Supernova Remnant (SNR) G338.3-0.0. This object is consistent with the position and flux previously measured by both ASCA and Swift-XRT but is now shown to be significantly extended. We argue that this object is very likely the counterpart to HESS J1640-465 and that both objects may represent the Pulsar Wind Nebula of an as of yet undiscovered pulsar associated with G338.3-0.0.

  11. CANGAROO-III OBSERVATION OF TeV GAMMA RAYS FROM THE UNIDENTIFIED GAMMA-RAY SOURCE HESS J1614-518

    SciTech Connect

    Mizukami, T.; Kubo, H.; Tanimori, T.; Kabuki, S.; Yoshida, T.; Nakamori, T.; Enomoto, R.; Kifune, T.; Akimoto, M.; Ishioka, H.; Kawachi, A.; Bicknell, G. V.; Clay, R. W.; Edwards, P. G.; Gunji, S.; Hara, S.; Hara, T.; Hayashi, S.; Kajino, F.; Katagiri, H. E-mail: kubo@cr.scphys.kyoto-u.ac.jp

    2011-10-20

    We report the detection, with the CANGAROO-III imaging atmospheric Cherenkov telescope array, of a very high energy gamma-ray signal from the unidentified gamma-ray source HESS J1614-518, which was discovered in the H.E.S.S. Galactic plane survey. Diffuse gamma-ray emission was detected above 760 GeV at the 8.9{sigma} level during an effective exposure of 54 hr from 2008 May to August. The spectrum can be represented by a power law: (8.2 {+-} 2.2{sub stat} {+-} 2.5{sub sys}) x 10{sup -12} x (E/1 TeV){sup -}{gamma} cm{sup -2} s{sup -1} TeV{sup -1} with a photon index {gamma} of 2.4 {+-} 0.3{sub stat} {+-} 0.2{sub sys}, which is compatible with that of the H.E.S.S. observations. By combining our result with multiwavelength data, we discuss the possible counterparts for HESS J1614-518 and consider radiation mechanisms based on hadronic and leptonic processes for a supernova remnant (SNR), stellar winds from massive stars, and a pulsar wind nebula (PWN). Although a leptonic origin from a PWN driven by an unknown pulsar remains possible, hadronic-origin emission from an unknown SNR is preferred.

  12. CANGAROO-III Observation of TeV Gamma Rays from the Unidentified Gamma-Ray Source HESS J1614-518

    NASA Astrophysics Data System (ADS)

    Mizukami, T.; Kubo, H.; Yoshida, T.; Nakamori, T.; Enomoto, R.; Tanimori, T.; Akimoto, M.; Bicknell, G. V.; Clay, R. W.; Edwards, P. G.; Gunji, S.; Hara, S.; Hara, T.; Hayashi, S.; Ishioka, H.; Kabuki, S.; Kajino, F.; Katagiri, H.; Kawachi, A.; Kifune, T.; Kiuchi, R.; Kunisawa, T.; Kushida, J.; Matoba, T.; Matsubara, Y.; Matsuzawa, I.; Mizumura, Y.; Mizumoto, Y.; Mori, M.; Muraishi, H.; Naito, T.; Nakayama, K.; Nishijima, K.; Ohishi, M.; Otake, Y.; Ryoki, S.; Saito, K.; Sakamoto, Y.; Stamatescu, V.; Suzuki, T.; Swaby, D. L.; Thornton, G.; Tokanai, F.; Toyota, Y.; Tsuchiya, K.; Yanagita, S.; Yokoe, Y.; Yoshikoshi, T.; Yukawa, Y.

    2011-10-01

    We report the detection, with the CANGAROO-III imaging atmospheric Cherenkov telescope array, of a very high energy gamma-ray signal from the unidentified gamma-ray source HESS J1614-518, which was discovered in the H.E.S.S. Galactic plane survey. Diffuse gamma-ray emission was detected above 760 GeV at the 8.9σ level during an effective exposure of 54 hr from 2008 May to August. The spectrum can be represented by a power law: (8.2 ± 2.2stat ± 2.5sys) × 10-12 × (E/1 TeV)-γ cm-2 s-1 TeV-1 with a photon index γ of 2.4 ± 0.3stat ± 0.2sys, which is compatible with that of the H.E.S.S. observations. By combining our result with multiwavelength data, we discuss the possible counterparts for HESS J1614-518 and consider radiation mechanisms based on hadronic and leptonic processes for a supernova remnant (SNR), stellar winds from massive stars, and a pulsar wind nebula (PWN). Although a leptonic origin from a PWN driven by an unknown pulsar remains possible, hadronic-origin emission from an unknown SNR is preferred.

  13. Nature of the Unidentified TeV Source HESS J1614-518, Revealed by Suzaku and XMM-Newton Observations

    NASA Astrophysics Data System (ADS)

    Sakai, Michito; Yajima, Yukie; Matsumoto, Hironori

    2011-11-01

    We report on new Suzaku and XMM-Newton results concerning HESS J1614-518, which is one of the brightest extended TeV γ-ray sources and has two regions with intense γ-ray emission. We newly observed the south and center regions of HESS J1614-518 with Suzaku, since the north region, including the position of the 1st brightest peak of the TeV γ-ray emission, has already been observed. No X-ray counterpart was found at the position of the 2nd brightest peak of the TeV γ-ray emission; we estimated the upper limit of the X-ray flux to be 1.6 × 10-13 erg cm-2 s-1 in the 2-10 keV band. The soft X-ray source Suzaku J1614-5152, which was found at the edge of the field of view in a previous observation, was also detected at the middle of HESS J1614-518. Analyzing the XMM-Newton archival data, we revealed that Suzaku J1614-5152 consists of multiple point sources. The X-ray spectrum of the brightest point source, XMMU J161406.0-515225, can be described by a power-law model with a photon index of Γ = 5.2+0.6-0.5, or a blackbody model with temperature kT = 0.38+0.04-0.04 keV. In the blackbody model, the hydrogen-equivalent column density is almost the same as that of the hard extended X-ray emission, Suzaku J1614-5141, which was found at the 1st peak position. If true, XMMU J161406.0-515225 may be physically related to Suzaku J1614-5141 and HESS J1614-518.

  14. Nature of the unidentified TeV source HESS J1614-518 revealed by Suzaku and XMM-Newton observations

    NASA Astrophysics Data System (ADS)

    Sakai, Michito; Yajima, Yukie; Matsumoto, Hironori

    2012-03-01

    We report new results concerning HESS J1614-518, which exhibits two regions with intense γ-ray emission. The south and center regions of HESS J1614-518 were observed with Suzaku in 2008, while the north region with the 1st brightest peak was observed in 2006. No X-ray counterpart is found at the 2nd brightest peak; the upper limit of the X-ray flux is estimated as 1.6×10-13 erg cm-2 s-1 in the 2-10 keV band. A previously-known soft X-ray source, Suzaku J1614-5152, is detected at the center of HESS J1614-518. Analyzing the XMM-Newton archival data, we reveal that Suzaku J1614-5152 consists of multiple point sources. The X-ray spectrum of the brightest point source, XMMU J161406.0-515225, could be described by a power-law model with the photon index Γ = 5.2+0.6-0.5 or a blackbody model with the temperature kT = 0.38+0.04-0.04keV. In the blackbody model, the estimated column density NH = 1.1+0.3-0.2×1022cm-2 is almost the same as that of the hard extended X-ray emission in Suzaku J1614-5141, spatially coincident with the 1st peak position. In this case, XMMU J161406.0-515225 may be physically related to Suzaku J1614-5141 and HESS J1614-518.

  15. Nature of the Unidentified TeV Source HESS J1614-518 Revealed by Suzaku and XMM-Newton Observations

    NASA Astrophysics Data System (ADS)

    Sakai, M.; Yajima, Y.; Matsumoto, H.

    2013-03-01

    We report new results concerning HESS J1614-518, which exhibits two regions with intense γ-ray emission. The south and center regions of HESS J1614-518 were observed with Suzaku in 2008, while the north region with the 1st brightest peak was observed in 2006. No X-ray counterpart is found at the 2nd brightest peak; the upper limit of the X-ray flux is estimated as 1.6 × 10-13 erg cm-2 s-1 in the 2-10 keV band. A previously-known soft X-ray source, Suzaku J1614-5152, is detected at the center of HESS J1614-518. Analyzing the XMM-Newton archival data, we reveal that Suzaku J1614-5152 consists of multiple point sources. The X-ray spectrum of the brightest point source, XMMU J161406.0-515225, could be described by a power-law model with the photon index Γ = 5.2+0.6-0.5 or a blackbody model with the temperature kT = 0.38+0.04-0.04 {keV}. In the blackbody model, the estimated column density N H = 1.1+0.3-0.2 × 1022 {cm}-2 is almost the same as that of the hard extended X-ray emission in Suzaku J1614-5141, spatially coincident with the 1st peak position. In this case, XMMU J161406.0-515225 may be physically related to Suzaku J1614-5141 and HESS J1614-518.

  16. Observed deep energetic eddies by seamount wake

    NASA Astrophysics Data System (ADS)

    Chen, Gengxin; Wang, Dongxiao; Dong, Changming; Zu, Tingting; Xue, Huijie; Shu, Yeqiang; Chu, Xiaoqing; Qi, Yiquan; Chen, Hui

    2015-11-01

    Despite numerous surface eddies are observed in the ocean, deep eddies (a type of eddies which have no footprints at the sea surface) are much less reported in the literature due to the scarcity of their observation. In this letter, from recently collected current and temperature data by mooring arrays, a deep energetic and baroclinic eddy is detected in the northwestern South China Sea (SCS) with its intensity, size, polarity and structure being characterized. It remarkably deepens isotherm at deep layers by the amplitude of ~120 m and induces a maximal velocity amplitude about 0.18 m/s, which is far larger than the median velocity (0.02 m/s). The deep eddy is generated in a wake when a steering flow in the upper layer passes a seamount, induced by a surface cyclonic eddy. More observations suggest that the deep eddy should not be an episode in the area. Deep eddies significantly increase the velocity intensity and enhance the mixing in the deep ocean, also have potential implication for deep-sea sediments transport.

  17. Observed deep energetic eddies by seamount wake

    PubMed Central

    Chen, Gengxin; Wang, Dongxiao; Dong, Changming; Zu, Tingting; Xue, Huijie; Shu, Yeqiang; Chu, Xiaoqing; Qi, Yiquan; Chen, Hui

    2015-01-01

    Despite numerous surface eddies are observed in the ocean, deep eddies (a type of eddies which have no footprints at the sea surface) are much less reported in the literature due to the scarcity of their observation. In this letter, from recently collected current and temperature data by mooring arrays, a deep energetic and baroclinic eddy is detected in the northwestern South China Sea (SCS) with its intensity, size, polarity and structure being characterized. It remarkably deepens isotherm at deep layers by the amplitude of ~120 m and induces a maximal velocity amplitude about 0.18 m/s, which is far larger than the median velocity (0.02 m/s). The deep eddy is generated in a wake when a steering flow in the upper layer passes a seamount, induced by a surface cyclonic eddy. More observations suggest that the deep eddy should not be an episode in the area. Deep eddies significantly increase the velocity intensity and enhance the mixing in the deep ocean, also have potential implication for deep-sea sediments transport. PMID:26617343

  18. Observed deep energetic eddies by seamount wake.

    PubMed

    Chen, Gengxin; Wang, Dongxiao; Dong, Changming; Zu, Tingting; Xue, Huijie; Shu, Yeqiang; Chu, Xiaoqing; Qi, Yiquan; Chen, Hui

    2015-01-01

    Despite numerous surface eddies are observed in the ocean, deep eddies (a type of eddies which have no footprints at the sea surface) are much less reported in the literature due to the scarcity of their observation. In this letter, from recently collected current and temperature data by mooring arrays, a deep energetic and baroclinic eddy is detected in the northwestern South China Sea (SCS) with its intensity, size, polarity and structure being characterized. It remarkably deepens isotherm at deep layers by the amplitude of ~120 m and induces a maximal velocity amplitude about 0.18 m/s, which is far larger than the median velocity (0.02 m/s). The deep eddy is generated in a wake when a steering flow in the upper layer passes a seamount, induced by a surface cyclonic eddy. More observations suggest that the deep eddy should not be an episode in the area. Deep eddies significantly increase the velocity intensity and enhance the mixing in the deep ocean, also have potential implication for deep-sea sediments transport.

  19. Geochemical characteristics of fast-spreading lower oceanic crust: an example of troctolites at the Hess Deep Rift (IODP Expedition 345)

    NASA Astrophysics Data System (ADS)

    Akizawa, N.; Godard, M.; Ildefonse, B.; Arai, S.

    2014-12-01

    Troctolites were recovered during IODP Expedition 345 (Dec 2012 - Feb 2013), which targeted plutonic rocks from fast-spread lower oceanic crust at the Hess Deep Rift. The troctolites are divided into three groups based on textural diversity; "skeletal olivine-bearing", "fine-grained" and "coarse-grained" troctolites. For major- and trace-element compositions of olivine and plagioclase, the skeletal olivine-bearing and fine-grained troctolites are more evolved (olivine Fo and NiO contents, 83 to 86 and 0.08 to 0.2 wt.%, respectively, and plagioclase An content, 77 to 84) than coarse-grained ones (olivine Fo and NiO contents, 87to 89 and 0.2 to 0.3 wt.%, respectively, and plagioclase An content, 85 to 90). Clinopyroxenes show scattered chemical compositions in the skeletal olivine-bearing and fine-grained troctolites, down to the scale of a single thin section. Clinopyroxenes, some of which show no Eu anomaly, are clearly zoned in the coarse-grained troctolites: the rims are chemically more evolved than the cores. The skeletal olivine-bearing and fine-grained troctolites record signs of melt invasion, which caused the chemical heterogeneity of the clinopyroxenes. In contrast, the coarse-grained troctolites show no such sign, and contain the zoned clinopyroxenes, which were co-precipitated with plagioclases. MORB (mid-ocean ridge basalt) melts experience multi-stage evolution, including fractional crystallization and melt/troctolite interaction during migration. Such various melt migration processes in the lower oceanic crust possibly cause regional diversity of MORB chemistry.

  20. Long-term TeV and X-Ray Observations of the Gamma-Ray Binary HESS J0632+057

    NASA Astrophysics Data System (ADS)

    Aliu, E.; Archambault, S.; Aune, T.; Behera, B.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Duke, C.; Dumm, J.; Errando, M.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fortin, P.; Fortson, L.; Furniss, A.; Galante, N.; Gillanders, G. H.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Hughes, G.; Humensky, T. B.; Kaaret, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Madhavan, A. S.; Maier, G.; Majumdar, P.; McCann, A.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Otte, A. N.; Park, N.; Perkins, J. S.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rousselle, J.; Sembroski, G. H.; Sheidaei, F.; Skole, C.; Smith, A. W.; Staszak, D.; Stroh, M.; Telezhinsky, I.; Theiling, M.; Tucci, J. V.; Tyler, J.; Varlotta, A.; Vincent, S.; Wakely, S. P.; Weinstein, A.; Welsing, R.; Williams, D. A.; Zajczyk, A.; Zitzer, B.; VERITAS Collaboration; Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füssling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; H. E. S. S. Collaboration

    2014-01-01

    HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories in both the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057 conducted with the Very Energetic Radiation Imaging Telescope Array System and High Energy Stereoscopic System Cherenkov telescopes and the X-ray satellite Swift, spanning a time range from 2004 to 2012 and covering most of the system's orbit. The very-high-energy (VHE) emission is found to be variable and is correlated with that at X-ray energies. An orbital period of 315 ^{+6}_{-4} days is derived from the X-ray data set, which is compatible with previous results, P = (321 ± 5) days. The VHE light curve shows a distinct maximum at orbital phases close to 0.3, or about 100 days after periastron passage, which coincides with the periodic enhancement of the X-ray emission. Furthermore, the analysis of the TeV data shows for the first time a statistically significant (>6.5σ) detection at orbital phases 0.6-0.9. The obtained gamma-ray and X-ray light curves and the correlation of the source emission at these two energy bands are discussed in the context of the recent ephemeris obtained for the system. Our results are compared to those reported for other gamma-ray binaries.

  1. Long-term TeV and X-ray observations of the gamma-ray binary HESS J0632+057

    SciTech Connect

    Aliu, E.; Errando, M.; Archambault, S.; Aune, T.; Behera, B.; Chen, X.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Benbow, W.; Cerruti, M.; Berger, K.; Bird, R.; Bouvier, A.; Byrum, K.; Ciupik, L.; Connolly, M. P.; Cui, W.; Duke, C.; Dumm, J. E-mail: afalcone@astro.psu.edu; Collaboration: VERITAS Collaboration; H.E.S.S. Collaboration; and others

    2014-01-10

    HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories in both the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057 conducted with the Very Energetic Radiation Imaging Telescope Array System and High Energy Stereoscopic System Cherenkov telescopes and the X-ray satellite Swift, spanning a time range from 2004 to 2012 and covering most of the system's orbit. The very-high-energy (VHE) emission is found to be variable and is correlated with that at X-ray energies. An orbital period of 315{sub −4}{sup +6} days is derived from the X-ray data set, which is compatible with previous results, P = (321 ± 5) days. The VHE light curve shows a distinct maximum at orbital phases close to 0.3, or about 100 days after periastron passage, which coincides with the periodic enhancement of the X-ray emission. Furthermore, the analysis of the TeV data shows for the first time a statistically significant (>6.5σ) detection at orbital phases 0.6-0.9. The obtained gamma-ray and X-ray light curves and the correlation of the source emission at these two energy bands are discussed in the context of the recent ephemeris obtained for the system. Our results are compared to those reported for other gamma-ray binaries.

  2. Anders receives Hess Medal

    NASA Astrophysics Data System (ADS)

    Cameron, A. G. W.; Anders, Edward

    Edward Anders was awarded the Harry H. Hess Medal at the AGU Spring Meeting Honors Ceremony on May 31 in Baltimore. The Hess Medal recognizes outstanding achievements in research in the constitution and evolution of Earth and its sister planets. The award citation and Anders' response are given here.

  3. Detailed 21 cm observations towards the TeV γ-ray SNR HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Fukuda, Tatsuya; Yamamoto, Hiroaki; Fukui, Yasuo; Torii, Kazufumi; Hayakawa, Takahiro; Okuda, Takeshi; Sano, Hidetoshi; Yoshiike, Satoshi

    2012-10-01

    HESS J1731-347 is one of the unique SNRs which show the TeV gamma-ray shell like morphology. Our new study succeeded to reveal the distributions of the ISM proton that coincide well with the TeV gamma-ray distributions and discussed that both the hadronic and leptonic processes are possibly working in this region. However, the present ISM resolutions of a few arcmin of the given data sets are not sufficient to understand the detailed ISM distributions and the origin of the gamma-ray emission. We will use the ATCA to image 21cm radio continuum emission and HI emission in the region to a resolution of ~30" and study the interaction between the shock wave and the ISM in detail. Such results are a crucial component in testing for the origin of SNR gamma-rays.

  4. Geochemistry of Fast-Spreading Lower Oceanic Crust: Results from Drilling at the Hess Deep Rift (ODP Leg 147 and IODP Expedition 345; East Pacific Rise)

    NASA Astrophysics Data System (ADS)

    Godard, M.; Falloon, T.; Gillis, K. M.; Akizawa, N.; de Brito Adriao, A.; Koepke, J.; Marks, N.; Meyer, R.; Saha, A.; Garbe-Schoenberg, C. D.

    2014-12-01

    The Hess Deep Rift, where the Cocos Nazca Ridge propagates into the young, fast-spread East Pacific Rise crust, exposes a dismembered, but nearly complete, lower crustal section. The extensive exposures of the plutonic crust were drilled at 3 sites during ODP Leg 147 (Nov. 1992-Jan. 1993) and IODP Expedition 345 (Dec. 2012-Feb. 2013). We report preliminary results of a bulk rock geochemical study (major and trace elements) carried out on 109 samples representative of the different drilled lithologies. The shallowest gabbroic rocks were sampled at ODP Site 894. They comprise gabbronorite, gabbro, olivine gabbro and gabbronorite. They have evolved compositions with Mg# 39-55, Yb 4-8 x chondrite and Eu/Eu* 1-1.6. Olivine gabbro and troctolite were dominant at IODP Site U1415, with minor gabbro, gabbronorite and clinopyroxene oikocryst-bearing troctolite and gabbro. All U1415 gabbroic rocks have primitive compositions except for one gabbronorite rubble that is similar in composition to the shallow gabbros. Olivine gabbro, gabbro and gabbronorite overlap in composition: they have high Mg# (79-87) and Ni (130-570 ppm), low TiO2 (0.1-0.3 wt.%) and Yb (1.3-2.3 x chondrite) and positive Eu anomaly (Eu/Eu*=1.9-2.7). Troctolite has high Mg# (81-89), Ni (260-1500 ppm) and low TiO2 (<0.1 wt.%) and Yb (~0.5xchondrite) and large Eu/Eu* (>4). ODP Site 895 recovered sequences of highly depleted harzburgite, dunite and troctolite (Yb down to <0.1xchondrite) that are interpreted as a mantle-crust transition zone. Basalts were recovered at Sites 894 and U1415: they have low Yb (0.5-0.9xN6MORB) and are depleted in the most incompatible elements (Ce/Yb=0.6-0.9xN-MORB). The main geochemical characteristics of Site U1415 and 894 gabbroic rocks are consistent with formation as a cumulate sequence from a common parental MORB melt; troctolites are the most primitive end-member of this sequence. They overlap in composition with the most primitive of slow and fast spread crust gabbroic rocks.

  5. Occurrences of Orthopyroxene in the "Multi-textured" Layered Gabbros from the Hess Deep Rift, East Pacific Rise (the Site U1415P, IODP Expedition 345)

    NASA Astrophysics Data System (ADS)

    Hoshide, T.; Machi, S.; Maeda, J. I.

    2015-12-01

    IODP Exp.345 drilled three main holes (Holes U1415 I, J & P) from the lowermost plutonic crust exposed at the Hess Deep Rift, East Pacific Rise and primitive layered gabbroic rocks were newly discovered from these holes (Gillis et al., 2014). One of the mysteries about the layered gabbros is the fact that Opx, which is considered to appear in the late stage of crystallization on the basis of crystallization experiments of MORB, occurs as a dominant phase in many of the layered gabbros. In this presentation, we report the occurrence of Opx from the Hole U1415P and consider the significance of Opx in the origin of the layered gabbros. Hole U1415P (about 100m in thickness) is divided into two units, the upper Multi-textured Layered Gabbro Series (MLGS) and lower Troctolite Series (TS). Gabbroic rocks from the MLGS contain Opx (< 4 vol%) and are macroscopically classified into Opx-bearing olivine gabbro. However, these rocks are mesoscopically (on cm scale) inhomogeneous and have a great variation of mode, grain size and texture. On the other hand, TS consists of homogeneous troctolites and Opx rarely occurs in the series. The occurrences of Opx from the MLGS are as follows: (i) coarse-grained Opx+Cpx+Pl vein parallel to the layered structure of the surrounding troctolite (ii) undeformed Opx+Pl veinlets in kinked Ol (iii) Opx in the concave of anhedral Ol (iv) Opx rimming Cr-spl crystals in contact with Ol. The occurrence of Opx like (ii) and (iii) resembles the texture which is considered to be formed by the reaction between mantle peridotite and a SiO2-saturated melt (e.g, Piccardo et al., 2007). The facts that Opx is often found in association with Cr-spl and Cr-spl lamellae occur in pyroxenes of the Opx+Cpx+Pl vein suggest that the SiO2-saturated melt which reacted with Ol was rich in chromium. In addition, Cr-spl crystals rimmed by Opx contain multiphase-solid inclusions. The inclusions should be key in understanding the chemical composition of the reacted melt.

  6. Crystallographic Preferred Orientations and Seismic Properties of troctolitic rocks from fast-spread lower ocean crust (IODP Expedition 345 at Hess Deep

    NASA Astrophysics Data System (ADS)

    Ildefonse, B.; Akizawa, N.; Mainprice, D.; Godard, M.; Arai, S.

    2014-12-01

    IODP Expedition 345 (Dec 2012 - Feb 2013) recovered the first significant sections of modally layered gabbroic rocks from fast-spread lower ocean crust exposed at the Hess Deep Rift (Gillis et al., 2014, doi:10.1038/nature12778). Olivine gabbro and troctolite are the dominant plutonic rock types recovered, with minor gabbro and gabbronorite. Magmatic foliation is moderate to strong in intervals with simple modal layering but weak to absent in troctolitic intervals, and typically absent in intervals with heterogeneous textures and/or diffuse banding. We present crystallographic preferred orientations (CPO) of primary igneous phases (plagioclase, olivine, cpx) in troctolitic samples, measured using the Electron-Backscattered Electron Diffraction (EBSD) technique at Géosciences Montpellier. The samples are divided into 12 coarse-grained troctolites, 3 fine-grained troctolites, 9 clinopyroxene oikocryst-bearing troctolites, 1 skeletal olivine-bearing troctolite, and 3 olivine gabbros. Plagioclase CPO are typical magmatic fabrics, dominantly axial-B, or intermediate between axial-B and type P (BA-index ranges from 0.1 to 0.6; Satsukawa et al., 2013, doi:10.5194/se-4-511-2013). BA increases when the [100] point maximum, indicating the mineral lineation, becomes better defined. The coarse-grained troctolite samples, from the troctolite series in Holes U1415 J and P, generally display too large grains for the CPO to be statistically meaningful; fabrics appear poorly defined at the scale of the thin sections. Large olivine grains commonly display subgrains resulting from crystal-plastic deformation. In the other troctolitic samples, the plagioclase fabrics are generally well defined, and vary in intensity (J-index) from 1.8 to 7. The olivine gabbros are from banded intervals in Hole U1415P; they display weak, oblate plagioclase CPO (J = 1.5 to 2, BA < 0.2). CPO are used to model seismic properties of the samples. The fast direction of elastic P-wave propagation in

  7. H.E.S.S. observations of the binary system PSR B1259-63/LS 2883 around the 2010/2011 periastron passage

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chaves, R. C. G.; Cheesebrough, A.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Grondin, M.-H.; Grudzińska, M.; Häer, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Krüger, P. P.; Lan, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Menzler, U.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nguyen, N.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Willmann, P.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2013-03-01

    Aims: We present very high energy (VHE; E > 100 GeV) data from the γ-ray binary system PSR B1259-63/LS 2883 taken around its periastron passage on 15th of December 2010 with the High Energy Stereoscopic System (H.E.S.S.) of Cherenkov Telescopes. We aim to search for a possible TeV counterpart of the GeV flare detected by the Fermi LAT. In addition, we aim to study the current periastron passage in the context of previous observations taken at similar orbital phases, testing the repetitive behaviour of the source. Methods: Observations at VHEs were conducted with H.E.S.S. from 9th to 16th of January 2011. The total dataset amounts to ~6 h of observing time. The data taken around the 2004 periastron passage were also re-analysed with the current analysis techniques in order to extend the energy spectrum above 3 TeV to fully compare observation results from 2004 and 2011. Results: The source is detected in the 2011 data at a significance level of 11.5σ revealing an averaged integral flux above 1 TeV of (1.01 ± 0.18stat ± 0.20sys) × 10-12 cm-2 s-1. The differential energy spectrum follows a power-law shape with a spectral index Γ = 2.92 ± 0.30stat ± 0.20sys and a flux normalisation at 1 TeV of N0 = (1.95 ± 0.32stat ± 0.39sys) × 10-12 TeV-1 cm-2 s-1. The measured light curve does not show any evidence for variability of the source on the daily scale. The re-analysis of the 2004 data yields results compatible with the published ones. The differential energy spectrum measured up to ~10 TeV is consistent with a power law with a spectral index Γ = 2.81 ± 0.10stat ± 0.20sys and a flux normalisation at 1 TeV of N0 = (1.29 ± 0.08stat ± 0.26sys) × 10-12 TeV-1 cm-2 s-1. Conclusions: The measured integral flux and the spectral shape of the 2011 data are compatible with the results obtained around previous periastron passages. The absence of variability in the H.E.S.S. data indicates that the GeV flare observed by Fermi LAT in the time period covered also by H.E.S.S

  8. Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    Abdallah, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Hahn, J.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Lui, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morâ, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; Odaka, H.; Ohm, S.; Öttl, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seyffert, A. S.; Shafi, N.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spieß, F.; Stawarz, L.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Tuffs, R.; van der Walt, J.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.; H. E. S. S. Collaboration

    2016-09-01

    The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using γ -ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant γ -ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section ⟨σ v ⟩. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach ⟨σ v ⟩ values of 6 ×10-26 cm3 s-1 in the W+W- channel for a DM particle mass of 1.5 TeV, and 2 ×10-26 cm3 s-1 in the τ+τ- channel for a 1 TeV mass. For the first time, ground-based γ -ray observations have reached sufficient sensitivity to probe ⟨σ v ⟩ values expected from the thermal relic density for TeV DM particles.

  9. Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with H.E.S.S.

    PubMed

    Abdallah, H; Abramowski, A; Aharonian, F; Ait Benkhali, F; Akhperjanian, A G; Angüner, E; Arrieta, M; Aubert, P; Backes, M; Balzer, A; Barnard, M; Becherini, Y; Becker Tjus, J; Berge, D; Bernhard, S; Bernlöhr, K; Birsin, E; Blackwell, R; Böttcher, M; Boisson, C; Bolmont, J; Bordas, P; Bregeon, J; Brun, F; Brun, P; Bryan, M; Bulik, T; Capasso, M; Carr, J; Casanova, S; Chakraborty, N; Chalme-Calvet, R; Chaves, R C G; Chen, A; Chevalier, J; Chrétien, M; Colafrancesco, S; Cologna, G; Condon, B; Conrad, J; Couturier, C; Cui, Y; Davids, I D; Degrange, B; Deil, C; deWilt, P; Djannati-Ataï, A; Domainko, W; Donath, A; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Edwards, T; Egberts, K; Eger, P; Ernenwein, J-P; Eschbach, S; Farnier, C; Fegan, S; Fernandes, M V; Fiasson, A; Fontaine, G; Förster, A; Funk, S; Füßling, M; Gabici, S; Gajdus, M; Gallant, Y A; Garrigoux, T; Giavitto, G; Giebels, B; Glicenstein, J F; Gottschall, D; Goyal, A; Grondin, M-H; Grudzińska, M; Hadasch, D; Hahn, J; Hawkes, J; Heinzelmann, G; Henri, G; Hermann, G; Hervet, O; Hillert, A; Hinton, J A; Hofmann, W; Hoischen, C; Holler, M; Horns, D; Ivascenko, A; Jacholkowska, A; Jamrozy, M; Janiak, M; Jankowsky, D; Jankowsky, F; Jingo, M; Jogler, T; Jouvin, L; Jung-Richardt, I; Kastendieck, M A; Katarzyński, K; Katz, U; Kerszberg, D; Khélifi, B; Kieffer, M; King, J; Klepser, S; Klochkov, D; Kluźniak, W; Kolitzus, D; Komin, Nu; Kosack, K; Krakau, S; Kraus, M; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lau, J; Lees, J-P; Lefaucheur, J; Lefranc, V; Lemière, A; Lemoine-Goumard, M; Lenain, J-P; Leser, E; Lohse, T; Lorentz, M; Lui, R; Lypova, I; Marandon, V; Marcowith, A; Mariaud, C; Marx, R; Maurin, G; Maxted, N; Mayer, M; Meintjes, P J; Menzler, U; Meyer, M; Mitchell, A M W; Moderski, R; Mohamed, M; Morå, K; Moulin, E; Murach, T; de Naurois, M; Niederwanger, F; Niemiec, J; Oakes, L; Odaka, H; Ohm, S; Öttl, S; Ostrowski, M; Oya, I; Padovani, M; Panter, M; Parsons, R D; Paz Arribas, M; Pekeur, N W; Pelletier, G; Petrucci, P-O; Peyaud, B; Pita, S; Poon, H; Prokhorov, D; Prokoph, H; Pühlhofer, G; Punch, M; Quirrenbach, A; Raab, S; Reimer, A; Reimer, O; Renaud, M; de Los Reyes, R; Rieger, F; Romoli, C; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Salek, D; Sanchez, D A; Santangelo, A; Sasaki, M; Schlickeiser, R; Schüssler, F; Schulz, A; Schwanke, U; Schwemmer, S; Seyffert, A S; Shafi, N; Simoni, R; Sol, H; Spanier, F; Spengler, G; Spieß, F; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Tavernet, J-P; Tavernier, T; Taylor, A M; Terrier, R; Tluczykont, M; Trichard, C; Tuffs, R; van der Walt, J; van Eldik, C; van Soelen, B; Vasileiadis, G; Veh, J; Venter, C; Viana, A; Vincent, P; Vink, J; Voisin, F; Völk, H J; Vuillaume, T; Wadiasingh, Z; Wagner, S J; Wagner, P; Wagner, R M; White, R; Wierzcholska, A; Willmann, P; Wörnlein, A; Wouters, D; Yang, R; Zabalza, V; Zaborov, D; Zacharias, M; Zdziarski, A A; Zech, A; Zefi, F; Ziegler, A; Żywucka, N

    2016-09-01

    The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using γ-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant γ-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section ⟨σv⟩. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach ⟨σv⟩ values of 6×10^{-26}  cm^{3} s^{-1} in the W^{+}W^{-} channel for a DM particle mass of 1.5 TeV, and 2×10^{-26}  cm^{3} s^{-1} in the τ^{+}τ^{-} channel for a 1 TeV mass. For the first time, ground-based γ-ray observations have reached sufficient sensitivity to probe ⟨σv⟩ values expected from the thermal relic density for TeV DM particles. PMID:27661677

  10. Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with H.E.S.S.

    PubMed

    Abdallah, H; Abramowski, A; Aharonian, F; Ait Benkhali, F; Akhperjanian, A G; Angüner, E; Arrieta, M; Aubert, P; Backes, M; Balzer, A; Barnard, M; Becherini, Y; Becker Tjus, J; Berge, D; Bernhard, S; Bernlöhr, K; Birsin, E; Blackwell, R; Böttcher, M; Boisson, C; Bolmont, J; Bordas, P; Bregeon, J; Brun, F; Brun, P; Bryan, M; Bulik, T; Capasso, M; Carr, J; Casanova, S; Chakraborty, N; Chalme-Calvet, R; Chaves, R C G; Chen, A; Chevalier, J; Chrétien, M; Colafrancesco, S; Cologna, G; Condon, B; Conrad, J; Couturier, C; Cui, Y; Davids, I D; Degrange, B; Deil, C; deWilt, P; Djannati-Ataï, A; Domainko, W; Donath, A; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Edwards, T; Egberts, K; Eger, P; Ernenwein, J-P; Eschbach, S; Farnier, C; Fegan, S; Fernandes, M V; Fiasson, A; Fontaine, G; Förster, A; Funk, S; Füßling, M; Gabici, S; Gajdus, M; Gallant, Y A; Garrigoux, T; Giavitto, G; Giebels, B; Glicenstein, J F; Gottschall, D; Goyal, A; Grondin, M-H; Grudzińska, M; Hadasch, D; Hahn, J; Hawkes, J; Heinzelmann, G; Henri, G; Hermann, G; Hervet, O; Hillert, A; Hinton, J A; Hofmann, W; Hoischen, C; Holler, M; Horns, D; Ivascenko, A; Jacholkowska, A; Jamrozy, M; Janiak, M; Jankowsky, D; Jankowsky, F; Jingo, M; Jogler, T; Jouvin, L; Jung-Richardt, I; Kastendieck, M A; Katarzyński, K; Katz, U; Kerszberg, D; Khélifi, B; Kieffer, M; King, J; Klepser, S; Klochkov, D; Kluźniak, W; Kolitzus, D; Komin, Nu; Kosack, K; Krakau, S; Kraus, M; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lau, J; Lees, J-P; Lefaucheur, J; Lefranc, V; Lemière, A; Lemoine-Goumard, M; Lenain, J-P; Leser, E; Lohse, T; Lorentz, M; Lui, R; Lypova, I; Marandon, V; Marcowith, A; Mariaud, C; Marx, R; Maurin, G; Maxted, N; Mayer, M; Meintjes, P J; Menzler, U; Meyer, M; Mitchell, A M W; Moderski, R; Mohamed, M; Morå, K; Moulin, E; Murach, T; de Naurois, M; Niederwanger, F; Niemiec, J; Oakes, L; Odaka, H; Ohm, S; Öttl, S; Ostrowski, M; Oya, I; Padovani, M; Panter, M; Parsons, R D; Paz Arribas, M; Pekeur, N W; Pelletier, G; Petrucci, P-O; Peyaud, B; Pita, S; Poon, H; Prokhorov, D; Prokoph, H; Pühlhofer, G; Punch, M; Quirrenbach, A; Raab, S; Reimer, A; Reimer, O; Renaud, M; de Los Reyes, R; Rieger, F; Romoli, C; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Salek, D; Sanchez, D A; Santangelo, A; Sasaki, M; Schlickeiser, R; Schüssler, F; Schulz, A; Schwanke, U; Schwemmer, S; Seyffert, A S; Shafi, N; Simoni, R; Sol, H; Spanier, F; Spengler, G; Spieß, F; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Tavernet, J-P; Tavernier, T; Taylor, A M; Terrier, R; Tluczykont, M; Trichard, C; Tuffs, R; van der Walt, J; van Eldik, C; van Soelen, B; Vasileiadis, G; Veh, J; Venter, C; Viana, A; Vincent, P; Vink, J; Voisin, F; Völk, H J; Vuillaume, T; Wadiasingh, Z; Wagner, S J; Wagner, P; Wagner, R M; White, R; Wierzcholska, A; Willmann, P; Wörnlein, A; Wouters, D; Yang, R; Zabalza, V; Zaborov, D; Zacharias, M; Zdziarski, A A; Zech, A; Zefi, F; Ziegler, A; Żywucka, N

    2016-09-01

    The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using γ-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant γ-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section ⟨σv⟩. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach ⟨σv⟩ values of 6×10^{-26}  cm^{3} s^{-1} in the W^{+}W^{-} channel for a DM particle mass of 1.5 TeV, and 2×10^{-26}  cm^{3} s^{-1} in the τ^{+}τ^{-} channel for a 1 TeV mass. For the first time, ground-based γ-ray observations have reached sufficient sensitivity to probe ⟨σv⟩ values expected from the thermal relic density for TeV DM particles.

  11. Bi-telescopic, deep, simultaneous meteor observations

    NASA Technical Reports Server (NTRS)

    Taff, L. G.

    1986-01-01

    A statistical summary is presented of 10 hours of observing sporadic meteors and two meteor showers using the Experimental Test System of the Lincoln Laboratory. The observatory is briefly described along with the real-time and post-processing hardware, the analysis, and the data reduction. The principal observational results are given for the sporadic meteor zenithal hourly rates. The unique properties of the observatory include twin telescopes to allow the discrimination of meteors by parallax, deep limiting magnitude, good time resolution, and sophisticated real-time and post-observing video processing.

  12. Simultaneous Observations of PKS 2155--304 with H.E.S.S., Fermi, RXTE and ATOM: Spectral Energy Distributions and Variability in a Low State

    SciTech Connect

    Aharonian, F.; Akhperjanian, A.G.; Anton, G.; Barres de Almeida, U.; Bazer-Bachi, A.R.; Becherini, Y.; Behera, B.; Bernlohr, K.; Boisson, C.; Bochow, A.; Borrel, V.; Brion, E.; Brucker, J.; Brun, P.; Buhler, R.; Bulik, T.; Busching, I.; Boutelier, T.; Chadwick, P.M.; Charbonnier, A.; Chaves, R.C.G.; /more authors..

    2009-05-07

    We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of {gamma}-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; >100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little ({approx}30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated variability we find in the various bands for PKS 2155-304.

  13. SIMULTANEOUS OBSERVATIONS OF PKS 2155-304 WITH HESS, FERMI, RXTE, AND ATOM: SPECTRAL ENERGY DISTRIBUTIONS AND VARIABILITY IN A LOW STATE

    SciTech Connect

    Aharonian, F.; Bernloehr, K.; Bochow, A.; Buehler, R.; Akhperjanian, A. G.; Anton, G.; Brucker, J.; Barres de Almeida, U.; Chadwick, P. M.; Bazer-Bachi, A. R.; Borrel, V.; Behera, B.; Boisson, C.; Brion, E.; Brun, P.; Buesching, I.; Boutelier, T. E-mail: berrie@in2p3.fr E-mail: jchiang@slac.stanford.edu

    2009-05-10

    We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of {gamma}-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; >100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little ({approx}30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated variability we find in the various bands for PKS 2155-304.

  14. GALEX Observations of the NTT Deep Field

    NASA Astrophysics Data System (ADS)

    Wei, L. H.; Baker, A. J.; Lutz, D.; Lehnert, M. D.; Vogel, S. N.; Bertoldi, F.

    2005-12-01

    We report on near- and far-UV observations of the NTT Deep Field with the Galaxy Evolution Explorer (GALEX). To investigate the cold dust content of UV-selected galaxy populations, we compare the GALEX catalog with 1.2mm continuum mapping obtained with the Max-Planck Millimeter Bolometer (MAMBO) array at the IRAM 30m telescope. We discuss the implications of our results for understanding the dust SEDs of high-redshift galaxies. This project is funded by NASA via GALEX Guest Investigator grant 04-0000-0074.

  15. The Whisper of Deep Basins: Observation & Modelling

    NASA Astrophysics Data System (ADS)

    Burjanek, J.; Ermert, L. A.; Poggi, V.; Michel, C.; Fäh, D.

    2013-12-01

    Free oscillations of Earth have been used for a long time to retrieve information about the deep Earth's interior. On a much smaller scale, standing waves develop in deep sedimentary basins and can possibly be used in a similar way. The sensitivity of these waves to subsurface properties makes them a potential source of information about the deep basin characteristics. We investigated the sequence of two-dimensional resonance modes occurring in Rhône Valley, a strongly over-deepened, glacially carved basin with a sediment fill reaching up to 900 m thickness. We obtained two synchronous linear-array recordings of ambient vibrations and analysed them with two different processing techniques. First, both 2D resonance frequencies and their corresponding modal shapes were identified by frequency-domain decomposition of the signal cross-spectral density matrix. Second, time-frequency polarization analysis was applied to support the addressing of the modes and to determine the relative contributions of the vertical and horizontal components of the fundamental in-plane mode. Simplified 2-D finite element models were then used to support the interpretation of the observations. We were able to identify several resonance modes including previously unmeasured higher modes at all investigated locations in the valley. Good agreement was found between results of our study and previous studies, between the two processing techniques and between observed and modelled results. Finally, a parametric study was performed to qualitatively assess the sensitivity of the mode's order, shape and frequency to subsurface properties like bedrock geometry, Poisson's ratio and shear wave velocity of the sediments. We concluded that the sequence of modes as they appear by frequency depends strongly on subsurface properties. Therefore addressing of the higher modes can be done reliably only with prior information on the sediment structure.

  16. Remote observing with NASA's Deep Space Network

    NASA Astrophysics Data System (ADS)

    Kuiper, T. B. H.; Majid, W. A.; Martinez, S.; Garcia-Miro, C.; Rizzo, J. R.

    2012-09-01

    The Deep Space Network (DSN) communicates with spacecraft as far away as the boundary between the Solar System and the interstellar medium. To make this possible, large sensitive antennas at Canberra, Australia, Goldstone, California, and Madrid, Spain, provide for constant communication with interplanetary missions. We describe the procedures for radioastronomical observations using this network. Remote access to science monitor and control computers by authorized observers is provided by two-factor authentication through a gateway at the Jet Propulsion Laboratory (JPL) in Pasadena. To make such observations practical, we have devised schemes based on SSH tunnels and distributed computing. At the very minimum, one can use SSH tunnels and VNC (Virtual Network Computing, a remote desktop software suite) to control the science hosts within the DSN Flight Operations network. In this way we have controlled up to three telescopes simultaneously. However, X-window updates can be slow and there are issues involving incompatible screen sizes and multi-screen displays. Consequently, we are now developing SSH tunnel-based schemes in which instrument control and monitoring, and intense data processing, are done on-site by the remote DSN hosts while data manipulation and graphical display are done at the observer's host. We describe our approaches to various challenges, our experience with what worked well and lessons learned, and directions for future development.

  17. Toward a comprehensive model for feedback by active galactic nuclei: New insights from M87 observations by LOFAR, Fermi, and H.E.S.S

    SciTech Connect

    Pfrommer, Christoph

    2013-12-10

    Feedback by active galactic nuclei (AGNs) appears to be critical in balancing radiative cooling of the low-entropy gas at the centers of galaxy clusters and in mitigating the star formation of elliptical galaxies. New observations of M87 enable us to put forward a comprehensive model for the physical heating mechanism. Low-frequency radio observations by LOFAR revealed the absence of fossil cosmic-ray (CR) electrons in the radio halo surrounding M87. This puzzle can be resolved by accounting for the CR release from the radio lobes and the subsequent mixing of CRs with the dense ambient intracluster gas, which thermalizes the electrons on a timescale similar to the radio halo age of 40 Myr. Hadronic interactions of similarly injected CR protons with the ambient gas should produce an observable gamma-ray signal in accordance with the steady emission of the low state of M87 detected by Fermi and H.E.S.S. Hence, we normalize the CR population to the gamma-ray emission, which shows the same spectral slope as the CR injection spectrum probed by LOFAR, thereby supporting a common origin. We show that CRs, which stream at the Alfvén velocity with respect to the plasma rest frame, heat the surrounding thermal plasma at a rate that balances that of radiative cooling on average at each radius. However, the resulting global thermal equilibrium is locally unstable and allows for the formation of the observed cooling multi-phase medium through thermal instability. Provided that CR heating balances cooling during the emerging 'cooling flow', the collapse of the majority of the gas is halted around 1 keV—in accordance with X-ray data. We show that both the existence of a temperature floor and the similar radial scaling of the heating and cooling rates are generic predictions of the CR heating model.

  18. Science Observations of Deep Space One

    NASA Technical Reports Server (NTRS)

    Nelson, Robert M.; Baganal, Fran; Boice, Daniel C.; Britt, Daniel T.; Brown, Robert H.; Buratti, Bonnie J.; Creary, Frank; Ip, Wing-Huan; Meier, Roland; Oberst, Juergen

    1999-01-01

    During the Deep Space One (DS1) primary mission, the spacecraft will fly by asteroid 1992 KD and possibly comet Borrelly. There are two technologies being validated on DS1 that will provide science observations of these targets, the Miniature Integrated Camera Spectrometer (MICAS) and the Plasma Experiment for Planetary Exploration (PEPE). MICAS encompasses a camera, an ultraviolet imaging spectrometer and an infrared imaging spectrometer. PEPE combines an ion and electron analyzer designed to determine the three-dimensional distribution of plasma over its field of view. MICAS includes two visible wavelength imaging channels, an ultraviolet imaging spectrometer, and an infrared imaging spectrometer all of which share a single 10-cm diameter telescope. Two types of visible wavelength detectors, both operating between about 500 and 1000 nm are used: a CCD with 13-microrad pixels and an 18-microrad-per-pixel, metal-on-silicon active pixel sensor (APS). Unlike the CCD the APS includes the timing and control electronics on the chip along with the detector. The UV spectrometer spans 80 to 185 nm with 0.64-nm spectral resolution and 316-microrad pixels. The IR spectrometer covers the range from 1200 to 2400 nm with 6.6-nm resolution and 54-microrad pixels PEPE includes a very low-power, low-mass micro-calorimeter to help understand plasma-surface interactions and a plasma analyzer to identify de individual molecules and atoms in the immediate vicinity of the spacecraft that have been eroded off the surface of asteroid 1992 KD. It employs common apertures with separate electrostatic energy analyzers. It measures electron and ion energies spanning a range of 3 eV to 30 keV, with a resolution of five percent. and measures ion mass from one to 135 atomic mass units with 5 percent resolution. It electrostatically sweeps its field of view both in elevation and azimuth. Both MICAS and PEPE represent a new direction for the evolution of science instruments for interplanetary

  19. Unveiling the origin of HESS J1809-193

    NASA Astrophysics Data System (ADS)

    Castelletti, G.; Giacani, E.; Petriella, A.

    2016-03-01

    Aims: The main goal of this paper is to provide new insights on the origin of the observable flux of γ rays from HESS J1809-193 using new high-quality observations in the radio domain. Methods: We used the Expanded Very Large Array (now known as the Karl G. Jansky Very large Array, JVLA) to produce a deep full-synthesis imaging at 1.4 GHz of the vicinity of PSR J1809-1917. These data were used in conjunction with 12CO observations from the James Clerk Maxwell Telescope in the transition line J = 3-2 and atomic hydrogen data from the Southern Galactic Plane Survey to investigate the properties of the interstellar medium in the direction of the source HESS J1809-193. Results: The new radio continuum image, obtained with a synthesized beam of 8'' × 4'' and a sensitivity of 0.17 mJy beam-1, reveals with unprecedented detail all the intensity structures in the field. No radio counterpart to the observed X-ray emission supposed to be a pulsar wind nebula powered by PSR J1809-1917 is seen in the new JVLA image. We discovered a system of molecular clouds on the edge of the supernova remnant (SNR) G11.0-0.0 shock front, which is positionally coincident with the brightest part of the TeV source HESS J1809-193. We determine, on the basis of kinematic and morphological evidences, a physical link of the SNR with the clouds for which we estimated a total (molecular plus atomic) mass of ~3 × 103M⊙ and a total proton density in the range 2-3 × 103 cm-3. Conclusions: We propose as the most likely origin of the very high-energy γ-ray radiation from HESS J1809-193 a hadronic mechanism through collisions of ions accelerated at the SNR G11.0-0.0 shock with the molecular matter in the vicinity of the remnant. The new JVLA image (in FITS format) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A71

  20. Deep Chandra observations of Pictor A

    NASA Astrophysics Data System (ADS)

    Hardcastle, M. J.; Lenc, E.; Birkinshaw, M.; Croston, J. H.; Goodger, J. L.; Marshall, H. L.; Perlman, E. S.; Siemiginowska, A.; Stawarz, Ł.; Worrall, D. M.

    2016-02-01

    We report on deep Chandra observations of the nearby broad-line radio galaxy Pictor A, which we combine with new Australia Telescope Compact Array (ATCA) observations. The new X-ray data have a factor of 4 more exposure than observations previously presented and span a 15 yr time baseline, allowing a detailed study of the spatial, temporal and spectral properties of the AGN, jet, hotspot and lobes. We present evidence for further time variation of the jet, though the flare that we reported in previous work remains the most significantly detected time-varying feature. We also confirm previous tentative evidence for a faint counterjet. Based on the radio through X-ray spectrum of the jet and its detailed spatial structure, and on the properties of the counterjet, we argue that inverse-Compton models can be conclusively rejected, and propose that the X-ray emission from the jet is synchrotron emission from particles accelerated in the boundary layer of a relativistic jet. For the first time, we find evidence that the bright western hotspot is also time-varying in X-rays, and we connect this to the small-scale structure in the hotspot seen in high-resolution radio observations. The new data allow us to confirm that the spectrum of the lobes is in good agreement with the predictions of an inverse-Compton model and we show that the data favour models in which the filaments seen in the radio images are predominantly the result of spatial variation of magnetic fields in the presence of a relatively uniform electron distribution.

  1. Interpreting the strongest deep earthquake ever observed

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-12-01

    Massive earthquakes that strike deep within the Earth may be more efficient at dissipating pent-up energy than similar quakes near the surface, according to new research by Wei et al. The authors analyzed the rupture of the most powerful deep earthquake ever recorded.

  2. Identification of HESS J1303-631 as a pulsar wind nebula through γ-ray, X-ray, and radio observations

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker, J.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Gérard, L.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Grondin, M.-H.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Laffon, H.; Lamanna, G.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Menzler, U.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2012-12-01

    Aims: The previously unidentified very high-energy (VHE; E > 100 GeV) γ-ray source HESS J1303-631, discovered in 2004, is re-examined including new data from the H.E.S.S. Cherenkov telescope array in order to identify this object. Archival data from the XMM-Newton X-ray satellite and from the PMN radio survey are also examined. Methods: Detailed morphological and spectral studies of VHE γ-ray emission as well as of the XMM-Newton X-ray data are performed. Radio data from the PMN survey are used as well to construct a leptonic model of the source. The γ-ray and X-ray spectra and radio upper limit are used to construct a one zone leptonic model of the spectral energy distribution (SED). Results: Significant energy-dependent morphology of the γ-ray source is detected with high-energy emission (E > 10 TeV) positionally coincident with the pulsar PSR J1301-6305 and lower energy emission (E < 2 TeV) extending 0.4° to the southeast of the pulsar. The spectrum of the VHE source can be described with a power-law with an exponential cut-off N0 = (5.6 ± 0.5) × 10-12 TeV-1 cm-2 s-1, Γ = 1.5 ± 0.2) and Ecut = (7.7 ± 2.2) TeV. The pulsar wind nebula (PWN) is also detected in X-rays, extending 2-3' from the pulsar position towards the center of the γ-ray emission region. A potential radio counterpart from the PMN survey is also discussed, showing a hint for a counterpart at the edge of the X-ray PWN trail and is taken as an upper limit in the SED. The extended X-ray PWN has an unabsorbed flux of F_2{-10 keV ˜ 1.6+0.2-0.4× 10-13 erg cm-2 s-1} and is detected at a significance of 6.5σ. The SED is well described by a one zone leptonic scenario which, with its associated caveats, predicts a very low average magnetic field for this source. Conclusions: Significant energy-dependent morphology of this source, as well as the identification of an associated X-ray PWN from XMM-Newton observations enable identification of the VHE source as an evolved PWN associated to the

  3. The jet and arc molecular clouds toward Westerlund 2, RCW 49, and HESS J1023–575; {sup 12}CO and {sup 13}CO (J = 2-1 and J = 1-0) observations with NANTEN2 and Mopra telescope

    SciTech Connect

    Furukawa, N.; Ohama, A.; Fukuda, T.; Torii, K.; Hayakawa, T.; Sano, H.; Okuda, T.; Yamamoto, H.; Moribe, N.; Mizuno, A.; Maezawa, H.; Onishi, T.; Kawamura, A.; Mizuno, N.; Dawson, J. R.; Dame, T. M.; Yonekura, Y.; Aharonian, F.; De Oña Wilhelmi, E.; Rowell, G. P. E-mail: fukui@a.phys.nagoya-u.ac.jp; and others

    2014-02-01

    We have made new CO observations of two molecular clouds, which we call 'jet' and 'arc' clouds, toward the stellar cluster Westerlund 2 and the TeV γ-ray source HESS J1023–575. The jet cloud shows a linear structure from the position of Westerlund 2 on the east. In addition, we have found a new counter jet cloud on the west. The arc cloud shows a crescent shape in the west of HESS J1023–575. A sign of star formation is found at the edge of the jet cloud and gives a constraint on the age of the jet cloud to be ∼Myr. An analysis with the multi CO transitions gives temperature as high as 20 K in a few places of the jet cloud, suggesting that some additional heating may be operating locally. The new TeV γ-ray images by H.E.S.S. correspond to the jet and arc clouds spatially better than the giant molecular clouds associated with Westerlund 2. We suggest that the jet and arc clouds are not physically linked with Westerlund 2 but are located at a greater distance around 7.5 kpc. A microquasar with long-term activity may be able to offer a possible engine to form the jet and arc clouds and to produce the TeV γ-rays, although none of the known microquasars have a Myr age or steady TeV γ-rays. Alternatively, an anisotropic supernova explosion which occurred ∼Myr ago may be able to form the jet and arc clouds, whereas the TeV γ-ray emission requires a microquasar formed after the explosion.

  4. Extreme Blazars Studied with Fermi-LAT and Suzaku: 1ES 0347-121 and Blazar Candidate HESS J1943+213

    NASA Astrophysics Data System (ADS)

    Tanaka, Y. T.; Stawarz, Ł.; Finke, J.; Cheung, C. C.; Dermer, C. D.; Kataoka, J.; Bamba, A.; Dubus, G.; De Naurois, M.; Wagner, S. J.; Fukazawa, Y.; Thompson, D. J.

    2014-06-01

    We report on our study of high-energy properties of two peculiar TeV emitters: the "extreme blazar" 1ES 0347-121 and the "extreme blazar candidate" HESS J1943+213 located near the Galactic plane. Both objects are characterized by quiescent synchrotron emission with flat spectra extending up to the hard X-ray range, and both were reported to be missing GeV counterparts in the Fermi Large Area Telescope (LAT) two-year Source Catalog. We analyze a 4.5 yr accumulation of the Fermi-LAT data, resulting in the detection of 1ES 0347-121 in the GeV band, as well as in improved upper limits for HESS J1943+213. We also present the analysis results of newly acquired Suzaku data for HESS J1943+213. The X-ray spectrum is well represented by a single power law extending up to 25 keV with photon index 2.00 ± 0.02 and a moderate absorption in excess of the Galactic value, which is in agreement with previous X-ray observations. No short-term X-ray variability was found over the 80 ks duration of the Suzaku exposure. Under the blazar hypothesis, we modeled the spectral energy distributions of 1ES 0347-121 and HESS J1943+213, and we derived constraints on the intergalactic magnetic field strength and source energetics. We conclude that although the classification of HESS J1943+213 has not yet been determined, the blazar hypothesis remains the most plausible option since, in particular, the broadband spectra of the two analyzed sources along with the source model parameters closely resemble each other, and the newly available Wide-field Infrared Survey Explorer and UKIRT Infrared Deep Sky Survey data for HESS J1943+213 are consistent with the presence of an elliptical host at the distance of approximately ~600 Mpc.

  5. Dark matter searches with H.E.S.S

    SciTech Connect

    Opitz, Bjoern

    2010-03-26

    Astrophysical observations require the existence of non-baryonic dark matter (DM). If the dark matter particle has a mass in the TeV range and decays or annihilates via the weak interaction, very high energy (VHE)gamma-ray telescopes like H.E.S.S., MAGIC and VERITAS are well-suited to search for dark matter signals, as photons produced in dark matter annihilations allow directional back-tracking to their source. Dark matter searches and related observations performed by the H.E.S.S. collaboration are summarized here.

  6. Deep Radio Observations of the Toothbrush Galaxy Cluster

    NASA Astrophysics Data System (ADS)

    Van Weeren, Reinout J.; Jones, C.; Forman, W. R.; Röttgering, H.; Brüggen, M.; Brunetti, G.; de Gasperin, F.; Bonafede, A.; Pizzo, R.; Ferrari, C.; Orrù, E.; Ogrean, G. A.; LOFAR Busyweek Team; surveys KSP, LOFAR

    2014-01-01

    We present LOFAR and JVLA radio observations of the Toothbrush galaxy cluster. The Toothbrush cluster hosts diffuse 2 Mpc extended radio emission in the form of a radio relic and halo. XMM-Newton X-ray observations show that the cluster is undergoing a major merger event. Both the radio relic and halo are likely related to this ongoing merger. Radio relics are proposed to be direct tracers of shock waves in the intracluster medium. The XMM observations indeed reveal a shock, but there is a puzzling 200 kpc spatial offset between the shock position and relic. Our deep LOFAR and JVLA observations allow a detailed spectral study to test the shock origin of the relic and underlying particle acceleration mechanisms. Finally, the LOFAR observations highlight the science that could be obtained from a deep low-frequency all-sky survey.

  7. HESS J1943+213: A Non-classical High-frequency-peaked BL Lac Object

    NASA Astrophysics Data System (ADS)

    Straal, S. M.; Gabányi, K. É.; van Leeuwen, J.; Clarke, T. E.; Dubner, G.; Frey, S.; Giacani, E.; Paragi, Z.

    2016-05-01

    HESS J1943+213 is an unidentified TeV source that is likely a high-frequency-peaked BL Lac (HBL) object, but that is also compatible with a pulsar wind nebula (PWN) nature. Each of these enormously different astronomical interpretations is supported by some of the observed unusual characteristics. In order to finally classify and understand this object, we took a three-pronged approach, through time-domain, high angular resolution, and multi-frequency radio studies. First, our deep time-domain observations with the Arecibo telescope failed to uncover the putative pulsar powering the proposed PWN. We conclude with ˜70% certainty that HESS J1943+213 does not host a pulsar. Second, long-baseline interferometry of the source with e-MERLIN at 1.5 and 5 GHz shows only a core, that is, a point source at ˜ 1-100 mas resolution. Its 2013 flux density is about one-third lower than that detected in the 2011 observations with similar resolution. This radio variability of the core strengthens the HBL object hypothesis. Third, additional evidence against the PWN scenario comes from the radio spectrum we compiled. The extended structure follows a power-law behavior with spectral index α \\=\\-0.54+/- 0.04 while the core component displays a flat spectrum (α \\=\\-0.03+/- 0.03). In contrast, the radio synchrotron emission of PWNe predicts a single power-law distribution. Overall, we rule out the PWN hypothesis and conclude that the source is a BL Lac object. The consistently high fraction (70%) of the flux density from the extended structure then leads us to conclude that HESS J1943+213 must be a non-classical HBL object.

  8. HESS J1943+213: A Non-classical High-frequency-peaked BL Lac Object

    NASA Astrophysics Data System (ADS)

    Straal, S. M.; Gabányi, K. É.; van Leeuwen, J.; Clarke, T. E.; Dubner, G.; Frey, S.; Giacani, E.; Paragi, Z.

    2016-05-01

    HESS J1943+213 is an unidentified TeV source that is likely a high-frequency-peaked BL Lac (HBL) object, but that is also compatible with a pulsar wind nebula (PWN) nature. Each of these enormously different astronomical interpretations is supported by some of the observed unusual characteristics. In order to finally classify and understand this object, we took a three-pronged approach, through time-domain, high angular resolution, and multi-frequency radio studies. First, our deep time-domain observations with the Arecibo telescope failed to uncover the putative pulsar powering the proposed PWN. We conclude with ˜70% certainty that HESS J1943+213 does not host a pulsar. Second, long-baseline interferometry of the source with e-MERLIN at 1.5 and 5 GHz shows only a core, that is, a point source at ˜ 1–100 mas resolution. Its 2013 flux density is about one-third lower than that detected in the 2011 observations with similar resolution. This radio variability of the core strengthens the HBL object hypothesis. Third, additional evidence against the PWN scenario comes from the radio spectrum we compiled. The extended structure follows a power-law behavior with spectral index α \\=\\-0.54+/- 0.04 while the core component displays a flat spectrum (α \\=\\-0.03+/- 0.03). In contrast, the radio synchrotron emission of PWNe predicts a single power-law distribution. Overall, we rule out the PWN hypothesis and conclude that the source is a BL Lac object. The consistently high fraction (70%) of the flux density from the extended structure then leads us to conclude that HESS J1943+213 must be a non-classical HBL object.

  9. Using near infrared light for deep sea mining observation systems

    NASA Astrophysics Data System (ADS)

    Lu, Huimin; Li, Yujie; Li, Xin; Yang, Jianmin; Serikawa, Seiichi

    2015-10-01

    In this paper, we design a novel deep-sea near infrared light based imaging equipment for deep-sea mining observation systems. The spectral sensitivity peaks are in the red region of the invisible spectrum, ranging from 750nm to 900nm. In addition, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. The proposed model fully considered the effects of absorption, scattering and refraction. We also develop a locally adaptive Laplacian filtering for enhancing underwater transmission map after underwater dark channel prior estimation. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. In water tank experiments, we made a linear scale of eight turbidity steps ranging from clean to heavily scattered by adding deep sea soil to the seawater (from 500 to 2000 mg/L). We compared the results of different turbidity underwater scene, illuminated alternately with near infrared light vs. white light. Experiments demonstrate that the enhanced NIR images have a reasonable noise level after the illumination compensation in the dark regions and demonstrates an improved global contrast by which the finest details and edges are significantly enhanced. We also demonstrate that the effective distance of the designed imaging system is about 1.5 meters, which can meet the requirement of micro-terrain observation around the deep-sea mining systems. Remotely Operated Underwater Vehicle (ROV)-based experiments also certified the effectiveness of the proposed method.

  10. TeV γ-ray observations of the young synchrotron-dominated SNRs G1.9+0.3 and G330.2+1.0 with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Oña; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; Reyes, R. de los; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-06-01

    The non-thermal nature of the X-ray emission from the shell-type supernova remnants (SNRs) G1.9+0.3 and G330.2+1.0 is an indication of intense particle acceleration in the shock fronts of both objects. This suggests that the SNRs are prime candidates for very-high-energy (VHE; E > 0.1 TeV) γ-ray observations. G1.9+0.3, recently established as the youngest known SNR in the Galaxy, also offers a unique opportunity to study the earliest stages of SNR evolution in the VHE domain. The purpose of this work is to probe the level of VHE γ-ray emission from both SNRs and use this to constrain their physical properties. Observations were conducted with the H.E.S.S. (High Energy Stereoscopic System) Cherenkov Telescope Array over a more than six-year period spanning 2004-2010. The obtained data have effective livetimes of 67 h for G1.9+0.3 and 16 h for G330.2+1.0. The data are analysed in the context of the multiwavelength observations currently available and in the framework of both leptonic and hadronic particle acceleration scenarios. No significant γ-ray signal from G1.9+0.3 or G330.2+1.0 was detected. Upper limits (99 per cent confidence level) to the TeV flux from G1.9+0.3 and G330.2+1.0 for the assumed spectral index Γ = 2.5 were set at 5.6 × 10-13 cm-2 s-1 above 0.26 TeV and 3.2 × 10-12 cm-2 s-1 above 0.38 TeV, respectively. In a one-zone leptonic scenario, these upper limits imply lower limits on the interior magnetic field to BG1.9 ≳ 12 μG for G1.9+0.3 and to BG330 ≳ 8 μG for G330.2+1.0. In a hadronic scenario, the low ambient densities and the large distances to the SNRs result in very low predicted fluxes, for which the H.E.S.S. upper limits are not constraining.

  11. Deep Observations of the Open Cluster NGC 6253

    NASA Astrophysics Data System (ADS)

    Jeffery, E. J.

    2015-06-01

    We have obtained deep observations of the metal-rich open cluster NGC 6253 with GMOS on the Gemini-South telescope, with the goal of observing the cluster white dwarfs for the first time. These observations are an important piece and further test of the variously proposed scenarios to explain the formation of the strange white dwarfs in the metal rich open cluster NGC 6791. We will use the new observations of NGC 6253 to measure the cluster's white dwarf age and search for any anomalies in the white dwarf luminosity function. The high metallicity of this cluster will allow us to explore and better understand the formation of white dwarfs in such a high metallicity environment. These observations are an important piece in the continuing puzzle that has important implications on mass loss, white dwarf cooling, and stellar evolution as a whole.

  12. X-ray follow-ups of TeV unID sources using Suzaku--HESS J1745--303--

    SciTech Connect

    Bamba, Aya; Kohri, Kazunori; Matsumoto, Hironori; Wagner, Stefan; Puehlhofer, Gerd; Kosack, Karl

    2008-12-24

    H.E.S.S. TeV gamma-ray telescope discovered many new sources on the Galactic plane. They should be Galactic particle accelerators but their nature is still unknown since they have few information in other wavelength. Jp-US X-ray telescope Suzaku has made follow-up observations for several TeV unID sources, using the low and stable background and the large effective area. The results are full of varieties; compact counterparts (HESS J1804-216, HESS J1837-609) and diffuse counterparts (HESS J1614-518, CTB 37B). Most interesting results are no-detection even with long exposure (HESS J1616-508, HESS J1745-303). In this talk, we present one of the most interesting result, HESS J1745-303, which is located on near the Galactic center.

  13. THE 2012 HUBBLE ULTRA DEEP FIELD (UDF12): OBSERVATIONAL OVERVIEW

    SciTech Connect

    Koekemoer, Anton M.; Ellis, Richard S.; Schenker, Matthew A.; McLure, Ross J.; Dunlop, James S.; Bowler, Rebecca A. A.; Rogers, Alexander B.; Curtis-Lake, Emma; Cirasuolo, Michele; Wild, V.; Targett, T.; Robertson, Brant E.; Schneider, Evan; Stark, Daniel P.; Ono, Yoshiaki; Ouchi, Masami; Charlot, Stephane; Furlanetto, Steven R.

    2013-11-01

    We present the 2012 Hubble Ultra Deep Field campaign (UDF12), a large 128 orbit Cycle 19 Hubble Space Telescope program aimed at extending previous Wide Field Camera 3 (WFC3)/IR observations of the UDF by quadrupling the exposure time in the F105W filter, imaging in an additional F140W filter, and extending the F160W exposure time by 50%, as well as adding an extremely deep parallel field with the Advanced Camera for Surveys (ACS) in the F814W filter with a total exposure time of 128 orbits. The principal scientific goal of this project is to determine whether galaxies reionized the universe; our observations are designed to provide a robust determination of the star formation density at z ∼> 8, improve measurements of the ultraviolet continuum slope at z ∼ 7-8, facilitate the construction of new samples of z ∼ 9-10 candidates, and enable the detection of sources up to z ∼ 12. For this project we committed to combining these and other WFC3/IR imaging observations of the UDF area into a single homogeneous dataset to provide the deepest near-infrared observations of the sky. In this paper we present the observational overview of the project and describe the procedures used in reducing the data as well as the final products that were produced. We present the details of several special procedures that we implemented to correct calibration issues in the data for both the WFC3/IR observations of the main UDF field and our deep 128 orbit ACS/WFC F814W parallel field image, including treatment for persistence, correction for time-variable sky backgrounds, and astrometric alignment to an accuracy of a few milliarcseconds. We release the full, combined mosaics comprising a single, unified set of mosaics of the UDF, providing the deepest near-infrared blank-field view of the universe currently achievable, reaching magnitudes as deep as AB ∼ 30 mag in the near-infrared, and yielding a legacy dataset on this field.

  14. Informing a strategy for Deep Argo temperature observations

    NASA Astrophysics Data System (ADS)

    Garry, Freya; Roberts, Chris; McDonagh, Elaine; Blaker, Adam

    2015-04-01

    The ocean has the largest available capacity for heat uptake in the Earth's climate system. However, sparse and infrequent measurements of ocean temperatures below 2000 m limit our ability to observe deep ocean heat content changes and therefore close the global heat budget. Recent analyses of surface temperatures and ocean heat content variability have suggested that variations in ocean heat uptake may have played a role in the recent `hiatus' in surface temperature trends. Such results highlight the importance of improved estimates of top-to-bottom ocean heat content changes to progress our understanding of internal climate variability and advance projection capability for future climate change and sea level rise. We present results from state of the art climate model experiments that inform the optimal design of a deep ocean observing system of automated floats that repeatedly sample to either 4000 or 6000 m and transmit data via satellite (a deep water extension of the current core Argo array). Using long control simulations and forced experiments, we consider to what depths and in which regions we need observations to effectively capture internal variability of temperature in the oceans and emergent signals of climate change. Our results highlight the continuing importance of the core Argo array (to 2000 m) for measuring total ocean heat content variability accurately (with associated implications for climate prediction and sea level rise estimates). In forced scenarios we find additional deep ocean sampling below 2000 m is essential in most ocean basins to accurately estimate total ocean heat content changes, but monitoring in the Atlantic and Southern Ocean is most critical. In a likely future forced scenario, regions for additional sub-2000 m sampling are the Indian Ocean and southern/westerly Pacific Ocean. Model estimates suggest that over the next century, global sampling to 4000 m would offer a ~10% improvement on the percentage of total ocean heat

  15. The unidentified source HESS J1908+063/MGRO J1908+06

    SciTech Connect

    Ona Wilhelmi, E. de; Djannati-Atai, A.; Renaud, M.

    2008-12-24

    The extended H.E.S.S. Galactic Plane Survey overlaps with some regions covered by the water Cherenkov detector Milagro sky survey. The latter experiment has reported 3 new sources and 4 hot spots, including MGRO J1908+06 above 12 TeV. The H.E.S.S. observations around 40 degrees of longitude confirm this detection. We take advantage of the superior sensitivity of H.E.S.S. above 0.2 TeV and its better energy and angular resolution to study in detail the morphology, spectrum and possible counterparts for this source.

  16. An observational study of entrainment rate in deep convection

    SciTech Connect

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal, gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.

  17. An observational study of entrainment rate in deep convection

    DOE PAGESBeta

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal,more » gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.« less

  18. Observations of Deep Flow along the Central California Coast

    NASA Astrophysics Data System (ADS)

    Collins, Curtis; Margolina, Tetyana; Rago, Thomas

    2016-04-01

    A number of programs have collected observations of deep currents and water properties over the continental shelf off Central California during the past three decades. Here we summarize the results of these measurements. The oldest data set included bimonthly observations off Point Sur (33° 20'N) from April 1988 to April 1991 using an acoustically tracked dropsonde and a NBIS Mk III CTD. The poleward flow observed above 1000 m was weaker at depth but generally dominated the flow pattern. Deep (˜1000 m) currents were also observed off California from August 1994 to September 2009 using current meters and RAFOS floats. Current meter data were collected at nine locations for time periods ranging from two months to 76 months. A total of 144 months of float data were collected. Analysis of current meter data included histograms, progressive vector diagrams, stick plots, kinetic energy and rotary spectra, stick plots, means and standard deviations. Float data were analyzed using trajectories and calculating means, standard deviations, and diffusivities. For current meter data, semidiurnal tidal energy dominated the kinetic energy spectrum, anticyclonic rotary motion exceeded cyclonic motion, kinetic energy was typically an order of magnitude greater than for diurnal frequencies, and kinetic energy decreased about an order of magnitude as depth increased by 1000 m. Mean speed for current meter (float) data was 6.1 (4.0) cm s‑1 and alongshore variability exceeded across shore variability. Two floats were entrained in mesoscale eddies, one cyclonic and the other anticyclonic; the eddies moved westward at a speed of about one cm s‑1. Seasonal variability along the continental slope was marked by late summer or early fall warming; eddy kinetic energy was minimum in February, 3 cm2 s‑2.

  19. Deep Atmospheres of Saturn and Jupiter Observed from Orbiting Spacecraft

    NASA Astrophysics Data System (ADS)

    Janssen, M. A.

    2015-12-01

    The deep atmospheres of the giant planets Jupiter and Saturn can only be observed remotely in the microwave region, at wavelengths significantly longer than the ammonia rotational band around 1-cm. Observation by spacecraft offers unique capabilities for exploring the presently unknown compositional and dynamical properties of these atmospheres at depth. Currently two investigations are in progress. The first uses the 2-cm wavelength Cassini RADAR radiometer now orbiting Saturn, and observes its subcloud atmosphere to pressure levels near 3 bars. Secondly, the Juno spacecraft, which was launched in August 2011 to Jupiter, carries a multi-wavelength instrument (the Microwave Radiometer, or MWR), which operates over the wavelength range from 1.4-50 cm and reaches depths below 100 bars. It will arrive at Jupiter in 2016. Global maps of Saturn and their interpretation will be presented along with plans for high-resolution observations during the final (proximal) orbits of the Cassini mission. The capabilities and expectations for the Juno MWR will be described. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  20. Deep Impact observations by OSIRIS onboard the Rosetta spacecraft.

    PubMed

    Keller, Horst Uwe; Jorda, Laurent; Küppers, Michael; Gutierrez, Pedro J; Hviid, Stubbe F; Knollenberg, Jörg; Lara, Luisa-Maria; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rickman, Hans; Rodrigo, Rafael

    2005-10-14

    The OSIRIS cameras (optical, spectroscopic, and infrared remote imaging system) onboard the European Space Agency's Rosetta spacecraft observed comet 9P/Tempel 1 for 17 days continuously around the time of NASA's Deep Impact mission. The cyanide-to-water production ratio was slightly enhanced in the impact cloud, compared with that of normal comet activity. Dust particles were flowing outward in the coma at >160 meters per second, accelerated by the gas. The slope of the brightness increase showed a dip about 200 seconds after the impact. Dust Afrho values before and long after the impact confirm the slight decrease of cometary activity. The dust-to-water mass ratio was much larger than 1.

  1. Recent H.E.S.S. results

    NASA Astrophysics Data System (ADS)

    Degrange, B.

    2011-06-01

    Since 2003, the H.E.S.S. array of 4 Cherenkov telescopes, located in Namibia, has detected about 60 sources of very-high-energy gamma-rays from 100 GeV to about 30 TeV, both galactic and extragalactic. Some recent H.E.S.S. results are reviewed: the detections of shell-type supernova remnants (SN 1006 and HESS J1731-347), of the starburst galaxy NGC 253 and of new Active Galactic Nuclei. In addition, deeper variability studies on the blazar PKS 2155-304 are presented, which give some insight into the emission mechanisms at play.

  2. VERITAS deep observations of the dwarf spheroidal galaxy Segue 1

    NASA Astrophysics Data System (ADS)

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Bouvier, A.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Christiansen, J. L.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Decerprit, G.; Dickherber, R.; Dumm, J.; Errando, M.; Falcone, A.; Feng, Q.; Ferrer, F.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Godambe, S.; Griffin, S.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Huan, H.; Hughes, G.; Humensky, T. B.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lee, K.; Madhavan, A. S.; Maier, G.; Majumdar, P.; McArthur, S.; McCann, A.; Moriarty, P.; Mukherjee, R.; Ong, R. A.; Orr, M.; Otte, A. N.; Park, N.; Perkins, J. S.; Pohl, M.; Prokoph, H.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Ruppel, J.; Saxon, D. B.; Schroedter, M.; Sembroski, G. H.; Şentürk, G. D.; Skole, C.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Tešić, G.; Theiling, M.; Thibadeau, S.; Tsurusaki, K.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Vivier, M.; Wagner, R. G.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Zitzer, B.

    2012-03-01

    The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report on the results of nearly 48 hours of good quality selected data, taken between January 2010 and May 2011. No significant γ-ray emission is detected at the nominal position of Segue 1, and upper limits on the integrated flux are derived. According to recent studies, Segue 1 is the most dark matter-dominated dwarf spheroidal galaxy currently known. We derive stringent bounds on various annihilating and decaying dark matter particle models. The upper limits on the velocity-weighted annihilation cross-section are ⟨σv⟩95%CL≲10-23cm3s-1, improving our limits from previous observations of dwarf spheroidal galaxies by at least a factor of 2 for dark matter particle masses mχ≳300GeV. The lower limits on the decay lifetime are at the level of τ95%CL≳1024s. Finally, we address the interpretation of the cosmic ray lepton anomalies measured by ATIC and PAMELA in terms of dark matter annihilation, and show that the VERITAS observations of Segue 1 disfavor such a scenario.

  3. A-Train Observations of Deep Convective Storm Tops

    NASA Technical Reports Server (NTRS)

    Setvak, Martin; Bedka, Kristopher; Lindsey, Daniel T.; Sokol, Alois; Charvat, Zdenek; Stastka, Jindrich; Wang, Pao K.

    2013-01-01

    The paper highlights simultaneous observations of tops of deep convective clouds from several space-borne instruments including the Moderate Resolution Imaging Spectroradiometer (MODIS) of the Aqua satellite, Cloud Profiling Radar (CPR) of the CloudSat satellite, and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) flown on the CALIPSO satellite. These satellites share very close orbits, thus together with several other satellites they are referred to as the "A-Train" constellation. Though the primary responsibility of these satellites and their instrumentation is much broader than observations of fine-scale processes atop convective storms, in this study we document how data from the A-Train can contribute to a better understanding and interpretation of various storm-top features, such as overshooting tops, cold-U/V and cold ring features with their coupled embedded warm areas, above anvil ice plumes and jumping cirrus. The relationships between MODIS multi-spectral brightness temperature difference (BTD) fields and cloud top signatures observed by the CPR and CALIOP are also examined in detail to highlight the variability in BTD signals across convective storm events.

  4. H.E.S.S. OBSERVATIONS OF THE GLOBULAR CLUSTERS NGC 6388 AND M15 AND SEARCH FOR A DARK MATTER SIGNAL

    SciTech Connect

    Abramowski, A.; Acero, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Brucker, J.; Barnacka, A.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Borrel, V.; Becker, J.; Behera, B.; Boisson, C.; Bolmont, J.

    2011-07-01

    Observations of the globular clusters (GCs) NGC 6388 and M15 were carried out by the High Energy Stereoscopic System array of Cherenkov telescopes for a live time of 27.2 and 15.2 hr, respectively. No gamma-ray signal is found at the nominal target position of NGC 6388 and M15. In the primordial formation scenario, GCs are formed in a dark matter (DM) halo and DM could still be present in the baryon-dominated environment of GCs. This opens the possibility of observing a DM self-annihilation signal. The DM content of the GCs NGC 6388 and M15 is modeled taking into account the astrophysical processes that can be expected to influence the DM distribution during the evolution of the GC: the adiabatic contraction of DM by baryons, the adiabatic growth of a black hole in the DM halo, and the kinetic heating of DM by stars. Ninety-five percent confidence level exclusion limits on the DM particle velocity-weighted annihilation cross section are derived for these DM halos. In the TeV range, the limits on the velocity-weighted annihilation cross section are derived at the 10{sup -25} cm{sup 3} s{sup -1} level and a few 10{sup -24} cm{sup 3} s{sup -1} for NGC 6388 and M15, respectively.

  5. Discovery of the Hard Spectrum VHE γ-Ray Source HESS J1641-463

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E. O.; Backes, M.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carrigan, S.; Casanova, S.; Chadwick, P. M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; Fukui, Y.; Sano, H.; Fukuda, T.; Yoshiike, S.; H. E. S. S. Collaboration

    2014-10-01

    This Letter reports the discovery of a remarkably hard spectrum source, HESS J1641-463, by the High Energy Stereoscopic System (H.E.S.S.) in the very high energy (VHE) domain. HESS J1641-463 remained unnoticed by the usual analysis techniques due to confusion with the bright nearby source HESS J1640-465. It emerged at a significance level of 8.5 standard deviations after restricting the analysis to events with energies above 4 TeV. It shows a moderate flux level of phi(E>1 TeV) = (3.64 ± 0.44stat ± 0.73sys) × 10-13 cm-2 s-1, corresponding to 1.8% of the Crab Nebula flux above the same energy, and a hard spectrum with a photon index of Γ = 2.07 ± 0.11stat ± 0.20sys. It is a point-like source, although an extension up to a Gaussian width of σ = 3 arcmin cannot be discounted due to uncertainties in the H.E.S.S. point-spread function. The VHE γ-ray flux of HESS J1641-463 is found to be constant over the observed period when checking time binnings from the year-by-year to the 28 minute exposure timescales. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1. No X-ray candidate stands out as a clear association; however, Chandra and XMM-Newton data reveal some potential weak counterparts. Various VHE γ-ray production scenarios are discussed. If the emission from HESS J1641-463 is produced by cosmic ray protons colliding with the ambient gas, then their spectrum must extend close to 1 PeV. This object may represent a source population contributing significantly to the galactic cosmic ray flux around the knee.

  6. Pulsars at very high energies with HESS-II

    NASA Astrophysics Data System (ADS)

    Giavitto, Gianluca

    Pulsed gamma-rays above 100 GeV, recently discovered from the Crab pulsar by the imaging atmospheric Cherenkov telescopes (IACTs) VERITAS and MAGIC, have demonstrated the possibility of detecting pulsars at very high energies (VHE). In order to clarify the many questions that this unexpected discovery has opened, the detection of more VHE pulsars is now of paramount importance. With an expected threshold below 50 GeV and being the only operating IACT in the Southern Hemisphere, the new 28 m class H.E.S.S. II telescope is in a unique position to observe the pulsar population visible from the Southern Hemisphere. Indeed, several pulsars are promising candidates for VHE emission based on theoretical expectations and on the extrapolation of their Fermi-LAT measured gamma-ray spectra. The selection criteria for candidate pulsars, including the prospects of detection by HESS-II, will be discussed.

  7. Energy Dependent Morphology in the PWN Candidate HESS J1825-137

    SciTech Connect

    Funk, S.; Hinton, J.A.; deJager, O.C.; /North West U., South Africa

    2007-09-26

    Observations with H.E.S.S. revealed a new source of very high-energy (VHE) gamma-rays above 100 GeV - HESS J1825-137 - extending mainly to the south of the energetic pulsar PSRB1823-13. A detailed spectral and morphological analysis of HESS J1825-137 reveals for the first time in VHE gamma-ray astronomy a steepening of the energy spectrum with increasing distance from the pulsar. This behavior can be understood by invoking radiative cooling of the IC-Compton gamma-ray emitting electrons during their propagation. In this scenario the vastly different sizes between the VHE gamma-ray emitting region and the X-ray PWN associated with PSRB1823-13 can be naturally explained by different cooling timescales for the radiating electron populations. If this scenario is correct, HESS J1825-137 can serve as a prototype for a whole class of asymmetric PWN in which the X-rays are extended over a much smaller angular scales than the gamma-rays and can help understanding recent detections of X-ray PWN in systems such as HESS J1640-465 and HESS J1813-178. The future GLAST satellite will probe lower electron energies shedding further light on cooling and diffusion processes in this source.

  8. Discovery of VHE emission towards the Carina arm region with the H.E.S.S. telescope array: HESS J1018-589

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker, J.; Bernlöh, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Cologna, G.; Conrad, J.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gallant, Y. A.; Gast, H.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Keogh, D.; Khélifi, B.; Klochkov, D.; Klużniak, D.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Laffon, H.; Lamanna, G.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S. M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2012-05-01

    The Carina arm region, containing the supernova remnant SNR G284.3-1.8, the high-energy (HE; E > 100 MeV) binary 1FGL J1018.6-5856 and the energetic pulsar PSR J1016-5857 and its nebula, has been observed with the H.E.S.S. telescope array. The observational coverage of the region in very-high-energy (VHE; E > 0.1 TeV) γ-rays benefits from deep exposure (40 h) of the neighboring open cluster Westerlund 2. The observations have revealed a new extended region of VHE γ-ray emission. The new VHE source HESS J1018-589 shows a bright, point-like emission region positionally coincident with SNR G284.3-1.8 and 1FGL J1018.6-5856 and a diffuse extension towards the direction of PSR J1016-5857. A soft (Γ = 2.7 ± 0.5stat)photon index, with a differential flux at 1 TeV of N0 = (4.2 ± 1.1) × 10-13 TeV-1 cm-2 s-1 is found for the point-like source, whereas the total emission region including the diffuse emission region is well fit by a power-law function with spectral index Γ = 2.9 ± 0.4stat and differential flux at 1 TeV of N0 = (6.8 ± 1.6) × 10-13 TeV-1 cm-2 s-1. This H.E.S.S. detection motivated follow-up X-ray observations with the XMM-Newton satellite to investigate the origin of the VHE emission. The analysis of the XMM-Newton data resulted in the discovery of a bright, non-thermal point-like source (XMMU J101855.4-58564) with a photon index of Γ = 1.65 ± 0.08 in the center of SNR G284.3-1.8, and a thermal, extended emission region coincident with its bright northern filament. The characteristics of this thermal emission are used to estimate the plasma density in the region as n ≈ 0.5 cm-3 (2.9 kpc/d)2. The position of XMMU J101855.4-58564 is compatible with the position reported by the Fermi-LAT collaboration for the binary system 1FGL J1018.6-5856 and the variable Swift XRT source identified with it. The new X-ray data are used alongside archival multi-wavelength data to investigate the relationship between the VHE γ-ray emission from HESS J1018-589 and the

  9. Deep z-band observations of the coolest Y dwarf

    SciTech Connect

    Kopytova, Taisiya G.; Crossfield, Ian J. M.; Deacon, Niall R.; Brandner, Wolfgang; Buenzli, Esther; Bayo, Amelia; Schlieder, Joshua E.; Manjavacas, Elena; Kopon, Derek; Biller, Beth A.

    2014-12-10

    WISE J085510.83-071442.5 (hereafter, WISE 0855-07) is the coolest Y dwarf known to date and is located at a distance of 2.31 ± 0.08 pc, giving it the fourth largest parallax of any known star or brown dwarf system. We report deep z-band observations of WISE 0855-07 using FORS2 on UT1/Very Large Telescope. We do not detect any counterpart to WISE 0855-07 in our z-band images and estimate a brightness upper limit of AB mag > 24.8 (F {sub ν} < 0.45 μJy) at 910 ± 65 nm with 3σ confidence. We combine our z-band upper limit with previous near- and mid-infrared photometry to place constraints on the atmospheric properties of WISE 0855-07 via comparison to models which implement water clouds in the atmospheres of T {sub eff} < 300 K substellar objects. We find that none of the available models that implement water clouds can completely reproduce the observed spectral energy distribution of WISE 0855-07. Every model significantly disagrees with the (3.6 μm/4.5 μm) flux ratio and at least one other bandpass. Since methane is predicted to be the dominant absorber at 3-4 μm, these mismatches might point to an incorrect or incomplete treatment of methane in current models. We conclude that (a) WISE0855-07 has T {sub eff} ∼ 200-250 K, (b) <80% of its surface is covered by clouds, and (c) deeper observations, and improved models of substellar evolution, atmospheres, clouds, and opacities will be necessary to better characterize this object.

  10. Aircraft microwave observations and simulations of deep convection from 18 to 183 GHz. I - Observations

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Mack, Robert A.; Prasad, N.; Hakkarinen, Ida M.; Yeh, H.-Y. M.

    1990-01-01

    Aircraft passive microwave observations of deep atmospheric convection at frequencies between 18 and 183 GHz are presented in conjunction with visible and infrared satellite and aircraft observations and ground-based radar observations. Deep convective cores are indicated in the microwave data by negative brightness temperature, T/(B) deviations from the land background (270 K) to extreme T(B) values below 100 K at 37, 92, and 183 GHz and below 200 K at 18 GHz. These T(B) minima, due to scattering by ice held aloft by the intense updrafts, are well correlated with areas of high radar reflectivity. For this land background case, T(B) is inversely correlated with rain rate at all frequencies due to T(B)-ice-rain correlations. Mean Delta-T between vertically polarized and horizontally polarized radiance in precipitation areas is approximately 6 K at both 18 GHz and 37 GHz, indicating nonspherical precipitation-size ice particles with a preferred horizontal orientation. Convective cores not observed in the visible and infrared data are clearly defined in the microwave observations, and borders of convective rain areas are well defined using the high-frequency (90 GHz and greater) microwave observations.

  11. HESS upper limits for Kepler's supernova remnant

    NASA Astrophysics Data System (ADS)

    Aharonian, F.; Akhperjanian, A. G.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Behera, B.; Beilicke, M.; Benbow, W.; Berge, D.; Bernlöhr, K.; Boisson, C.; Bolz, O.; Borrel, V.; Braun, I.; Brion, E.; Brucker, J.; Bühler, R.; Bulik, T.; Büsching, I.; Boutelier, T.; Carrigan, S.; Chadwick, P. M.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Cornils, R.; Costamante, L.; Dalton, M.; Degrange, B.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubois, F.; Dubus, G.; Dyks, J.; Egberts, K.; Emmanoulopoulos, D.; Espigat, P.; Farnier, C.; Feinstein, F.; Fiasson, A.; Förster, A.; Fontaine, G.; Füßling, M.; Gallant, Y. A.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Hadjichristidis, C.; Hauser, D.; Hauser, M.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Holleran, M.; Hoppe, S.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jung, I.; Katarzyński, K.; Kendziorra, E.; Kerschhaggl, M.; Khélifi, B.; Keogh, D.; Komin, Nu.; Kosack, K.; Lamanna, G.; Latham, I. J.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Martin, J. M.; Martineau-Huynh, O.; Marcowith, A.; Masterson, C.; Maurin, D.; McComb, T. J. L.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nolan, S. J.; Ohm, S.; Olive, J.-P.; de Oña Wilhelmi, E.; Orford, K. J.; Osborne, J. L.; Ostrowski, M.; Panter, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raubenheimer, B. C.; Raue, M.; Rayner, S. M.; Renaud, M.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Ruppel, J.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schröder, R.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sol, H.; Spangler, D.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Superina, G.; Tam, P. H.; Tavernet, J.-P.; Terrier, R.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Vialle, J. P.; Vincent, P.; Vivier, M.; Völk, H. J.; Volpe, F.; Wagner, S. J.; Ward, M.; Zdziarski, A. A.; Zech, A.

    2008-09-01

    Aims: Observations of Kepler's supernova remnant (G4.5+6.8) with the HESS telescope array in 2004 and 2005 with a total live time of 13 h are presented. Methods: Stereoscopic imaging of Cherenkov radiation from extensive air showers is used to reconstruct the energy and direction of the incident gamma rays. Results: No evidence for a very high energy (VHE: >100 GeV) gamma-ray signal from the direction of the remnant is found. An upper limit (99% confidence level) on the energy flux in the range 230 GeV{-}12.8 TeV of 8.6 × 10-13 erg cm-2 s-1 is obtained. Conclusions: In the context of an existing theoretical model for the remnant, the lack of a detectable gamma-ray flux implies a distance of at least 6.4 kpc. A corresponding upper limit for the density of the ambient matter of 0.7 cm-3 is derived. With this distance limit, and assuming a spectral index Γ = 2, the total energy in accelerated protons is limited to Ep < 8.6 × 1049 erg. In the synchrotron/inverse Compton framework, extrapolating the power law measured by RXTE between 10 and 20 keV down in energy, the predicted gamma-ray flux from inverse Compton scattering is below the measured upper limit for magnetic field values greater than 52 μ G.

  12. Deep ROSAT HRI observations of the Orion nebula region

    NASA Technical Reports Server (NTRS)

    Gagne, Marc; Caillault, Jean-Pierre; Stauffer, John R.

    1995-01-01

    We present results from three deep ROSAT high-resolution imager observations of the Orion Nebula star-forming region. The X-ray images contain over 1500 cataloged stars in a roughly 0.8 sq deg region centered on the Trapezium. In all, 389 distinct X-ray sources have been detected, at least two-thirds of which are associated with a single proper-motion cluster member. X-ray emission is detected from stars of all spectral types, from massive O- and B-type components of the Trapezium to the coolest, low-mass pre-main-sequence (PMS) stars. In this paper we focus primarily on X-ray emission from the late-type PMS stars. Of the approximately 100 late-type cluster members with measured spectral types, approximately three-fourths have been detected; we have derived X-ray luminosity upper limits for the remaining stars. We found coronal X-ray emission turns on around spectral type F6, with the upper envelope of activity increasing with deceasing effective temperature. When plotted in an X-ray luminosity versus bolometric luminosity diagram, late-type PMS stars lie below a 'saturation' line corresponding to L(sub x)/L(sub bol) approximately 10(exp -3). For approximately solar-mass PMS stars, we find a median X-ray luminosity approximately 1 x 10(exp 30) ergs/s. The late G, K, and M stars exhibit nearly a two order of magnitude spread in X-ray luminosity and in L(sub x)/L(sub bol) at a given effective temperature. Plots of X-ray activity versus v sin i rotational velocity and rotational period appear to show no clear dependence of activity on rotation. However, because only a small fraction of late-type PMS stars in the Orion Nebula have measured v sin i or P(sub rot) and because of uncertainties in L(sub x) and L(sub x)/L(sub bol), we believe the data are not conclusive on this point. Light curves of the detected X-ray sources have revealed at least 10 strong X-ray flares with characteristic rise times greater than or approximately equal to 1 hr and decay times ranging from

  13. Status of the H.E.S.S. telescope

    SciTech Connect

    Ona Wilhelmi, E. de

    2009-04-08

    Over the past few years, very-high-energy gamma-ray astronomy has emerged as a truly observational discipline, with many detected sources representing different galactic and extragalactic source populations -supernova remnants, pulsar wind nebulae, giant molecular clouds, star formation regions, compact binary systems and active galactic nuclei. The H.E.S.S. array of imaging atmospheric Cherenkov telescopes has revealed a sky full of sources of very high energy {gamma}-rays, challenging our knowledge of particle acceleration (either hadronic or leptonic) and propagation in environments with extreme conditions. We will review the latest results published and discus the most interesting cases.

  14. Hess, Victor Franz (1883-1964)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Physicist, born in Waldstein Castle, near Peggau in Steiermark, Austria, Nobel prizewinner in physics (1936, shared with CARL ANDERSON) `for his discovery of cosmic radiation'. In a distinguished career in atomic, nuclear and atmospheric physics, Hess held positions in Vienna, Graz, New Jersey, Washington, DC, and Innsbruck. In 1911-13 he discovered `ultra-radiation' (cosmic radiation), and la...

  15. Bernard J. Wood Receives 2013 Harry H. Hess Medal: Citation

    NASA Astrophysics Data System (ADS)

    Hofmann, Albrecht W.

    2014-01-01

    As Harry Hess recognized over 50 years ago, mantle melting is the fundamental motor for planetary evolution and differentiation. Melting generates the major divisions of crust mantle and core. The distribution of chemical elements between solids, melts, and gaseous phases is fundamental to understanding these differentiation processes. Bernie Wood, together with Jon Blundy, has combined experimental petrology and physicochemical theory to revolutionize the understanding of the distribution of trace elements between melts and solids in the Earth. Knowledge of these distribution laws allows the reconstruction of the source compositions of the melts (deep in Earth's interior) from their abundances in volcanic rocks. Bernie's theoretical treatment relates the elastic strain of the lattice caused by the substitution of a trace element in a crystal to the ionic radius and charge of this element. This theory, and its experimental calibrations, brought order to a literature of badly scattered, rather chaotic experimental data that allowed no satisfactory quantitative modeling of melting processes in the mantle.

  16. Constraints on the spectrum of HESS J0632+057 from Fermi-LAT data

    NASA Astrophysics Data System (ADS)

    Malyshev, D.; Chernyakova, M.

    2016-09-01

    We report on the results of ˜7.5 yrs of the very-high energy (10-600 GeV) observations of HESS J0632+057 with Fermi-LAT. In the highest energy band, 200 - 600 GeV, the source is detected with the statistical significance ≳ 4.7σ at orbital phases 0.2 - 0.4 and 0.6 - 0.8 at which HESS J0632+057 is known to demonstrate enhanced emission in TeV energy band. The analysis did not reveal the emission from HESS J0632+057 at lower energies and different orbital phases. Using the upper limits on source's flux we locate the break of the spectrum to >140 GeV and low-energy slope <1.6 (3σ statistical significance).

  17. Discovery of the VHE gamma-ray source HESS J1832-093 in the vicinity of SNR G22.7-0.2

    NASA Astrophysics Data System (ADS)

    HESS Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Clapson, A.-C.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2015-01-01

    The region around the supernova remnant (SNR) W41 contains several TeV sources and has prompted the HESS Collaboration to perform deep observations of this field of view. This resulted in the discovery of the new very high energy (VHE) source HESS J1832-093, at the position {RA=18^h 32^m 50^s ± 3^s_{stat} ± 2^s_{syst}}, {Dec=-9*deg;22'36" ± 32"}_{stat} ± 20^' '}_{syst} (J2000)}, spatially coincident with a part of the radio shell of the neighbouring remnant G22.7-0.2. The photon spectrum is well described by a power law of index Γ = 2.6 ± 0.3stat ± 0.1syst and a normalization at 1 TeV of Φ _0=(4.8 ± 0.8_stat± 1.0_syst) × 10^{-13} cm ^{-2} s^{-1} TeV^{-1}. The location of the gamma-ray emission on the edge of the SNR rim first suggested a signature of escaping cosmic rays illuminating a nearby molecular cloud. Then a dedicated XMM-Newton observation led to the discovery of a new X-ray point source spatially coincident with the TeV excess. Two other scenarios were hence proposed to identify the nature of HESS J1832-093. Gamma-rays from inverse Compton radiation in the framework of a pulsar wind nebula scenario or the possibility of gamma-ray production within a binary system are therefore also considered. Deeper multiwavelength observations will help to shed new light on this intriguing VHE source.

  18. Online Analysis of {gamma}-ray Sources with H.E.S.S

    SciTech Connect

    Fuessling, M.; Dalton, M.; Kerschhaggl, M.; Schwanke, U.; Jung, I.; Stegmann, C.

    2008-12-24

    Some of the {gamma}-ray sources detected by the H.E.S.S. experiment display irregular, often flare-like emission behaviour. A method to detect these outbursts as fast as possible is highly desirable. At H.E.S.S., first results from an offline analysis of pre-calibrated data can be obtained on-site approximately one hour after run end. We present a development and implementation of online analysis software that performs calibration and analysis of data at the time they are being taken allowing for a fast confirmation of observational results and appropriate reaction by the on-site shift crew.

  19. Deep Chandra Observations of NGC 3115: Properties of Point Sources

    NASA Astrophysics Data System (ADS)

    Lin, Dacheng; Irwin, J.; Wong, K.; Romanowsky, A. J.; Strader, J.; Sivakoff, G. R.

    2013-01-01

    Our recent Chandra X-ray Visionary Project to observe the nearby S0 galaxy NGC3115 for 1 Msec has provided the deepest look to date of the low-mass X-ray binary (LMXB) population of a normal early-type galaxy. Here we report our study of the 450 point sources detected in these long observations, including many supersoft and highly variable sources. We compare the luminosity distribution of the LMXBs with those obtained from other galaxies. We also investigate their possible nature based on the spectral evolution and multiwavelength cross-correlation and matching with globular clusters.

  20. Snapshots from deep magma chambers: decoding field observations

    NASA Astrophysics Data System (ADS)

    De Campos, Cristina P.

    2014-05-01

    mingling, between contrasting magmas generated from different sources and depths. When flow patterns from these plutonic structures are compared to those obtained from experiments and numerical modeling, vortex-like systems may be locally recognized with chaotic regions among concentric regular flow cells, separated by major flow shearing zones. These patterns may be in remarkable good agreement with less complex flow patterns obtained for simpler dynamic systems. Differences in the magma supply and flow regimes between distinct plutons, in time and space, depict frozen moments in their evolution and therefore may explain some of the discrepancies in the different hybridization degrees for different complexes. The combination of detailed mapping of flow patterns in the field, numerical modeling and experimental results using natural magmatic products as end-members may provide new insights into the dynamics of magma chambers, specially for shallow chambers in a volcanic environment. Due to high viscosities and non-Newtonian behavior during a long time-interval, the application of fluid dynamics to understanding magmatic processes, especially those taking place in the deep crust, is still a major challenge to Geosciences. Extrapolation for plutonic environments remains therefore a great defiance. This discussion aims to show that it is nevertheless worthwhile.

  1. Observation of the moon shadow in deep underground muon flux.

    SciTech Connect

    Allison, W. W. M.; Alner, G. J.; Ayres, D. S.; Cobb, J. H.; Fields, T. H.; Goodman, M. C.; Joffe-Minor, T.; Marshak, M. L.; Price, L. E.; Seidlein, R.; Soudan 2 Collaboration; Thron, J. L.

    1999-06-22

    A shadow of the moon, with a statistical significance of 5{sigma}, has been observed in the underground muon flux at a depth of 2090 mwe using the Soudan 2 detector. The angular resolution of the detector is well described by a Gaussian with {sigma} {le}0.3{degree}. The position of the shadow confirms the alignment of the detector to better than 0.15{degree}. This alignment has remained stable during 10 years of data taking from 1989 through 1998.

  2. 75 FR 32210 - United States v. Idaho Orthopaedic Society, Timothy Doerr, Jeffrey Hessing, Idaho Sports Medicine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-07

    ... Antitrust Division United States v. Idaho Orthopaedic Society, Timothy Doerr, Jeffrey Hessing, Idaho Sports.... Idaho Orthopaedic Society, Timothy Doerr, Jeffrey Hessing, Idaho Sports Medicine Institute, John Kloss..., Plaintiffs, vs. Idaho Orthopaedic Society, Timothy Doerr, Jeffrey Hessing, Idaho Sports Medicine...

  3. Deep observation of A2163: studying a new bullet cluster

    NASA Astrophysics Data System (ADS)

    Bourdin, Herve

    2011-10-01

    Exhibiting a clear spatial separation between the gas and dark matter component of a fastly accreted subcluster, the `bullet cluster', 1E 0657-56, has provided us a unique laboratory to investigate the impact of violent cluster mergers on the Intra-Cluster Medium, galaxies and dark matter properties. In recent analyses of X-ray, optical and weak-lensing data, we show that the massive cluster A2163 also exhibits a crossing gas bullet separated from a galaxy and dark matter over-density, and suggest that both A2163 and 1E 0657-56 share a common merging scenario possibly just differing in the time elapsed after the closest cluster encounters. With this deeper XMM observation of A2163, we propose to refine our knowledge of the dynamics and geometry of the on-going subcluster accretion.

  4. HESS J1640-465 - an exceptionally luminous TeV γ-ray supernova remnant

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Oña; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; Reyes, R. de los; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-04-01

    The results of follow-up observations of the TeV γ-ray source HESS J1640-465 from 2004 to 2011 with the High Energy Stereoscopic System (HESS) are reported in this work. The spectrum is well described by an exponential cut-off power law with photon index Γ = 2.11 ± 0.09stat ± 0.10sys, and a cut-off energy of E_c = 6.0^{+2.0}_{-1.2} TeV. The TeV emission is significantly extended and overlaps with the northwestern part of the shell of the SNR G338.3-0.0. The new HESS results, a re-analysis of archival XMM-Newton data and multiwavelength observations suggest that a significant part of the γ-ray emission from HESS J1640-465 originates in the supernova remnant shell. In a hadronic scenario, as suggested by the smooth connection of the GeV and TeV spectra, the product of total proton energy and mean target density could be as high as WpnH ˜ 4 × 1052(d/10kpc)2 erg cm-3.

  5. A new SNR with TeV shell-type morphology: HESS J1731-347

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Barnacka, A.; Barres de Almeida, U.; Becherini, Y.; Becker, J.; Behera, B.; Bernlöhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Cologna, G.; Conrad, J.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubois, F.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gallant, Y. A.; Gast, H.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Göring, D.; Häffner, S.; Hague, J. D.; Hampf, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Keogh, D.; Khangulyan, D.; Khélifi, B.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Laffon, H.; Lamanna, G.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, D.; Maxted, N.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, D.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S. M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Ryde, F.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sikora, M.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Vialle, J. P.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2011-07-01

    Aims: The recent discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731-347 has motivated further observations of the source with the High Energy Stereoscopic System (HESS) Cherenkov telescope array to test a possible association of the γ-ray emission with the SNR. Methods: With a total of 59 h of observation, representing about four times the initial exposure available in the discovery paper of HESS J1731-347, the γ-ray morphology is investigated and compared with the radio morphology. An estimate of the distance is derived by comparing the interstellar absorption derived from X-rays and the one obtained from 12CO and HI observations. Results: The deeper γ-ray observation of the source has revealed a large shell-type structure with similar position and extension (r ~ 0.25°) as the radio SNR, thus confirming their association. By accounting for the HESS angular resolution and projection effects within a simple shell model, the radial profile is compatible with a thin, spatially unresolved, rim. Together with RX J1713.7-3946, RX J0852.0-4622 and SN 1006, HESS J1731-347 is now the fourth SNR with a significant shell morphology at TeV energies. The derived lower limit on the distance of the SNR of 3.2 kpc is used together with radio and X-ray data to discuss the possible origin of the γ-ray emission, either via inverse Compton scattering of electrons or the decay of neutral pions resulting from proton-proton interaction.

  6. DEEP-South: Automated Observation Scheduling, Data Reduction and Analysis Software Subsystem

    NASA Astrophysics Data System (ADS)

    Yim, Hong-Suh; Kim, Myung-Jin; Bae, Young-Ho; Moon, Hong-Kyu; Choi, Young-Jun; Roh, Dong-Goo; Park, Jintae; Moon, Bora

    2016-01-01

    We started `DEep Ecliptic Patrol of the Southern sky' (DEEP-South, DS) (Moon et al. 2015) in late 2012, and conducted test runs with the first Korea Microlensing Telescope Network (KMTNet) (Park et al. 2012), a 1.6 m telescope with 18k x 18k CCD stationed at CTIO in early 2015. While the primary objective of DEEP-South is the physical characterization of small Solar System bodies, it is also expected to discover a large number of such bodies, many of them previously unknown. An automated observation scheduling, data reduction and analysis software subsystem called `DEEP-South Scheduling and Data reduction System' (DS SDS) is thus being designed and implemented to enable observation planning, data reduction and analysis with minimal human intervention.

  7. Deep-sea macrourid fishes scavenge on plant material: Evidence from in situ observations

    NASA Astrophysics Data System (ADS)

    Jeffreys, Rachel M.; Lavaleye, Marc S. S.; Bergman, Magda J. N.; Duineveld, Gerard C. A.; Witbaard, Rob; Linley, Thom

    2010-04-01

    Deep-sea benthic communities primarily rely on an allochthonous food source. This may be in the form of phytodetritus or as food falls e.g. sinking carcasses of nekton or debris of marine macrophyte algae. Deep-sea macrourids are the most abundant demersal fish in the deep ocean. Macrourids are generally considered to be the apex predators/scavengers in deep-sea communities. Baited camera experiments and stable isotope analyses have demonstrated that animal carrion derived from the surface waters is an important component in the diets of macrourids; some macrourid stomachs also contained vegetable/plant material e.g. onion peels, oranges, algae. The latter observations led us to the question: is plant material an attractive food source for deep-sea scavenging fish? We simulated a plant food fall using in situ benthic lander systems equipped with a baited time-lapse camera. Abyssal macrourids and cusk-eels were attracted to the bait, both feeding vigorously on the bait, and the majority of the bait was consumed in <30 h. These observations indicate (1) plant material can produce an odour plume similar to that of animal carrion and attracts deep-sea fish, and (2) deep-sea fish readily eat plant material. This represents to our knowledge the first in situ documentation of deep-sea fish ingesting plant material and highlights the variability in the scavenging nature of deep-sea fishes. This may have implications for food webs in areas where macrophyte/seagrass detritus is abundant at the seafloor e.g. canyon systems and continental shelves close to seagrass meadows (Bahamas and Mediterranean).

  8. HESS J1640-465 - an exceptionally luminous TeV gamma-ray SNR

    NASA Astrophysics Data System (ADS)

    Eger, Peter; Ohm, Stefan

    HESS J1640-465 is among the brightest Galactic TeV gamma-ray sources ever discovered by the High Energy Stereoscopic System (H.E.S.S.). Its likely association with the shell-type supernova remnant (SNR) G338.3-0.0 at a distance of ˜10 kpc makes it the most luminous Galactic source in the TeV regime. Our recent analysis of follow-up observations with H.E.S.S. reveal a significantly extended TeV morphology with a substantial overlap with the northern part of the SNR shell. Furthermore, the source features a seamless powerlaw spectrum over four orders of magnitude from GeV to TeV energies, with a spectral index of Gamma = 2.15± 0.10_mathrm{stat}± 0.10_mathrm{sys} and a cut-off energy of E_c = 7.3(+2.5}_{-1.8) TeV. These new spectral and morphological results suggest that a significant fraction of the TeV emission is likely of hadronic origin where the product of total proton energy and mean target density could be as high as W_p n_H ˜ 4 × 10(52}(d/10mathrm{kpc) )(2) erg cm(-3) . This would make HESS J1640-465 one of the most extreme and efficient Galactic particle accelerators.

  9. An X-Ray Counterpart of HESS J1427-608 Discovered with Suzaku

    NASA Astrophysics Data System (ADS)

    Fujinaga, Takahisa; Mori, Koji; Bamba, Aya; Kimura, Shoichi; Dotani, Tadayasu; Ozaki, Masanobu; Matsuta, Keiko; Pülhofer, Gerd; Uchiyama, Hideki; Hiraga, Junko S.; Matsumoto, Hironori; Terada, Yukikatsu

    2013-06-01

    We report on the discovery of an X-ray counterpart of the unidentified very high-energy gamma-ray source HESS J1427-608. In the sky field coincident with HESS J1427-608, an extended source was found in the 2-8 keV band, and was designated as Suzaku J1427-6051. Its X-ray radial profile has an extension of σ = 0.'9 ± 0.'1 if approximated by a Gaussian. The spectrum was well fitted by an absorbed power-law with NH = (1.1 ± 0.3) × 1023 cm-2, Γ = 3.1+0.6-0.5, and the unabsorbed flux FX = (9+4-2) × 10-13 erg s-1 cm-2 in the 2-10 keV band. Using XMM-Newton archive data, we found seven point sources in the Suzaku source region. However, because their total flux and absorbing column densities are more than an order of magnitude lower than those of Suzaku J1427-6051, we consider that they are unrelated to the Suzaku source. Thus, Suzaku J1427-6051 is considered to be a truly diffuse source and an X-ray counterpart of HESS J1427-608. The possible nature of HESS J1427-608 is discussed based on the observational properties.

  10. Wortschatzliste und Synonyme: Hermann Hesse, "Siddhartha" (Vocabulary List and Synonyms for Hermann Hesse's "Siddhartha").

    ERIC Educational Resources Information Center

    Schwartzburg, John A.

    This vocabulary and synonym list for Hermann Hesse's "Siddhartha" (presently on the German Advanced Placement Program required reading list) is keyed to the Dunham and Wensinger edition published by the Macmillan Company. Selected German vocabulary found on each page of the text is briefly translated into English or clarified through the use of…

  11. Deep ocean impact of a Madden-Julian oscillation observed by Argo floats.

    PubMed

    Matthews, Adrian J; Singhruck, Patama; Heywood, Karen J

    2007-12-14

    Using the new Argo array of profiling floats that gives unprecedented space-time coverage of the upper 2000 meters of the global ocean, we present definitive evidence of a deep tropical ocean component of the Madden-Julian Oscillation (MJO). The surface wind stress anomalies associated with the MJO force eastward-propagating oceanic equatorial Kelvin waves that extend downward to 1500 meters. The amplitude of the deep ocean anomalies is up to six times the amplitude of the observed annual cycle. This deep ocean sink of energy input from the wind is potentially important for understanding phenomena such as El Niño-Southern Oscillation and for interpreting deep ocean measurements made from ships.

  12. Possible deep fault slip preceding the 2004 Parkfield earthquake, inferred from detailed observations of tectonic tremor

    USGS Publications Warehouse

    Shelly, D.R.

    2009-01-01

    Earthquake predictability depends, in part, on the degree to which sudden slip is preceded by slow aseismic slip. Recently, observations of deep tremor have enabled inferences of deep slow slip even when detection by other means is not possible, but these data are limited to certain areas and mostly the last decade. The region near Parkfield, California, provides a unique convergence of several years of high-quality tremor data bracketing a moderate earthquake, the 2004 magnitude 6.0 event. Here, I present detailed observations of tectonic tremor from mid-2001 through 2008 that indicate deep fault slip both before and after the Parkfield earthquake that cannot be detected with surface geodetic instruments. While there is no obvious short-term precursor, I find unidirectional tremor migration accompanied by elevated tremor rates in the 3 months prior to the earthquake, which suggests accelerated creep on the fault ???16 km beneath the eventual earthquake hypocenter. Copyright 2009 by the American Geophysical Union.

  13. Marine geology of the hess rise, 1, bathymetry, surface sediment distribution, and environment of deposition

    SciTech Connect

    Nemoto, K.; Kroenke, L.W.

    1981-11-10

    New charts of bathymetry, acoustic character, and sediment distribution describe the Hess Rise, a large oceanic plateau in the central north Pacific. Discrete physiographic provinces on the Hess Rise are the High Plateau, shallower than 3900 m, trending N30/sup 0/W; the Northeastern Flank, a smooth, gentle slope gradually increasing in depth to the northeast; the Woollard Abyssal Plain, extending farther to the northeast; the Volcanic Province with its high peaks and ridges along the southern margin of the Hess Rise; the Mendocino Fracture Zone to the south, expressed by broad, planar seafloor regions bordered by ridges and scarps; the Western Steps, formed by structural benches on the western side of the Rise; and the Emperor Deep, between the rise and the Emperor Seamounts. Five types of acoustic units have been mapped and interpreted: a transparent layer, predominantly of biosiliceous pelagic clay; a stratified layer, predominantly of nannofossil ooze; a diffuse layer of debris flows that seem to have originated mostly in the Volcanic Province; an opaque horizon commonly formed of volcaniclastic sediments that are usually found on the seafloor of the Mendocino Fracture Zone; and a hyperbolic horizon, indicating outcrops of igneous rock. The pronounced effect of bottom currents on the present-day environment of deposition in the Hess Rise is evidenced by the presence of the opaque horizon, which is interpreted as an erosion surface, and by current moating, abrupt thinning of surface layers and truncation of subbottom reflectors. The widespread erosion on the seafloor of the Mendocino Fracture Zone is attributed to the flow of Antarctic bottom water.

  14. Dust around young stars. Observations of the polarization of UX Ori in deep minima

    SciTech Connect

    Voshchinnikov, N.V.; Grinin, V.P.; Kiselev, N.N.; Minikulov, N.K.

    1988-09-01

    Photometric and polarimetric monitoring observations of UX Ori begun in 1986 in the Crimea and Bolivia have resulted in the observation of two deep minima of the brightness during which a growth of the linear polarization (to approx. =7%) was observed, together with a tendency for the circular polarization to increase (up to approx. =1%). Analysis of the observational data shows that the main source of the polarized radiation in the deep minima is the emission of the star scattered by grains of circumstellar dust. On the basis of Mie's theory for a polydisperse graphite-silicate mixtures of particles the optical properties of ellipsoidal dust envelopes have been calculated and a model of the Algol-like minimum constructed.

  15. Petrology and geochemistry of primitive lower oceanic crust from Pito Deep: Implications for the accretion of the lower crust at the Southern East Pacific Rise

    USGS Publications Warehouse

    Perk, N.W.; Coogan, L.A.; Karson, J.A.; Klein, E.M.; Hanna, H.D.

    2007-01-01

    A suite of samples collected from the uppermost part of the plutonic section of the oceanic crust formed at the southern East Pacific Rise and exposed at the Pito Deep has been examined. These rocks were sampled in situ by ROV and lie beneath a complete upper crustal section providing geological context. This is only the second area (after the Hess Deep) in which a substantial depth into the plutonic complex formed at the East Pacific Rise has been sampled in situ and reveals significant spatial heterogeneity in the plutonic complex. In contrast to the uppermost plutonic rocks at Hess Deep, the rocks studied here are generally primitive with olivine forsterite contents mainly between 85 and 88 and including many troctolites. The melt that the majority of the samples crystallized from was aggregated normal mid-ocean ridge basalt (MORB). Despite this high Mg# clinopyroxene is common despite model predictions that clinopyroxene should not reach the liquidus early during low-pressure crystallization of MORB. Stochastic modeling of melt crystallisation at various levels in the crust suggests that it is unlikely that a significant melt mass crystallized in the deeper crust (for example in sills) because this would lead to more evolved shallow level plutonic rocks. Similar to the upper plutonic section at Hess Deep, and in the Oman ophiolite, many samples show a steeply dipping, axis-parallel, magmatic fabric. This suggests that vertical magmatic flow is an important process in the upper part of the seismic low velocity zone beneath fast-spreading ridges. We suggest that both temporal and spatial (along-axis) variability in the magmatic and hydrothermal systems can explain the differences observed between the Hess Deep and Pito Deep plutonics. ?? Springer-Verlag 2007.

  16. Diffuse Galactic gamma-ray emission with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E. O.; Backes, M.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carrigan, S.; Casanova, S.; Chadwick, P. M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morâ, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; Fukui, Y.; H. E. S. S. Collaboration

    2014-12-01

    Diffuse γ -ray emission is the most prominent observable signature of celestial cosmic-ray interactions at high energies. While already being investigated at GeV energies over several decades, assessments of diffuse γ -ray emission at TeV energies remain sparse. After completion of the systematic survey of the inner Galaxy, the H.E.S.S. experiment is in a prime position to observe large-scale diffuse emission at TeV energies. Data of the H.E.S.S. Galactic Plane Survey are investigated in regions off known γ -ray sources. Corresponding γ -ray flux measurements were made over an extensive grid of celestial locations. Longitudinal and latitudinal profiles of the observed γ -ray fluxes show characteristic excess emission not attributable to known γ -ray sources. For the first time large-scale γ -ray emission along the Galactic plane using imaging atmospheric Cherenkov telescopes has been observed. While the background subtraction technique limits the ability to recover modest variation on the scale of the H.E.S.S. field of view or larger, which is characteristic of the inverse Compton scatter-induced Galactic diffuse emission, contributions of neutral pion decay as well as emission from unresolved γ -ray sources can be recovered in the observed signal to a large fraction. Calculations show that the minimum γ -ray emission from π0 decay represents a significant contribution to the total signal. This detection is interpreted as a mix of diffuse Galactic γ -ray emission and unresolved sources.

  17. Classification of Clouds and Deep Convection from GEOS-5 Using Satellite Observations

    NASA Technical Reports Server (NTRS)

    Putman, William; Suarez, Max

    2010-01-01

    With the increased resolution of global atmospheric models and the push toward global cloud resolving models, the resemblance of model output to satellite observations has become strikingly similar. As we progress with our adaptation of the Goddard Earth Observing System Model, Version 5 (GEOS-5) as a high resolution cloud system resolving model, evaluation of cloud properties and deep convection require in-depth analysis beyond a visual comparison. Outgoing long-wave radiation (OLR) provides a sufficient comparison with infrared (IR) satellite imagery to isolate areas of deep convection. We have adopted a binning technique to generate a series of histograms for OLR which classify the presence and fraction of clear sky versus deep convection in the tropics that can be compared with a similar analyses of IR imagery from composite Geostationary Operational Environmental Satellite (GOES) observations. We will present initial results that have been used to evaluate the amount of deep convective parameterization required within the model as we move toward cloud system resolving resolutions of 10- to 1-km globally.

  18. Observation of high-energy neutrinos using Cerenkov detectors embedded deep in Antarctic ice.

    PubMed

    Andrés, E; Askebjer, P; Bai, X; Barouch, G; Barwick, S W; Bay, R C; Becker, K H; Bergström, L; Bertrand, D; Bierenbaum, D; Biron, A; Booth, J; Botner, O; Bouchta, A; Boyce, M M; Carius, S; Chen, A; Chirkin, D; Conrad, J; Cooley, J; Costa, C G; Cowen, D F; Dailing, J; Dalberg, E; DeYoung, T; Desiati, P; Dewulf, J P; Doksus, P; Edsjö, J; Ekström, P; Erlandsson, B; Feser, T; Gaug, M; Goldschmidt, A; Goobar, A; Gray, L; Haase, H; Hallgren, A; Halzen, F; Hanson, K; Hardtke, R; He, Y D; Hellwig, M; Heukenkamp, H; Hill, G C; Hulth, P O; Hundertmark, S; Jacobsen, J; Kandhadai, V; Karle, A; Kim, J; Koci, B; Köpke, L; Kowalski, M; Leich, H; Leuthold, M; Lindahl, P; Liubarsky, I; Loaiza, P; Lowder, D M; Ludvig, J; Madsen, J; Marciniewski, P; Matis, H S; Mihalyi, A; Mikolajski, T; Miller, T C; Minaeva, Y; Miocinović, P; Mock, P C; Morse, R; Neunhöffer, T; Newcomer, F M; Niessen, P; Nygren, D R; Ogelman, H; Pérez de los Heros, C; Porrata, R; Price, P B; Rawlins, K; Reed, C; Rhode, W; Richards, A; Richter, S; Martino, J R; Romenesko, P; Ross, D; Rubinstein, H; Sander, H G; Scheider, T; Schmidt, T; Schneider, D; Schneider, E; Schwarz, R; Silvestri, A; Solarz, M; Spiczak, G M; Spiering, C; Starinsky, N; Steele, D; Steffen, P; Stokstad, R G; Streicher, O; Sun, Q; Taboada, I; Thollander, L; Thon, T; Tilav, S; Usechak, N; Vander Donckt, M; Walck, C; Weinheimer, C; Wiebusch, C H; Wischnewski, R; Wissing, H; Woschnagg, K; Wu, W; Yodh, G; Young, S

    2001-03-22

    Neutrinos are elementary particles that carry no electric charge and have little mass. As they interact only weakly with other particles, they can penetrate enormous amounts of matter, and therefore have the potential to directly convey astrophysical information from the edge of the Universe and from deep inside the most cataclysmic high-energy regions. The neutrino's great penetrating power, however, also makes this particle difficult to detect. Underground detectors have observed low-energy neutrinos from the Sun and a nearby supernova, as well as neutrinos generated in the Earth's atmosphere. But the very low fluxes of high-energy neutrinos from cosmic sources can be observed only by much larger, expandable detectors in, for example, deep water or ice. Here we report the detection of upwardly propagating atmospheric neutrinos by the ice-based Antarctic muon and neutrino detector array (AMANDA). These results establish a technology with which to build a kilometre-scale neutrino observatory necessary for astrophysical observations.

  19. H.E.S.S. follow-up of IceCube-160731A

    NASA Astrophysics Data System (ADS)

    de Naurois, Mathieu; H.E.S.S. Collaborarion

    2016-08-01

    The H.E.S.S. instrument was used to carry out follow-up observations of a high energy neutrino detected by IceCube on the 31st July 2016 at 01:55:04 UTC. The IceCube best fit position is Ra = 214.54, Dec = -0.33 with a radius of 0.75 deg at 90% confidence.

  20. Microsecond Time Resolution Optical Photometry using a H.E.S.S. Cherenkov Telescope

    SciTech Connect

    Deil, Christoph; Domainko, Wilfried; Hermann, German

    2008-02-22

    We have constructed an optical photometer with microsecond time resolution, which is currently being operated on one of the H.E.S.S. telescopes. H.E.S.S. is an array of four Cherenkov telescopes, each with a 107 m{sup 2} mirror, located in the Khomas highland in Namibia. In its normal mode of operation H.E.S.S. observes Cherenkov light from air showers generated by very high energy gamma-rays in the upper atmosphere. Our detector consists of seven photomultipliers, one in the center to record the lightcurve from the target and six concentric photomultipliers as a veto system to reject disturbing signals e.g. from meteorites or lightning at the horizon. The data acquisition system has been designed to continuously record the signals with zero deadtime. The Crab pulsar has been observed to verify the performance of the instrument and the GPS timing system. Compact galactic targets were observed to search for flares on timescales of a few microseconds to {approx}100 ms. The design and sensitivity of the instrument as well as the data analysis method are presented.

  1. An elastic lidar system for the H.E.S.S. Experiment

    NASA Astrophysics Data System (ADS)

    Bregeon, J.; Compin, M.; Rivoire, S.; Sanguillon, M.; Vasileiadis, G.

    2016-05-01

    The H.E.S.S. experiment in Namibia, Africa, is a high energy gamma ray telescope sensitive in the energy range from ~100 Gev to a few tens of TeV, via the use of the atmospheric Cherenkov technique. To minimize the systematic errors on the derived fluxes of the measured sources, one has to calculate the impact of the atmospheric properties, in particular the extinction parameter of the Cherenkov light (~300-650 nm) exploited to observe and reconstruct atmospheric particle showers initiated by gamma-ray photons. A lidar can provide this kind of information for some given wavelengths within this range. In this paper we report on the hardware components, operation and data acquisition of such a system installed at the H.E.S.S. site.

  2. The DEEP2 Galaxy Redshift Survey: Design, Observations, Data Reduction, and Redshifts

    NASA Astrophysics Data System (ADS)

    Newman, Jeffrey A.; Cooper, Michael C.; Davis, Marc; Faber, S. M.; Coil, Alison L.; Guhathakurta, Puragra; Koo, David C.; Phillips, Andrew C.; Conroy, Charlie; Dutton, Aaron A.; Finkbeiner, Douglas P.; Gerke, Brian F.; Rosario, David J.; Weiner, Benjamin J.; Willmer, C. N. A.; Yan, Renbin; Harker, Justin J.; Kassin, Susan A.; Konidaris, N. P.; Lai, Kamson; Madgwick, Darren S.; Noeske, K. G.; Wirth, Gregory D.; Connolly, A. J.; Kaiser, N.; Kirby, Evan N.; Lemaux, Brian C.; Lin, Lihwai; Lotz, Jennifer M.; Luppino, G. A.; Marinoni, C.; Matthews, Daniel J.; Metevier, Anne; Schiavon, Ricardo P.

    2013-09-01

    We describe the design and data analysis of the DEEP2 Galaxy Redshift Survey, the densest and largest high-precision redshift survey of galaxies at z ~ 1 completed to date. The survey was designed to conduct a comprehensive census of massive galaxies, their properties, environments, and large-scale structure down to absolute magnitude MB = -20 at z ~ 1 via ~90 nights of observation on the Keck telescope. The survey covers an area of 2.8 deg2 divided into four separate fields observed to a limiting apparent magnitude of R AB = 24.1. Objects with z <~ 0.7 are readily identifiable using BRI photometry and rejected in three of the four DEEP2 fields, allowing galaxies with z > 0.7 to be targeted ~2.5 times more efficiently than in a purely magnitude-limited sample. Approximately 60% of eligible targets are chosen for spectroscopy, yielding nearly 53,000 spectra and more than 38,000 reliable redshift measurements. Most of the targets that fail to yield secure redshifts are blue objects that lie beyond z ~ 1.45, where the [O II] 3727 Å doublet lies in the infrared. The DEIMOS 1200 line mm-1 grating used for the survey delivers high spectral resolution (R ~ 6000), accurate and secure redshifts, and unique internal kinematic information. Extensive ancillary data are available in the DEEP2 fields, particularly in the Extended Groth Strip, which has evolved into one of the richest multiwavelength regions on the sky. This paper is intended as a handbook for users of the DEEP2 Data Release 4, which includes all DEEP2 spectra and redshifts, as well as for the DEEP2 DEIMOS data reduction pipelines. Extensive details are provided on object selection, mask design, biases in target selection and redshift measurements, the spec2d two-dimensional data-reduction pipeline, the spec1d automated redshift pipeline, and the zspec visual redshift verification process, along with examples of instrumental signatures or other artifacts that in some cases remain after data reduction. Redshift

  3. DEEP 21 cm H I OBSERVATIONS AT z {approx} 0.1: THE PRECURSOR TO THE ARECIBO ULTRA DEEP SURVEY

    SciTech Connect

    Freudling, Wolfram; Zwaan, Martin; Staveley-Smith, Lister; Meyer, Martin; Catinella, Barbara; Minchin, Robert; Calabretta, Mark; Momjian, Emmanuel; O'Neil, Karen

    2011-01-20

    The 'ALFA Ultra Deep Survey' (AUDS) is an ongoing 21 cm spectral survey with the Arecibo 305 m telescope. AUDS will be the most sensitive blind survey undertaken with Arecibo's 300 MHz Mock spectrometer. The survey searches for 21 cm H I line emission at redshifts between 0 and 0.16. The main goals of the survey are to investigate the H I content and probe the evolution of H I gas within that redshift region. In this paper, we report on a set of precursor observations with a total integration time of 53 hr. The survey detected a total of eighteen 21 cm emission lines at redshifts between 0.07 and 0.15 in a region centered around {alpha}{sub 2000} {approx} 0{sup h}, {delta} {approx} 15{sup 0}42'. The rate of detection is consistent with the one expected from the local H I mass function. The derived relative H I density at the median redshift of the survey is {rho}{sub H{sub I}}[z = 0.125] = (1.0 {+-} 0.3){rho}{sub 0}, where {rho}{sub 0} is the H I density at zero redshift.

  4. Correlated observations of substorm effects in the near-earth region and the deep magnetotail

    NASA Technical Reports Server (NTRS)

    Scholer, M.; Baumjohann, W.; Baker, D. N.; Bame, S. J.; Gloeckler, G.; Ipavich, F. M.; Smith, E. J.; Tsurutani, B. T.

    1985-01-01

    Simultaneous observations of energetic particle measurements from the geosynchronous satellite 1982-019 and magnetic field, electron plasma, and energetic proton and electron measurements obtained with ISEE 3 in the deep tail are presented. The data are supplemented by ground magnetograms. A substorm occurred on March 22, 1983, close to 0300 UT as identified in the ground magnetograms and by a particle injection at geosynchronous orbit. About 10 min later, ISEE 3 observed (at a distance of approximately 130 RE in the deep tail) magnetic field, plasma, and energetic particle signatures consistent with the passage of a plasmoid. After the passage of the plasmoid the satellite enters shortly into a lobelike environment, in which an energetic proton beam is observed. High-resolution magnetic field data are indicative of small-scale structures in the postplasmoid plasma sheet. From the plasma sheet flow speed during the plasmoid's passage it is concluded that the 0300 UT substorm is responsible for its origin. This allows an approximate timing of the plasmoid release at a near-earth neutral line and of the plasma sheet recovery after substorm onset, and it indicates a close relationship between processes in the near-earth plasma sheet and the deep tail during substorms.

  5. HESS and Fermi-LAT discovery of γ-rays from the blazar 1ES 1312-423

    NASA Astrophysics Data System (ADS)

    HESS Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Göring, D.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hague, J. D.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Nedbal, D.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spieß, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.; Perkins, J. S.; Ojha, R.; Stevens, J.; Edwards, P. G.; Kadler, M.

    2013-09-01

    A deep observation campaign carried out by the High Energy Stereoscopic System (HESS) on Centaurus A enabled the discovery of γ-rays from the blazar 1ES 1312-423, 2° away from the radio galaxy. With a differential flux at 1 TeV of φ(1 TeV) = (1.9 ± 0.6stat ± 0.4sys) × 10-13 cm-2 s-1 TeV-1 corresponding to 0.5 per cent of the Crab nebula differential flux and a spectral index Γ = 2.9 ± 0.5stat ± 0.2sys, 1ES 1312-423 is one of the faintest sources ever detected in the very high energy (E > 100 GeV) extragalactic sky. A careful analysis using three and a half years of Fermi Large Area Telescope (Fermi-LAT) data allows the discovery at high energies (E > 100 MeV) of a hard spectrum (Γ = 1.4 ± 0.4stat ± 0.2sys) source coincident with 1ES 1312-423. Radio, optical, UV and X-ray observations complete the spectral energy distribution of this blazar, now covering 16 decades in energy. The emission is successfully fitted with a synchrotron self-Compton model for the non-thermal component, combined with a blackbody spectrum for the optical emission from the host galaxy.

  6. Deep view of the Large Magellanic Cloud with six years of Fermi-LAT observations

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hill, A. B.; Horan, D.; Jóhannesson, G.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Martin, P.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, M.; Zimmer, S.

    2016-02-01

    Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in γ-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims: Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the γ-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods: We revisited the γ-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results: In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1-100 GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations

  7. Volcanic rocks cored on hess rise, Western Pacific Ocean

    USGS Publications Warehouse

    Vallier, T.L.; Windom, K.E.; Seifert, K.E.; Thiede, Jorn

    1980-01-01

    Large aseismic rises and plateaus in the western Pacific include the Ontong-Java Plateau, Magellan Rise, Shatsky Rise, Mid-Pacific Mountains, and Hess Rise. These are relatively old features that rise above surrounding sea floors as bathymetric highs. Thick sequences of carbonate sediments overlie, what are believed to be, Upper Jurassic and Lower Cretaceous volcanic pedestals. We discuss here petrological and tectonic implications of data from volcanic rocks cored on Hess Rise. The data suggest that Hess Rise originated at a spreading centre in the late early Cretaceous (Aptian-Albian stages). Subsequent off-ridge volcanism in the late Albian-early Cenomanian stages built a large archipelago of oceanic islands and seamounts composed, at least in part, of alkalic rocks. The volcanic platform subsided during its northward passage through the mid-Cretaceousequatorial zone. Faulting and uplift, and possibly volcanism, occurred in the latest Cretaceous (Campanian-Maastrichtian stages). Since then, Hess Rise continued its northward movement and subsidence. Volcanic rocks from holes drilled on Hess Rise during IPOD Leg 62 (Fig. 1) are briefly described here and we relate the petrological data to the origin and evolution of that rise. These are the first volcanic rocks reported from Hess Rise. ?? 1980 Nature Publishing Group.

  8. AGN populations in GOODS-N through eMERGE ultra-deep JVLA observations

    NASA Astrophysics Data System (ADS)

    Guidetti, Daria; Bondi, M.; Prandoni, I.; Beswick, R. J.; Muxlow, T. W. B.; Wrigley, N.; Smail, I. R.; McHardy, I.; Ivison, R.; eMERGE Collaboration

    2016-08-01

    Multi-wavelength studies of deep radio fields show a composite population of star-forming galaxies, radio-quiet and radio-loud AGNs, with the formers dominating at the lowest flux densities (< 100 microJy). However, the exact mixture between these types of radio sources is still matter of debate. The most direct way to identify faint AGN-driven radio emission is the detection of embedded radio cores in the host galaxies, through ultra-deep and very high resolution radio observations. This would open the perspective of studying the whole AGN population in the radio band, including the radio-quiet component traditionally selected at other wavelengths (opt/IR/X-ray). Assessing the faint AGN component in deep radio fields, will provide an important tool to understand the role of nuclear activity in distant galaxies and its possible co-evolution with star-formation processes, as radio wavelengths are not affected by dust extinction and/or gas absorption. In my talk I will report about the e-MERLIN Galaxy Evolution Survey (eMERGE, PI: Muxlow), a legacy project which aims at undertaking a spatially-resolved study of AGN and star formation processes up to high redshift in a 30 arcmin diameter field in the GOODS-N region, through ultra-deep (sub-microJy rms), sub-arcsec (50-500 mas) imaging at 1.4 and 5 GHz, using combined JVLA and eMERLIN observations. I will focus on the 5 GHz JVLA mosaic observations and catalogue of GOODS-N (94 sources), in the framework of the eMERGE project, and on the study of a larger sample of GOODS-N galaxies (300 objects) selected at 1.4 GHz to constrain the presence of AGN cores in moderate-to-high redshift (1

  9. THE DEEP2 GALAXY REDSHIFT SURVEY: DESIGN, OBSERVATIONS, DATA REDUCTION, AND REDSHIFTS

    SciTech Connect

    Newman, Jeffrey A.; Cooper, Michael C.; Davis, Marc; Faber, S. M.; Guhathakurta, Puragra; Koo, David C.; Phillips, Andrew C.; Conroy, Charlie; Harker, Justin J.; Lai, Kamson; Dutton, Aaron A.; Finkbeiner, Douglas P.; Gerke, Brian F.; Rosario, David J.; Weiner, Benjamin J.; Willmer, C. N. A.; Yan Renbin; Kassin, Susan A.; Konidaris, N. P. E-mail: djm70@pitt.edu E-mail: mdavis@berkeley.edu E-mail: koo@ucolick.org E-mail: phillips@ucolick.org; and others

    2013-09-15

    We describe the design and data analysis of the DEEP2 Galaxy Redshift Survey, the densest and largest high-precision redshift survey of galaxies at z {approx} 1 completed to date. The survey was designed to conduct a comprehensive census of massive galaxies, their properties, environments, and large-scale structure down to absolute magnitude M{sub B} = -20 at z {approx} 1 via {approx}90 nights of observation on the Keck telescope. The survey covers an area of 2.8 deg{sup 2} divided into four separate fields observed to a limiting apparent magnitude of R{sub AB} = 24.1. Objects with z {approx}< 0.7 are readily identifiable using BRI photometry and rejected in three of the four DEEP2 fields, allowing galaxies with z > 0.7 to be targeted {approx}2.5 times more efficiently than in a purely magnitude-limited sample. Approximately 60% of eligible targets are chosen for spectroscopy, yielding nearly 53,000 spectra and more than 38,000 reliable redshift measurements. Most of the targets that fail to yield secure redshifts are blue objects that lie beyond z {approx} 1.45, where the [O II] 3727 A doublet lies in the infrared. The DEIMOS 1200 line mm{sup -1} grating used for the survey delivers high spectral resolution (R {approx} 6000), accurate and secure redshifts, and unique internal kinematic information. Extensive ancillary data are available in the DEEP2 fields, particularly in the Extended Groth Strip, which has evolved into one of the richest multiwavelength regions on the sky. This paper is intended as a handbook for users of the DEEP2 Data Release 4, which includes all DEEP2 spectra and redshifts, as well as for the DEEP2 DEIMOS data reduction pipelines. Extensive details are provided on object selection, mask design, biases in target selection and redshift measurements, the spec2d two-dimensional data-reduction pipeline, the spec1d automated redshift pipeline, and the zspec visual redshift verification process, along with examples of instrumental signatures or

  10. The DEEP2 Galaxy Redshift Survey: Design, Observations, Data Reduction, and Redshifts

    NASA Technical Reports Server (NTRS)

    Newman, Jeffrey A.; Cooper, Michael C.; Davis, Marc; Faber, S. M.; Coil, Alison L; Guhathakurta, Puraga; Koo, David C.; Phillips, Andrew C.; Conroy, Charlie; Dutton, Aaron A.; Finkbeiner, Douglas P.; Gerke, Brian F.; Rosario, David J.; Weiner, Benjamin J.; Wilmer, C. N. A.; Yan, Renbin; Harker, Justin J.; Kassin, Susan A.; Konidaris, N. P.; Lai, Kamson; Madgwick, Darren S.; Noeske, K. G.; Wirth, Gregory D.; Kirby, Evan N.; Lotz, Jennifer M.

    2013-01-01

    We describe the design and data analysis of the DEEP2 Galaxy Redshift Survey, the densest and largest high-precision redshift survey of galaxies at z approx. 1 completed to date. The survey was designed to conduct a comprehensive census of massive galaxies, their properties, environments, and large-scale structure down to absolute magnitude MB = -20 at z approx. 1 via approx.90 nights of observation on the Keck telescope. The survey covers an area of 2.8 Sq. deg divided into four separate fields observed to a limiting apparent magnitude of R(sub AB) = 24.1. Objects with z approx. < 0.7 are readily identifiable using BRI photometry and rejected in three of the four DEEP2 fields, allowing galaxies with z > 0.7 to be targeted approx. 2.5 times more efficiently than in a purely magnitude-limited sample. Approximately 60% of eligible targets are chosen for spectroscopy, yielding nearly 53,000 spectra and more than 38,000 reliable redshift measurements. Most of the targets that fail to yield secure redshifts are blue objects that lie beyond z approx. 1.45, where the [O ii] 3727 Ang. doublet lies in the infrared. The DEIMOS 1200 line mm(exp -1) grating used for the survey delivers high spectral resolution (R approx. 6000), accurate and secure redshifts, and unique internal kinematic information. Extensive ancillary data are available in the DEEP2 fields, particularly in the Extended Groth Strip, which has evolved into one of the richest multiwavelength regions on the sky. This paper is intended as a handbook for users of the DEEP2 Data Release 4, which includes all DEEP2 spectra and redshifts, as well as for the DEEP2 DEIMOS data reduction pipelines. Extensive details are provided on object selection, mask design, biases in target selection and redshift measurements, the spec2d two-dimensional data-reduction pipeline, the spec1d automated redshift pipeline, and the zspec visual redshift verification process, along with examples of instrumental signatures or other

  11. Some observations on the pharmacology of 'deep-heat', a topical rubifacient.

    PubMed Central

    Collins, A J; Notarianni, L J; Ring, E F; Seed, M P

    1984-01-01

    A topically applied rubifacient delivered by aerosol (Deep-Heat) was studied. After spray application to the forearms of volunteers, without massage, the erythema produced was measured by thermography and correlated with the concentration of 2 salicylate components of the mixture found in local and systemic venous blood. Maximum erythema occurred at about 30 minutes, while blood salicylate levels were maximal between 20 and 30 minutes after application. Methyl salicylate was absorbed before ethyl salicylate. Over the time period of the erythematous response oxygen levels in local venous blood were raised. Finally, platelets collected from venous blood draining from the sprayed site, when induced to clump by the addition of arachidonic acid in an aggregometer, showed increased resistance to clumping when compared with control cells. The mechanism of these observed phenomena and the mode of action of the constituents of Deep-Heat are discussed. PMID:6547585

  12. TeV Remnants in the H.E.S.S. Galactic Plane Survey

    NASA Astrophysics Data System (ADS)

    Chaves, Ryan C. G.

    2016-06-01

    The H.E.S.S. Galactic Plane Survey (HGPS), sensitive to very-high-energy gamma rays from ~0.2 to ~50 TeV, is now complete and shows supernova remnants to be one of the dominant TeV source populations in the Galaxy. The HGPS is the culmination of a decade-long, 2800-hour observation program that provides the first comprehensive view of the TeV Galaxy with high angular resolution (~5 arcmin) and sensitivity (~1-2% Crab Nebula flux). In some composite SNRs, we are able to distentangle TeV emission originating in interior pulsar wind nebulae from that of the SNR shells. We also can resolve SNR shells themselves, and not only the most well-known high-energy SNRs, but some unexpected discoveries as well. We recently searched for new TeV shell morphologies in the HGPS dataset, revealing: HESS J1534-571, coincident with the cataloged SNR candidate G323.7-1.0; HESS J1912+101, intruigingly with noobvious MWL counterpart; and HESS J1614-518, with a possible GeV gamma-ray counterpart. The TeV properties of these and other shells can reveal the non-thermal particle acceleration processes at work in SNRs and shed light on the important questions concerning cosmic-ray acceleration up to PeV energies and young remnants in the Galaxy that are possibly missing from current surveys. A public release of the HGPS survey maps, as well as a standardized catalog of Galactic TeV sources and study of multi-wavelength associations (notably SNRcat), is in preparation and will also be presented.

  13. AN ENERGETIC MAGNETAR IN HESS J1713-381/CTB 37B

    SciTech Connect

    Halpern, J. P.; Gotthelf, E. V. E-mail: eric@astro.columbia.ed

    2010-12-10

    We obtained a second Chandra timing measurement of the 3.82 s pulsar CXOU J171405.7-381031 in the supernova remnant (SNR) CTB 37B, which shows that it is spinning down rapidly. The average period derivative of (5.88 {+-} 0.08) x 10{sup -11} over the 1 year time span corresponds to a dipole magnetic field strength B{sub s} = 4.8 x 10{sup 14} G, well into the magnetar range. The spin-down power E-dot = 4.2x10{sup 34} erg s{sup -1} is among the largest for magnetars, and the corresponding characteristic age {tau}{sub c{identical_to}}P/2 P-dot = 1030 years is comparable to estimates of the age of the SNR. The period derivative enables us to recover probable pulsations in an ASCA observation taken in 1996, which yields a mean characteristic age of 860 years over the longer 13 year time span. The source is well detected up to 10 keV, and its composite spectrum is typical of a magnetar. CTB 37B hosts HESS J1713-381, the first TeV source that is coincident with a magnetar. While the TeV emission has been attributed to the SNR shell, it is possibly centrally peaked, and we hypothesize that this particularly young, energetic magnetar may contribute to the HESS source. We also searched for pulsations from another source in a HESS SNR, XMMU J173203.3-344518 in HESS J1731-347/G353.6-0.7, but could not confirm pulsations or long-term flux variability, making it more likely that this source is a weakly magnetized central compact object.

  14. An Energetic Magnetar in HESS J1713-381/CTB 37B

    NASA Astrophysics Data System (ADS)

    Halpern, J. P.; Gotthelf, E. V.

    2010-12-01

    We obtained a second Chandra timing measurement of the 3.82 s pulsar CXOU J171405.7-381031 in the supernova remnant (SNR) CTB 37B, which shows that it is spinning down rapidly. The average period derivative of (5.88 ± 0.08) × 10-11 over the 1 year time span corresponds to a dipole magnetic field strength Bs = 4.8 × 1014 G, well into the magnetar range. The spin-down power \\dot{E} = 4.2 × 10^{34} erg s-1 is among the largest for magnetars, and the corresponding characteristic age τ_c ≡ P/2\\dot{P} = 1030 years is comparable to estimates of the age of the SNR. The period derivative enables us to recover probable pulsations in an ASCA observation taken in 1996, which yields a mean characteristic age of 860 years over the longer 13 year time span. The source is well detected up to 10 keV, and its composite spectrum is typical of a magnetar. CTB 37B hosts HESS J1713-381, the first TeV source that is coincident with a magnetar. While the TeV emission has been attributed to the SNR shell, it is possibly centrally peaked, and we hypothesize that this particularly young, energetic magnetar may contribute to the HESS source. We also searched for pulsations from another source in a HESS SNR, XMMU J173203.3-344518 in HESS J1731-347/G353.6-0.7, but could not confirm pulsations or long-term flux variability, making it more likely that this source is a weakly magnetized central compact object.

  15. Impacts of a Fire Smoke Plume on Deep Convective Clouds Observed during DC3

    NASA Astrophysics Data System (ADS)

    Takeishi, A.; Storelvmo, T.; Zagar, M.

    2014-12-01

    While the ability of aerosols to act as cloud condensation nuclei (CCN) and ice nuclei (IN) is well recognized, the effects of changing aerosol number concentrations on convective clouds have only been studied extensively in recent years. As deep convective clouds can produce heavy precipitation and may sometimes bring severe damages, especially in the tropics, we need to understand the changes in the convective systems that could stem from aerosol perturbations. By perturbing convective clouds, it has also been proposed that aerosols can affect large-scale climate. According to the convective invigoration mechanism, an increase in the aerosol concentration could lead to a larger amount of rainfall and higher vertical velocities in convective clouds, due to an increase in the latent heat release aloft. With some of the satellite observations supporting this mechanism, it is necessary to understand how sensitive the model simulations actually are to aerosol perturbations. This study uses the Weather Research and Forecasting (WRF) model as a cloud-resolving model to reproduce deep convective clouds observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. The convective cloud of our interest was observed in northeastern Colorado on June 22nd in 2012, with a plume of forest fire smoke flowing into its core. Compared to other convective cells observed in the same area on different days, our aircraft data analysis shows that the convective cloud in question included more organic aerosols and more CCN. These indicate the influence of the biomass burning. We compare the results from simulations with different microphysics schemes and different cloud or ice number concentrations. These sensitivity tests tell us how different the amount and the pattern of precipitation would have been if the aerosol concentration had been higher or lower on that day. Both the sensitivity to aerosol perturbation and the reproducibility of the storm are shown to highly

  16. SPIN-DOWN MEASUREMENT OF PSR J1813-1749: THE ENERGETIC PULSAR POWERING HESS J1813-178

    SciTech Connect

    Halpern, J. P.; Gotthelf, E. V.; Camilo, F.

    2012-07-01

    Two new X-ray timing observations of the 44.7 ms pulsar in G12.82-0.02/HESS J1813-178 were obtained with Chandra and XMM-Newton to determine its precise spin-down rate. With a period derivative of P-dot 1.265 Multiplication-Sign 10{sup -13}, PSR J1813-1749 is the third most energetic pulsar in the Galaxy, having spin-down luminosity E-dot 5.6 Multiplication-Sign 10{sup 37} erg s{sup -1}. Lack of pulsed detection in a deep radio search from the Green Bank Telescope, and in {gamma}-rays from Fermi, are reported. We reconsider the distance to PSR J1813-1749/G12.82-0.02 in view of its large X-ray measured column density, N{sub H} = 10 Multiplication-Sign 10{sup 22} cm{sup -2}, which exceeds the visual extinction A{sub V} = 9.1 to a young stellar cluster at d = 4.8 kpc that has been associated with it. Although the distance may well be larger, existing data do not constrain it further. The small radiative output of PSR J1813-1749/G12.82-0.02 in all bands would not exceed its spin-down power at any distance in the Galactic disk.

  17. Observations of the transition from shallow to deep convection during the North American Monsoon

    NASA Astrophysics Data System (ADS)

    Zehnder, J. A.; Hu, J.; Radzan, A.

    2007-05-01

    The regular development of deep convection over the mountains in southern Arizona makes them an ideal location to study the onset and transition from shallow to deep convection. The convection that occurs during the North American Monsoon develops over the peaks a few hours after sunrise and development occurs slowly and in stages despite the presence of sufficient convective available potential energy (CAPE). A number of explanations for the episodic development have been proposed. These involve a modification of the column above the mountain by shallow convection that conditions the atmosphere for deep convection. The modification is likely due to moistening and/or changes to the static stability by warming the profile. Details of the transition from shallow to deep convection were explored during summer 2006 with support from the National Science Foundation. The Cumulus Photogrammetric In-Situ and Doppler Observations (CuPIDO) program utilized a network of ten portable automated mesonet stations (PAM-III), four of which were equipped to measure surface latent and sensible heat flux, two GPS based mobile sounding systems (MGAUS), two stereo pairs of digital cameras and the University of Wyoming King Air (with 95 GHz Doppler radar) to examine the onset and evolution of monsoon thunderstorms. This talk will describe the CuPIDO 2006 field program and present some preliminary results. Stereo- photogrammetric techniques are utilized to determine the three-dimensional structure of the clouds during various stages of the development. Changes to the vertical profile during the course of the development are examined using the sounding data and augmented by in-situ data from the aircraft. One specific example will be presented in which the breakdown of a stable layer at about the 500 mb level coincides with the onset of deep convection. The breakdown appears to be associated with warming of the profile in the lowest portion of the inversion through the action of the

  18. Safety and Effectiveness of Vibration Massage by Deep Oscillations: A Prospective Observational Study

    PubMed Central

    Kraft, Karin; Kanter, Susanne; Janik, Hubert

    2013-01-01

    The objective of this study is to assess the safety of treatment with vibration massage using a deep oscillation device and the effects on symptom severity and quality of life in patients with primary fibromyalgia syndrome (FMS). Outpatients with FMS performed an observational prospective study with visits 2–4 weeks after the last treatment (control) and after further 2 months (follow-up). Patients were treated with 10 sessions of 45 min deep oscillation massage, 2/week. Primary outcome parameters were safety and tolerability (5-level Likert scale (1 = very good)) (after each treatment session and at control visit). Secondary outcome parameters were symptom severity (Fibromyalgia Impact Questionnaire (FIQ), pain) and quality of life (SF-36). Seventy patients (97.1% females) were included. At control visit, 41 patients (58.6%) reported 63 mild and short-lasting adverse events, mainly worsening of prevalent symptoms such as pain and fatigue. Tolerability was rated as 1.8 (95% confidence interval: 1.53; 2.07). Symptoms and quality of life were significantly improved at both control and follow-up visits (at least P < 0.01). In conclusion, deep oscillation massage is safe and well tolerated in patients with FMS and might improve symptoms and quality of life rather sustained. PMID:24222779

  19. Mature Deep Convective Cloud Morphology as Observed by CloudSat

    NASA Astrophysics Data System (ADS)

    Igel, M.; van den Heever, S. C.

    2013-12-01

    The role of oceanic deep convective tropical clouds in weather and climate systems remains poorly defined for individual, deep convective clouds in the tropics. It is the goal of this work to try to determine those roles by analyzing cloud length scales observed by CloudSat. It is shown that misperceptions of cloud scales could lead consequently to a misunderstanding of the roles of deep convection. Using a recently developed cloud identification algorithm, CloudSat data is parsed into individual cloud objects that are present in large enough numbers to provide powerful statistics. The methodology also provides a means of counting the number of convective cores within the 'pedestal' of a cloud object. As the number of convective cores within a single cloud object increases, various changes in the morphology of storms occur. Not only do they get wider as the number of cores increases, but the anvil base lowers and the storm deepens. Correlations between different aspects of cloud morphology are evaluated with a focus on the up scale relationship of pedestals to anvils. The results implicate mesoscale organization of tropical clouds as being important for the general circulation. Finally, the sensitivity to local environmental characteristics of the cloud morphology is assessed and connections are made between the environment and the role of the cloud.

  20. Joint US-Japan Observations with the Infrared Space Observatory (ISO): Deep Surveys and Observations of High-Z Objects

    NASA Technical Reports Server (NTRS)

    Sanders, David B.

    1997-01-01

    Several important milestones were passed during the past year of our ISO observing program: (1) Our first ISO data were successfully obtained. ISOCAM data were taken for our primary deep field target in the 'Lockman Hole'. Thirteen hours of integration (taken over 4 contiguous orbits) were obtained in the LW2 filter of a 3 ft x 3 ft region centered on the position of minimum HI column density in the Lockman Hole. The data were obtained in microscanning mode. This is the deepest integration attempted to date (by almost a factor of 4 in time) with ISOCAM. (2) The deep survey data obtained for the Lockman Hole were received by the Japanese P.I. (Yoshi Taniguchi) in early December, 1996 (following release of the improved pipeline formatted data from Vilspa), and a copy was forwarded to Hawaii shortly thereafter. These data were processed independently by the Japan and Hawaii groups during the latter part of December 1996, and early January, 1997. The Hawaii group made use of the U.S. ISO data center at IPAC/Caltech in Pasadena to carry out their data reduction, while the Japanese group used a copy of the ISOCAM data analysis package made available to them through an agreement with the head of the ISOCAM team, Catherine Cesarsky. (3) Results of our LW2 Deep Survey in the Lockman Hole were first reported at the ISO Workshop "Taking ISO to the Limits: Exploring the Faintest Sources in the Infrared" held at the ISO Science Operations Center in Villafranca, Spain (VILSPA) on 3-4 February, 1997. Yoshi Taniguchi gave an invited presentation summarizing the results of the U.S.-Japan team, and Dave Sanders gave an invited talk summarizing the results of the Workshop at the conclusion of the two day meeting. The text of the talks by Taniguchi and Sanders are included in the printed Workshop Proceedings, and are published in full on the Web. By several independent accounts, the U.S.-Japan Deep Survey results were one of the highlights of the Workshop; these data showed

  1. Multiwavelength study of the northeastern outskirts of the extended TeV source HESS J1809–193

    SciTech Connect

    Rangelov, Blagoy; Kargaltsev, Oleg; Hare, Jeremy; Volkov, Igor; Posselt, Bettina; Pavlov, George G.

    2014-11-20

    HESS J1809–193 is an extended TeV γ-ray source in the Galactic plane. Multiwavelength observations of the HESS J1809–193 field reveal a complex picture. We present results from three Chandra X-Ray Observatory and two Suzaku observations of a region in the northeastern outskirts of HESS J1809-193, where enhanced TeV emission has been reported. Our analysis also includes GeV γ-ray and radio data. One of the X-ray sources in the field is the X-ray binary XTE J1810-189, for which we present the outburst history from multiple observatories and confirm that XTE J1810-189 is a strongly variable type I X-ray burster, which can hardly produce TeV emission. We investigate whether there is any connection between the possible TeV extension of HESS J1809–193 and the sources seen at lower energies. We find that another X-ray binary candidate, Suzaku J1811-1900, and a radio supernova remnant, SNR G11.4–0.1, can hardly be responsible for the putative TeV emission. Our multiwavelength classification of fainter X-ray point sources also does not produce a plausible candidate. We conclude that the northeast extension of HESS J1809–193, if confirmed by deeper observations, can be considered a dark accelerator—a TeV source without a visible counterpart at lower energies.

  2. In-situ Observations of Mid-latitude Forest Fire Plumes Deep in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Jost, Hans-Juerg; Drdla, Katja; Stohl, Andreas; Pfister, Leonhard; Loewenstein, Max; Lopez, Jimena P.; Hudson, Paula K.; Murphy, Daniel M.; Cziczo, Daniel J.; Fromm, Michael

    2004-01-01

    We observed a plume of air highly enriched in carbon monoxide and particles in the stratosphere at altitudes up to 15.8 km. It can be unambiguously attributed to North American forest fires. This plume demonstrates an extratropical direct transport path from the planetary boundary layer several kilometers deep into the stratosphere, which is not fully captured by large-scale atmospheric transport models. This process indicates that the stratospheric ozone layer could be sensitive to changes in forest burning associated with climatic warming.

  3. Scaling Relationship Among Source Parameters of Microearthquake," From Near Source Observation in a Deep Mine

    NASA Astrophysics Data System (ADS)

    Hiramatsu, Y.; Yoshimura, M.; Furumoto, M.

    2004-12-01

    Scaling relationships among various source parameters are important clues to understand the source process. In particular the relationship between the corner frequency, fC, and the seismic moment, MO, has been investigated by many researchers. Aki(1967) investigated fC and MO using the spectra of seismic waves and reported that these parameters obeyed a relationship of MO ∝ fC-3. For small earthquakes, the breakdown of this relationship was often reported. On the other hand, no breakdown of the relationship for microearthquakes has been reported from high quality observation at deep boreholes and in a deep gold mine. We report here these scaling relationships using waveform of microearthquakes observed at the distance range of 15m to 1km. We installed nine tri-axial borehole accelerometers within 200 m along a haulage tunnel 2650m deep in Mponeng mine in South Africa from February to December in 1996. More than 25 thousand seismic events were recorded with a sampling frequency of 15 kHz and a dynamic range of 120 dB. The recording system has flat response up to 2 KHz. Among those events, we select 378 events with high S/N. We locate hypocenters assuming infinite medium with the P-wave velocity 5.5 km/s and the S-wave velocity 3.2 km/s. We calculate the green function using the discrete wavenumber integral method into account the effect of anelasticity by Takeo (1985) and determine the seismic moment and the mechanism using moment tensor inversion. We apply the omega square model by Brune (1970) to determine the corner frequency and the stress drop. Minimizing L2 norm between the observed spectra of P and S waves and the synthetic ones give the optimum source parameters. The earthquakes analyzed in this study show the constant stress drop of 0.4 ˜8MPa in the ranges of 40

  4. Sediments of deep canadian shield lakes: observations of gross structure and biological significance.

    PubMed

    Emery, A R

    1973-08-17

    Sediments of deep Canadian shield lakes have a firm mud-water interface and an intricately structured, oxygenated surface. Surface relief is not uniform, but is broken by small ridges and upright chironomid tubes. The sedimentary material behaves like a weak jelly and becomes flocculent only when violently disturbed. Sculpins were observed to rest on and, when started, to hide in the oxygenated layers. Sequestering of nutrients in the bottom sediments is enhanced by the structuring of the substrate surface below 10 meters, and may inhibit nutrient recycling at overturn. PMID:17736979

  5. Sediments of deep canadian shield lakes: observations of gross structure and biological significance.

    PubMed

    Emery, A R

    1973-08-17

    Sediments of deep Canadian shield lakes have a firm mud-water interface and an intricately structured, oxygenated surface. Surface relief is not uniform, but is broken by small ridges and upright chironomid tubes. The sedimentary material behaves like a weak jelly and becomes flocculent only when violently disturbed. Sculpins were observed to rest on and, when started, to hide in the oxygenated layers. Sequestering of nutrients in the bottom sediments is enhanced by the structuring of the substrate surface below 10 meters, and may inhibit nutrient recycling at overturn.

  6. MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026

    NASA Astrophysics Data System (ADS)

    MAGIC Collaboration; Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Hayashida, M.; Herrera, J.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Klepser, S.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Nowak, N.; de Oña Wilhelmi, E.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saggion, A.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Sun, S.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.

    2014-11-01

    Aims: HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H.E.S.S. as part of its Galactic plane survey. Given its broadband spectral energy distribution and its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN) candidate. MAGIC has performed follow-up observations aimed at mapping the source down to energies approaching 100 GeV in order to better understand its complex morphology. Methods: HESS J1857+026 was observed by MAGIC in 2010, yielding 29 h of good quality stereoscopic data that allowed us to map the source region in two separate ranges of energy. Results: We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of 12σ above 150 GeV. The differential energy spectrum between 100 GeV and 13 TeV is described well by a power law function dN/dE = N0(E/1TeV)-Γ with N0 = (5.37 ± 0.44stat ± 1.5sys) × 10-12 (TeV-1 cm-2 s-1) and Γ = 2.16 ± 0.07stat ± 0.15sys, which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multiwavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an Hii region and a possible gas cavity.

  7. Searching for WIMPs in Deep Radio Observations of Galactic dSphs

    NASA Astrophysics Data System (ADS)

    Spekkens, Kristine; Mason, B. S.; Aguirre, J. E.; Natarajan, A.; Nhan, B.; Peterson, J.; Willman, B.

    2013-07-01

    Weakly Interacting Massive Particles (WIMPs) are attractive dark matter candidates, and indirect searches for radiation resulting from their annihilations into Standard Model particles are a promising approach for constraining WIMP properties. While gamma-ray searches for neutral pion decays have been widely exploited, energy losses from charged annihilation products should also produce detectable signals. In this talk, I will present deep radio observations designed to detect degree-scale radio synchrotron halos in galactic dwarf spheroidal galaxies (dSphs), predicted to stem from electron and positron annihilation products spiraling in turbulent magnetic fields. I will describe i. the technical challenges associated with obtaining wide-field radio maps with sensitivities below the astrophysical confusion limit, ii. the theoretical challenges of modelling charged particle diffusion in dSphs, and iii. the prospects for overcoming these challenges. I will argue that despite these challenges, non-detections in our maps imply upper limits on the WIMP annihilation cross-section that rival those obtained by gamma-ray searches: deep radio observations of dSphs are highly complementary to indirect WIMP searches at higher energies.

  8. A VERY DEEP CHANDRA OBSERVATION OF A2052: BUBBLES, SHOCKS, AND SLOSHING

    SciTech Connect

    Blanton, E. L.; Douglass, E. M.; Randall, S. W.; McNamara, B. R.; Clarke, T. E.; Sarazin, C. L.; McDonald, M. E-mail: emdoug@bu.edu E-mail: tracy.clarke@nrl.navy.mil E-mail: mcnamara@sciborg.uwaterloo.ca

    2011-08-20

    We present the first results from a very deep ({approx}650 ks) Chandra X-ray observation of A2052, as well as archival Very Large Array radio observations. The data reveal detailed structure in the inner parts of the cluster, including bubbles evacuated by radio lobes of the active galactic nucleus (AGN), compressed bubble rims, filaments, and loops. Two concentric shocks are seen, and a temperature rise is measured for the innermost one. On larger scales, we report the first detection of an excess surface brightness spiral feature. The spiral has cooler temperatures, lower entropies, and higher abundances than its surroundings, and is likely the result of sloshing gas initiated by a previous cluster-cluster or sub-cluster merger. Initial evidence for previously unseen bubbles at larger radii related to earlier outbursts from the AGN is presented.

  9. Decaying dark matter: the case for a deep X-ray observation of Draco

    NASA Astrophysics Data System (ADS)

    Lovell, Mark R.; Bertone, Gianfranco; Boyarsky, Alexey; Jenkins, Adrian; Ruchayskiy, Oleg

    2015-08-01

    Recent studies of M31, the Galactic Centre (GC), and galaxy clusters have made tentative detections of an X-ray line at ˜3.5 keV that could be produced by decaying dark matter. We use high-resolution simulations of the Aquarius project to predict the likely amplitude of the X-ray decay flux observed in the GC relative to that observed in M31, and also of the GC relative to other parts of the Milky Way halo and to dwarf spheroidal galaxies. We show that the reported detections from M31 and the GC are compatible with each other, and with upper limits arising from high galactic latitude observations, and imply a decay time τ ˜ 1028 s. We argue that this interpretation can be tested with deep observations of dwarf spheroidal galaxies: in 95 per cent of our mock observations, a 1.3 Ms pointed observation of Draco with XMM-Newton will enable us to discover or rule out at the 3σ level an X-ray feature from dark matter decay at 3.5 keV, for decay times τ < 0.8 × 1028 s.

  10. From West to East and Back Again: Faith, Doubt and Education in Hermann Hesse's Later Work

    ERIC Educational Resources Information Center

    Roberts, Peter

    2008-01-01

    This paper examines Hermann Hesse's penultimate novel, "The Journey to the East", from an educational point of view. Hesse was a man of the West who turned to the idea of "the East" in seeking to understand himself and his society. While highly critical of elements of Western modernism, Hesse nonetheless viewed "the East" through Western lenses…

  11. Decoupling of Serpentinization and Prehnitization in Lower East Pacific Rise Crust at Hess Dee

    NASA Astrophysics Data System (ADS)

    Deasy, R. T.; Wintsch, R. P.; Meyer, R.; Bish, D. L.; Gasaway, C.; Heimdal, T.

    2014-12-01

    Our down-hole mineralogical and geochemical analyses from the East Pacific Rise fast-spreading lower oceanic crust indicate that alteration of olivine to serpentine and of plagioclase to prehnite were independent, and neither alone monitors the total "alteration." The results are based on representative channel sub-samples recovered from every Hole J core during IODP Expedition 345 to the Hess Deep tectonic window. Samples have been analyzed for trace element, Sr isotopic, and quantitative mineralogical compositions (the latter by Rietveld refinement using X-ray diffraction data). Hole J is the most representative rock succession drilled at the Hess Deep as it penetrated the two principle plutonic lithologies: an upper gabbro and a lower troctolite. Units are significantly distinguished by XRD modal mineralogy and trace element abundances. The more heterogeneous gabbro contains 23-32 wt% clinopyroxene (cpx), 34-54 wt% plagioclase (plag), and <4 wt% olivine (ol). The troctolite contains 3-11% cpx, 14-36% plag, and ≤6% ol. Alteration minerals comprise together 18-31% in the gabbro versus 55-80% of the troctolite. The most abundant alteration products are prehnite and chlorite. Gabbro samples with lowest abundances of alteration minerals (18-20 wt%) preserve 87Sr/86Sr ratios (0.70275-0.7028) consistent with unaltered mantle. The abundance of plag in the gabbro, the major host for Sr, suggests retention of mantle Sr isotopic compositions there is due to the large reservoir of magmatic Sr. 87Sr/86Sr ratios of 0.70300-0.70342 in the troctolite samples indicate seawater interaction, even where olivine is most abundant, and serpentine is at or below the ~1% detection limit by XRD. Significant alteration of the deep crust by seawater thus predates the first appearance of serpentine. These data suggest that the timing and operation of prehnite- and serpentine-producing alteration reactions are independent.

  12. VERITAS Studies of the TeV Emission from MGRO J1908+06/HESS J1908+063

    NASA Astrophysics Data System (ADS)

    Gall, Daniel D.; VERITAS Collaboration

    2013-04-01

    We will report on recent observations of complex TeV emission from MGRO J1908+06/HESS J1908+063. This extended source is located on the galactic plane at a longitude of 40.4 degrees and has a hard spectrum with an index of ~ 2.1. The TeV source has been attributed to the pulsar wind nebula of the nearby Fermi-LAT pulsar PSR J1907+0602. Initial VERITAS observations of the TeV gamma-ray source MGRO J1908+06/HESS J1908+063 were taken during July 2007 and May-June 2008. Further observations with VERITAS, obtained between 2009-2012, have been studied to determine the morphology of the TeV emission extending up to 30 TeV. The analysis of these VERITAS observations will be presented as well as some discussion of the implications on the emission scenario.

  13. Observations of deep convective influence on stratospheric water vapor and its isotopic composition

    NASA Astrophysics Data System (ADS)

    Hanisco, T. F.; Moyer, E. J.; Weinstock, E. M.; Dessler, A. E.; St. Clair, J. M.; Sayres, D. S.; Smith, J. B.; Lockwood, R.; Read, W. G.; Anderson, J. G.

    2006-12-01

    In situ observations of H2O and HDO from the NASA WB-57 and remote measurements of H2O from AURA MLS are used to evaluate the role of deep convection as a source of water to the overworld stratosphere (potential temperature above 380 K). Observations in different seasons and latitudes are used to identify and evaluate the different pathways by which convection influences water vapor and its isotopes, including convection above the 380 K surface in the tropics, subtropics, and midlatitudes. The water isotope observations show that water vapor in the overworld stratosphere in the tropics and mid-latitudes is isotopically heavy, an unambiguous signature of large scale convective influence on stratospheric water to near- tropopause altitudes. Model results constrained by MLS H2O and in situ H2O and HDO suggest that extratropical convection accounts for a large fraction of the observed water vapor in the summertime overworld stratosphere above the mid-North American continent. Discontinuities between the water isotope abundances in the tropical tropopause layer (TTL) and the overworld stratosphere suggest that local processes do not control the abundance of stratospheric water above the western tropical pacific. Observations of water vapor and water isotopes in the tropical stratosphere indicate a significant, but not yet quantified, role of convection.

  14. Long Term Seismic Observation in Mariana by OBSs : Activity of Deep Earthquakes

    NASA Astrophysics Data System (ADS)

    Shiobara, H.; Mochizuki, K.; Ohki, S.; Kanazawa, T.; Fukao, Y.; Sugioka, H.; Suyehiro, K.

    2003-12-01

    In order to obtain the deep arc structural image of Mariana, a large-scale seismic observation by using 58 long-term ocean bottom seismometers (LTOBS) has been started since June 2003 for about one year. It is a part of the MARGINS program (US-JAPAN COLLABORATIVE RESEARCH: MULTI-SCALE SEISMIC IMAGING OF THE MARIANA SUBDUCTION FACTORY), and the aim of this observation is the crustal and mantle structure modeling by using passive and active seismic sources. The 50 and 8 LTOBSs are owned by LDEO and ERI, respectively, and they were deployed during the cruise of R/V Kaiyo (Jamstec), KY03-06. Prior to this experiment, we made a pilot long-term seismic array observation in the same area by using 10 LTOBSs, deployed in Oct. 2001 by R/V Yokosuka (Jamstec) and recovered in Feb. 2003 by R/V Kaiyo. This LTOBS has been developed by ERI, which has the PMD sensor (WB2023LP) and a titanium sphere housing (D=50cm) and was already used in several long-term observations (ex. trans-PHS array observation presented at the AGU fall meeting, 2000, S51B-02). Two of 10 LTOBSs could not be recovered due to malfunction of the releasing system, and one recovered had a trouble in the sensor control unit. But, seven others have obtained more than 11 months long data continuously. As passive source studies of these observations use characteristic deep earthquakes in this area, the activity of them will be introduced in this presentation, from the data obtained just above them. At the first step, difference of hypocenters of known events, listed on the PDE catalog, is examined. There are 59 events of epicenters within a circular area centered at 19° N, 145° E with radius of 1000km from the catalog during the observation. P and S arrivals are picked by using the WIN system, and the iasp91 model (only {VP} with {{VP}/{V_S}=1.732}) is used for the hypocenter determination. Station corrections are applied only for the sediment layer, estimated from several arrival time data of P and P-S converted

  15. Long-term continuous observation of vertical gradient of water temperature on the deep seafloor

    NASA Astrophysics Data System (ADS)

    Suzuki, S.; Hino, R.; Ito, Y.; Kubota, T.; Inazu, D.

    2015-12-01

    We have conducted ocean bottom pressure observations near the Japan Trench and the Kuril Trench using self-pop-up type instruments to detect seafloor vertical displacement accompanied by slip events along the plate boundary faults. Recently, we have started similar observation campaigns in the Hikurangi subduction zone, off the North Island of New Zealand since 2013. As a result of the observations, we have observed an uplift of 5 m due to the 2011 Tohoku-Oki earthquake (Ito et al., 2011) and transient crustal deformations accompanied by slow slip events preceding the earthquake (Ito et al., 2013). Precision thermometer, usually used for temperature compensation of the pressure readings, occasionally recorded strange temperature changes related to occurrence of submarine earthquakes or tsunamis. Arai et al. (2013) interpreted noticeable temperature changes observed after the 2011 Tohoku-Oki earthquake and interpreted it as the result of the turbidity current induced by massive tsunami. Inazu et al. (2015) pointed out a possibility that the temperature disturbance recorded just after the Tohoku-Oki earthquake above the large coseismic slip zone was due to the discharged of submarine groundwater associated with the earthquake. In order to describe these strange temperature signals more quantitatively, we started trial observations allowing investigation of water temperature field on the deep seafloor. In this study, we installed two precision temperature loggers top and bottom of the ocean bottom pressure recorders, with ~ 60 cm in height, to measure vertical gradients of seawater temperature as well as the ocean bottom pressures. Here, we report about 1-year continuous records retrieved from the Japan Trench and off New Zealand. During the observation off New Zealand, an evident slow slip event was identified by the onshore geodetic observations near the locations of our seafloor pressure-temperature monitoring. We are now exploring possible thermal and pressure

  16. Deep VLA observations of nearby star forming regions I: Barnard 59 and Lupus 1

    NASA Astrophysics Data System (ADS)

    Dzib, S. A.; Loinard, L.; Medina, S.-N. X.; Rodríguez, L. F.; Mioduszewski, A. J.; Torres, R. M.

    2016-04-01

    Barnard 59 and Lupus 1 are two nearby star-forming regions visible from the southern hemisphere. In this manuscript, we present deep (σ˜15 μJy) radio observations (ν=6 GHz) of these regions, and report the detection of a total of 114 sources. Thirteen of these sources are associated with known young stellar objects, nine in Barnard 59 and four in Lupus 1. The properties of the radio emission (spectral index and, in some cases, polarization) suggest a thermal origin for most young stellar objects. Only for two sources (Sz 65 and Sz 67) are there indications for a possible non-thermal origin. The remaining radio detections do not have counterparts at other wavelengths, and the number of sources detected per unit solid angle is in agreement with extragalactic number counts, suggesting that they are extragalactic sources.

  17. Instability observations associated with wave breaking in the stable-stratified deep-ocean

    NASA Astrophysics Data System (ADS)

    van Haren, Hans

    2015-02-01

    High-resolution temperature observations above underwater topography in the deep, stably stratified ocean have revealed two distinctive turbulence processes. These processes are associated with different phases of a large-scale (here tidal) internal gravity wave: (i) highly nonlinear turbulent bores during the upslope propagating phase, and (ii) Kelvin-Helmholtz billows, at some distance above the slope, during the downslope phase. Whilst the former may be associated in part with convective turbulent overturning following Rayleigh-Taylor instabilities 'RTi', the latter is mainly related to shear-induced Kelvin-Helmholtz instabilities. In this paper, details are particularly presented of rare (convective) RTi penetrating stable density stratification under high-frequency internal waves. Such 'apparent RTi' can be explained using both stability parameterization of entrainment across a density interface, and, more relevant here, internal wave acceleration overcoming the reduced gravity.

  18. A Deep Chandra Observation of the Centaurus Cluster:Bubbles, Filaments and Edges

    SciTech Connect

    Fabian, A.C.

    2005-03-14

    X-ray images and gas temperatures taken from a deep {approx}200 ks Chandra observation of the Centaurus cluster are presented. Multiple inner bubbles and outer semicircular edges are revealed, together with wispy filaments of soft X-ray emitting gas. The frothy central structure and eastern edge are likely due to the central radio source blowing bubbles in the intracluster gas. The semicircular edges to the surface brightness maps 32 kpc to the east and 17.5 kpc to the west are marked by sharp temperature increases and abundance drops. The edges could be due to sloshing motions of the central potential, or are possibly enhanced by earlier radio activity. The high abundance of the innermost gas (about 2.5 times Solar) limits the amount of diffusion and mixing taking place.

  19. Observed and Simulated Relationships Between Tropical Deep Convective Updraft Dynamics and Ice Microphysics

    NASA Astrophysics Data System (ADS)

    Varble, A.; Stanford, M.; Zipser, E. J.; Strapp, J. W.; Delanoë, J.; Korolev, A.; Leroy, D.; Potts, R.; Protat, A.; Schwarzenboeck, A.

    2015-12-01

    Relationships between tropical deep convective updraft cores and regions of high ice water content encountered by the Falcon-20 aircraft during the High Altitude Ice Crystals/High Ice Water Content (HAIC/HIWC) campaign in Darwin, Australia are analyzed and compared with high-resolution WRF simulation output. Most flight legs were performed at temperatures near -30°C and -40°C, where relationships between ice water content and vertical velocity are somewhat similar in observations and simulations, although observed ice water contents tend to be a bit higher for a given vertical velocity. This difference can be traced to substantial differences in ice and liquid properties in convective updraft cores at -10°C, where simulated updrafts tend to have far more graupel and liquid water than observed updrafts for a given vertical velocity, although total condensate contents are similar. This partly leads to the commonly observed reflectivity high bias in simulations, which overshadows observed and simulated large snow water contents that commonly exceed 2 g m-3 without reflectivities exceeding 25 dBZ. It appears that magnitudes of microphysical processes operating in mixed phase conditions between 0 and -10°C are quite different in observed and simulated updrafts of similar size and strength, and this difference may be common to most microphysics schemes. Mixed phase properties in convective updrafts end up impacting ice sedimentation and detrainment from convective cores, which go on to impact precipitation efficiency, distribution of rain rates, and likely the life cycle of the convective system. Possible reasons for differences in observed and simulated updrafts are explored.

  20. Deep Chandra observations of HCG 16. I. Active nuclei, star formation, and galactic winds

    SciTech Connect

    O'Sullivan, E.; Zezas, A.; Vrtilek, J. M.; David, L. P.; Giacintucci, S.; Trevisan, M.; Ponman, T. J.; Raychaudhury, S.; Mamon, G. A.

    2014-10-01

    We present new, deep Chandra X-ray and Giant Metrewave Radio Telescope 610 MHz observations of the spiral-galaxy-rich compact group HCG 16, which we use to examine nuclear activity, star formation, and high-luminosity X-ray binary populations in the major galaxies. We confirm the presence of obscured active nuclei in NGC 833 and NGC 835, and identify a previously unrecognized nuclear source in NGC 838. All three nuclei are variable on timescales of months to years, and for NGC 833 and NGC 835 this is most likely caused by changes in accretion rate. The deep Chandra observations allow us to detect for the first time an Fe Kα emission line in the spectrum of the Seyfert 2 nucleus of NGC 835. We find that NGC 838 and NGC 839 are both starburst-dominated systems, with only weak nuclear activity, in agreement with previous optical studies. We estimate the star formation rates in the two galaxies from their X-ray and radio emission, and compare these results with estimates from the infrared and ultraviolet bands to confirm that star formation in both galaxies is probably declining after galaxy-wide starbursts were triggered ∼400-500 Myr ago. We examine the physical properties of their galactic superwinds, and find that both have temperatures of ∼0.8 keV. We also examine the X-ray and radio properties of NGC 848, the fifth largest galaxy in the group, and show that it is dominated by emission from its starburst.

  1. Observing the Moon at Microwave Frequencies Using a Large-Diameter Deep Space Network Antenna

    NASA Astrophysics Data System (ADS)

    Morabito, David D.; Imbriale, William; Keihm, Stephen

    2008-03-01

    The Moon radiates energy at infrared and microwave wavelengths, in addition to reflecting sunlight at optical wavelengths. As a result, an antenna pointed at or near the Moon will result in an increase in system operating noise temperature, which needs to be accounted for in RF telecommunications, radio science or radiometric link calculations. The NASA Deep Space Network (DSN) may use its large-diameter antennas in future lunar robotic or human missions, and thus it is important to understand the nature of this temperature incre ase as a function of observing frequency, lunar phase, and angular position of the antenna beam on the lunar disk. This paper reports on a comprehensive lunar noise temperature measurement campaign and associated theoretical treatment for a 34-m diameter Deep Space Network antenna observing an extended source such as the Moon. A set of measurements over a wide range of lunar phase angles was acquired at DSS-13, a 34-m diameter beam waveguide antenna (BWG) located at Goldstone, California at 2.3 GHz (S-band), 8.4 GHz (X-band) and 32 GHz (Ka-band). For validation purposes, independent predictions of noise temperature increase were derived using a physical optics characterization of the 34-m diameter antenna gain patterns and Apollo model-based brightness temperature maps of the Moon as input. The model-based predictions of noise temperature increase were compared with the measurements at all three frequencies. In addition, a methodology is presented that relates noise temperature increase due to the Moon to disk-centered or disk-averaged brightness temperature of the Moon at the microwave frequencies of interest. Comparisons were made between the measurements and models in the domain of lunar disk-centered and disk-averaged brightness temperatures. It is anticipated that the measurements and associated theoretical development will be useful in developing telecommunications strategies for future high-rate Ka-band communications where large

  2. DEEP GALEX OBSERVATIONS OF THE COMA CLUSTER: SOURCE CATALOG AND GALAXY COUNTS

    SciTech Connect

    Hammer, D.; Hornschemeier, A. E.; Miller, N.; Jenkins, L.; Mobasher, B.; Smith, R.; Arnouts, S.; Milliard, B.

    2010-09-15

    We present a source catalog from a deep 26 ks Galaxy Evolution Explorer (GALEX) observation of the Coma cluster in the far-UV (FUV; 1530 A) and near-UV (NUV; 2310 A) wavebands. The observed field is centered {approx}0.{sup 0}9 (1.6 Mpc) southwest of the Coma core in a well-studied region of the cluster known as 'Coma-3'. The entire field is located within the apparent virial radius of the Coma cluster, and has optical photometric coverage with Sloan Digital Sky Survey (SDSS) and deep spectroscopic coverage to r {approx} 21. We detect GALEX sources to NUV = 24.5 and FUV = 25.0, which corresponds to a star formation rate of {approx}10{sup -3} M {sub sun} yr{sup -1} for galaxies at the distance of Coma. We have assembled a catalog of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically confirmed Coma member galaxies that span a large range of galaxy types from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is {approx}80% complete to NUV = 23 and FUV = 23.5. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g., object blends, source confusion, Eddington Bias) that influence the source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is free from source confusion over the UV magnitude range studied here; we estimate that

  3. Constraints on the Progenitor System and the Environs of SN 2014J from Deep Radio Observations

    NASA Astrophysics Data System (ADS)

    Pérez-Torres, M. A.; Lundqvist, P.; Beswick, R. J.; Björnsson, C. I.; Muxlow, T. W. B.; Paragi, Z.; Ryder, S.; Alberdi, A.; Fransson, C.; Marcaide, J. M.; Martí-Vidal, I.; Ros, E.; Argo, M. K.; Guirado, J. C.

    2014-09-01

    We report deep EVN and eMERLIN observations of the Type Ia SN 2014J in the nearby galaxy M82. Our observations represent, together with JVLA observations of SNe 2011fe and 2014J, the most sensitive radio studies of Type Ia SNe ever. By combining data and a proper modeling of the radio emission, we constrain the mass-loss rate from the progenitor system of SN 2014J to \\dot{M} ≲ 7.0× 10-10 { {M⊙ yr-1}} (for a wind speed of 100 km s-1). If the medium around the supernova is uniform, then n ISM <~ 1.3 cm-3, which is the most stringent limit for the (uniform) density around a Type Ia SN. Our deep upper limits favor a double-degenerate (DD) scenario—involving two WD stars—for the progenitor system of SN 2014J, as such systems have less circumstellar gas than our upper limits. By contrast, most single-degenerate (SD) scenarios, i.e., the wide family of progenitor systems where a red giant, main-sequence, or sub-giant star donates mass to an exploding WD, are ruled out by our observations. (While completing our work, we noticed that a paper by Margutti et al. was submitted to The Astrophysical Journal. From a non-detection of X-ray emission from SN 2014J, the authors obtain limits of \\dot{M} ≲ 1.2 × 10-9 M ⊙ yr-1 (for a wind speed of 100 km s-1) and n ISM <~ 3.5 cm-3, for the ρvpropr -2 wind and constant density cases, respectively. As these limits are less constraining than ours, the findings by Margutti et al. do not alter our conclusions. The X-ray results are, however, important to rule out free-free and synchrotron self-absorption as a reason for the radio non-detections.) Our estimates on the limits on the gas density surrounding SN2011fe, using the flux density limits from Chomiuk et al., agree well with their results. Although we discuss the possibilities of an SD scenario passing observational tests, as well as uncertainties in the modeling of the radio emission, the evidence from SNe 2011fe and 2014J points in the direction of a DD scenario for

  4. Constraints on the progenitor system and the environs of SN 2014J from deep radio observations

    SciTech Connect

    Pérez-Torres, M. A.; Alberdi, A.; Beswick, R. J.; Muxlow, T. W. B.; Argo, M. K.; Paragi, Z.; Ryder, S.; Marcaide, J. M.; Ros, E.; Guirado, J. C.; Martí-Vidal, I.

    2014-09-01

    We report deep EVN and eMERLIN observations of the Type Ia SN 2014J in the nearby galaxy M82. Our observations represent, together with JVLA observations of SNe 2011fe and 2014J, the most sensitive radio studies of Type Ia SNe ever. By combining data and a proper modeling of the radio emission, we constrain the mass-loss rate from the progenitor system of SN 2014J to M-dot ≲7.0×10{sup −10} M{sub ⊙} yr{sup −1} (for a wind speed of 100 km s{sup –1}). If the medium around the supernova is uniform, then n {sub ISM} ≲ 1.3 cm{sup –3}, which is the most stringent limit for the (uniform) density around a Type Ia SN. Our deep upper limits favor a double-degenerate (DD) scenario—involving two WD stars—for the progenitor system of SN 2014J, as such systems have less circumstellar gas than our upper limits. By contrast, most single-degenerate (SD) scenarios, i.e., the wide family of progenitor systems where a red giant, main-sequence, or sub-giant star donates mass to an exploding WD, are ruled out by our observations. (While completing our work, we noticed that a paper by Margutti et al. was submitted to The Astrophysical Journal. From a non-detection of X-ray emission from SN 2014J, the authors obtain limits of M-dot ≲1.2×10{sup −9} M {sub ☉} yr{sup –1} (for a wind speed of 100 km s{sup –1}) and n {sub ISM} ≲ 3.5 cm{sup –3}, for the ρ∝r {sup –2} wind and constant density cases, respectively. As these limits are less constraining than ours, the findings by Margutti et al. do not alter our conclusions. The X-ray results are, however, important to rule out free-free and synchrotron self-absorption as a reason for the radio non-detections.) Our estimates on the limits on the gas density surrounding SN2011fe, using the flux density limits from Chomiuk et al., agree well with their results. Although we discuss the possibilities of an SD scenario passing observational tests, as well as uncertainties in the modeling of the radio emission, the

  5. Voyager Observations in the Distant Heliosheath - an Analogy With ISEE-3 Observations in theDeep Geomagnetic Tail

    NASA Astrophysics Data System (ADS)

    Richardson, Ian

    2015-04-01

    We suggest an analogy between energetic particle and magnetic field observations made by the Voyager 1 spacecraft in the distant heliosheath at 122 AU in August 2012 and those made in the distant geomagnetic tail by the Energetic Particle Anisotropy Spectrometer (EPAS) on the ISEE 3 spacecraft in 1982-1983, including remarkable similarities in the behavior of the energetic particle intensities and anisotropies despite large differences in the time and distance scales.The analogy suggests that Voyager 1 may have moved not into the interstellar medium from heliosheath but instead into a region equivalent to the “lobes” of the geomagnetic tail. This region may be composed of heliospheric field lines which have reconnected with the interstellar medium beyond the spacecraft and so are open to the entry of cosmic rays, while heliospheric particles (e.g., Anomalous Cosmic Rays) are free to escape, leaving only a weak population of large pitch-angle ACRs with “pancake” distributions similar to those also seen by ISEE 3 in the lobes of the tail. If this is the case, the actual heliopause (equivalent to the magnetopause), where the ambient interstellar medium is entered, lies beyond the current distance of Voyager 1.Temporary variations in the energetic particle and magnetic field intensities at Voyager over a period of around 27 days prior to the final boundary crossing are interpreted as the boundary twice approaching Voyager 1 and then retreating Sunward before the final crossing occurred. Similar features were frequently observed in the deep tail due to tail dynamics and “flapping” in the solar wind. The 27 day interval suggests that rotation of the heliosphere may have contributed to this boundary motion.Energetic particles in the tail are accelerated by reconnection in the plasma sheet which can lead to the formation of plasmoids. Both are elements of some recent models of the heliopause.

  6. DEEP CHANDRA OBSERVATIONS OF THE EXTENDED GAS SLOSHING SPIRAL IN A2029

    SciTech Connect

    Paterno-Mahler, R.; Blanton, E. L.; Randall, S. W.; Clarke, T. E. E-mail: eblanton@bu.edu E-mail: tracy.clarke@nrl.navy.mil

    2013-08-20

    Recent X-ray observations of galaxy clusters have shown that there is substructure present in the intracluster medium (ICM), even in clusters that are seemingly relaxed. This substructure is sometimes a result of sloshing of the ICM, which occurs in cool core clusters that have been disturbed by an off-axis merger with a sub-cluster or group. We present deep Chandra observations of the cool core cluster Abell 2029, which has a sloshing spiral extending radially outward from the center of the cluster to approximately 400 kpc at its fullest extent-the largest continuous spiral observed to date. We find a surface brightness excess, a temperature decrement, a density enhancement, an elemental abundance enhancement, and a smooth pressure profile in the area of the spiral. The sloshing gas seems to be interacting with the southern lobe of the central radio galaxy, causing it to bend and giving the radio source a wide-angle tail (WAT) morphology. This shows that WATs can be produced in clusters that are relatively relaxed on large scales. We explore the interaction between heating and cooling in the central region of the cluster. Energy injection from the active galactic nucleus is likely insufficient to offset the cooling, and sloshing may be an important additional mechanism in preventing large amounts of gas from cooling to very low temperatures.

  7. Dick receives 2011 Harry H. Hess Medal: Response

    NASA Astrophysics Data System (ADS)

    Dick, Henry J. B.

    2012-01-01

    Henry J. B. Dick was awarded the 2011 Harry H. Hess Medal at the AGU Fall Meeting Honors Ceremony, held on 7 December 2011 in San Francisco, Calif. The medal is for "outstanding achievements in research on the constitution and evolution of Earth and other planets."

  8. Maria T. Zuber Receives 2012 Harry H. Hess Medal: Citation

    NASA Astrophysics Data System (ADS)

    Solomon, Sean C.

    2013-01-01

    Maria T. Zuber was awarded the 2012 Harry H. Hess Medal at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The medal is for "outstanding achievements in research on the constitution and evolution of Earth and other planets."

  9. Dick receives 2011 Harry H. Hess Medal: Citation

    NASA Astrophysics Data System (ADS)

    Niu, Yaoling

    2012-01-01

    Henry J. B. Dick was awarded the 2011 Harry H. Hess Medal at the AGU Fall Meeting Honors Ceremony, held on 7 December 2011 in San Francisco, Calif. The medal is for "outstanding achievements in research on the constitution and evolution of Earth and other planets."

  10. A Response to Frederick Hess: An Ongoing Conversation

    ERIC Educational Resources Information Center

    Bacchetti, Ray

    2004-01-01

    In this article, the author comments on the article "An Ongoing Conversation", by Frederick Hess. The author points out that the increasing polarization of the public's views on public education serves us poorly and we need to revive the skill and will to engage in more thoughtful dialogue.

  11. Where Are Our Greenfields?: A Conversation with Frederick M. Hess

    ERIC Educational Resources Information Center

    Perkins-Gough, Deborah

    2010-01-01

    In an interview with Educational Leadership, Frederick M. Hess talks about greenfield schooling--a policy approach that attempts to knock down the formal and informal barriers that stand in the way of innovation in education. Greenfield schooling, he explains, "doesn't imagine that we should go around razing districts or schools or taking…

  12. Hesse: A Collection of Critical Essays. Twentieth Century Views Series.

    ERIC Educational Resources Information Center

    Ziolkowski, Theodore, Ed.

    One of a series of works aimed at presenting contemporary critical opinion on major authors, this collection contains essays by Thomas Mann, Andre Gide, Martin Buber, Ernst Robert Curtius, Oskar Seidlin, Hans Mayer, G. W. Field, Jeffrey Sammons, and the editor, Theodore Ziolkowski--all dealing with the biography and literary work of Hermann Hesse.…

  13. Observing Campaign for Potential Deep Impact Flyby Target 163249 (2002 GT)

    NASA Technical Reports Server (NTRS)

    Pittichova, Jana; Chesley, S. R.; Abell, P. A.; Benner, L. A. M.

    2012-01-01

    The Deep Impact spacecraft is currently on course for a Jan. 4, 2020 flyby of the sub-kilometer near-Earth asteroid 163249 (2002 GT). The re-targeting will be complete with a final small maneuver scheduled for Oct. 4, 2012. 2002 GT, which is also designated as a Potentially Hazardous Asteroid (PHA), has a well-determined orbit and is approx 800 m in diameter (H=18.3). Little more is known about the nature of this object, but in mid-2013 it will pass near the Earth, affording an exceptional opportunity for ground-based characterization. At this apparition 2002 GT will be in range of Arecibo. In addition to Doppler measurements, radar delay observations with precisions of a few microseconds are expected and have a good chance of revealing whether the system is binary or not. The asteroid will be brighter than 16th mag., which will facilitate a host of observations at a variety of wavelengths. Light curve measurements across a wide range of viewing perspectives will reveal the rotation rate and ultimately lead to strong constraints on the shape and pole orientation. Visible and infrared spectra will constrain the mineralogy, taxonomy, albedo and size. Along with the radar observations, optical astrometry will further constrain the orbit, both to facilitate terminal guidance operations and to potentially reveal nongravitational forces acting on the asteroid. Coordinating all of these observations will be a significant task and we encourage interested observers to collaborate in this effort. The 2013 apparition of 2002 GT represents a unique opportunity to characterize a potential flyby target, which will aid interpretation of the high-resolution flyby imagery and aid planning and development of the flyby imaging sequence. The knowledge gained from this flyby will be highly relevant to the human exploration program at NASA, which desires more information on the physical characteristics of sub-kilometer near-Earth asteroids.

  14. X-ray observations of dust obscured galaxies in the Chandra deep field south

    NASA Astrophysics Data System (ADS)

    Corral, A.; Georgantopoulos, I.; Comastri, A.; Ranalli, P.; Akylas, A.; Salvato, M.; Lanzuisi, G.; Vignali, C.; Koutoulidis, L.

    2016-08-01

    We present the properties of X-ray detected dust obscured galaxies (DOGs) in the Chandra deep field south. In recent years, it has been proposed that a significant percentage of the elusive Compton-thick (CT) active galactic nuclei (AGN) could be hidden among DOGs. This type of galaxy is characterized by a very high infrared (IR) to optical flux ratio (f24 μm/fR > 1000), which in the case of CT AGN could be due to the suppression of AGN emission by absorption and its subsequent re-emission in the IR. The most reliable way of confirming the CT nature of an AGN is by X-ray spectroscopy. In a previous work, we presented the properties of X-ray detected DOGs by making use of the deepest X-ray observations available at that time, the 2Ms observations of the Chandra deep fields, the Chandra deep field north (CDF-N), and the Chandra deep field south (CDF-S). In that work, we only found a moderate percentage (<50%) of CT AGN among the DOGs sample. However, we pointed out that the limited photon statistics for most of the sources in the sample did not allow us to strongly constrain this number. In this paper, we further explore the properties of the sample of DOGs in the CDF-S presented in that work by using not only a deeper 6Ms Chandra survey of the CDF-S, but also by combining these data with the 3Ms XMM-Newton survey of the CDF-S. We also take advantage of the great coverage of the CDF-S region from the UV to the far-IR to fit the spectral energy distributions (SEDs) of our sources. Out of the 14 AGN composing our sample, 9 are highly absorbed (NH > 1023 cm-2), whereas 2 look unabsorbed, and the other 3 are only moderately absorbed. Among the highly absorbed AGN, we find that only three could be considered CT AGN. In only one of these three cases, we detect a strong Fe Kα emission line; the source is already classified as a CT AGN with Chandra data in a previous work. Here we confirm its CT nature by combining Chandra and XMM-Newton data. For the other two CT

  15. Mapping the TeV PWN candidate source HESS J1857+026 down to Fermi-LAT energies with the MAGIC telescopes

    NASA Astrophysics Data System (ADS)

    Stamatescu, V.; Krause, J.; Klepser, S.; Gozzini, R.; Paneque, D.; MAGIC Collaboration

    2012-12-01

    HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H.E.S.S. close to the Galactic plane. Given its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source represents a pulsar wind nebula (PWN) candidate. The source has now also been detected and analyzed using Fermi-LAT data. HESS J1857+026 was observed by MAGIC in 2010, yielding 29 hours of good quality stereoscopic data that resulted in a highly significant detection. We present an updated energy spectrum that ranges from 100 GeV to 10 TeV, together with a detailed analysis of the source morphology, which uses skymaps for two different energy regimes. We outline the evidence for the possible PWN nature of the source based on the spectral and morphological information obtained with MAGIC together with existing multi-wavelength data.

  16. Accurate CT-MR image registration for deep brain stimulation: a multi-observer evaluation study

    NASA Astrophysics Data System (ADS)

    Rühaak, Jan; Derksen, Alexander; Heldmann, Stefan; Hallmann, Marc; Meine, Hans

    2015-03-01

    Since the first clinical interventions in the late 1980s, Deep Brain Stimulation (DBS) of the subthalamic nucleus has evolved into a very effective treatment option for patients with severe Parkinson's disease. DBS entails the implantation of an electrode that performs high frequency stimulations to a target area deep inside the brain. A very accurate placement of the electrode is a prerequisite for positive therapy outcome. The assessment of the intervention result is of central importance in DBS treatment and involves the registration of pre- and postinterventional scans. In this paper, we present an image processing pipeline for highly accurate registration of postoperative CT to preoperative MR. Our method consists of two steps: a fully automatic pre-alignment using a detection of the skull tip in the CT based on fuzzy connectedness, and an intensity-based rigid registration. The registration uses the Normalized Gradient Fields distance measure in a multilevel Gauss-Newton optimization framework and focuses on a region around the subthalamic nucleus in the MR. The accuracy of our method was extensively evaluated on 20 DBS datasets from clinical routine and compared with manual expert registrations. For each dataset, three independent registrations were available, thus allowing to relate algorithmic with expert performance. Our method achieved an average registration error of 0.95mm in the target region around the subthalamic nucleus as compared to an inter-observer variability of 1.12 mm. Together with the short registration time of about five seconds on average, our method forms a very attractive package that can be considered ready for clinical use.

  17. The Effect of Environmental Conditions on Tropical Deep Convective Systems Observed from the TRMM Satellite

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Wielicki, Bruce A.; Minnis, Patrick; Chambers, Lin H.; Xu, Kuan-Man; Hu, Yongxiang; Fan, Tai-Fang

    2005-01-01

    This study uses measurements of radiation and cloud properties taken between January and August 1998 by three Tropical Rainfall Measuring Mission (TRMM) instruments, the Clouds and the Earth's Radiant Energy System (CERES) scanner, the TRMM Microwave Imager (TMI), and the Visible and InfraRed Scanner (VIRS), to evaluate the variations of tropical deep convective systems (DCS) with sea surface temperature (SST) and precipitation. This study finds that DCS precipitation efficiency increases with SST at a rate of approx. 2%/K. Despite increasing rainfall efficiency, the cloud areal coverage rises with SST at a rate of about 7%/K in the warm tropical seas. There, the boundary layer moisture supply for deep convection and the moisture transported to the upper troposphere for cirrus-anvil cloud formation increase by approx. 6.3%/K and approx. 4.0%/K, respectively. The changes in cloud formation efficiency, along with the increased transport of moisture available for cloud formation, likely contribute to the large rate of increasing DCS areal coverage. Although no direct observations are available, the increase of cloud formation efficiency with rising SST is deduced indirectly from measurements of changes in the ratio of DCS ice water path and boundary layer water vapor amount with SST. Besides the cloud areal coverage, DCS cluster effective sizes also increase with precipitation. Furthermore, other cloud properties, such as cloud total water and ice water paths, increase with SST. These changes in DCS properties will produce a negative radiative feedback for the earth's climate system due to strong reflection of shortwave radiation by the DCS. These results significantly differ from some previous hypothesized dehydration scenarios for warmer climates, and have great potential in testing current cloud-system resolving models and convective parameterizations of general circulation models.

  18. Deep Fabry-Perot Hα observations of two Sculptor group galaxies, NGC 247 and 300

    NASA Astrophysics Data System (ADS)

    Hlavacek-Larrondo, J.; Marcelin, M.; Epinat, B.; Carignan, C.; de Denus-Baillargeon, M.-M.; Daigle, O.; Hernandez, O.

    2011-09-01

    It has been suggested that diffuse ionized gas can extend all the way to the end of the H I disc, and even beyond, such as in the case of the warped galaxyNGC 253 (Bland-Hawthorn et al.). Detecting ionized gas at these radii could carry significant implications as to the distribution of dark matter in galaxies. With the aim of detecting this gas, we carried out a deep Hα kinematical analysis of two Sculptor group galaxies, NGC 247 and 300. The Fabry-Perot data were taken at the 36-cm Marseille Telescope in La Silla, Chile, offering a large field of view. With almost 20 hours of observations for each galaxy, very faint diffuse emission is detected. Typical emission measures of 0.1 cm-6 pc are reached. For NGC 247, emission extending up to a radius comparable with that of the H I disc (r˜ 13 arcmin) is found, but no emission is seen beyond the H I disc. For NGC 300, we detect ionized gas on the entirety of our field of view (rmax˜ 14 arcmin), and find that the bright H II regions are embedded in a diffuse background. Using the deep data, extended optical rotation curves are obtained, as well as mass models. These are the most extended optical rotation curves thus far for these galaxies. We find no evidence suggesting that NGC 247 has a warped disc, and to account for our non-detection of Hα emission beyond its H I disc, as opposed to the warped galaxy NGC 253, our results favour the model in which, only through a warp, ionization by hot young stars in the central region of a galaxy can let photons escape and ionize the interstellar medium in the outer parts.

  19. D" Discontinuity Structure Beneath the North Atlantic Based on Observations from the Deep 2010 Spanish Earthquake

    NASA Astrophysics Data System (ADS)

    Yao, Y.; Whittaker, S.; Thorne, M. S.

    2014-12-01

    The D" discontinuity is typically observed as an increase in P- and S-wave velocity of 1-3% roughly 150-300 km above the CMB. The discontinuity shows strong laterally variability in spatial location and height above the CMB. Previous studies have revealed strong evidence for the existence of the discontinuity under North Central Asia, Alaska, the Arctic, Australasia, and Central America, but only a handful of observations have been made beneath the North Atlantic due to the limited numbers of deep earthquakes in Europe. We collected transverse component recordings from all available broadband stations in the USArray to examine the D" discontinuity structure under the North Atlantic using array processing techniques. We searched for earthquakes in the European region between Jan. 2005 and Jun. 2014 with moment magnitudes between 5.5 and 7.5, event depths greater than 75 km, and epicentral distances from 55° to 90°. A total of five events were found matching these criteria. We collected a total of 2077 transverse component seismograms. We inspected each trace manually and removed traces without clear S and ScS arrivals. The remaining traces were aligned and normalized to unity on the S-wave arrival and collected into 3° geographic bins. We calculated velocity seismograms (vespagrams) for each geographic bin and screened vespagrams based on signal-to-noise ratio and slowness resolution of S and ScS. Only the 616 km deep M6.3 southern Spain event of April 11th, 2010 demonstrated high enough data quality. A total of 372 transverse traces from this event were collected into 39 3° geographic bins. Clear Scd arrivals indicative of the D" discontinuity were identified on 20 out of 39 vespagrams. We calculated the height of the D" discontinuity above the CMB for each Scd observation based on the travel time difference between S and Scd. The results indicate a D" discontinuity with an average thickness of 261 km above the CMB beneath the North Atlantic between 45°-60° N

  20. Observations of near-bottom currents in Bornholm Basin, Slupsk Furrow and Gdansk Deep

    NASA Astrophysics Data System (ADS)

    Bulczak, A. I.; Rak, D.; Schmidt, B.; Beldowski, J.

    2016-06-01

    Dense bottom currents are responsible for transport of the salty inflow waters from the North Sea driving ventilation and renewal of Baltic deep waters. This study characterises dense currents in three deep locations of the Baltic Proper: Bornholm Basin (BB), Gdansk Basin (GB) and Slupsk Furrow (SF). These locations are of fundamental importance for the transport and pollution associated with chemical munitions deposited in BB and GB after 2nd World War. Of further importance the sub-basins are situated along the pathway of dense inflowing water.Current velocities were measured in the majority of the water column during regular cruises of r/v Oceania and r/v Baltica in 2001-2012 (38 cruises) by 307 kHz vessel mounted (VM), downlooking ADCP. Additionally, the high-resolution CTD and oxygen profiles were collected. Three moorings measured current velocity profiles in SF and GB over the summer 2012. In addition, temperature, salinity, oxygen and turbidity were measured at about 1 m above the bottom in GB. The results showed that mean current speed across the Baltic Proper was around 12 cm s-1 and the stronger flow was characteristic to the regions located above the sills, in the Bornholm and Slupsk Channels, reaching on average about 20 cm s-1. The results suggest that these regions are important for the inflow of saline waters into the eastern Baltic and are the areas of intense vertical mixing. The VM ADCP observations indicate that the average near-bottom flow across the basin can reach 35±6 cm s-1. The mooring observations also showed similar near-bottom flow velocities. However, they showed that the increased speed of the near-bottom layer occurred frequently in SF and GB during short time periods lasting for about few to several days or 10-20% of time. The observations showed that the bottom mixed layer occupies at least 10% of the water column and the turbulent mixing induced by near-bottom currents is likely to produce sediment resuspension and transport

  1. STAR FORMATION IN THE CHANDRA DEEP FIELD SOUTH: OBSERVATIONS CONFRONT SIMULATIONS

    SciTech Connect

    Damen, Maaike; Franx, Marijn; Foerster Schreiber, Natascha M.; Labbe, Ivo; Toft, Sune; Van Dokkum, Pieter G.; Wuyts, Stijn

    2009-11-01

    We investigate the star formation history of the universe using FIREWORKS, a multiwavelength survey of the Chandra Deep Field South. We study the evolution of the specific star formation rate (sSFR) with redshift in different mass bins from z = 0 to z approx 3. We find that the sSFR increases with redshift for all masses. The logarithmic increase of the sSFR with redshift is nearly independent of mass, but this cannot yet be verified at the lowest-mass bins at z>0.8, due to incompleteness. We convert the sSFRs to a dimensionless growth rate to facilitate a comparison with a semianalytic galaxy formation model that was implemented on the Millennium Simulation. The model predicts that the growth rates and sSFRs increase similarly with redshift for all masses, consistent with the observations. However, we find that for all masses, the inferred observed growth rates increase more rapidly with redshift than the model predictions. We discuss several possible causes for this discrepancy, ranging from field-to-field variance, conversions to SFR, and shape of the initial mass function. We find that none of these can solve the discrepancy completely. We conclude that the models need to be adapted to produce the steep increase in growth rate between redshift z = 0 and z = 1.

  2. Deep Magma Accumulation at Nyamulagira Volcano in 2011 Detected by GNSS Observations

    NASA Astrophysics Data System (ADS)

    Ji, K. H.; Stamps, D. S.; Geirsson, H.; Mashagiro, N.; Syauswa, M.; Kafudu, B.; Subira, J.; d'Oreye, N.

    2015-12-01

    The Virunga Volcanic Province of the Democratic Republic of Congo is at very high natural risk due to active volcanism. A Global Navigation Satellite System network, KivuGNet (Kivu Geodetic Network), has operated since 2009 for monitoring and research of the deformation of Nyamulagira and Nyiragongo volcanoes as well as tectonic deformation in the region. We detected an inflationary signal from the position time series observed in the network using our detection method, which is a combination of Kalman filtering and principal component analysis. The inflation occurred in October 2010 and lasted for about 6 months prior to the 2011 eruption at Nyamulagira volcano. The pre-eruptive inflationary signal is much weaker than the co-eruptive signal, but our method successfully detected the signal. The maximum horizontal and vertical displacements observed are ~14 mm and ~10 mm, respectively. A Mogi point source at a depth > 10 km can explain the displacement field suggesting a relatively deep source for the magma chamber. Continuous monitoring of the volcanic activity is essential for understanding the eruption cycle and assessing potential volcanic hazards.

  3. SMART-COMMIT Observations and Deep-Blue Retrievals of Saharan Dust Properties during NAMMA

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Hsu, N. Christina; Ji, Qiang; Jeong, Myeong-Jae

    2007-01-01

    Monsoon rainfalls sustain the livelihood of more than half of the world's population. The interaction between natural/anthropogenic aerosols, clouds, and precipitation is a critical mechanism that drives the water cycle and fresh water distribution. Analyses of the longterm trend of July-August precipitation anomaly for the last 50 years in the 20" century depict that the largest regional precipitation deficit occurs over the Sahel, where the monsoon water cycle plays an important role. Thus, it is of paramount importance to study how dust aerosols, as well as air pollution and smoke, influence monsoon variability. The NASA African Monsoon Multidisciplinary Activities (NAMMA) was conducted during the international AMMA Special Observation Period (SOP-3) of September 2006 to better comprehend the key attributes of the Saharan Air Layer (SAL) and how they evolve from the source regions to the Atlantic Ocean. The SAL occurs during the late spring through early fall and originates as a result of low-level convergence induced by heat lows over the Sahara that lifts hot, dry, dust laden air aloft into a well mixed layer that extends up to 500mb. This is crucial for understanding the impact of SAL on the key atmospheric processes that determine precipitation over West Africa and tropical cyclogenesis. Results obtained from the synergy of satellite (Deep- Blue) and surface (SMART-COMMIT) observations will be presented and discussed how the physical, optical and radiative properties of the dust in the SAL evolve from the continental to the marine environment.

  4. Breakup of temperature inversions in deep mountain valleys. Part I. Observations

    SciTech Connect

    Whiteman, C.D.

    1982-03-01

    The breakup of temperature inversions in the deep mountain valleys of western Colorado has been studied by means of tethered balloon observations of wind and temperature structure on clear weather days in different seasons. Vertical potential temperature structure profiles evolve following one of three patterns. Two of the patterns are special cases of the third pattern, in which inversions are destroyed by two continuous processes - upward growth of a convective boundary layer (CBL) into the base of the valley inversion, and descent of the inversion top. The three idealized patterns are described and 21 case studies of inversion breakup following the patterns are summarized. Inversion breakup begins at sunrise and is generally completed in 3-1/2 to 5 h, unless the valley is snow covered or the ground is wet. Warming of the inversion layer is consistent with subsidence heating. An hypothesis is offered to explain the observations, stressing the role of the sensible heat flux in causing the CBL to grow and an upslope flow to develop over the sidewalls. As mass is removed from the base of the inversion layer in the upslope flows, the inversion sinks and warms.

  5. Munitions integrity and corrosion features observed during the HUMMA deep-sea munitions disposal site investigations

    NASA Astrophysics Data System (ADS)

    Silva, Jeff A. K.; Chock, Taylor

    2016-06-01

    An evaluation of the current condition of sea-disposed military munitions observed during the 2009 Hawaii Undersea Military Munitions Assessment Project investigation is presented. The 69 km2 study area is located south of Pearl Harbor, Oahu, Hawaii, and is positioned within a former deep-sea disposal area designated as Hawaii-05 or HI-05 by the United States Department of Defense. HI-05 is known to contain both conventional and chemical munitions that were sea-disposed between 1920 and 1951. Digital images and video reconnaissance logs collected during six remotely operated vehicle and 16 human-occupied vehicle surveys were used to classify the integrity and state of corrosion of the 1842 discarded military munitions (DMM) objects encountered. Of these, 5% (or 90 individual DMM objects) were found to exhibit a mild-moderate degree of corrosion. The majority (66% or 1222 DMM objects) were observed to be significantly corroded, but visually intact on the seafloor. The remaining 29% of DMM encountered were found to be severely corroded and breached, with their contents exposed. Chemical munitions were not identified during the 2009 investigation. In general, identified munitions known to have been constructed with thicker casings were better preserved. Unusual corrosion features were also observed, including what are termed here as 'corrosion skirts' that resembled the flow and cementation of corrosion products at and away from the base of many munitions, and 'corrosion pedestal' features resembling a combination of cemented corrosion products and seafloor sediments that were observed to be supporting munitions above the surface of the seafloor. The origin of these corrosion features could not be determined due to the lack of physical samples collected. However, a microbial-mediated formation hypothesis is presented, based on visual analysis, which can serve as a testable model for future field programs.

  6. A Deep XMM-Newton Observation of the Enigmatic Microquasar 1E 1740.7-2942

    NASA Astrophysics Data System (ADS)

    Miller, Jon

    1E 1740.7-2942 is a microquasar residing in the Galactic center. It is persistently bright at X-ray energies and has been shown to power large scale bi-polar jets, thus making it an ideal source to probe the jet generation/launching mechanism in accreting black holes. Analysis of archival data hinted at the presence of a relativistically broadened iron line, providing a means to constrain the spin of the black hole in this system for the first time. In AO-10 we were awarded a 130 ks XMM-Newton category B target of oppurtunity (ToO) observation, with the aim of observing this system in the low-hard state. This observation was triggered in April 2012 and the data have been obtained, where a preliminary analysis reveals the expected broad iron line. Modeling this iron line will allow us to constrain the spin of the black hole and probe its relation to the presence of large scale jets in this system. We request a total of $63.7k funding to support the analysis of this deep XMM-Newton observation, including the primary target (1E 1740.7-2942) and the serendipitous sources in the field of view (< 60). This proposal will enhance our understanding of the interaction of the accretion flow with the black hole and the generation of astrophysical jets, thus addressing NASA strategic objectives 2.4.1: Improve understanding of the origin and destiny of the universe, and the nature of black holes, dark energy, dark matter, and gravity. and 2.4.2: Improve understanding of the many phenomena and processes associated with galaxy, stellar, and planetary system formation and evolution from the earliest epochs to today.

  7. High-contrast imaging with Spitzer: deep observations of Vega, Fomalhaut, and ɛ Eridani

    NASA Astrophysics Data System (ADS)

    Janson, Markus; Quanz, Sascha P.; Carson, Joseph C.; Thalmann, Christian; Lafrenière, David; Amara, Adam

    2015-02-01

    Stars with debris disks are intriguing targets for direct-imaging exoplanet searches, owing both to previous detections of wide planets in debris disk systems, and to commonly existing morphological features in the disks themselves that may be indicative of a planetary influence. Here we present observations of three of the most nearby young stars, which are also known to host massive debris disks: Vega, Fomalhaut, and ɛ Eri. The Spitzer Space Telescope is used at a range of orientation angles for each star to supply a deep contrast through angular differential imaging combined with high-contrast algorithms. The observations provide the opportunity to probe substantially colder bound planets (120-330 K) than is possible with any other technique or instrument. For Vega, some apparently very red candidate point sources detected in the 4.5 μm image remain to be tested for common proper motion. The images are sensitive to ~2 Mjup companions at 150 AU in this system. The observations presented here represent the first search for planets around Vega using Spitzer. The upper 4.5 μm flux limit on Fomalhaut b could be further constrained relative to previous data. In the case of ɛ Eri, planets below both the effective temperature and the mass of Jupiter could be probed from 80 AU and outward, although no such planets were found. The data sensitively probe the regions around the edges of the debris rings in the systems where planets can be expected to reside. These observations validate previous results showing that more than an order of magnitude improvement in performance in the contrast-limited regime can be acquired with respect to conventional methods by applying sophisticated high-contrast techniques to space-based telescopes, thanks to the high degree of PSF stability provided in this environment.

  8. Observing Campaign for Potential Deep Impact Flyby Target 163249 (2002 GT)

    NASA Astrophysics Data System (ADS)

    Pittichova, Jana; Chesley, S. R.; Abell, P. A.; Benner, L. A. M.

    2012-10-01

    The Deep Impact spacecraft is currently on course for a proposed 2020-Jan-4 flyby of Potentially Hazardous Asteroid 163249 (2002 GT). The re-targeting will be complete with a final small maneuver scheduled for 2012-Oct-04. 2002 GT has a well-determined orbit and absolute magnitude 18.3 ( 800m diameter). Little more is known about the nature of this object, but in late June 2013 it will pass 0.012 AU from Earth, affording an exceptional opportunity for ground-based characterization. At this apparition 2002 GT will be in range of Arecibo, which should provide radar delay observations with precisions of a few microseconds, potentially revealing whether the system is binary or not. The asteroid will reach magnitude V=16.1 and will be brighter than V=18 for over two months, facilitating a host of observations at a variety of wavelengths. Light curve measurements across a wide range of viewing perspectives will reveal the rotation rate and ultimately lead to strong constraints on the shape and pole orientation. Visible and infrared spectra will constrain the mineralogy, taxonomy, albedo and size. Radar and optical astrometry will further constrain the orbit, both to facilitate terminal guidance operations and, when combined with spacecraft flyby data, to potentially reveal nongravitational forces acting on the asteroid. Coordinating all of these observations will be a significant task and we encourage interested observers to collaborate in this effort. The 2013 apparition will be the last time 2002 GT will be brighter than magnitude 18 until after the 2020 spacecraft flyby and thus represents a unique opportunity to characterize a potential flyby target, which will aid planning and development of the flyby imaging sequence and interpretation of flyby imagery. The knowledge gained from this proposed flyby will be highly relevant to NASA’s human exploration program, which desires more information on the characteristics of sub-kilometer near-Earth asteroids.

  9. The host galaxy and Fermi-LAT counterpart of HESS J1943+213

    NASA Astrophysics Data System (ADS)

    Peter, D.; Domainko, W.; Sanchez, D. A.; van der Wel, A.; Gässler, W.

    2014-11-01

    Context. The very-high energy (VHE, E> 100 GeV) gamma-ray sky shows diverse Galactic and extragalactic source populations. For some sources the astrophysical object class could not be identified so far. Aims: The nature (Galactic or extragalactic) of the VHE gamma-ray source HESS J1943+213 is explored. We specifically investigate the proposed near-infrared counterpart 2MASS J19435624+2118233 of HESS J1943+213 and investigate the implications of a physical association. Methods: We present K-band imaging from the 3.5 m CAHA telescope of 2MASS J19435624+2118233. Furthermore, 5 years of Fermi-LAT data were analyzed to search for a high-energy (HE, 100 MeV observations revealed that the near-infrared counterpart is extended with an intrinsic half light radius of 2''-2.5''. These observations also show a smooth, centrally concentrated light profile that is typical of a galaxy, and thus point toward an extragalactic scenario for the VHE gamma-ray source, assuming that the near-infrared source is the counterpart of HESS J1943+213. A high-Sérsic index profile provides a better fit than an exponential profile, indicating that the surface brightness profile of 2MASS J19435624+2118233 follows that of a typical, massive elliptical galaxy more closely than that of a disk galaxy. With Fermi-LAT a HE counterpart is found with a power-law spectrum above 1 GeV, with a normalization of (3.0 ± 0.8stat ± 0.6sys) × 10-15 cm-2 s-1 MeV-1 at the decorrelation energy Edec = 15.1 GeV and a spectral index of Γ = 1.59 ± 0.19stat ± 0.13sys. This gamma-ray spectrum shows a rather sharp break between the HE and VHE regimes of ΔΓ = 1.47 ± 0.36. Conclusions: The infrared and HE data strongly favor an extragalactic origin of HESS J1943+213, where the infrared counterpart traces the host galaxy of an extreme blazar and where the rather sharp spectral break between the HE and VHE regime indicates attenuation on extragalactic background light. The

  10. Is the gamma-ray emission from the SNR HESS J1731-347 leptonic dominated ?

    NASA Astrophysics Data System (ADS)

    Acero, Fabio; Renaud, Matthieu; Lemoine-Goumard, Marianne; Rousseau, Romain

    2012-07-01

    HESS J1731-347 is the first supernova remnant (SNR) that has been discovered based on TeV observation. First an unassociated source discovered in the survey of the Galactic plane by the HESS experiment, it has later been identified as a new SNR (through radio and X-rays observations) and is now the 4th object in the restricted club of SNRs with a TeV shell morphology. This new SNR shares many similarities with the brightest TeV SNR RX J1713.7-3946: comparable TeV luminosities, lack of thermal X-ray emission and the remnants from a gravitational core collapse (compact objects observed at the center). Using the spectral and morphological information derived in TeV, the GeV emission of the SNR is investigated with data from the Fermi Gamma-ray Space Telescope in order to test whether the nature of the gamma-ray emission is of leptonic (as it has been found for RX J1713.7-3946) or hadronic origin.

  11. Tev Protons From Sgr A* As The Origin For The Galactic Center HESS Source

    NASA Astrophysics Data System (ADS)

    Ballantyne, David R.; Melia, F.

    2006-09-01

    Recent observations by the HESS array of Cerenkov telescopes have uncovered a point-source emitter of TeV gamma-rays, whose centroid is located within 30" of the supermassive black hole Sgr A*. A likely origin of these TeV photons is pion decay in the particle cascade initiated by a TeV proton accelerated by Sgr A* and a proton in the ambient medium. Liu et al. (2006) have shown that stochastic acceleration of protons close to the central supermassive black hole can account for the observed flux and spectral index of the HESS source. Here, we present results of an exact numerical simulation of proton transport within the central 6 pc^3 of the Galaxy, and the subsequent pion decays and gamma ray emissivity. Utilizing a self-consistent model of the gas density and distribution around Sgr A* (Rockefeller et al. 2005), we predict the location, spectrum and flux of TeV gamma-rays from Sgr A*, with an expectation that this model may be tested with future high-resolution TeV observations.

  12. Deep Galex Observations of the Coma Cluster: Source Catalog and Galaxy Counts

    NASA Technical Reports Server (NTRS)

    Hammer, D.; Hornschemeier, A. E.; Mobasher, B.; Miller, N.; Smith, R.; Arnouts, S.; Milliard, B.; Jenkins, L.

    2010-01-01

    We present a source catalog from deep 26 ks GALEX observations of the Coma cluster in the far-UV (FUV; 1530 Angstroms) and near-UV (NUV; 2310 Angstroms) wavebands. The observed field is centered 0.9 deg. (1.6 Mpc) south-west of the Coma core, and has full optical photometric coverage by SDSS and spectroscopic coverage to r-21. The catalog consists of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically-confirmed Coma member galaxies that range from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is 80% complete to NUV=23 and FUV=23.5, and has a limiting depth at NUV=24.5 and FUV=25.0 which corresponds to a star formation rate of 10(exp -3) solar mass yr(sup -1) at the distance of Coma. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as a position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g. object blends, source confusion, Eddington Bias) that influence source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is also free from source confusion over the UV magnitude range studied here: conversely, we estimate that the GALEX pipeline catalogs are confusion limited at NUV approximately 23 and FUV approximately 24. We have measured the total UV galaxy counts using our catalog and report a 50% excess of counts across FUV=22-23.5 and NUV=21.5-23 relative to previous GALEX

  13. Deep Broadband Observations of the Distant Gamma-Ray Blazar PKS 1424+240

    NASA Astrophysics Data System (ADS)

    Archambault, S.; Aune, T.; Behera, B.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Biteau, J.; Bugaev, V.; Byrum, K.; Cardenzana, J. V.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Dumm, J.; Errando, M.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortson, L.; Furniss, A.; Galante, N.; Gillanders, G. H.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Hughes, G.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Kumar, S.; Lang, M. J.; Madhavan, A. S.; Maier, G.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Otte, A. N.; Park, N.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Sembroski, G. H.; Shahinyan, K.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakely, S. P.; Weinstein, A.; Welsing, R.; Wilhelm, A.; Williams, D. A.; VERITAS Collaboration; Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bregeon, J.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Charles, E.; Chiang, J.; Ciprini, S.; Claus, R.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Grenier, I. A.; Guiriec, S.; Jogler, T.; Kuss, M.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lubrano, P.; Madejski, G. M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Piron, F.; Pivato, G.; Rainò, S.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Schaal, M.; Sgrò, C.; Siskind, E. J.; Spinelli, P.; Takahashi, H.; Tibaldo, L.; Tinivella, M.; Troja, E.; Vianello, G.; Werner, M.; Wood, M.; Fermi LAT Collaboration

    2014-04-01

    We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z >= 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 ± 0.3) × 10-7 photons m-2 s-1 above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02 ± 0.08) × 10-7 photons m-2 s-1 above 120 GeV. The measured differential very high energy (VHE; E >= 100 GeV) spectral indices are Γ = 3.8 ± 0.3, 4.3 ± 0.6 and 4.5 ± 0.2 in 2009, 2011, and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than τ = 2, where it is postulated that any variability would be small and occur on timescales longer than a year if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics.

  14. Oscillation Responses to an Extreme Weather Event from a Deep Moored Observing System

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Dimarco, S. F.; Stoessel, M. M.; Zhang, X.; Ingle, S.

    2011-12-01

    In June 2007 tropical Cyclone Gonu passed directly over an ocean observing system consisting of four, deep autonomous mooring stations along the 3000 m isobath in the northern Arabian Sea. Gonu was the largest cyclone known to have occurred in the Arabian Sea or to strike the Arabian Peninsula. The mooring system was designed by Lighthouse R & D Enterprises, Inc. and installed in cooperation with the Oman Ministry of Agriculture and Fisheries Wealth. The instruments on the moorings continuously recorded water velocities, temperature, conductivity, pressure, dissolved oxygen and turbidity at multiple depths and at hourly intervals during the storm. Near-inertial oscillations at all moorings from thermocline to seafloor are coincident with the arrival of Gonu. Sub-inertial oscillations with periods of 2-10 days are recorded at the post-storm relaxation stage of Gonu, primarily in the thermocline. These oscillations consist of warm, saline water masses, likely originating from the Persian Gulf. Prominent 12.7-day sub-inertial waves, measured at a station ~300 km offshore, are bottom-intensified and have characteristics of baroclinic, topographically-trapped waves. Theoretical results from a topographically-trapped wave model are in a good agreement with the observed 12.7-day waves. The wavelength of the 12.7-day waves is about 590 km calculated from the dispersion relationship. Further analysis suggests that a resonant standing wave is responsible for trapping the 12.7-day wave energy inside the Sea of Oman basin. The observational results reported here are the first measurements of deepwater responses to a tropical cyclone in the Sea of Oman/Arabian Sea. Our study demonstrates the utility of sustained monitoring for studying the impact of extreme weather events on the ocean.

  15. A VERY DEEP CHANDRA OBSERVATION OF A1795: THE COLD FRONT AND COOLING WAKE

    SciTech Connect

    Ehlert, Steven; McDonald, Michael; Miller, Eric D.; Bautz, Mark W.; David, Laurence P.

    2015-02-01

    We present a new analysis of very deep Chandra observations of the galaxy cluster A1795. Utilizing nearly 750 ks of net ACIS imaging, we are able to resolve the thermodynamic structure of the intracluster medium (ICM) on length scales of ∼1 kpc near the cool core. We find several previously unresolved structures, including a high pressure feature to the north of the Brightest Cluster Galaxy (BCG) that appears to arise from the bulk motion of A1795's cool core. To the south of the cool core, we find low temperature (∼3 keV), diffuse ICM gas extending for distances of ∼50 kpc spatially coincident with previously identified filaments of Hα emission. Gas at similar temperatures is also detected in adjacent regions without any Hα emission. The X-ray gas coincident with the Hα filament has been measured to be cooling spectroscopically at a rate of ∼1 M{sub ⊙} yr{sup −1}, consistent with measurements of the star formation rate in this region as inferred from ultraviolet (UV) observations, suggesting that the star formation in this filament as inferred by its Hα and UV emission can trace its origin to the rapid cooling of dense, X-ray emitting gas. The Hα filament is not a unique site of cooler ICM, however, as ICM at similar temperatures and even higher metallicities not cospatial with Hα emission is observed just to the west of the Hα filament, suggesting that it may have been uplifted by A1795's central active galaxy. Further simulations of cool core sloshing and active galactic nucleus feedback operating in concert with one another will be necessary to understand how such a dynamic cool core region may have originated and why the Hα emission is so localized with respect to the cool X-ray gas.

  16. DEEP BROADBAND OBSERVATIONS OF THE DISTANT GAMMA-RAY BLAZAR PKS 1424+240

    SciTech Connect

    Archambault, S.; Aune, T.; Behera, B.; Chen, X.; Federici, S.; Beilicke, M.; Bugaev, V.; Benbow, W.; Cerruti, M.; Berger, K.; Bird, R.; Biteau, J.; Byrum, K.; Cardenzana, J. V; Ciupik, L.; Connolly, M. P.; Cui, W.; Dumm, J.; Errando, M.; Falcone, A.; Collaboration: VERITAS Collaboration; Fermi LAT Collaboration; and others

    2014-04-10

    We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z ≥ 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 ± 0.3) × 10{sup –7} photons m{sup –2} s{sup –1} above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02 ± 0.08) × 10{sup –7} photons m{sup –2} s{sup –1} above 120 GeV. The measured differential very high energy (VHE; E ≥ 100 GeV) spectral indices are Γ = 3.8 ± 0.3, 4.3 ± 0.6 and 4.5 ± 0.2 in 2009, 2011, and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than τ = 2, where it is postulated that any variability would be small and occur on timescales longer than a year if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics.

  17. Dark matter searches with H.E.S.S.: nearby dwarf galaxies and IMBH mini-spikes

    SciTech Connect

    Moulin, E.; Vivier, M.; Brun, P.; Glicenstein, J.-F.; Peyaud, B.

    2008-12-24

    WIMP pair annihilations produce high energy gamma-rays in the final state, which can be detected by Imaging Atmospheric Cherenkov Telescopes such as the H.E.S.S. array. We focus in this contribution on searches towards dwarf galaxies and mini-spikes around intermediate mass black holes (IMBHs) in the Galactic halo. H.E.S.S. observations towards the nearby dwarf galaxies Sagittarius and Canis Major are presented. Using realistic modellings for the dark matter (DM) density profiles, constraints on the velocity-weighted annihilation cross section {sigma}v of DM particles are derived in the framework of Supersymmetric and Kaluza-Klein models. A search for DM mini-spikes around IMBHs is described as well as constraints on the particle physics parameters.

  18. HESS-II reconstruction strategy and performance in the low-energy (20-150 GeV) domain

    SciTech Connect

    Becherini, Y.; Djannati-Atai, A.; Punch, M.; Bernloehr, K.; Ehlert, S.; Masbou, J.; Moulin, E.

    2008-12-24

    In mid-2009 a notable upgrade of the H.E.S.S. telescope system will take place: a new telescope with a 600 m{sup 2} mirror area and very-high-resolution camera (0.07 deg.) will be positioned at the centre of the present configuration, with the aim of lowering the threshold and enhance its sensitivity in the 100 GeV to several TeV energy range. HESS-II will permit the investigation of the lower energy {gamma}-ray spectra in various cosmic accelerators, giving information on the origin of the {gamma}-rays observed, and will detect AGNs with a redshift greater than 0.2 (being less affected by absorption by Extragalactic Background Light--EBL--in this energy range) and will search for new classes of very high energy {gamma}-ray emitters (pulsars, microquasars, GRB, and dark matter candidates)

  19. DISK EVOLUTION IN OB ASSOCIATIONS: DEEP SPITZER/IRAC OBSERVATIONS OF IC 1795

    SciTech Connect

    Roccatagliata, Veronica; Bouwman, Jeroen; Henning, Thomas; Gennaro, Mario; Sicilia-Aguilar, Aurora; Feigelson, Eric; Kim, Jinyoung Serena; Lawson, Warrick A.

    2011-06-01

    We present a deep Spitzer/Infrared Array Camera (IRAC) survey of the OB association IC 1795 carried out to investigate the evolution of protoplanetary disks in regions of massive star formation. Combining Spitzer/IRAC data with Chandra/Advanced CCD Imaging Spectrometer observations, we find 289 cluster members. An additional 340 sources with an infrared excess, but without X-ray counterpart, are classified as cluster member candidates. Both surveys are complete down to stellar masses of about 1 M{sub sun}. We present pre-main-sequence isochrones computed for the first time in the Spitzer/IRAC colors. The age of the cluster, determined via the location of the Class III sources in the [3.6]-[4.5]/[3.6] color-magnitude diagram, is in the range of 3-5 Myr. As theoretically expected, we do not find any systematic variation in the spatial distribution of disks within 0.6 pc of either O-type star in the association. However, the disk fraction in IC 1795 does depend on the stellar mass: sources with masses >2 M{sub sun} have a disk fraction of {approx}20%, while lower mass objects (2-0.8 M{sub sun}) have a disk fraction of {approx}50%. This implies that disks around massive stars have a shorter dissipation timescale.

  20. Nonlinear Gulf Stream Interaction with the Deep Western Boundary Current System: Observations and a Numerical Simulation

    NASA Technical Reports Server (NTRS)

    Dietrich, David E.; Mehra, Avichal; Haney, Robert L.; Bowman, Malcolm J.; Tseng, Yu-Heng

    2003-01-01

    Gulf Stream (GS) separation near its observed Cape Hatteras (CH) separation location, and its ensuing path and dynamics, is a challenging ocean modeling problem. If a model GS separates much farther north than CH, then northward GS meanders, which pinch off warm core eddies (rings), are not possible or are strongly constrained by the Grand Banks shelfbreak. Cold core rings pinch off the southward GS meanders. The rings are often re-absorbed by the GS. The important warm core rings enhance heat exchange and, especially, affect the northern GS branch after GS bifurcation near the New England Seamount Chain. This northern branch gains heat by contact with the southern branch water upstream of bifurcation, and warms the Arctic Ocean and northern seas, thus playing a major role in ice dynamics, thermohaline circulation and possible global climate warming. These rings transport heat northward between the separated GS and shelf slope/Deep Western Boundary Current system (DWBC). This region has nearly level time mean isopycnals. The eddy heat transport convergence/divergence enhances the shelfbreak and GS front intensities and thus also increases watermass transformation. The fronts are maintained by warm advection by the Florida Current and cool advection by the DWBC. Thus, the GS interaction with the DWBC through the intermediate eddy field is climatologically important.

  1. Deep Brain Stimulation of the Pedunculopontine Tegmental Nucleus (PPN) Influences Visual Contrast Sensitivity in Human Observers

    PubMed Central

    Strumpf, Hendrik; Noesselt, Toemme; Schoenfeld, Mircea Ariel; Voges, Jürgen; Panther, Patricia; Kaufmann, Joern; Heinze, Hans-Jochen; Hopf, Jens-Max

    2016-01-01

    The parapontine nucleus of the thalamus (PPN) is a neuromodulatory midbrain structure with widespread connectivity to cortical and subcortical motor structures, as well as the spinal cord. The PPN also projects to the thalamus, including visual relay nuclei like the LGN and the pulvinar. Moreover, there is intense connectivity with sensory structures of the tegmentum in particular with the superior colliculus (SC). Given the existence and abundance of projections to visual sensory structures, it is likely that activity in the PPN has some modulatory influence on visual sensory selection. Here we address this possibility by measuring the visual discrimination performance (luminance contrast thresholds) in a group of patients with Parkinson’s Disease (PD) treated with deep-brain stimulation (DBS) of the PPN to control gait and postural motor deficits. In each patient we measured the luminance-contrast threshold of being able to discriminate an orientation-target (Gabor-grating) as a function of stimulation frequency (high 60Hz, low 8/10, no stimulation). Thresholds were determined using a standard staircase-protocol that is based on parameter estimation by sequential testing (PEST). We observed that under low frequency stimulation thresholds increased relative to no and high frequency stimulation in five out of six patients, suggesting that DBS of the PPN has a frequency-dependent impact on visual selection processes at a rather elementary perceptual level. PMID:27167979

  2. Deep optical observations of the γ-ray pulsar J0357+3205

    NASA Astrophysics Data System (ADS)

    Kirichenko, A.; Danilenko, A.; Shibanov, Yu.; Shternin, P.; Zharikov, S.; Zyuzin, D.

    2014-04-01

    Context. A middle-aged radio-quiet pulsar J0357+3205 was discovered in gamma rays with Fermi and later in X-rays with Chandra and XMM-Newton observatories. It produces an unusual thermally emitting pulsar wind nebula that is observed in X-rays. Aims: Deep optical observations were obtained to search for the pulsar optical counterpart and its nebula using the Gran Telescopio Canarias (GTC). Methods: The direct imaging mode in the Sloan g' band was used. Archival X-ray data were reanalysed and compared with the optical data. Results: No pulsar optical counterpart was detected down to g'≥slant 28.1m. No pulsar nebula was identified in the optical either. We confirm early results that the X-ray spectrum of the pulsar consists of a nonthermal power-law component of the pulsar magnetospheric origin dominating at high energies and a soft thermal component from the neutron star surface. Using magnetised, partially ionised hydrogen atmosphere models in X-ray spectral fits, we found that the thermal component can come from the entire surface of the cooling neutron star with a temperature of 36+8-6 eV, making it one of the coldest among cooling neutron stars known. The surface temperature agrees with the standard neutron star cooling scenario. The optical upper limit does not put any additional constraints on the thermal component, however it does imply a strong spectral break for the nonthermal component between the optical and X-rays as is observed in other middle-aged pulsars. Conclusions: The thermal emission from the entire surface of the neutron star very likely dominates the nonthermal emission in the UV range. Observations of PSR J0357+3205 in this range are promising to put more stringent constraints on its thermal properties. Based on observations made with the Gran Telescopio Canarias (GTC), instaled in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma under Programme GTC3-12BMEX

  3. A high energy Space Station (HESS) array for studying extremely energetic cosmic rays

    NASA Technical Reports Server (NTRS)

    Ormes, J. F.; Streitmatter, R. E.

    1985-01-01

    The scientific aims and design concept of a High-Energy Space Station (HESS) cosmic-ray detector array are discussed. The current state of knowledge on cosmic-ray acceleration and high-energy interactions is briefly reviewed, and the need for observations yielding elemental composition and spectra in the 10-10,000-TeV/nucleon range is demonstrated. It is predicted that 2 yr of observations with a space-borne detector of geometry factor 30 sq m sr would provide adequate data to determine the acceleration mechanism (by comparing the energy level at which the spectra of He nuclei and protons break). A modular HESS array comprising W/scintillator/PM-tube calorimeter modules and Cerenkov charge-sensitive detector modules and weighing about 30 tonnes is described. The array could be assembled on orbit after transport in the Space Shuttle cargo bay, and data could be taken as soon as one or two layers of modules had been attached to the mounting-frame/support-electronics unit.

  4. VHE gamma-ray Emitting Pulsar Wind Nebulae Discovered by H.E.S.S.

    SciTech Connect

    Gallant, Y.A.; Carrigan, S.; Djannati-Atai, A.; Funk, S.; Hinton, J.A.; Hoppe, S.; de Jager, O.C.; Khelifi, B.; Komin, Nu.; Kosack, K.; Lemiere, A. Masterson, C.; /Dublin Inst.

    2008-06-05

    Recent advances in very-high-energy (VHE) gamma-ray astronomy have opened a new observational window on the physics of pulsars. The high sensitivity of current imaging atmospheric Cherenkov telescopes, and in particular of the H.E.S.S. array, has already led to the discovery of about a dozen VHE-emitting pulsar wind nebulae (PWNe) and PWN candidates. These include the plerions in the composite supernova remnants MSH 15-52, G21.5-0.9, Kes 75, and Vela, two sources in the Kookaburra, and the nebula of PSR B1823-13. This VHE emission is generally interpreted as inverse Compton emission from the relativistic electrons and positrons accelerated by the pulsar and its wind; as such, it can yield a more direct spatial and spectral view of the accelerated particles than can be inferred from observations of their synchrotron emission. The VHE-emitting PWNe detected by the H.E.S.S. telescopes are reviewed and the implications for pulsar physics discussed.

  5. Radar observations of the asteroid's structure from deep interior to regolith

    NASA Astrophysics Data System (ADS)

    Ciarletti, Valerie; Herique, Alain

    2016-04-01

    Our knowledge of the internal structure of asteroids entirely relies on inferences from remote sensing observations of the surface and theoretical modeling. Is the body a monolithic piece of rock or a rubble-pile, how high is the porosity? What is the typical size of the constituent blocs? Are these blocs homogeneous or heterogeneous? The body is covered by a regolith whose properties remain largely unknown in term of depth, size distribution and spatial variability. Is it resulting from fine particles re-accretion or from thermal fracturing? After several asteroid orbiting missions, theses crucial and yet basic questions remain open. Direct measurements of asteroid deep interior and regolith structure are needed to better understand the asteroid accretion and dynamical evolution and to provide answers that will directly improve our ability to understand the formation and evolution of the Near Earth Asteroids (NEA), that will allow us to model the mechanisms driving NEA deflection and other risk mitigation techniques. Radars operating at distance from a spacecraft are the only instruments capable of achieving this science objective of characterizing the internal structure and heterogeneity from submetric to global scale for the benefit of science as well as for planetary defense or exploration. The AIM mission will have two complementary radars on-board, operating at different frequencies in order to meet the objectives requirements. The deep interior structure tomography requires a low-frequency radar (LFR) in order to propagate throughout the complete body (this LFR will be a direct heritage of the CONSERT radar designed for the Rosetta mission). Ihe characterization of the first ten meters of the subsurface with a metric resolution to identify layering and to reconnect surface measurements to internal structure will be achieved with a higher frequency radar(HFR), the design of which is based on the WISDOM radar developed for the ExoMars mission. Both radars are

  6. Deep Optical Observations of Unusual Neutron Star Calvera with the GTC

    NASA Astrophysics Data System (ADS)

    Shibanov, Yury; Danilenko, Andrey; Zharikov, Sergey; Shternin, Peter; Zyuzin, Dima

    2016-11-01

    Calvera is an unusual, isolated neutron star with a pure thermal X-ray spectrum typical of central compact objects in supernova remnants. On the other hand, its rotation period and spin-down rate are typical of ordinary rotation-powered pulsars. It was discovered and studied through X-rays, and has not yet been detected in other spectral domains. We present deep optical imaging of the Calvera field, obtained with the Gran Telescopio Canarias, in the g\\prime and i\\prime bands. Within the vicinity of ≈ 1\\prime\\prime of Calvera, we detected two point-like objects that were invisible at previous shallow observations. However, accurate astrometry showed that neither of them can be identified with the pulsar. We put new upper limits of g\\prime \\gt 27.87 and i\\prime \\gt 26.84 on its optical brightness. We also reanalyzed all available archival X-ray data on Calvera. Comparison of the Calvera thermal emission parameters and upper limits on optical and non-thermal X-ray emission with respective data on rotation-powered pulsars shows that Calvera might belong to the class of ordinary middle-aged pulsars, if we assume that its distance is in the range of 1.5–5 kpc. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, on the island of La Palma, program GTC1-14AMEX.

  7. Observations of deep long-period (DLP) seismic events beneath Aleutian arc volcanoes; 1989-2002

    USGS Publications Warehouse

    Power, J.A.; Stihler, S.D.; White, R.A.; Moran, S.C.

    2004-01-01

    Between October 12, 1989 and December 31, 2002, the Alaska Volcano Observatory (AVO) located 162 deep long-period (DLP) events beneath 11 volcanic centers in the Aleutian arc. These events generally occur at mid- to lower-crustal depths (10-45 km) and are characterized by emergent phases, extended codas, and a strong spectral peak between 1.0 and 3.0 Hz. Observed wave velocities and particle motions indicate that the dominant phases are P- and S-waves. DLP epicenters often extend over broad areas (5-20 km) surrounding the active volcanoes. The average reduced displacement of Aleutian DLPs is 26.5 cm2 and the largest event has a reduced displacement of 589 cm2 (or ML 2.5). Aleutian DLP events occur both as solitary events and as sequences of events with several occurring over a period of 1-30 min. Within the sequences, individual DLPs are often separated by lower-amplitude volcanic tremor with a similar spectral character. Occasionally, volcano-tectonic earthquakes that locate at similar depths are contained within the DLP sequences. At most, Aleutian volcanoes DLPs appear to loosely surround the main volcanic vent and occur as part of background seismicity. A likely explanation is that they reflect a relatively steady-state process of magma ascent over broad areas in the lower and middle portions of the crust. At Mount Spurr, DLP seismicity was initiated by the 1992 eruptions and then slowly declined until 1997. At Shishaldin Volcano, a short-lived increase in DLP seismicity occurred about 10 months prior to the April 19, 1999 eruption. These observations suggest a link between eruptive activity and magma flux in the mid- to lower-crust and uppermost mantle.

  8. A Multi-Wavelength Investigation of the Unidentified Gamma-Ray Source HESS J1708-410

    SciTech Connect

    Van Etten, Adam; Funk, Stefan; Hinton, Jim; /Leeds U.

    2009-12-16

    We report on recent XMM-Newton observations, archival radio continuum and CO data, and SED modeling of the unidentified Galactic plane source HESS J1708-410. No significant extended X-ray emission is observed, and we place an upper limit of 3.2 x 10{sup -13} erg cm{sup -2} s{sup -1} in the 2-4 keV range for the region of TeV emission. Molonglo Galactic Plane Survey data is used to place an upper limit of 0.27 Jy at 843 MHz for the source, with a 2.4 GHz limit of 0.4 Jy from the Parkes survey of the southern Galactic plane. {sup 12}CO (J 1 {yields} 0) data of this region indicates a plausible distance of 3 kpc for HESS J1708-410. SED modeling of both the H.E.S.S. detection and flux upper limits offer useful constraints on the emission mechanisms, magnetic field, injection spectrum, and ambient medium surrounding this source.

  9. Deep observation and sampling of the earth's continental crust (DOSECC): Continental scientific drilling workshop

    SciTech Connect

    Not Available

    1985-01-01

    Research summaries are presented of ongoing or proposed deep drilling programs to explore hydrothermal systems, buried astroblemes, continental crust, magma systems, mountain belt tectonics, subduction zones, and volcanoes. Separate abstracts have been prepared for individual papers. (ACR)

  10. Deep-seated gas emission induced by the earth tide: a basic observation for geochemical earthquake prediction

    SciTech Connect

    Sugisaki, R.

    1981-06-12

    Variations of the helium/argon ratio of gas bubbles in a mineral spring along a fault zone coincide with fluctuations of areal dilation induced by the earth tide. This observation suggests that deep-seated gases characterized by higher helium/argon ratios are squeezed out by stress preceding an earthquake.

  11. Deep-seated gas emission induced by the Earth tide: a basic observation for geochemical earthquake prediction.

    PubMed

    Sugisaki, R

    1981-06-12

    Variations of the helium/argon ratio of gas bubbles in a mineral spring along a fault zone coincide with fluctuations of areal dilation induced by the earth tide. This observation suggests that deep-seated gases characterized by higher heliumlargon ratios are squeezed out by stress preceding an earthquake.

  12. The deep structure of the Western Pyrenees: constraints from tomographic imaging, field and marine geological observations

    NASA Astrophysics Data System (ADS)

    Tugend, Julie; Manatschal, Gianreto; Chevrot, Sébastien; Mohn, Geoffroy

    2015-04-01

    alternative interpretation can not only explain the progressive attenuation of the velocity anomaly at depth that is observed on tomographic images, but also the occurrence of hyperthinned crust and mantle in the internal parts of the orogen. Moreover, this interpretation suggests that the final stage of collision was controlled by the former European margin acting as an indentor, illustrating the complex role of rift architecture in structuring the Pyrenean orogen. This new interpretation of the deep structure of the Western Pyrenees results in (1) different restorations of the total amount of shortening accommodated in the Pyrenean domain and (2) new insights on the evolution and architecture of Alpine-type collisional orogens.

  13. A Very Deep Chandra Observation of the Perseus Cluster: Shocks, Ripples And Conduction

    SciTech Connect

    Fabian, A.C.; Sanders, Jeremy S.; Taylor, G.B.; Allen, S.W.; Crawford, C.S.; Johnstone, R.M.; Iwasawa, K.; /Cambridge U., Inst. of Astron.

    2005-10-26

    We present the first results from a very deep Chandra X-ray observation of the core of the Perseus cluster of galaxies. A pressure map reveals a clear thick band of high pressure around the inner radio bubbles. The gas in the band must be expanding outward and the sharp front to it is identified as a shock front, yet we see no temperature jump across it; indeed there is more soft emission behind the shock than in front of it. We conclude that in this inner region either thermal conduction operates efficiently or the co-existing relativistic plasma seen as the radio mini-halo is mediating the shock. If common, isothermal shocks in cluster cores mean that we cannot diagnose the expansion speed of radio bubbles from temperature measurements alone. They can at times expand more rapidly than currently assumed without producing significant regions of hot gas. Bubbles may also be significantly more energetic. The pressure ripples found in earlier images are identified as isothermal sound waves. A simple estimate based on their amplitude confirms that they can be an effective distributed heat source able to balance radiative cooling.We see multiphase gas with about 10{sup 9}M{sub {circle_dot}} at a temperature of about 0.5 keV. Much, but not all, of this cooler gas is spatially associated with the optical filamentary nebula around the central galaxy, NGC1275. A residual cooling flow of about 50M{sub {circle_dot}} yr{sup -1} may be taking place. A channel is found in the pressure map along the path of the bubbles, with indications found of outer bubbles. The channel connects in the S with a curious cold front.

  14. Jupiter’s Deep Cloud Structure Revealed Using Keck Observations of Spectrally Resolved Line Shapes

    NASA Astrophysics Data System (ADS)

    Bjoraker, G. L.; Wong, M. H.; de Pater, I.; Ádámkovics, M.

    2015-09-01

    Technique: We present a method to determine the pressure at which significant cloud opacity is present between 2 and 6 bars on Jupiter. We use (a) the strength of a Fraunhofer absorption line in a zone to determine the ratio of reflected sunlight to thermal emission, and (b) pressure-broadened line profiles of deuterated methane (CH3D) at 4.66 μm to determine the location of clouds. We use radiative transfer models to constrain the altitude region of both the solar and thermal components of Jupiter’s 5 μm spectrum. Results: For nearly all latitudes on Jupiter the thermal component is large enough to constrain the deep cloud structure even when upper clouds are present. We find that hot spots, belts, and high latitudes have broader line profiles than do zones. Radiative transfer models show that hot spots in the North Equatorial Belt and South Equatorial Belt (SEB) typically do not have opaque clouds at pressures greater than 2 bars. The South Tropical Zone (STZ) at 32{}^\\circ S has an opaque cloud top between 4 and 5 bars. From thermochemical models this must be a water cloud. We measured the variation of the equivalent width of CH3D with latitude for comparison with Jupiter’s belt-zone structure. We also constrained the vertical profile of H2O in an SEB hot spot and in the STZ. The hot spot is very dry for P < 4.5 bars and then follows the H2O profile observed by the Galileo Probe. The STZ has a saturated H2O profile above its cloud top between 4 and 5 bars.

  15. HESS J1023-575: Non-Thermal Particle Acceleration Associated With the Young Stellar Cluster Westerlund 2

    SciTech Connect

    Reimer, O.; Hinton, J.; Hofmann, W.; Hoppe, S.; Masterson, C.; Raue, M.; /Hamburg U.

    2007-11-14

    The results from H.E.S.S. observations towards Westerlund 2 are presented. The detection of very-high-energy gamma-ray emission towards the young stellar cluster Westerlund 2 in the HII complex RCW49 by H.E.S.S. provides ample evidence that particle acceleration to extreme energies is associated with this region. A variety of possible emission scenarios is mentioned, ranging from high-energy gamma-ray production in the colliding wind zone of the massive Wolf-Rayet binary WR 20a, collective wind scenarios, diffusive shock acceleration at the boundaries of wind-blown bubbles in the stellar cluster, and outbreak phenomena from hot stellar winds into the interstellar medium. These scenarios are briefly compared to the characteristics of the associated new VHE gamma-ray source HESS J1023-575, and conclusions on the validity of the respective emission scenarios for high-energy gamma-ray production in the Westerlund 2 system are drawn.

  16. Discovery of new X-ray sources near the unidentified gamma-ray source HESS J1841-055

    NASA Astrophysics Data System (ADS)

    Nobukawa, K. K.; Nobukawa, M.; Tsuru, T. G.; Koyama, K.

    2015-06-01

    HESS J1841-055 is a diffuse unidentified gamma-ray source with the size of ∼1°.3 × 1°. No conclusive counterpart in other wavelengths has so far detected. To search for X-rays responsible for the TeV emission, the Suzaku observations were conducted, which covered a half region of the HESS source. In the soft band (0.5-2.0 keV), we discovered a diffuse emission, Suzaku J1840.2-0552, with the size of ∼10‧ . Since its spectrum was fitted by an optically thin thermal plasma model, Suzaku J1840.2-0552 is likely to be a supernova remnant. We also discovered an extended source, Suzaku J1840.2-0544, in the hard band (2.0-8.0 keV) with an emission line at 6.1 keV. From the spectral feature and large interstellar absorption, this source is likely to be a cluster of galaxies behind the Galactic plane at the red-shift of ∼0.09. The other diffuse source spatially overlaps with the SNR candidate G26.6-0.2, which shows a non-thermal dominant spectrum. Since no other candidate is found in the hard X-ray band, we infer that these largely extended sources could be possible counterparts of HESS J1841-055.

  17. A NEW TeV BINARY: THE DISCOVERY OF AN ORBITAL PERIOD IN HESS J0632+057

    SciTech Connect

    Bongiorno, S. D.; Falcone, A. D.; Stroh, M.; Holder, J.; Skilton, J. L.; Hinton, J. A.; Gehrels, N.; Grube, J. E-mail: afalcone@astro.psu.edu

    2011-08-10

    HESS J0632+057 is a variable, point-like source of very high energy (>100 GeV) gamma rays located in the Galactic plane. It is positionally coincident with a Be star, it is a variable radio and X-ray source, has a hard X-ray spectrum, and has low radio flux. These properties suggest that the object may be a member of the rare class of TeV/X-ray binary systems. The definitive confirmation of this would be the detection of a periodic orbital modulation of the flux at any wavelength. We have obtained Swift X-Ray Telescope observations of the source from MJD 54857 to 55647 (2009 January-2011 March) to test the hypothesis that HESS J0632+057 is an X-ray/TeV binary. We show that these data exhibit flux modulation with a period of 321 {+-} 5 days and we evaluate the significance of this period by calculating the null hypothesis probability, allowing for stochastic flaring. This periodicity establishes the binary nature of HESS J0632+057.

  18. Deep Imaging Observations of the Lupus 3 Cloud: Dark Cloud Revealed as Infrared Reflection Nebula

    NASA Astrophysics Data System (ADS)

    Nakajima, Yasushi; Nagata, Tetsuya; Sato, Shuji; Nagayama, Takahiro; Nagashima, Chie; Kato, Daisuke; Kurita, Mikio; Kawai, Toshihide; Tamura, Motohide; Nakaya, Hidehiko; Sugitani, Koji

    2003-03-01

    We carried out deep imaging observations of the Lupus 3 dark cloud in near-infrared J, H, and Ks bands. An area of ~8'×8' was observed, which corresponds to a projected area of ~0.4×0.4 pc at the distance of the cloud, ~150 pc. Lupus 3 showed itself as a near-infrared nebula that has a surface brightness higher than the adjacent sky at all the three wavelengths. In a JHKs color composite image (blue, green, and red are assigned to J, H, and Ks, respectively), three dark red cores are surrounded by a blue halo. The surface brightness was measured with 5 σ limiting magnitudes of J=21.6, H=21.3, and Ks=20.6 mag arcsec-2. The appearance of the nebula depends on the wavelength. In the J band, dark cores are surrounded by a brighter halo, while in the Ks band, the dark cores of the J band are bright except for the central part of two of the cores. The appearance in the H band is intermediate between those of the J and Ks bands, having dark cores surrounded by local maxima of the surface brightness and decreased surface brightness farther out. The surface brightness is J=20.6, H=19.8, and Ks=19.4 mag arcsec-2 at the maximum in each band. Photometry of the point sources was done with 10 σ limiting magnitudes of J=20.1, H=18.8, and Ks=17.7. We constructed an extinction map of the background stars, using the H-K color of 1974 sources and the standard reddening law of Rieke & Lebofsky. The maximum value for the extinction is AV=47 mag. There are three local maxima of the extinction with AV>~30 mag, which we consider to be dense cores. Their positions agree with the cores identified with the surface brightness appearance. The surface brightness and its relationship with the extinction are understood in terms of scattering of starlight by dust. The values of the maximum surface brightness can be explained by scattering of starlight by dust in the cloud if we adopt a model of grain size distribution by Weingartner & Draine.

  19. Analysing neutron star in HESS J1731-347 from thermal emission and cooling theory

    NASA Astrophysics Data System (ADS)

    Ofengeim, D. D.; Kaminker, A. D.; Klochkov, D.; Suleimanov, V.; Yakovlev, D. G.

    2015-12-01

    The central compact object in the supernova remnant HESS J1731-347 appears to be the hottest observed isolated cooling neutron star. The cooling theory of neutron stars enables one to explain observations of this star by assuming the presence of strong proton superfluidity in the stellar core and the existence of the surface heat blanketing envelope which almost fully consists of carbon. The cooling model of this star is elaborated to take proper account of the neutrino emission due to neutron-neutron collisions which is not suppressed by proton superfluidity. Using the results of spectral fits of observed thermal spectra for the distance of 3.2 kpc and the cooling theory for the neutron star of age 27 kyr, new constraints on the stellar mass and radius are obtained which are more stringent than those derived from the spectral fits alone.

  20. The sources of deep ocean infragravity waves observed in the North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Crawford, Wayne; Ballu, Valerie; Bertin, Xavier; Karpytchev, Mikhail

    2015-07-01

    Infragravity waves are long-period (25-250 s) ocean surface gravity waves generated in coastal zones through wave-wave interactions or oscillation of the breaking point. Most of the infragravity wave energy is trapped or dissipated near coastlines, but a small percentage escapes into the open oceans. The source of deep ocean infragravity waves is debated, specifically whether they come mostly from regions with strong source waves or from sites with particular morphologies/orientations. We correlate measurements of infragravity waves in the deep North Atlantic Ocean with infragravity wave generation parameters throughout the Atlantic Ocean to find the dominant sources of deep ocean infragravity wave energy in the North Atlantic Ocean. The deep ocean infragravity wave data are from a 5 year deployment of absolute pressure gauges west of the Azores islands (37°N, 35°W) and shorter data sets from seafloor tsunami gauges (DART buoys). Two main sources are identified: one off of the west coast of southern Europe and northern Africa (25°N-40°N) in northern hemisphere winter and the other off the west coast of equatorial Africa (the Gulf of Guinea) in southern hemisphere winter. These regions have relatively weak source waves and weak infragravity wave propagation paths to the main measurement site, indicating that that the site morphology/orientation dominates the creation of deep ocean infragravity waves. Both regions have also been identified as potential sources of global seismological noise, suggesting that the same mechanisms may be behind the generation of deep ocean infragravity waves and global seismological noise in the frequency band from 0.001 to 0.04 Hz.

  1. Magnetic resonance elastography to observe deep areas: comparison of external vibration systems.

    PubMed

    Suga, Mikio; Obata, Takayuki; Hirano, Masaya; Tanaka, Takashi; Ikehira, Hiroo

    2007-01-01

    MRE methods deform the sample using an external vibration system. We have been using a transverse driver, which generates shear waves at the object surface. One of the problems is that shear waves rapidly attenuate at the surface of tissue and do not propagate into the body. In this study, we compared the shear waves generated by transverse and longitudinal drivers. The longitudinal driver was found to induce shear waves deep inside a porcine liver phantom. These results suggest that the longitudinal driver will allow measurement of the shear modulus deep inside the body.

  2. An Algorithm to Generate Deep-Layer Temperatures from Microwave Satellite Observations for the Purpose of Monitoring Climate Change. Revised

    NASA Technical Reports Server (NTRS)

    Goldberg, Mitchell D.; Fleming, Henry E.

    1994-01-01

    An algorithm for generating deep-layer mean temperatures from satellite-observed microwave observations is presented. Unlike traditional temperature retrieval methods, this algorithm does not require a first guess temperature of the ambient atmosphere. By eliminating the first guess a potentially systematic source of error has been removed. The algorithm is expected to yield long-term records that are suitable for detecting small changes in climate. The atmospheric contribution to the deep-layer mean temperature is given by the averaging kernel. The algorithm computes the coefficients that will best approximate a desired averaging kernel from a linear combination of the satellite radiometer's weighting functions. The coefficients are then applied to the measurements to yield the deep-layer mean temperature. Three constraints were used in deriving the algorithm: (1) the sum of the coefficients must be one, (2) the noise of the product is minimized, and (3) the shape of the approximated averaging kernel is well-behaved. Note that a trade-off between constraints 2 and 3 is unavoidable. The algorithm can also be used to combine measurements from a future sensor (i.e., the 20-channel Advanced Microwave Sounding Unit (AMSU)) to yield the same averaging kernel as that based on an earlier sensor (i.e., the 4-channel Microwave Sounding Unit (MSU)). This will allow a time series of deep-layer mean temperatures based on MSU measurements to be continued with AMSU measurements. The AMSU is expected to replace the MSU in 1996.

  3. Search for TeV Gamma-ray Emission from GRB 100621A, an extremely bright GRB in X-rays, with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; O'Brien, P. T.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tam, P. H. T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-05-01

    The long gamma-ray burst (GRB) 100621A, at the time the brightest X-ray transient ever detected by Swift-XRT in the 0.3-10 keV range, has been observed with the H.E.S.S. imaging air Cherenkov telescope array, sensitive to gamma radiation in the very-high-energy (VHE, >100 GeV) regime. Due to its relatively small redshift of z ~ 0.5, the favourable position in the southern sky and the relatively short follow-up time (<700 s after the satellite trigger) of the H.E.S.S. observations, this GRB could be within the sensitivity reach of the H.E.S.S. instrument. The analysis of the H.E.S.S. data shows no indication of emission and yields an integral flux upper limit above ~380 GeV of 4.2 × 10-12 cm-2 s-1 (95% confidence level), assuming a simple Band function extension model. A comparison to a spectral-temporal model, normalised to the prompt flux at sub-MeV energies, constraints the existence of a temporally extended and strong additional hard power law, as has been observed in the other bright X-ray GRB 130427A. A comparison between the H.E.S.S. upper limit and the contemporaneous energy output in X-rays constrains the ratio between the X-ray and VHE gamma-ray fluxes to be greater than 0.4. This value is an important quantity for modelling the afterglow and can constrain leptonic emission scenarios, where leptons are responsible for the X-ray emission and might produce VHE gamma rays.

  4. Geochemistry and age of Shatsky, Hess, and Ojin Rise seamounts: Implications for a connection between the Shatsky and Hess Rises

    NASA Astrophysics Data System (ADS)

    Tejada, Maria Luisa G.; Geldmacher, Jörg; Hauff, Folkmar; Heaton, Daniel; Koppers, Anthony A. P.; Garbe-Schönberg, Dieter; Hoernle, Kaj; Heydolph, Ken; Sager, William W.

    2016-07-01

    Shatsky Rise in the Northwest Pacific is the best example so far of an oceanic plateau with two potential hotspot tracks emanating from it: the linear Papanin volcanic ridge and the seamounts comprising Ojin Rise. Arguably, these hotspot tracks also project toward the direction of Hess Rise, located ∼1200 km away, leading to speculations that the two plateaus are connected. Dredging was conducted on the massifs and seamounts around Shatsky Rise in an effort to understand the relationship between these plateaus and associated seamounts. Here, we present new 40Ar/39Ar ages and trace element and Nd, Pb, and Hf isotopic data for the recovered dredged rocks and new trace elements and isotopic data for a few drill core samples from Hess Rise. Chemically, the samples can be subdivided into plateau basalt-like tholeiites and trachytic to alkalic ocean-island basalt compositions, indicating at least two types of volcanic activity. Tholeiites from the northern Hess Rise (DSDP Site 464) and the trachytes from Toronto Ridge on Shatsky's TAMU massif have isotopic compositions that overlap with those of the drilled Shatsky Rise plateau basalts, suggesting that both Rises formed from the same mantle source. In contrast, trachytes from the southern Hess Rise (DSDP Site 465A) have more radiogenic Pb isotopic ratios that are shifted toward a high time-integrated U/Pb (HIMU-type mantle) composition. The compositions of the dredged seamount samples show two trends relative to Shatsky Rise data: one toward lower 143Nd/144Nd but similar 206Pb/204Pb ratios, the other toward similar 143Nd/144Nd but more radiogenic 206Pb/204Pb ratios. These trends can be attributed to lower degrees of melting either from lower mantle material during hotspot-related transition to plume tail or from less refractory shallow mantle components tapped during intermittent deformation-related volcanism induced by local tectonic extension between and after the main volcanic-edifice building episodes on Shatsky

  5. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys

    USGS Publications Warehouse

    Quattrini, Andrea; Demopoulos, Amanda

    2016-01-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013–2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494–4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities

  6. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys.

    PubMed

    Quattrini, Andrea M; Demopoulos, Amanda W J

    2016-12-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013-2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494-4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities, our

  7. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys.

    PubMed

    Quattrini, Andrea M; Demopoulos, Amanda W J

    2016-12-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013-2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494-4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities, our

  8. DETECTION OF VHE {gamma}-RAYS FROM HESS J0632+057 DURING THE 2011 FEBRUARY X-RAY OUTBURST WITH THE MAGIC TELESCOPES

    SciTech Connect

    Aleksic, J.; Blanch, O.; Alvarez, E. A.; Asensio, M.; Barrio, J. A.; Antonelli, L. A.; Bonnoli, G.; Antoranz, P.; Backes, M.; Barres de Almeida, U.; Bock, R. K.; Borla Tridon, D.; Bastieri, D.; Becerra Gonzalez, J.; Berger, K.; Bednarek, W.; Bernardini, E.; Biland, A.; Boller, A.; Bosch-Ramon, V. E-mail: pmunar@am.ub.es; and others

    2012-07-20

    The very high energy (VHE) {gamma}-ray source HESS J0632+057 has recently been confirmed to be a {gamma}-ray binary. The optical counterpart is the Be star MWC 148, and a compact object of unknown nature orbits it every {approx}321 days with a high eccentricity of {approx}0.8. We monitored HESS J0632+057 with the stereoscopic MAGIC telescopes from 2010 October to 2011 March and detected significant VHE {gamma}-ray emission during 2011 February, when the system exhibited an X-ray outburst. We find no {gamma}-ray signal in the other observation periods when the system did not show increased X-ray flux. Thus, HESS J0632+057 exhibits {gamma}-ray variability on timescales of the order of one to two months possibly linked to the X-ray outburst that takes place about 100 days after the periastron passage. Furthermore, our measurements provide for the first time the {gamma}-ray spectrum down to about 140 GeV and indicate no turnover of the spectrum at low energies. We compare the properties of HESS J0632+057 with the similar {gamma}-ray binary LS I +61 Degree-Sign 303 and discuss the possible origin of the multi-wavelength emission of the source.

  9. GOODS-Herschel: ultra-deep XMM-Newton observations reveal AGN/star-formation connection

    NASA Astrophysics Data System (ADS)

    Rovilos, E.; Comastri, A.; Gilli, R.; Georgantopoulos, I.; Ranalli, P.; Vignali, C.; Lusso, E.; Cappelluti, N.; Zamorani, G.; Elbaz, D.; Dickinson, M.; Hwang, H. S.; Charmandaris, V.; Ivison, R. J.; Merloni, A.; Daddi, E.; Carrera, F. J.; Brandt, W. N.; Mullaney, J. R.; Scott, D.; Alexander, D. M.; Del Moro, A.; Morrison, G.; Murphy, E. J.; Altieri, B.; Aussel, H.; Dannerbauer, H.; Kartaltepe, J.; Leiton, R.; Magdis, G.; Magnelli, B.; Popesso, P.; Valtchanov, I.

    2012-10-01

    Models of galaxy evolution assume some connection between the AGN and star formation activity in galaxies. We use the multi-wavelength information of the CDFS to assess this issue. We select the AGNs from the 3 Ms XMM-Newton survey and measure the star-formation rates of their hosts using data that probe rest-frame wavelengths longward of 20 μm, predominantly from deep 100 μm and 160 μm Herschel observations, but also from Spitzer-MIPS-70 μm. Star-formation rates are obtained from spectral energy distribution fits, identifying and subtracting an AGN component. Our sample consists of sources in the z ≈ 0.5-4 redshift range, with star-formation rates SFR ≈ 101-103 M⊙ yr-1 and stellar masses M⋆ ≈ 1010-1011.5 M⊙. We divide the star-formation rates by the stellar masses of the hosts to derive specific star-formation rates (sSFR) and find evidence for a positive correlation between the AGN activity (proxied by the X-ray luminosity) and the sSFR for themost active systems with X-ray luminosities exceeding Lx ≃ 1043 erg s-1 and redshifts z ≳ 1. We do not find evidence for such a correlation for lower luminosity systems or those at lower redshifts, consistent with previous studies. We do not find any correlation between the SFR (or the sSFR) and the X-ray absorption derived from high-quality XMM-Newton spectra either, showing that the absorption is likely to be linked to the nuclear region rather than the host, while the star-formation is not nuclear. Comparing the sSFR of the hosts to the characteristic sSFR of star-forming galaxies at the same redshift (the so-called "main sequence") we find that the AGNs reside mostly in main-sequence and starburst hosts, reflecting the AGN-sSFR connection; however the infrared selection might bias this result. Limiting our analysis to the highest X-ray luminosity AGNs (X-ray QSOs with Lx > 1044 erg s-1), we find that the highest-redshift QSOs (with z ≳ 2) reside predominantly in starburst hosts, with an average s

  10. Perturbative QCD effects observed in 490 GeV deep-inelastic muon scattering

    SciTech Connect

    Adams, M.R.; Aied, S.; Anthony, P.L.; Baker, M.D.; Bartlett, J.; Bhatti, A.A.; Braun, H.M.; Busza, W.; Conrad, J.M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S.K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Figiel, J.; Gebauer, H.J.; Geesaman, D.F.; Gilman, R.; Green, M.C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V.W.; Jackson, H.E.; Jaffe, D.E.; Jancso, G.; Jansen, D.M.; Kaufman, S.; Kennedy, R.D.; Kirk, T.; Kobrak, H.G.E.; Krzywdzinski, S.; Kunori, S.; Lord, J.J.; Lubatti, H.J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D.G.; Mohr, W.; Montgomery, H.E.; Morfin, J.G.; Nickerson, R.B.; O'Day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F.M.; Ramberg, E.J.; Roeser, A.; Ryan, J.J.; Salgado, C.W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schueler, K.P.; Skuja, A.; Snow, G.A.; Soeldner-Rembold, S.; Steinberg, P.H.; Stier, H.E.; Stopa, P.; Swanso

    1993-12-01

    Results on forward charged hadrons in 490 GeV deep-inelastic muon scattering are presented. The transverse momenta, azimuthal asymmetry, and energy flow of events with four or more forward charged hadrons are studied. The range of the invariant hadronic mass squared 300[lt][ital W][sup 2][lt]900 GeV[sup 2]/[ital c][sup 4] extends higher than previous deep-inelastic muon scattering experiments. Data are compared to the predictions of the Lund Monte Carlo model with perturbative QCD simulated by matrix elements, parton showers, and color dipole radiation. All of the QCD-based models are consistent with the data while a model without QCD processes is not. Correlations with the multiplicity-independent event variable [Pi][congruent][summation][vert bar][ital p][sub [ital T

  11. Discovery of a variable X-ray counterpart to HESS J1832-093: a new gamma-ray binary?

    NASA Astrophysics Data System (ADS)

    Eger, P.; Laffon, H.; Bordas, P.; de Oña Whilhelmi, E.; Hinton, J.; Pühlhofer, G.

    2016-04-01

    The TeV gamma-ray point source HESS J1832-093 remains unidentified despite extensive multiwavelength studies. The gamma-ray emission could originate in a very compact pulsar wind nebula or an X-ray binary system composed of the X-ray source XMMU J183245-0921539, and a companion star (2MASS J18324516-0921545). To unveil the nature of XMMU J183245-0921539 and its relation to HESS J1832-093, we performed deeper follow-up observations in X-rays with Chandra and Swift to improve source localization and to investigate time variability. We observed an increase of the X-ray flux by a factor of ˜6 in the Chandra data compared to previous observations. The source is point-like for Chandra and its updated position is only 0.3 arcsec offset from 2MASS J18324516-0921545, confirming the association with this infrared source. Subsequent Swift target of opportunity observations resulted in a lower flux, again compatible with the one previously measured with XMM-Newton, indicating a variability time-scale of the order of two months or shorter. The now-established association of XMMU J183245-0921539 and 2MASS J18324516-0921545, and the observed variability in X-rays are strong evidence for binary nature of HESS J1832-093. Furthermore, observations to characterize the optical counterpart as well as to search for orbital periodicity are needed to confirm this scenario.

  12. Very deep spectroscopy of the bright Saturn nebula NGC 7009 - I. Observations and plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Fang, X.; Liu, X.-W.

    2011-07-01

    We present very deep CCD spectrum of the bright, medium-excitation planetary nebula NGC 7009, with a wavelength coverage from 3040 to 11 000 Å. Traditional emission line identification is carried out to identify all the emission features in the spectra, based on the available laboratory atomic transition data. Since the spectra are of medium resolution, we use multi-Gaussian line profile fitting to deblend faint blended lines, most of which are optical recombination lines (ORLs) emitted by singly ionized ions of abundant second-row elements such as C, N, O and Ne. Computer-aided emission-line identification, using the code EMILI developed by Sharpee et al., is then employed to further identify all the emission lines thus obtained. In total about 1200 emission features are identified, with the faintest ones down to fluxes 10-4 of Hβ. The flux errors for all emission lines, estimated from multi-Gaussian fitting, are presented. Plots of the whole optical spectrum, with identified emission lines labelled, are presented along with the results of multi-Gaussian fits. Of all the properly identified emission lines, permitted lines contribute 81 per cent to the total line number. More than 200 O II permitted lines are presented, as well as many others from N II and Ne II. Due to its relatively simple atomic structure, C II presents few lines. Within the flux range 10-2-10-4 Hβ where most permitted lines of C II, N II, O II and Ne II fall, the average flux measurement uncertainties are about 10-20 per cent. Comparison is also made of the number of emission lines identified in the current work of NGC 7009 and those of several other planetary nebulae (PNe) that have been extensively studied in the recent literature, and it shows that our line-deblending procedure increases the total line number significantly, especially for emission lines with fluxes lower than 10-3 of Hβ. Higher resolution is still needed to obtain more reliable fluxes for those extremely faint emission

  13. Technology, Utopia and Scholarly Life: Ideals and Realities in the Work of Hermann Hesse

    ERIC Educational Resources Information Center

    Roberts, Peter

    2009-01-01

    This article considers the relationship between technology, utopia and scholarly life in Hermann Hesse's novel, "The Glass Bead Game." In the first part of Hesse's book, the Glass Bead Game and the society of which it is a part, Castalia, are portrayed in idealistic terms. The second part of the novel chronicles the educational life of Joseph…

  14. Education, Death and Awakening: Hesse, Freire and the Process of Transformation

    ERIC Educational Resources Information Center

    Roberts, Peter

    2009-01-01

    Education is a key theme in a number of Hermann Hesse's novels and short stories. This paper focuses on Hesse's last and longest fictional work, "The Glass Bead Game", and analyses the transformation of Joseph Knecht, the central character, in the light of Paulo Freire's theory of education. It is argued that over time Knecht develops a critical…

  15. Life, Death and Transformation: Education and Incompleteness in Hermann Hesse's "The Glass Bead Game"

    ERIC Educational Resources Information Center

    Roberts, Peter

    2008-01-01

    At the end of the main part of Hermann Hesse's classic novel, "The Glass Bead Game," the central character, Joseph Knecht, dies suddenly. In this article, I consider the educational significance of Hesse's portrayal of Knecht's death. This pivotal moment in the book tells readers much about the process of educational transformation. I argue that…

  16. Maria T. Zuber Receives 2012 Harry H. Hess Medal: Response

    NASA Astrophysics Data System (ADS)

    Zuber, Maria T.

    2013-01-01

    Thank you, Sean, and other colleagues who took the time to nominate me for this extraordinary honor. It is deeply meaningful to be recognized by the AGU, the primary scientific society in which I've participated throughout my career. The ever-expanding reach of AGU provides an outlet for our research much beyond our immediate field, important because, as I tell my students: "It doesn't matter how good your work is if no one knows about it." Viewing the list of distinguished past Hess recipients, many of whom have influenced me greatly, it is impossible to overstate how humbled I am.

  17. INTEGRAL IGR J18135-1751 = HESS J1813-178: A New Cosmic High-Energy Accelerator from keV to TeV Energies

    NASA Astrophysics Data System (ADS)

    Ubertini, P.; Bassani, L.; Malizia, A.; Bazzano, A.; Bird, A. J.; Dean, A. J.; De Rosa, A.; Lebrun, F.; Moran, L.; Renaud, M.; Stephen, J. B.; Terrier, R.; Walter, R.

    2005-08-01

    We report the discovery of a soft gamma-ray source, namely, IGR J18135-1751, detected with IBIS, the Imager on Board the INTEGRAL Satellite. The source is persistent and has a 20-100 keV luminosity of ~5.7× 1034 ergs s-1 (assuming a distance of 4 kpc). This source is coincident with one of the eight unidentified objects recently reported by the HESS collaboration as part of the first TeV survey of the inner part of the Galaxy. Two of these new sources found along the Galactic plane, HESS J1813-178 and HESS J1614-518, have no obvious lower energy counterparts, a fact that motivated the suggestion that they might be dark cosmic ray accelerators. HESS J1813-178 has a strongly absorbed X-ray counterpart, the ASCA source AGPS 273.4-17.8, showing a power-law spectrum with photon index ~1.8 and a total (Galactic plus intrinsic) absorption corresponding to NH~5×1022 cm-2. We hypothesize that the source is a pulsar wind nebula embedded in its supernova remnant. The lack of X-ray or gamma-ray variability, the radio morphology, and the ASCA spectrum are all compatible with this interpretation. In any case we rule out the hypothesis that HESS J1813-178 belongs to a new class of TeV objects or that it is a cosmic ``dark particle'' accelerator. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), the Czech Republic, and Poland and with the participation of Russia and the US.

  18. Comparative studies on pheno- and genotypic properties of Staphylococcus aureus isolated from bovine subclinical mastitis in central Java in Indonesia and Hesse in Germany.

    PubMed

    Salasia, Siti Isrina Oktavia; Khusnan, Zaini; Lammler, Christoph; Zschock, Michael

    2004-06-01

    In the present study, 35 Staphylococcal strain isolated from milk samples of 16 cows from eight farms of three different geographic locations in Central Java, Indonesia, and from milk samples of 19 cows from 19 farms of different geographic locations in Hesse, Germany, were compared pheno- and genotypically. On the basis of cultural and biochemical properties as well as by amplification of the 23S rRNA specific to Staphylococcus aureus, all isolates could be identified as S. aureus. In addition, all S. aureus isolates harboured the genes clfA and coa encoding staphylococcal clumping factor and coagulase, and the gene segments encoding the immunoglobulin G binding region and the X-region of protein A gene spa. By PCR amplification, the genes seb, seg, seh, and sei was observed for the S. aureus cultures isolated in Central Java, Indonesia and the genes sec, sed, seg, seh, sei, sej and tst for the S. aureus cultures isolated in Hesse, Germany. None of the S. aureus of both origins harboured the genes sea, see, eta and etb. All isolates were additionally positive for the genes nuc, fnbA, hla, and set1. The gene hlb was found for 6 cultures from Central Java, Indonesia and 16 cultures from Hesse, Germany. However, the gene fnbB and the gene segments cnaA and cnaB were not present among the strains isolated in Central Java, Indonesia and rare among the strains isolated in Hesse, Germany. It was of interest that most of the S. aureus isolated in Central Java, Indonesia harboured the gene cap5 and most of the strains isolated in Hesse, Germany the gene cap8. The phenotypic and genotypic results of the present study might help to understand the distribution of prevalent S. aureus clones among bovine mastitis isolates of both countries and might help to control S. aureus infections in dairy herds.

  19. Deep nightside photoelectron observations by MAVEN SWEA: Implications for Martian northern hemispheric magnetic topology and nightside ionosphere source

    NASA Astrophysics Data System (ADS)

    Xu, Shaosui; Mitchell, David; Liemohn, Michael; Dong, Chuanfei; Bougher, Stephen; Fillingim, Matthew; Lillis, Robert; McFadden, James; Mazelle, Christian; Connerney, Jack; Jakosky, Bruce

    2016-09-01

    The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission samples the Mars ionosphere down to altitudes of ˜150 km over a wide range of local times and solar zenith angles. On 5 January 2015 (Orbit 520) when the spacecraft was in darkness at high northern latitudes (solar zenith angle, SZA >120° latitude >60°), the Solar Wind Electron Analyzer (SWEA) instrument observed photoelectrons at altitudes below 200 km. Such observations imply the presence of closed crustal magnetic field loops that cross the terminator and extend thousands of kilometers to the deep nightside. This occurs over the weak northern crustal magnetic source regions, where the magnetic field has been thought to be dominated by draped interplanetary magnetic fields (IMF). Such a day-night magnetic connectivity also provides a source of plasma and energy to the deep nightside. Simulations with the SuperThermal Electron Transport (STET) model show that photoelectron fluxes measured by SWEA precipitating onto the nightside atmosphere provide a source of ionization that can account for the O2+ density measured by the Suprathermal and Thermal Ion Composition (STATIC) instrument below 200 km. This finding indicates another channel for Martian energy redistribution to the deep nightside and consequently localized ionosphere patches and potentially aurora.

  20. Radiocarbon in the Weddell Sea as observed in a deep-sea coral and in krill

    SciTech Connect

    Michel, R.L.; Druffel, E.M.

    1983-03-01

    Radiocarbon mesurements were performed on krill and coral samples collected from the Weddell Sea during IWSOE '80. These are the first radiocarbon measurements available from this area since 1973. These data reveal carbon-14 levels for Weddell surface water and southern Weddell Shelf water. These data indicate that the radiocarbon levels in surface waters in 1980 were the same or slightly lower than those present in 1973. In addition, an unusually low ..delta../sup 14/C value for shelf water (from coral) at 500 m is evidence that Warm Deep Water (WDW) may penetrate much further and more frequently onto the shelf region than had previously been expected.

  1. Deep observation and sampling of the earth's continental crust (DOSECC). Final report

    SciTech Connect

    Not Available

    1985-05-01

    The need to validate and refine concepts regarding the structure, properties, and dynamic processes of the earth's continental crust through the use of the drill was the subject of the workshop sponsored by DOSECC, Inc. and held April 29 through May 1, 1985 in Houston, Texas and attended by more than 145 scientists. Scientific objectives and targets for a program of research drilling as part of basic studies of the continental lithosphere were discussed, with over 30 scientific proposals presented. Individual drilling proposals were grouped under several themes; basement structures and deep continental basins, active fault zones, thermal regimes and fossil mineralized hydrothermal/magma systems.

  2. Sustained observations in the Weddell Sea spanning more than 20 years show gradual increase of the deep water heat content

    NASA Astrophysics Data System (ADS)

    Strass, Volker; Rohardt, Gerd; Hoppema, Mario

    2014-05-01

    Beginning in 1989, Eberhard Fahrbach established and maintained until his premature death an observational programme in the Weddell Sea, which outstandingly contributed to alleviate the grave problem of undersampling of the Southern Ocean. Continuation of his legacy by the Alfred-Wegener-Institut has yielded a time series that now extends into 2013, hence covers almost 24 years. Here we analyse this data set for long-term changes of the heat content in the deep Weddell Sea. We exclusively evaluate the calibrated temperature records obtained with ship-lowered CTD (conductivity-temperature-depth sonde) casts at repeated hydrographic stations and along repeated sections. Using this approach we avoid introducing potential temperature offsets that can result from combination of different measurement technologies and potential biases resultant from differences in geographic positions. Our results show that the deep water masses below 700 m gradually warmed over the past two decades by 0.001 - 0.004 K a-1. Superimposed inter-annual to multi-annual variations appear as largely uncorrelated horizontally across the Weddell Gyre. The long-term (21 - 24 years) trends of increasing temperatures in different depth layers below 700 m at all stations and sections can be approximated by linear regression that explains between 27 and 91 % of the variance, where the coefficients of correlation tend to increase with depth. No significant trends are found in the top 700 m. The heating rate of the water masses below 700 m is estimated to 0.79 ± 0.14 W m-2, which is more than twice as high as determined for the global deep ocean in general. Our results hence corroborate the view that Southern Ocean processes make an above-average contribution to the deep ocean warming, and so add to bring global estimates of the deep ocean heating rate and of the net energy flux into the Earth's climate system at the top of the atmosphere of 0.5 - 1 W m-2 closer in line with each other. Thus they help

  3. Two radars for AIM mission: A direct observation of the asteroid's structure from deep interior to regolith

    NASA Astrophysics Data System (ADS)

    Herique, A.; Ciarletti, V.

    2015-10-01

    Our knowledge of the internal structure of asteroids is, so far, indirect - relying entirely on inferences from remote sensing observations of the surface, and theoretical modeling. What are the bulk properties of the regolith and deep interior? And what are the physical processes that shape their internal structures? Direct measurements are needed to provide answers that will directly improve our ability to understand and model the mechanisms driving Near Earth Asteroids (NEA) for the benefit of science as well as for planetary defense or exploration. Radar tomography is the only technique to characterize internal structure from decimetric scale to global scale. This paper reviews the benefits of direct measurement of the asteroid interior. Then the radar concepts for both deep interior and shallow subsurface are presented and the radar payload proposed for the AIDA/AIM mission is outlined.

  4. Cryogenically cooled low-noise amplifier for radio-astronomical observations and centimeter-wave deep-space communications systems

    NASA Astrophysics Data System (ADS)

    Vdovin, V. F.; Grachev, V. G.; Dryagin, S. Yu.; Eliseev, A. I.; Kamaletdinov, R. K.; Korotaev, D. V.; Lesnov, I. V.; Mansfeld, M. A.; Pevzner, E. L.; Perminov, V. G.; Pilipenko, A. M.; Sapozhnikov, B. D.; Saurin, V. P.

    2016-01-01

    We report a design solution for a highly reliable, low-noise and extremely efficient cryogenically cooled transmit/receive unit for a large antenna system meant for radio-astronomical observations and deep-space communications in the X band. We describe our design solution and the results of a series of laboratory and antenna tests carried out in order to investigate the properties of the cryogenically cooled low-noise amplifier developed. The transmit/receive unit designed for deep-space communications (Mars missions, radio observatories located at Lagrangian point L2, etc.) was used in practice for communication with live satellites including "Radioastron" observatory, which moves in a highly elliptical orbit.

  5. Argo float observations of basin-scale deep convection in the Irminger sea during winter 2011-2012

    NASA Astrophysics Data System (ADS)

    Piron, Anne; Thierry, Virginie; Mercier, Herlé; Caniaux, Guy

    2016-03-01

    Analysis of Argo data obtained during winter 2011-2012 revealed the presence over the Irminger Basin of an exceptionally large number of profiles (41) with mixed layer depths (MLD) exceeding 700 m, which was deep enough to reach the pool of the intermediate Labrador Sea Water located in the Irminger Sea. Four of these profiles exhibited an MLD of 1000 m, which was the maximum value observed for the winter in question. The Argo sampling in the Irminger Sea during that winter, which was 3-4 times greater than for the preceding winters, enabled the different phases of the mixed layer deepening down to 1000 m, together with their spatial extents, to be observed for the first time. Two intense convective periods occurred: in late January south of Cape Farewell and in late February-early March east of Greenland. A final deepening period was observed in mid-March, during which the deepest mixed layers were observed. This long deepening period occurred in large regional areas and was followed by a rapid restratification phase. The temporal evolution of oxygen profiles from one Argo float testifies to the local and rapid ventilation of the mixed layer by the deep convection. A mixed layer heat budget along the trajectories of the 4 floats that sampled the deepest mixed layers showed that heat loss at the air-sea interface was mainly responsible for heat content variations in the mixed layer. Greenland Tip Jets were of primary importance for the development of deep convection in the Irminger Sea in the winter of 2011-2012. They enhanced the winter heat loss and two long (more than 24 h), intense late events close together in time pushed the mixed layer deepening down to 1000 m. Net air-sea fluxes, the number of Greenland Tip Jets, the stratification of the water column, the NAO index and the Ekman-induced heat flux are pertinent indicators to assess conditions that are favorable for the development of deep convection in the Irminger Sea. By considering each of those

  6. Perturbative QCD effects observed in 490 GeV deep-inelastic muon scattering

    NASA Astrophysics Data System (ADS)

    Adams, M. R.; Aïd, S.; Anthony, P. L.; Baker, M. D.; Bartlett, J.; Bhatti, A. A.; Braun, H. M.; Busza, W.; Conrad, J. M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S. K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Figiel, J.; Gebauer, H. J.; Geesaman, D. F.; Gilman, R.; Green, M. C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V. W.; Jackson, H. E.; Jaffe, D. E.; Jancso, G.; Jansen, D. M.; Kaufman, S.; Kennedy, R. D.; Kirk, T.; Kobrak, H. G.; Krzywdzinski, S.; Kunori, S.; Lord, J. J.; Lubatti, H. J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D. G.; Mohr, W.; Montgomery, H. E.; Morfin, J. G.; Nickerson, R. B.; O'day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F. M.; Ramberg, E. J.; Röser, A.; Ryan, J. J.; Salgado, C. W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schüler, K. P.; Skuja, A.; Snow, G. A.; Söldner-Rembold, S.; Steinberg, P. H.; Stier, H. E.; Stopa, P.; Swanson, R. A.; Talaga, R.; Tentindo-Repond, S.; Trost, H.-J.; Venkataramania, H.; Wilhelm, M.; Wilkes, J.; Wilson, Richard; Wittek, W.; Wolbers, S. A.; Zhao, T.

    1993-12-01

    Results on forward charged hadrons in 490 GeV deep-inelastic muon scattering are presented. The transverse momenta, azimuthal asymmetry, and energy flow of events with four or more forward charged hadrons are studied. The range of the invariant hadronic mass squared 300deep-inelastic muon scattering experiments. Data are compared to the predictions of the Lund Monte Carlo model with perturbative QCD simulated by matrix elements, parton showers, and color dipole radiation. All of the QCD-based models are consistent with the data while a model without QCD processes is not. Correlations with the multiplicity-independent event variable Π~=J||pT|| are studied. The relationship between the azimuthal asymmetry and transverse momentum of forward hadrons is also presented. The data are most consistent with intrinsic parton transverse momentum squared k2T of 0.25 GeV2/c2.

  7. Atmospheric sensing for the H.E.S.S. array

    SciTech Connect

    Aye, K.-M.; Brown, A.M.; Chadwick, P.M.; Hadjichristidis, C.; Latham, I.J.; Le Gallou, R.; McComb, T.J.L.; Nolan, S.J.; Noutsos, A.; Orford, K.J.; Osborne, J.L.; Rayner, S.M.

    2005-02-21

    Several atmospheric monitoring instruments have been installed at the H.E.S.S. gamma-ray observatory in Namibia. Firstly, Heitronics KT19 infrared radiometers, aligned paraxially with the H.E.S.S. telescopes, measure the infrared radiation of the water molecules. These allow us to detect clouds crossing the telescopes' field of view and to estimate the humidity present in the atmosphere. For a general estimate of the atmosphere's transmittance, i.e. the detection of any light-attenuating aerosols, a ceilometer, which is a LIDAR with built-in atmospheric data reduction code, is being used. It will be complemented soon by an instrument which will measure the transmissivity of the atmosphere at different wavelengths up to 500m above the ground. The overall status of the weather is monitored by a fully automated weatherstation. This paper describes the setup, the data analysis and how this will be used in order to improve the knowledge of the telescopes' effective collection area.

  8. Galaxy Populations and Evolution in Clusters IV Deep H 1 Observations of Dwarf Elliptical Galaxies in the Virgo Cluster

    NASA Technical Reports Server (NTRS)

    Conselice, Christopher J.; ONeil, Karen; Gallagher, John S.; Wyse, Rosemary F. G.

    2003-01-01

    In this paper we present deep Arecibo H I and WIYN optical observations of Virgo Cluster dwarf elliptical galaxies. Based on this data we argue that a significant fraction of low-mass galaxies in the Virgo Cluster recently underwent evolution. Our new observations consist of H I 21 cm line observations for 22 classified dE galaxies with optical radial velocities consistent with membership in the Virgo Cluster. Cluster members VCC 390 and VCC 1713 are detected with H 1 masses M H1= 6 x 10 sup 7 and 8 x 10 sup 7 M , respectively, while MH I values in the remaining 20 dE galaxies have upper limits as low as about 5 x 1O sup 5 M. We combine our results with those for 26 other Virgo Cluster dE galaxies with H 1 observations in the literature, seven of which have H I detection claims.

  9. Stirring by deep cyclones and the evolution of Denmark strait overflow water observed at line W

    NASA Astrophysics Data System (ADS)

    Andres, M.; Toole, J. M.; Torres, D. J.; Smethie, W. M.; Joyce, T. M.; Curry, R. G.

    2016-03-01

    Shipboard velocity and water property data from 18 transects across the North Atlantic Deep Western Boundary Current (DWBC) near 40 °N are examined to study the evolution of the Denmark Strait Overflow Water (DSOW) component of the DWBC and mixing between DSOW and the interior. The examined transects along Line W - which stretches from the continental shelf south of New England to Bermuda - were made between 1994 and 2014. The shipboard data comprise measurements at regular stations of velocity from lowered acoustic Doppler current profilers, CTD profiles and trace gas chlorofluorocarbon (CFC) concentrations from bottle samples at discrete depths. Comparison of the Line W velocity sections with concurrent sea surface height maps from satellite altimetry indicates that large cyclones in the deep ocean accompany intermittent quasi-stationary meander troughs in the Gulf Stream path at Line W. A composite of 5 velocity sections along Line W suggests that a typical cyclone reaches swirl speeds of greater than 30 cm s-1 at 3400-m depth and has a radius (distance between the center and the maximum velocity) of 75 km. Tracer data suggest that these cyclones affect not only the deep velocity structure along Line W, but also provide a mechanism for water exchange between the DWBC's DSOW and the interior. Vigorous exchange is corroborated by a mismatch in the CFC-11:CFC-12 and CFC-113:CFC-12 ratio ages calculated for DSOW at Line W. During the most recent 5-year period (2010-2014), a decrease in DSOW density has been driven by warming (increasing by almost 0.1 °C) as salinity has increased only slightly (by 0.003, which is close to the 0.002 uncertainty of the measurements). The abyssal ocean offshore of the DWBC and Gulf Stream and deeper than 3000-m depth has freshened at a rate of 6×10-4 yr-1 since at least 2003. Density here remains nearly unchanged over this period, due to temperature compensation, though a linear cooling trend in the abyssal ocean (to compensate the

  10. ULTRA DEEP AKARI OBSERVATIONS OF ABELL 2218: RESOLVING THE 15 {mu}m EXTRAGALACTIC BACKGROUND LIGHT

    SciTech Connect

    Hopwood, R.; Serjeant, S.; Negrello, M.; Pearson, C.; Egami, E.; Im, M.; Ko, J.; Lee, H. M.; Lee, M. G.; Kneib, J.-P.; Matsuhara, H.; Nakagawa, T.; Takagi, T.; Smail, I.

    2010-06-10

    We present extragalactic number counts and a lower limit estimate for the cosmic infrared background (CIRB) at 15 {mu}m from AKARI ultra deep mapping of the gravitational lensing cluster Abell 2218. These data are the deepest taken by any facility at this wavelength and uniquely sample the normal galaxy population. We have de-blended our sources, to resolve photometric confusion, and de-lensed our photometry to probe beyond AKARI's blank-field sensitivity. We estimate a de-blended 5{sigma} sensitivity of 28.7 {mu}Jy. The resulting 15 {mu}m galaxy number counts are a factor of 3 fainter than previous results, extending to a depth of {approx} 0.01 mJy and providing a stronger lower limit constraint on the CIRB at 15 {mu}m of 1.9 {+-} 0.5 nW m{sup -2} sr{sup -1}.

  11. Photographic observations of the life style of a deep-sea ophiuroid Asteronyx loveni (Echinodermata)

    NASA Astrophysics Data System (ADS)

    Fujita, Toshihiko; Ohta, Suguru

    1988-12-01

    The life style of a deep-sea ophiuroid, Asteronyx loveni was studied from underwater photographs (7 stations) and trawled samples (11 stations) between about 800 and 1700 m along the Pacific coast of Japan and in the Flores Sea, Indonesia. This ophiuroid typically clings to gorgonians ( Radicipes spp.) and pennatulids ( Funiculina quadrangularis and Anthoptilum sp.). The stomach contents of A. loveni included fragments of crustaceans, polychaete setae, sediment particles and flocculent material, but no tissues of the host coelenterates. Bottom photographs show the ophiuroids extending several arms into the water column presumably for suspension feeding. There was rarely more than one ophiuroid per coelenterate host, perhaps due to intraspecific competition for perch sites. Stereoscopic analysis of photographs revealed that most of the ophiuroids perched 20-35 cm above the sea floor. This may be the most effective height for feeding on particulate material resuspended from the sea floor by bottom currents.

  12. Observations of wind-forced deep ocean currents in the North Pacific

    NASA Technical Reports Server (NTRS)

    Koblinsky, C. J.; Niiler, P. P.; Schmitz, W. J., Jr.

    1989-01-01

    The role of the quasi-steady Sverdrup balance in the midlatitude atmospheric response in the North Pacific was investigated by examining 200 instrument-years of moored current measurements in the deep ocean across the breadth of the midlatitude North Pacific. These data provide evidence of a seasonal modulation in the ocean eddy kinetic energy beneath the thermocline at several locations north of 35 deg N, which was often found to be in phase with the local atmospheric forcing function. Results of the measurements indicate that, throughout the midlatitude North Pacific, topography plays a crucial role in the wind forced response; the bottom slope tends to enhance the beta effect in this basin. Topography narrows the available bandwidth for forced barotropic Rossby waves, facilitating a quasi-steady topographic Sverdrup response over most of the basin. However, the enhanced beta effect reduces the magnitude of the ocean's response to wind forcing.

  13. Long-term observations of epibenthic fish zonation in the deep northern Gulf of Mexico.

    PubMed

    Wei, Chih-Lin; Rowe, Gilbert T; Haedrich, Richard L; Boland, Gregory S

    2012-01-01

    A total of 172 bottom trawl/skimmer samples (183 to 3655-m depth) from three deep-sea studies, R/V Alaminos cruises (1964-1973), Northern Gulf of Mexico Continental Slope (NGoMCS) study (1983-1985) and Deep Gulf of Mexico Benthos (DGoMB) program (2000 to 2002), were compiled to examine temporal and large-scale changes in epibenthic fish species composition. Based on percent species shared among samples, faunal groups (≥10% species shared) consistently reoccurred over time on the shelf-break (ca. 200 m), upper-slope (ca. 300 to 500 m) and upper-to-mid slope (ca. 500 to 1500 m) depths. These similar depth groups also merged when the three studies were pooled together, suggesting that there has been no large-scale temporal change in depth zonation on the upper section of the continental margin. Permutational multivariate analysis of variance (PERMANOVA) also detected no significant species changes on the limited sites and areas that have been revisited across the studies (P>0.05). Based on the ordination of the species shared among samples, species replacement was a continuum along a depth or macrobenthos biomass gradient. Despite the well-known, close, negative relationship between water depth and macrofaunal biomass, the fish species changed more rapidly at depth shallower than 1,000 m, but the rate of change was surprisingly slow at the highest macrofaunal biomass (>100 mg C m(-2)), suggesting that the composition of epibenthic fishes was not altered in response to the extremely high macrofaunal biomass in the upper Mississippi and De Soto Submarine Canyons. An alternative is that the pattern of fish species turnover is related to the decline in macrofaunal biomass, the presumptive prey of the fish, along the depth gradient. PMID:23056412

  14. Long-Term Observations of Epibenthic Fish Zonation in the Deep Northern Gulf of Mexico

    PubMed Central

    Wei, Chih-Lin; Rowe, Gilbert T.; Haedrich, Richard L.; Boland, Gregory S.

    2012-01-01

    A total of 172 bottom trawl/skimmer samples (183 to 3655-m depth) from three deep-sea studies, R/V Alaminos cruises (1964–1973), Northern Gulf of Mexico Continental Slope (NGoMCS) study (1983–1985) and Deep Gulf of Mexico Benthos (DGoMB) program (2000 to 2002), were compiled to examine temporal and large-scale changes in epibenthic fish species composition. Based on percent species shared among samples, faunal groups (≥10% species shared) consistently reoccurred over time on the shelf-break (ca. 200 m), upper-slope (ca. 300 to 500 m) and upper-to-mid slope (ca. 500 to 1500 m) depths. These similar depth groups also merged when the three studies were pooled together, suggesting that there has been no large-scale temporal change in depth zonation on the upper section of the continental margin. Permutational multivariate analysis of variance (PERMANOVA) also detected no significant species changes on the limited sites and areas that have been revisited across the studies (P>0.05). Based on the ordination of the species shared among samples, species replacement was a continuum along a depth or macrobenthos biomass gradient. Despite the well-known, close, negative relationship between water depth and macrofaunal biomass, the fish species changed more rapidly at depth shallower than 1,000 m, but the rate of change was surprisingly slow at the highest macrofaunal biomass (>100 mg C m−2), suggesting that the composition of epibenthic fishes was not altered in response to the extremely high macrofaunal biomass in the upper Mississippi and De Soto Submarine Canyons. An alternative is that the pattern of fish species turnover is related to the decline in macrofaunal biomass, the presumptive prey of the fish, along the depth gradient. PMID:23056412

  15. Long-term observations of epibenthic fish zonation in the deep northern Gulf of Mexico.

    PubMed

    Wei, Chih-Lin; Rowe, Gilbert T; Haedrich, Richard L; Boland, Gregory S

    2012-01-01

    A total of 172 bottom trawl/skimmer samples (183 to 3655-m depth) from three deep-sea studies, R/V Alaminos cruises (1964-1973), Northern Gulf of Mexico Continental Slope (NGoMCS) study (1983-1985) and Deep Gulf of Mexico Benthos (DGoMB) program (2000 to 2002), were compiled to examine temporal and large-scale changes in epibenthic fish species composition. Based on percent species shared among samples, faunal groups (≥10% species shared) consistently reoccurred over time on the shelf-break (ca. 200 m), upper-slope (ca. 300 to 500 m) and upper-to-mid slope (ca. 500 to 1500 m) depths. These similar depth groups also merged when the three studies were pooled together, suggesting that there has been no large-scale temporal change in depth zonation on the upper section of the continental margin. Permutational multivariate analysis of variance (PERMANOVA) also detected no significant species changes on the limited sites and areas that have been revisited across the studies (P>0.05). Based on the ordination of the species shared among samples, species replacement was a continuum along a depth or macrobenthos biomass gradient. Despite the well-known, close, negative relationship between water depth and macrofaunal biomass, the fish species changed more rapidly at depth shallower than 1,000 m, but the rate of change was surprisingly slow at the highest macrofaunal biomass (>100 mg C m(-2)), suggesting that the composition of epibenthic fishes was not altered in response to the extremely high macrofaunal biomass in the upper Mississippi and De Soto Submarine Canyons. An alternative is that the pattern of fish species turnover is related to the decline in macrofaunal biomass, the presumptive prey of the fish, along the depth gradient.

  16. Observation on ultrastructure and histopathology of cornea following femtosecond laser-assisted deep lamellar keratoplasty for acute corneal alkaline burns

    PubMed Central

    Li, Wen-Jing; Hu, Yu-Kun; Song, Hui; Gao, Xiao-Wei; Zhao, Xu-Dong; Dong, Jing; Guo, Yun-Lin; Cai, Yan

    2016-01-01

    AIM To demonstrate the changes in ultrastructure and histopathology of the cornea in acute corneal alkaline burns after femtosecond laser-assisted deep lamellar keratoplasty. METHODS The New Zealand white rabbits treated with alkaline corneal burn were randomized into two groups, Group A (16 eyes) with femtosecond laser-assisted deep lamellar keratoplasty 24h after burn and Group B (16 eyes) without keratoplasty as controls. All eyes were evaluated with transmission electron microscopy (TEM) at 1, 2, 3, and 4wk follow-up, then all corneas were tested by hematoxylin and eosin staining histology. RESULTS The corneal grafts in Group A were transparent, while those in Group B showed corneal stromal edema and loosely arranged collagen fibers. One week after treatment, TEM revealed the intercellular desmosomes in the epithelial layers and intact non-dissolving nuclei in Group A. At week 4, the center of the corneas in Group A was transparent with regularly arranged collagen fibers and fibroblasts in the stroma. In Group B, squamous cells were observed on the corneal surface and some epithelial cells were detached. CONCLUSION Femtosecond laser-assisted deep lamellar keratoplasty can suppress inflammatory responses, prevent toxic substance-induced injury to the corneal endothelium and inner tissues with quicker recovery and better visual outcomes. PMID:27162716

  17. Integration of posture and movement: contributions of Sherrington, Hess, and Bernstein.

    PubMed

    Stuart, Douglas G

    2005-01-01

    Neural mechanisms that integrate posture with movement are widespread throughout the central nervous system (CNS), and they are recruited in patterns that are both task- and context-dependent. Scientists from several countries who were born in the 19th century provided essential groundwork for these modern-day concepts. Here, the focus is on three of this group with each selected for a somewhat different reason. Charles Sherrington (1857-1952) had innumerable contributions that were certainly needed in the subsequent study of posture and movement: inhibition as an active coordinative mechanism, the functional anatomy of spinal cord-muscle connectivity, and helping set the stage for modern work on the sensorimotor cortex and the corticospinal tract. Sadly, however, by not championing the work of his trainee and collaborator, Thomas Graham Brown (1882-1965), he delayed progress on two key motor control mechanisms: central programming and pattern generation. Walter Hess (1881-1973), a self-taught experimentalist, is now best known for his work on CNS coordination of autonomic (visceral) and emotional behavior. His contributions to posture and movement, however, were also far-reaching: the coordination of eye movements and integration of goal-directed and "framework" (anticipatory set) motor behavior. Nikolai Bernstein (1896-1966), the quintessence of an interdisciplinary, self-taught movement neuroscientist, made far-reaching contributions that were barely recognized by Western workers prior to the 1960s. Today, he is widely praised for showing that the CNS's hierarchy of control mechanisms for posture and movement is organized hand-in-hand with distributed and parallel processing, with all three subject to evolutionary pressures. He also made important observations, like those of several previous workers, on the goal focus of voluntary movements. The contributions of Sherrington, Hess, and Bernstein are enduring. They prompt thought on the philosophical axioms that

  18. MULTI-ZONE MODELING OF THE PULSAR WIND NEBULA HESS J1825-137

    SciTech Connect

    Van Etten, Adam; Romani, Roger W.

    2011-12-01

    The pulsar wind nebula associated with PSR J1826-1334, HESS J1825-137, is a bright very high energy (VHE) source with an angular extent of {approx}1 Degree-Sign and spatially resolved spectroscopic TeV measurements. The gamma-ray spectral index is observed to soften with increasing distance from the pulsar, likely the result of cooling losses as electrons traverse the nebula. We describe analysis of X-ray data of the extended nebula, as well as three-dimensional time-dependent spectral energy distribution modeling, with emphasis on the spatial variations within HESS J1825-137. The multi-wavelength data place significant constraints on electron injection, transport, and cooling within the nebula. The large size and high nebular energy budget imply a relatively rapid initial pulsar spin period of 13 {+-} 7 ms and an age of 40 {+-} 9 kyr. The relative fluxes of each VHE zone can be explained by advective particle transport with a radially decreasing velocity profile with v(r){proportional_to}r{sup -0.5}. The evolution of the cooling break requires an evolving magnetic field which also decreases radially from the pulsar, B(r,t){proportional_to}r{sup -0.7} E-dot (t){sup 1/2}. Detection of 10 TeV flux {approx}80 pc from the pulsar requires rapid diffusion of high-energy particles, contrary to the common assumption of toroidal magnetic fields with strong magnetic confinement. The model predicts a rather uniform Fermi Large Area Telescope (LAT) surface brightness out to {approx}1 Degree-Sign from the pulsar, in good agreement with the recently discovered LAT source centered 0.{sup 0}5 southwest of PSR J1826-1334 with extension 0.{sup 0}6 {+-} 0.{sup 0}1.

  19. Multi-Zone Modeling of the Pulsar Win Nebula HESS J1825-137

    SciTech Connect

    Van Etten, Adam; Romani, Roger W.; /Stanford U., Phys. Dept.

    2011-11-08

    The pulsar wind nebula associated with PSR J1826-1334, HESS J1825-137, is a bright very high energy source with an angular extent of {approx} 1{sup o} and spatially-resolved spectroscopic TeV measurements. The gamma-ray spectral index is observed to soften with increasing distance from the pulsar, likely the result of cooling losses as electrons traverse the nebula. We describe analysis of X-ray data of the extended nebula, as well as 3-D time-dependent spectral energy distribution modeling, with emphasis on the spatial variations within HESS J1825-137. The multi-wavelength data places significant constraints on electron injection, transport, and cooling within the nebula. The large size and high nebular energy budget imply a relatively rapid initial pulsar spin period of 13 {+-} 7 ms and an age of 40 {+-} 9 kyr. The relative fluxes of each VHE zone can be explained by advective particle transport with a radially decreasing velocity profile with v(r) {proportional_to} r{sup -0.5}. The evolution of the cooling break requires an evolving magnetic field which also decreases radially from the pulsar, B(r, t) {proportional_to} r{sup -0.7} E(t){sup 1/2}. Detection of 10 TeV flux {approx} 80 pc from the pulsar requires rapid diffusion of high energy particles with {tau}{sub esc} {approx} 90 (R/10 pc){sup 2}(E{sub e}/100TeV){sup -1} year, contrary to the common assumption of toroidal magnetic fields with strong magnetic confinement. The model predicts a rather uniform Fermi LAT surface brightness out to {approx} 1{sup o} from the pulsar, in good agreement with the recently discovered LAT source centered 0.5{sup o} southwest of PSR J1826-1334 with extension 0.6 {+-} 0.1{sup o}.

  20. Ocean Response to Tropical Storms as Observed by a Moored Ocean Observing System in the Deep Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Oropeza, F.; Jaramillo, S.; Fan, S.

    2013-05-01

    As part of the support activities for a deepwater development in the Gulf of Mexico, a moored ocean observing system (OOS) was deployed in a water depth of approximately 2500m, 300km south of the Louisiana Coast. From June 2007 to May 2009, the system comprised seven single point Aanderaa Recording Current Meters (RCM), deployed at 450m, 700m, 1,100m, 1,500m, 2,000m, 2,400m and 2,490m below surface, and an RDI 75kHz Longranger Acoustic Doppler Current Profiler (ADCP), deployed between 249 and 373m below surface in upward-looking mode. Since May 2009, the OOS was upgraded to a Wavescan Buoy based moored system including meteorological sensors for: atmospheric pressure, air temperature, wind speed and direction; directional waves sensor; a Doppler Current Sensor (DCS) at 1.5 m depth for surface currents; and two downward-looking ADCP's covering the upper 1,000m of the water column. This OOS has been operating without interruptions from 2007 to the present and has registered data associated with nine tropical storms, including the direct passage of Hurricane Ike, in September of 2008, and loop current events with speeds of up to 4 knots. It has provided one of the most comprehensive set of velocity observations in the Gulf of Mexico, especially, the near surface currents, during pre-storm conditions, response, and ocean relaxation following hurricanes/tropical storms. Based on these observations the upper ocean responses to the energy input from tropical storms are characterized in terms of the associated mixing processes and momentum balances.

  1. Deep-sea in situ observations of gonatid squid and their prey reveal high occurrence of cannibalism

    NASA Astrophysics Data System (ADS)

    Hoving, H. J. T.; Robison, B. H.

    2016-10-01

    In situ observations are rarely applied in food web studies of deep-sea organisms. Using deep-sea observations obtained by remotely operated vehicles in the Monterey Submarine Canyon, we examined the prey choices of more than 100 individual squids of the genus Gonatus. Off the California coast, these squids are abundant, semelparous (one reproductive cycle) oceanic predators but their diet has remained virtually unknown. Gonatus onyx and Gonatus berryi were observed to feed on mesopelagic fishes (in particular the myctophid Stenobrachius leucopsarus) as often as on squids but inter-specific differences in feeding were apparent. Gonatids were the most common squid prey and while cannibalism occurred in both species it was particularly high in Gonatus onyx (42% of all prey items). Typically, the size of prey was similar to the size of the predator but the squids were also seen to take much larger prey. Postjuvenile gonatids are opportunistic predators that consume nektonic members of the meso-and bathypelagic communities, including their own species. Such voracious feeding is likely necessary to support the high energetic demands associated with the single reproductive event; and for females the long brooding period during which they must depend on stored resources.

  2. The XMM Deep Survey in the CDF-S. VII. UV catalogue of the Optical Monitor observations

    NASA Astrophysics Data System (ADS)

    Antonucci, M.; Talavera, A.; Vagnetti, F.; Trevese, D.; Comastri, A.; Paolillo, M.; Ranalli, P.; Vignali, C.

    2015-02-01

    Context. The XMM-Newton X-ray observatory has repeatedly observed the Chandra Deep Field-South (CDF-S) in 33 epochs (2001-2010) through the XMM-CDFS Deep Survey. During the X-ray observations, XMM-OM targeted the central 17 × 17 arcmin2 region of the X-ray field of view, providing simultaneous optical/UV coverage of the CDF-S. The resulting set of data can be used to build an XMM-OM catalogue of the CDF-S, filling the UV spectral coverage between the optical surveys and GALEX observations. Aims: We present the UV catalogue of the XMM-CDFS Deep Survey. Its main purpose is to provide complementary UV average photometric measurements of known optical/UV sources in the CDF-S, taking advantage of the unique characteristics of the survey (UV and X-ray simultaneous data, time monitoring ~8.5 years, multi-wavelength photometry). The data reduction is also intended to improve the standard source detection on individual observations by cataloguing faint sources by stacking their exposure images. Methods: We re-processed the XMM-OM data of the survey and stacked the exposures from consecutive observations using the standard Science Analysis System (SAS) tools to process the data obtained during single observations. Average measurements of detections with SAS good quality flags from individual observations and from stacked images were joined to compile the catalogue. Sources were validated through the cross-identification within the ESO Imaging survey (Arnouts et al. 2001) and the COMBO-17 survey (Wolf et al. 2004). Results: Photometric data of 1129 CDF-S sources are provided in the catalogue, and optical/UV/X-ray photometric and spectroscopic information from other surveys are also included. The stacking extends the detection limits by ~1 mag in the three UV bands, contributing ~30% of the catalogued UV sources. The comparison with the available measurements in similar spectral bands confirms the validity of the XMM-OM calibration. The combined COMBO-17/X-ray classification

  3. Coincident Occurrences of Tropical Individual Cirrus Clouds and Deep Convective Systems Derived from TRMM Observations

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Xu, Kuan-Man; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Chambers, Lin; Fan, Alice; Sun, Wenbo

    2007-01-01

    Measurements of cloud properties and atmospheric radiation taken between January and August 1998 by the Tropical Rainfall Measuring Mission (TRMM) satellite were used to investigate the effect of spatial and temporal scales on the coincident occurrences of tropical individual cirrus clouds (ICCs) and deep convective systems (DCSs). It is found that there is little or even negative correlation between instantaneous occurrences of ICC and DCS in small areas, in which both types of clouds cannot grow and expand simultaneously. When spatial and temporal domains are increased, ICCs become more dependent on DCSs due to the origination of many ICCs from DCSs and moisture supply from the DCS in the upper troposphere for the ICCs to grow, resulting in significant positive correlation between the two types of tropical high clouds in large spatial and long temporal scales. This result may suggest that the decrease of tropical high clouds with SST from model simulations is likely caused by restricted spatial domains and limited temporal periods. Finally, the radiative feedback due to the change in tropical high cloud area coverage with sea surface temperature appears small and about -0.14 W/sq m per degree Kelvin.

  4. Initial seismic observations from a deep borehole drilled into the Canadian Shield in northeast Alberta

    NASA Astrophysics Data System (ADS)

    Chan, Judith; Schmitt, Douglas R.

    2015-09-01

    The availability of a deep borehole in northeastern Alberta provides an unprecedented opportunity to study the in situ metamorphic craton rocks. This borehole reaches a depth of 2.4 km, with 1.8 km in the crystalline rocks, and is the only known borehole allowing access into the deeper rocks of the metamorphic Canadian Shield. In 2011, a zero-offset vertical seismic profile (VSP) was acquired to assist in the interpretation of seismic reflection data and geophysical logs. Three sets of upgoing tube waves interpreted from the raw profile correspond to the small-scale fluctuations in the borehole diameters and fracture zone in the crystalline rocks. A comparison between sonic log velocities and VSP velocities reveals a zone with increased velocity that could be due to the change in rock composition and texture in the basement rocks. The final processed profile is used to generate corridor stacks for differentiating between primary reflections and multiples in the seismic reflection profile. Analysis of the zero-offset VSP verifies existing log interpretation on the presence of fractures and the possible lithological changes in the metamorphic rocks of the Canadian Shield.

  5. Glider observations of the biological response to Modified Circumpolar Deep Water Variability in the Ross Sea

    NASA Astrophysics Data System (ADS)

    O'Connell, D.; Kaufman, D.; Friedrichs, M. A.; Smith, W.

    2011-12-01

    The Ross Sea is the most productive area within the Southern Ocean, and is believed to play a significant role in the global marine carbon cycle. This region is also characterized by strong spatial and temporal variability in both physical and biogeochemical conditions; however this variability occurs on spatial and temporal scales that are difficult to resolve with traditional data sources. In order to better understand this variability, two gliders were deployed in the Ross Sea in late November 2010 during the early stages of the summer plankton bloom. Together, the two gliders made over 1500 dives and collected data (salinity, temperature, fluorescence and oxygen) throughout the water column for roughly two months. The data from these gliders were used to identify the presence of the relatively high-nutrient Modified Circumpolar Deep Water (MCDW), which has been hypothesized to be a significant factor affecting the spatial and temporal extent of the summer plankton blooms. Preliminary data analyses indicate a positive correlation between areas of MCDW and high chlorophyll concentrations. The glider data were also compared to contemporaneous cruise data and satellite data and were found to fit well with these other data, yet were better able to resolve the high temporal and spatial variability of this region. Specifically, the lower resolution of the cruise data, as compared to the glider data, made it difficult to resolve the correlation of MCDW to high chlorophyll from the cruise data alone.

  6. Deep scattering layer migration and composition: observations from a diving saucer.

    PubMed

    Barham, E G

    1966-03-18

    The distribution of a myctophid fish and physonect siphonophores observed during dives in the Soucoupe off Baja California closely correlates with scattering layers recorded simultaneously with a 12-kcy/sec echo sounder. These organisms were observed while they were migrating vertically, and at their night and daytime levels. They are capable of rapid, extensive changes in depth. PMID:17817303

  7. Extreme Ultraviolet Explorer deep survey observations of a large flare on AU Microscopii

    NASA Technical Reports Server (NTRS)

    Cully, Scott L.; Siegmund, Oswald H. W.; Vedder, Peter W.; Vallerga, John V.

    1993-01-01

    We have made the first extended observation of a stellar flare in the EUV with 100 s time resolution. The flare was detected on AU Mic by the Extreme Ultraviolet Explorer satellite at 12:38 UT on 1992 July 15 during a 4 d observation from 1992 July 14 to 18. This was a large flare detected in the Lexan/boron (65-190 A) band with an observed peak count rate of 7.0 +/- 0.5 counts/s, corresponding to a peak luminosity of 10 exp 30 erg/s in the Lexan/boron bandpass. This is significantly above the measured quiescent level of 0.4 +/- 0.2 counts/s. The flare consisted of a sharp peak lasting about 2 hr, followed by a decaying tail that lasted more than a day. The total EUV energy of the event is estimated to be 3 x 10 exp 34 ergs. A second, smaller flare was also observed and is described. We conclude that the large emission measures on order of 6 x 10 exp 53/cu cm are due to large volumes with characteristic length scales of order the stellar radius. We compare these EUV observations with stellar flare observations in other bandpasses and estimate the likelihood of seeing similar flares in future observations.

  8. Bernard J. Wood Receives 2013 Harry H. Hess Medal: Response

    NASA Astrophysics Data System (ADS)

    Wood, Bernard J.

    2014-01-01

    President Finn, friends, and colleagues, I am truly delighted to accept the Hess Medal for 2013. It is difficult to express one's feelings adequately on receipt of such a prestigious award, but a mixture of pride, humility, and thankfulness for a long and lucky career all occur. It did not start propitiously as my high school grades would only ensure undergraduate entry into the Northern Polytechnic, a second-tier institution in London. Nevertheless, I was enthused by several great teachers, including John Charalambous (inorganic chemistry) and Stephen Morel, a field geologist who had worked for many years in Malawi. They pushed me into trying for graduate school, and I was fortunate to find the eclectic Roger Strens my supervisor at Newcastle.

  9. Observationally constrained modeling of sound in curved ocean internal waves: examination of deep ducting and surface ducting at short range.

    PubMed

    Duda, Timothy F; Lin, Ying-Tsong; Reeder, D Benjamin

    2011-09-01

    A study of 400 Hz sound focusing and ducting effects in a packet of curved nonlinear internal waves in shallow water is presented. Sound propagation roughly along the crests of the waves is simulated with a three-dimensional parabolic equation computational code, and the results are compared to measured propagation along fixed 3 and 6 km source/receiver paths. The measurements were made on the shelf of the South China Sea northeast of Tung-Sha Island. Construction of the time-varying three-dimensional sound-speed fields used in the modeling simulations was guided by environmental data collected concurrently with the acoustic data. Computed three-dimensional propagation results compare well with field observations. The simulations allow identification of time-dependent sound forward scattering and ducting processes within the curved internal gravity waves. Strong acoustic intensity enhancement was observed during passage of high-amplitude nonlinear waves over the source/receiver paths, and is replicated in the model. The waves were typical of the region (35 m vertical displacement). Two types of ducting are found in the model, which occur asynchronously. One type is three-dimensional modal trapping in deep ducts within the wave crests (shallow thermocline zones). The second type is surface ducting within the wave troughs (deep thermocline zones).

  10. Observations of deep convective influence on stratospheric water vapor and its isotopic composition

    NASA Astrophysics Data System (ADS)

    Hanisco, Thomas F.; Moyer, E. J.; Weinstock, E. M.; St. Clair, J. M.; Sayres, D. S.; Smith, J. B.; Lockwood, R.; Anderson, J. G.; Dessler, A. E.; Keutsch, F. N.; Spackman, J. R.; Read, W. G.; Bui, T. P.

    2007-02-01

    In situ observations of H2O and HDO in the midlatitude stratosphere are used to evaluate the role of convection in determining the stratospheric water budget. The observations show that water vapor in the overworld stratosphere (potential temperature > 380 K) is isotopically heavier than expected. Measurements in an airmass with anomalously high concentrations of water vapor show isotopic water signatures that are characteristic of evaporated ice lofted from the troposphere during convective storms. Observed H2O and HDO concentrations in the plume of enhanced water and in the background stratosphere suggest that extratropical convection can account for a significant fraction of the observed water vapor in the summertime overworld stratosphere above the mid-North American continent.

  11. SPECTRA OF COSMIC RAY ELECTRONS AND DIFFUSE GAMMA RAYS WITH THE CONSTRAINTS OF AMS-02 AND HESS DATA

    SciTech Connect

    Chen, Ding; Jin, Hong-Bo; Huang, Jing

    2015-10-01

    Recently, AMS-02 reported their results of cosmic ray (CR) observations. In addition to the AMS-02 data, we add HESS data to estimate the spectra of CR electrons and the diffuse gamma rays above TeV. In the conventional diffusion model, a global analysis is performed on the spectral features of CR electrons and the diffuse gamma rays by the GALRPOP package. The results show that the spectrum structure of the primary component of CR electrons cannot be fully reproduced by a simple power law and that the relevant break is around 100 GeV. At the 99% confidence level (C.L.) the injection indices above the break decrease from 2.54 to 2.35, but the ones below the break are only in the range of 2.746–2.751. The spectrum of CR electrons does not need to add TeV cutoff to also match the features of the HESS data. Based on the difference between the fluxes of CR electrons and their primary components, the predicted excess of CR positrons is consistent with the interpretation that these positrons originate from a pulsar or dark matter. In the analysis of the Galactic diffuse gamma rays with the indirect constraint of AMS-02 and HESS data, it is found that the fluxes of Galactic diffuse gamma rays are consistent with the GeV data of the Fermi-Large Area Telescope (LAT) in the high-latitude regions. The results indicate that inverse Compton scattering is the dominant component in the range of hundreds of GeV to tens of TeV, respectively from the high-latitude regions to the low ones, and in all of the regions of the Galaxy the flux of diffuse gamma rays is less than that of CR electrons at the energy scale of 20 TeV.

  12. Spectra of Cosmic Ray Electrons and Diffuse Gamma Rays with the Constraints of AMS-02 and HESS Data

    NASA Astrophysics Data System (ADS)

    Chen, Ding; Huang, Jing; Jin, Hong-Bo

    2015-10-01

    Recently, AMS-02 reported their results of cosmic ray (CR) observations. In addition to the AMS-02 data, we add HESS data to estimate the spectra of CR electrons and the diffuse gamma rays above TeV. In the conventional diffusion model, a global analysis is performed on the spectral features of CR electrons and the diffuse gamma rays by the GALRPOP package. The results show that the spectrum structure of the primary component of CR electrons cannot be fully reproduced by a simple power law and that the relevant break is around 100 GeV. At the 99% confidence level (C.L.) the injection indices above the break decrease from 2.54 to 2.35, but the ones below the break are only in the range of 2.746–2.751. The spectrum of CR electrons does not need to add TeV cutoff to also match the features of the HESS data. Based on the difference between the fluxes of CR electrons and their primary components, the predicted excess of CR positrons is consistent with the interpretation that these positrons originate from a pulsar or dark matter. In the analysis of the Galactic diffuse gamma rays with the indirect constraint of AMS-02 and HESS data, it is found that the fluxes of Galactic diffuse gamma rays are consistent with the GeV data of the Fermi-Large Area Telescope (LAT) in the high-latitude regions. The results indicate that inverse Compton scattering is the dominant component in the range of hundreds of GeV to tens of TeV, respectively from the high-latitude regions to the low ones, and in all of the regions of the Galaxy the flux of diffuse gamma rays is less than that of CR electrons at the energy scale of 20 TeV.

  13. Calculation of intensity of high energy muon groups observed deep underground

    NASA Technical Reports Server (NTRS)

    Vavilov, Y. N.; Dedenko, L. G.

    1985-01-01

    The intensity of narrow muon groups observed in Kolar Gold Field (KGF) at the depth of 3375 m.w.e. was calculated in terms of quark-gluon strings model for high energy hadron - air nuclei interactions by the method of direct modeling of nuclear cascade in the air and muon propagation in the ground for normal primary cosmic ray composition. The calculated intensity has been found to be approx. 10 to the 4 times less than one observed experimentally.

  14. A SELF-CONSISTENT EXPLANATION OF TeV EMISSIONS FROM HESS J1640-465 AND HESS J1641-463

    SciTech Connect

    Tang, Yunyong; Yang, Chuyuan; Wang, Jiancheng; Zhang, Li

    2015-10-10

    The bright TeV source HESS J1640-465 is positionally coincident with the young supernova remnant (SNR) G338.3-0.0, and the nearby HESS J1641-463 with TeV gamma-ray emission seems to be closely associated with it. Based on the nonlinear diffusion shock acceleration model, we explore the emission from these two TeV sources, the particle diffusion is assumed to be different inside and outside the absorbing boundary of the particles accelerated in the SNR shock. The results indicate that (1) the GeV–TeV emission from the region of the HESS J1640-465 is produced as a result of the particle acceleration inside the SNR G338.3-0.0 and (2) the runaway cosmic-ray particles outside the SNR are interacting with the nearby dense molecular cloud (MC) at the region of the HESS J1641-463, corresponding π{sup 0} decay gamma-ray in proton–proton collision contribute to the TeV emission from the HESS J1641-463. Also, we investigate the possible X-ray emission in MC from the synchrotron procedure by secondary e{sup ±} produced through escaped protons interaction with the MC.

  15. Wave mode identification of electrostatic noise observed with ISEE 3 in the deep tail boundary layer

    NASA Technical Reports Server (NTRS)

    Tsutsui, M.; Matsumoto, H.; Strangeway, R. J.; Tsurutani, B. T.; Phillips, J. L.

    1991-01-01

    The characteristics of the VLF electrostatic noise observed with ISEE 3 in the low-latitude boundary layer of distant geomagnetic tail are examined using a display format for the wave dynamic spectra different from that used by Scarf et al. (1984). It is shown that the observed noise is composed of impulsive bursts. The results of the detailed analysis of the noise parameters are used to develop a model of plasma wave behavior in the plasma rest frame. A hypothesis is proposed that the wide frequency extent of the noise spectra is composed of Doppler effects of waves propagating nearly omnidirectionally within the plasma rest frame, which is moving with the electron bulk speed. On the basis of this hypothesis, the wavelength of the observed waves were determined from the width of the frequency extent and the measured electron bulk speed. It is shown that the wavelength ranges from 2 to 8 times the plasma Debye length.

  16. Initial OSSE Sky Survey Observation: Deep Survey in the Virgo Region

    NASA Technical Reports Server (NTRS)

    Cameron, Robert

    2000-01-01

    The OSSE Virgo survey covered about 1% of the sky, using eight weeks of observing time on the Compton Gamma Ray Observatory, and was performed in conjunction with the EGRET and COMPTEL instruments on CGRO. A fundamental aspect of the survey was the development of data reduction techniques for the scanning data from the OSSE detectors. A direct algebraic approach for spatially deconvolving the data was developed. For the survey work, no background observations isolated from the survey region were acquired, unlike normal discrete source observations. The survey, reduction method covers the mapped region with a grid of pixels, and estimates the flux from each pixel by least-squares agreement with the data, assuming positivity constraints. This technique has led to the detection of compact sources at hard X-ray energies within the Virgo region, and the OSSE survey studies have been extended to the south galactic pole and north Ecliptic pole, with similar analysis techniques.

  17. Model Evaluation of Aerosol Wet Scavenging in Deep Convective Clouds Based on Observations Collected during the DC3 Campaign

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Easter, R. C.; Fast, J. D.; Wang, H.; Ghan, S. J.; Campuzano Jost, P.; Barth, M. C.; Fan, J.; Morrison, H.; Jimenez, J. L.; Bela, M. M.; Markovic, M. Z.

    2014-12-01

    Deep convective storms greatly influence the vertical distribution of aerosols by transporting aerosols from the boundary layer to the upper troposphere and by removing aerosols through wet scavenging processes. Model representation of wet scavenging is a major uncertainty in simulating the vertical distribution of aerosols due partly to limited constraints by observations. The effect of wet scavenging on ambient aerosols in deep mid-latitude continental convective clouds is studied for a severe storm case in the vicinity of the ARM Southern Great Plains site on May 29, 2012 during the Deep Convective Clouds and Chemistry Project (DC3) field campaign. A new budget analysis approach is developed to characterize the convective transport to the upper troposphere based on the vertical distribution of several slowly reacting and nearly insoluble trace gases (i.e., CO, acetone, and benzene). A similar budget framework is applied to aerosols combined with the known transport efficiency to estimate wet-scavenging efficiency. The chemistry version of the Weather Research and Forecasting model (WRF-Chem) simulates the storm initiation timing and structure reasonably well when compared against radar observations from the NSSL national 3-D reflectivity Mosaic data. Simulated vertical profiles of humidity and temperature also closely agree with radiosonde measurements before and during the storm. High scavenging efficiencies (~80%) for aerosol number (Dp < 2.5μm) and mass (Dp < 1μm) are obtained from the observations. Both observation analyses and the simulation show that, between the two dominant aerosol species, organic aerosol shows a slightly higher scavenging efficiency than sulfate aerosol, and higher scavenging efficiency is found for larger particle sizes (0.15 - 2.5μm versus 0.03 - 0.15μm). However, the model underestimates the wet scavenging efficiency (by up to 50%), in general, for both mass and number concentrations. The effect of neglecting secondary

  18. The Deep Impact Campaign at ESO: Observations of the Gas Component

    NASA Astrophysics Data System (ADS)

    Rauer, H.; ESO DI Project Team

    2005-08-01

    The high velocity impact of a projectile on the nucleus of comet 9P/Tempel 1 could give for the first time access to pristine material preserved in the cometary interior. From two nights before impact to six nights after impact FORS2 at the VLT UT 1 is available every night to obtain low resolution optical spectra. These will be used to study the chemical composition of the coma by studying emissions from CN, C2, C3 and NH2, and to identify variations due to the impact. Possibly, a new surface of fresh ices in the impact crater will be present. We also intend to perform medium resolution near infrared spectroscopy using ISAAC at the VLT UT 1 to observe organic parent molecules directly instead of observing daughter products that can be addressed by optical observations. This contribution will present first results from the observations of the gas coma around the impact time. The project team comprises the following investigators: N. Ageores, M. A'Hearn, C. Arpigny, S. Bagnulo, H. Boehnhardt, T. Bonev, A. Cochran, C. Delahodde, Y. Fernandez, O. Hainaut, D. Hutsemekers, E. Jehin, H.U. Kaeufl, H. Kawakita, F. Kerber, J. Knollenberg, M. Kretlow, E. Kuehrt, M. Kueppers, L. Lara, J. Licandro, C. Lisse, J. Manfroid, O. Marco, K. Meech, H. Rauer, R. Schulz, G. Schwehm, C. Sterken, M. Sterzik, J.A. Stuewe, I. Surdej, G.P. Tozzi, M. Weiler, R. West, D. Wooden, J.-M. Zucconi

  19. The Planning of Lander Science Observations after ROSETTA Deep Space Hibernation

    NASA Astrophysics Data System (ADS)

    Barthelemy, Maud; Ulamec, Stephan; Gaudon, Philippe; Biele, Jens; Pätz, Brigitte; Ashman, Mike

    2014-05-01

    After 10 years of its interplanetary journey, Rosetta has woken up from hibernation to meet Churyumov-Gerasimenko comet in the second term of 2014. The Rosetta spacecraft is composed of an Orbiter and a Lander part. The spacecraft will deliver the Lander, named Philae, to land on the surface of the comet in November 2014. During the Cruise Phase, the Lander, attached to the Orbiter, participated in several commissioning and payload checkout observations. In April 2014, after almost 3 years of hibernation, the Lander and the Orbiter will enter a commissioning phase to check the health of all instruments. Then, from May to November, Prelanding science activities can be planned, although the priority will go to those observations that help to select the landing site. The Lander project has, in much the same way as the Orbiter, its own ground segment: the Rosetta Lander Ground Segment (RLGS). The RLGS is composed of the Science Operations and Navigation Center - SONC - at CNES in Toulouse and the Lander Control Center - LCC - at DLR in Cologne. There are 10 instruments on board of Philae trying to conduct science observations during the life of the Lander. As the comet travels closer to the sun the temperature will eventually become too hot for Philae. The Orbiter, however, is planned to operate for much longer, until end of 2015, passing perihelion. Each of the 10 instruments is represented by a principal investigator. The Lander project also has Lead Scientists, who make sure that the science objectives of the Lander are fulfilled and are on hand to solve any eventual conflicts in this regard. To plan their observations, the Lander team listed their science objectives and ranked them. From these objectives, Specific On-Comet Operation Plan (SOCOP) documents are written by LCC describing the proposed observations. Then, at SONC, the MOST (Mission Operation Scheduling Tool) is used to generate a science experiment plan. This plan is confirmed by the PIs and the Lead

  20. Palomar and Table Mountain Observations of 9P/Tempel 1 during the Deep Impact Encounter: First Results

    NASA Technical Reports Server (NTRS)

    Bauer, James M.; Weissman, Paul R.; Choi, Young-Jun; Troy, Mitchell; Young, James W.; Lisse, Carey M.; Dekany, Richard; Hanner, Martha S.; Buratti, Bonnie J.

    2007-01-01

    We present the first results of the Palomar Adaptive Optics observations taken during the Deep Impact encounter with 9P/Tempel 1 in July 2005. We have combined the Palomar near-IR imaging data with our visual wavelength images obtained simultaneously at JPL's Table Mountain Observatory to cover the total wavelength range from 0.4 to 2.3 micrometers in the B, V, R, I, J, H, and K filter bands, spanning the dates from 2005 July 03-07.We also include in our overall analysis images taken on the pre-encounter dates of June 1 and June 15, 2005. The broad wavelength range of our observations, along with high temporal resolution, near-IR sensitivity, and spatial resolution of our imaging, have enabled us to place constraints on the temperature of the impact flash and incandescent plume of greater than 700 K, and to provide mean dust velocities of order 197 +/- 16 m/s approximately 1.25 h after impact derived from our 1.64 micro observations. Our ejected dust mass estimates, as derived from our near-IR observations, are an order of magnitude less than those previously reported for visual wavelength observations.

  1. Extending Fermi-LAT and H.E.S.S. limits on gamma-ray lines from dark matter annihilation

    NASA Astrophysics Data System (ADS)

    Profumo, Stefano; Queiroz, Farinaldo S.; Yaguna, Carlos E.

    2016-10-01

    Gamma-ray lines from dark matter annihilation (χχ → γX, where X = γ, h, Z) are always accompanied, at lower energies, by a continuum gamma-ray spectrum stemming both from radiative corrections (X = γ) and from the decay debris of the second particle possibly present in the final state (X = h, Z). This model-independent gamma-ray emission can be exploited to derive novel limits on gamma-ray lines that do not rely on the line feature. Although such limits are not expected to be as stringent as those based on the line feature, they can be used to probe the existence of gamma-ray lines for dark matter masses beyond the largest energies accessible to current telescopes. Here, we use continuous gamma-ray searches from Fermi-LAT observations of Milky Way dwarf spheroidal galaxies and from H.E.S.S. observations of the Galactic halo to extend the limits on the annihilation cross-sections into monochromatic photons to dark matter masses well beyond 500 GeV (Fermi-LAT) and 20 TeV (H.E.S.S.). In this large-mass regime, our results provide the first constraints on gamma-ray lines from dark matter annihilation.

  2. A deep Chandra observation of the interacting star-forming galaxy Arp 299

    NASA Astrophysics Data System (ADS)

    Anastasopoulou, K.; Zezas, A.; Ballo, L.; Della Ceca, R.

    2016-08-01

    We present results from a 90 ks Chandra ACIS-S observation of the X-ray luminous interacting galaxy system Arp 299 (NGC 3690/IC 694). We detect 25 discrete X-ray sources with luminosities above ˜4.0 × 1038 erg s-1 covering the entire Ultra Luminous X-ray source (ULX) regime. Based on the hard X-ray spectra of the non-nuclear discrete sources identified in Arp 299, and their association with young, actively star-forming region of Arp 299 we identify them as HMXBs. We find in total 20 off-nuclear sources with luminosities above the ULX limit, 14 of which are point-like sources. Furthermore we observe a marginally significant deficit in the number of ULXs, with respect to the number expected from scaling relations of X-ray binaries with the star formation rate (SFR). Although the high metallicity of the galaxy could result in lower ULX numbers, the good agreement between the observed total X-ray luminosity of ULXs, and that expected from the relevant scaling relation indicates that this deficit could be the result of confusion effects. The integrated spectrum of the galaxy shows the presence of a hot gaseous component with kT = 0.72 ± 0.03 keV, contributing ˜20 per cent of the soft (0.1-2.0 keV) unabsorbed luminosity of the galaxy. A plume of soft X-ray emission in the west of the galaxy indicates a large scale outflow. We find that the AGN in NGC 3690 contributes only 22 per cent of the observed broad-band X-ray luminosity of Arp 299.

  3. Optimized dark matter searches in deep observations of Segue 1 with MAGIC

    SciTech Connect

    Aleksić, J.; Ansoldi, S.; Antonelli, L.A.; Antoranz, P.; Collaboration: The The MAGIC Collaboration; and others

    2014-02-06

    We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ∼500 GeV dark matter particle annihilating into τ{sup +}τ{sup −}, and is of order <σ{sub ann}v>≃ 1.2×10{sup −24} cm{sup 3} s{sup −1} — a factor ∼40 above the <σ{sub ann}v>≃ thermal value.

  4. Estimating the Deep Solar Meridional Circulation Using Magnetic Observations and a Dynamo Model: A Variational Approach

    NASA Astrophysics Data System (ADS)

    Hung, Ching Pui; Jouve, Laurène; Brun, Allan Sacha; Fournier, Alexandre; Talagrand, Olivier

    2015-12-01

    We show how magnetic observations of the Sun can be used in conjunction with an axisymmetric flux-transport solar dynamo model in order to estimate the large-scale meridional circulation throughout the convection zone. Our innovative approach rests on variational data assimilation, whereby the distance between predictions and observations (measured by an objective function) is iteratively minimized by means of an optimization algorithm seeking the meridional flow that best accounts for the data. The minimization is performed using a quasi-Newton technique, which requires knowledge of the sensitivity of the objective function to the meridional flow. That sensitivity is efficiently computed via the integration of the adjoint flux-transport dynamo model. Closed-loop (also known as twin) experiments using synthetic data demonstrate the validity and accuracy of this technique for a variety of meridional flow configurations, ranging from unicellular and equatorially symmetric to multicellular and equatorially asymmetric. In this well-controlled synthetic context, we perform a systematic study of the behavior of our variational approach under different observational configurations by varying their spatial density, temporal density, and noise level, as well as the width of the assimilation window. We find that the method is remarkably robust, leading in most cases to a recovery of the true meridional flow to within better than 1%. These encouraging results are a first step toward using this technique to (i) better constrain the physical processes occurring inside the Sun and (ii) better predict solar activity on decadal timescales.

  5. ESTIMATING THE DEEP SOLAR MERIDIONAL CIRCULATION USING MAGNETIC OBSERVATIONS AND A DYNAMO MODEL: A VARIATIONAL APPROACH

    SciTech Connect

    Hung, Ching Pui; Jouve, Laurène; Brun, Allan Sacha; Talagrand, Olivier

    2015-12-01

    We show how magnetic observations of the Sun can be used in conjunction with an axisymmetric flux-transport solar dynamo model in order to estimate the large-scale meridional circulation throughout the convection zone. Our innovative approach rests on variational data assimilation, whereby the distance between predictions and observations (measured by an objective function) is iteratively minimized by means of an optimization algorithm seeking the meridional flow that best accounts for the data. The minimization is performed using a quasi-Newton technique, which requires knowledge of the sensitivity of the objective function to the meridional flow. That sensitivity is efficiently computed via the integration of the adjoint flux-transport dynamo model. Closed-loop (also known as twin) experiments using synthetic data demonstrate the validity and accuracy of this technique for a variety of meridional flow configurations, ranging from unicellular and equatorially symmetric to multicellular and equatorially asymmetric. In this well-controlled synthetic context, we perform a systematic study of the behavior of our variational approach under different observational configurations by varying their spatial density, temporal density, and noise level, as well as the width of the assimilation window. We find that the method is remarkably robust, leading in most cases to a recovery of the true meridional flow to within better than 1%. These encouraging results are a first step toward using this technique to (i) better constrain the physical processes occurring inside the Sun and (ii) better predict solar activity on decadal timescales.

  6. Optimized dark matter searches in deep observations of Segue 1 with MAGIC

    SciTech Connect

    Aleksić, J.; Blanch, O.; Ansoldi, S.; Antonelli, L.A.; Bonnoli, G.; Antoranz, P.; Babic, A.; Bangale, P.; De Almeida, U. Barres; Bock, R.K.; Borracci, F.; Barrio, J.A.; Bonnefoy, S.; González, J. Becerra; Berger, K.; Bednarek, W.; Bernardini, E.; Biland, A.; Bretz, T.; Carmona, E. E-mail: jrico@ifae; and others

    2014-02-01

    We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ∼ 500 GeV dark matter particle annihilating into τ{sup +}τ{sup −}, and is of order (σ{sub ann}v) ≅  1.2 × 10{sup −24} cm{sup 3} s{sup −1} — a factor ∼ 40 above the (σ{sub ann}v) ≅  thermal value.

  7. Deep Structure and Evolution of The Central Graben, North Sea: Constraints From Seismic Observations and Numerical Dynamic Modelling.

    NASA Astrophysics Data System (ADS)

    Balling, N.; Frederiksen, S.; Nielsen, L.; Nørmark, E.; Nielsen, S. B.; Jacobsen, B. H.

    The Central Graben forms the southern arm of a three-arm rift system in the North Sea, with the Viking Graben as the northern arm and the Moray Firth Basin as the western arm. It is a 70-130 km wide graben with a length of about 550 km. High qual- ity normal-incidence and wide-angle seismic data from the MONA LISA deep seismic experiment across the Central Graben show crustal thinning by a factor of 2 in areas of thickest sedimentary sequences and localized seismic reflectivity in the upper mantle dipping away from the deepest parts of the graben. A numerical dynamic lithospheric model with significant Triassic and Late Jurassic extensional phases as well as Mid- dle Jurassic thermal doming accounts for the observed up to 8 km of Late Permian to Cenozoic sediments in the deepest parts of the Graben, for most of the observed lateral thickness variation of sedimentary formations and is consistent with both the deep-seismic data, present-day heat-flow and gravity data. The detailed crustal model produced by joint inverse modelling of seimic refraction data and gravity data shows a distinct thinning of the crust and local elevation of Moho by up to 5 km in a 40 km narrow zone below areas of thick upper Jurassic sediments. This Moho structure suggests that a relatively shallow and otherwise strong uppermost mantle has been interrupted, perhaps by mantle shear zones induced by strain softening as in our nu- merical model. The integrated seismic observational and numerical modelling results indicate that an initially pure-shear donimated extensional regime changed into an ex- tensional regime where simple shear played an important part with mantle shear zones developed during the Late Jurassic extension.

  8. First in situ observations of the deep-sea squid Grimalditeuthis bonplandi reveal unique use of tentacles

    PubMed Central

    Hoving, Hendrik J. T.; Zeidberg, Louis D.; Benfield, Mark C.; Bush, Stephanie L.; Robison, Bruce H.; Vecchione, Michael

    2013-01-01

    The deep-sea squid Grimalditeuthis bonplandi has tentacles unique among known squids. The elastic stalk is extremely thin and fragile, whereas the clubs bear no suckers, hooks or photophores. It is unknown whether and how these tentacles are used in prey capture and handling. We present, to our knowledge, the first in situ observations of this species obtained by remotely operated vehicles (ROVs) in the Atlantic and North Pacific. Unexpectedly, G. bonplandi is unable to rapidly extend and retract the tentacle stalk as do other squids, but instead manoeuvres the tentacles by undulation and flapping of the clubs’ trabecular protective membranes. These tentacle club movements superficially resemble the movements of small marine organisms and suggest the possibility that G. bonplandi uses aggressive mimicry by the tentacle clubs to lure prey, which we find to consist of crustaceans and cephalopods. In the darkness of the meso- and bathypelagic zones the flapping and undulatory movements of the tentacle may: (i) stimulate bioluminescence in the surrounding water, (ii) create low-frequency vibrations and/or (iii) produce a hydrodynamic wake. Potential prey of G. bonplandi may be attracted to one or more of these as signals. This singular use of the tentacle adds to the diverse foraging and feeding strategies known in deep-sea cephalopods. PMID:23986106

  9. DEEP CHANDRA MONITORING OBSERVATIONS OF NGC 4649. I. CATALOG OF SOURCE PROPERTIES

    SciTech Connect

    Luo, B.; Fabbiano, G.; Strader, J.; Kim, D.-W.; Fragos, T.; Brodie, J. P.; King, A.; Zezas, A.

    2013-02-15

    We present the X-ray source catalog for the Chandra monitoring observations of the elliptical galaxy, NGC 4649. The galaxy has been observed with Chandra ACIS-S3 in six separate pointings, reaching a total exposure of 299 ks. There are 501 X-ray sources detected in the 0.3-8.0 keV band in the merged observation or in one of the six individual observations; 399 sources are located within the D{sub 25} ellipse. The observed 0.3-8.0 keV luminosities of these 501 sources range from 9.3 Multiplication-Sign 10{sup 36} erg s{sup -1} to 5.4 Multiplication-Sign 10{sup 39} erg s{sup -1}. The 90% detection completeness limit within the D{sub 25} ellipse is 5.5 Multiplication-Sign 10{sup 37} erg s{sup -1}. Based on the surface density of background active galactic nuclei (AGNs) and detection completeness, we expect Almost-Equal-To 45 background AGNs among the catalog sources ( Almost-Equal-To 15 within the D{sub 25} ellipse). There are nine sources with luminosities greater than 10{sup 39} erg s{sup -1}, which are candidates for ultraluminous X-ray sources. The nuclear source of NGC 4649 is a low-luminosity AGN, with an intrinsic 2.0-8.0 keV X-ray luminosity of 1.5 Multiplication-Sign 10{sup 38} erg s{sup -1}. The X-ray colors suggest that the majority of the catalog sources are low-mass X-ray binaries (LMXBs). We find that 164 of the 501 X-ray sources show long-term variability, indicating that they are accreting compact objects. We discover four transient candidates and another four potential transients. We also identify 173 X-ray sources (141 within the D{sub 25} ellipse) that are associated with globular clusters (GCs) based on Hubble Space Telescope and ground-based data; these LMXBs tend to be hosted by red GCs. Although NGC 4649 has a much larger population of X-ray sources than the structurally similar early-type galaxies, NGC 3379 and NGC 4278, the X-ray source properties are comparable in all three systems.

  10. A multivariate analysis approach for the Imaging Atmospheric Cerenkov Telescopes System H.E.S.S

    SciTech Connect

    Dubois, F.; Lamanna, G.

    2008-12-24

    We present a multivariate classification approach applied to the analysis of data from the H.E.S.S. Very High Energy (VHE){gamma}-ray IACT stereoscopic system. This approach combines three complementary analysis methods already successfully applied in the H.E.S.S. data analysis. The proposed approach, with the combined effective estimator X{sub eff}, is conceived to improve the signal-to-background ratio and therefore particularly relevant to the morphological studies of faint extended sources.

  11. Observations on Tc-99m-erythrocyte venography in normal subjects and in patients with deep vein thrombosis

    SciTech Connect

    Lisbona, R.; Leger, J.; Stern, J.; Derbekyan, V.; Skinner, B.

    1981-07-01

    Blood pool imaging of the lower limbs with Tc-99m-erythrocytes demonstrates the deep venous channels of the leg. The radionuclide image of deep vein thrombosis, by this method, appears sufficiently distinctive to suggest that Tc-99m-erythrocyte venography may be a useful screening examination for deep vein patency.

  12. Development of precision acoustic transponders for GPS/Acoustic observation on the deep seafloor near the Japan Trench axis

    NASA Astrophysics Data System (ADS)

    Fujimoto, H.; Kido, M.

    2012-12-01

    The 2011 Tohoku-oki earthquake has let most of researchers recognize the importance of seafloor geodetic observation, especially near the trench axis. Iinuma et al. (2012a) estimated the coseismic slip distribution combining onshore GPS data with the seafloor geodetic data. Their results reveal that a huge (> 50 m) slip occurred in a small area (about 40 km in width and 120 km in length) near the Japan Trench and generated the huge tsunami. After the Tohoku-oki earthquake, seismic coupling near the trench axis has become a key to understand giant earthquakes in subduction zones, and it is GPS/Acoustic (GPS/A) repeated seafloor positioning that can give an observational constraint to it. Observation of postseimic deformation is another and urgent task required in the Japan Trench. Seafloor geodetic observation indicates posteseimic deformation near the Japan Trench axis in the north and south of the huge slip area (Iinuma et al., 2012b). The result is clearly different from that of onshore GPS observation. Postseismic deformation is estimated to be a key observation that can discriminate proper models from several ones that can explain the occurrence of the mega thrust. Tohoku University plans to deploy extensive GPS/A observation array along the Japan Trench in 2012 with a fund from MEXT, Japan, to cope with these requests (Kido et al., in this meeting). Precision acoustic transponders have newly been developed for the array to enable the following three requests: (1) observation on the deep seafloor, (2) compatibility among three institutions in Japan, and (3) observation for ten years. The first is the observation on the deep seafloor near the trench. While the Japan Trench axis is deeper than 7000 m, the existing GPS/A sites along the Japan Trench have remained on the seafloor shallower than 2500 m except the one nearest to the trench, where we observed coseismic slip of 31 m (Kido et al., 2011). We deployed 4 units of the new transponders supplied by Kaiyo

  13. Observations of a diapycnal shortcut to adiabatic upwelling of Antarctic Circumpolar Deep Water

    NASA Astrophysics Data System (ADS)

    Silvester, J. Mead; Lenn, Yueng-Djern; Polton, Jeff A.; Rippeth, Tom P.; Maqueda, M. Morales

    2014-11-01

    In the Southern Ocean, small-scale turbulence causes diapycnal mixing which influences important water mass transformations, in turn impacting large-scale ocean transports such as the Meridional Overturning Circulation (MOC), a key controller of Earth's climate. We present direct observations of mixing over the Antarctic continental slope between water masses that are part of the Southern Ocean MOC. A 12 h time series of microstructure turbulence measurements, hydrography, and velocity observations off Elephant Island, north of the Antarctic Peninsula, reveals two concurrent bursts of elevated dissipation of O(10-6) W kg-1, resulting in heat fluxes ˜10 times higher than basin-integrated Drake Passage estimates. This occurs across the boundary between adjacent adiabatic upwelling and downwelling overturning cells. Ray tracing to nearby topography shows mixing between 300 and 400 m is consistent with the breaking of locally generated internal tidal waves. Since similar conditions extend to much of the Antarctic continental slope where these water masses outcrop, diapycnal mixing may contribute significantly to upwelling.

  14. Initial deep LOFAR observations of epoch of reionization windows. I. The north celestial pole

    NASA Astrophysics Data System (ADS)

    Yatawatta, S.; de Bruyn, A. G.; Brentjens, M. A.; Labropoulos, P.; Pandey, V. N.; Kazemi, S.; Zaroubi, S.; Koopmans, L. V. E.; Offringa, A. R.; Jelić, V.; Martinez Rubi, O.; Veligatla, V.; Wijnholds, S. J.; Brouw, W. N.; Bernardi, G.; Ciardi, B.; Daiboo, S.; Harker, G.; Mellema, G.; Schaye, J.; Thomas, R.; Vedantham, H.; Chapman, E.; Abdalla, F. B.; Alexov, A.; Anderson, J.; Avruch, I. M.; Batejat, F.; Bell, M. E.; Bell, M. R.; Bentum, M.; Best, P.; Bonafede, A.; Bregman, J.; Breitling, F.; van de Brink, R. H.; Broderick, J. W.; Brüggen, M.; Conway, J.; de Gasperin, F.; de Geus, E.; Duscha, S.; Falcke, H.; Fallows, R. A.; Ferrari, C.; Frieswijk, W.; Garrett, M. A.; Griessmeier, J. M.; Gunst, A. W.; Hassall, T. E.; Hessels, J. W. T.; Hoeft, M.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Kondratiev, V. I.; Kramer, M.; Kuniyoshi, M.; Kuper, G.; van Leeuwen, J.; Maat, P.; Mann, G.; McKean, J. P.; Mevius, M.; Mol, J. D.; Munk, H.; Nijboer, R.; Noordam, J. E.; Norden, M. J.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H. J. A.; Sluman, J.; Smirnov, O.; Stappers, B.; Steinmetz, M.; Tagger, M.; Tang, Y.; Tasse, C.; ter Veen, S.; Vermeulen, R.; van Weeren, R. J.; Wise, M.; Wucknitz, O.; Zarka, P.

    2013-02-01

    Aims: The aim of the LOFAR epoch of reionization (EoR) project is to detect the spectral fluctuations of the redshifted HI 21 cm signal. This signal is weaker by several orders of magnitude than the astrophysical foreground signals and hence, in order to achieve this, very long integrations, accurate calibration for stations and ionosphere and reliable foreground removal are essential. Methods: One of the prospective observing windows for the LOFAR EoR project will be centered at the north celestial pole (NCP). We present results from observations of the NCP window using the LOFAR highband antenna (HBA) array in the frequency range 115 MHz to 163 MHz. The data were obtained in April 2011 during the commissioning phase of LOFAR. We used baselines up to about 30 km. The data was processed using a dedicated processing pipeline which is an enhanced version of the standard LOFAR processing pipeline. Results: With about 3 nights, of 6 h each, effective integration we have achieved a noise level of about 100 μJy/PSF in the NCP window. Close to the NCP, the noise level increases to about 180 μJy/PSF, mainly due to additional contamination from unsubtracted nearby sources. We estimate that in our best night, we have reached a noise level only a factor of 1.4 above the thermal limit set by the noise from our Galaxy and the receivers. Our continuum images are several times deeper than have been achieved previously using the WSRT and GMRT arrays. We derive an analytical explanation for the excess noise that we believe to be mainly due to sources at large angular separation from the NCP. We present some details of the data processing challenges and how we solved them. Conclusions: Although many LOFAR stations were, at the time of the observations, in a still poorly calibrated state we have seen no artefacts in our images which would prevent us from producing deeper images in much longer integrations on the NCP window which are about to commence. The limitations present in our

  15. A new acoustically telemetering deep-sea photometer with some observations on underwater light in the northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Roe, H. S. J.; Harris, M. J.

    1980-02-01

    A new deep-sea photometer that uses a silicon photodiode as a light sensor is described. The photometer is interfaced with the Institute of Oceanographic Sciences' net monitor, and it measures and acoustically telemeters underwater irradiance. Using the photometer in conjunction with the I.O.S. rectangular midwater trawls it is possible simultaneously to collect biological samples and measure irradiance at the depth of the net. The photometer has measured light to a depth of 700 m in the northeast Atlantic. It records at least seven decades of irradiance and its response is independent of temperature between -3 and +30°C. Measurements of the attenuation coefficient at various stations agree with previous results, and observations are presented on the effects of cloud cover on underwater light. A biological sampling programme using the photometer is described. Preliminary analysis of the samples suggests that different animal populations inhabit different light regimes.

  16. Deep space observations of the east-west asymmetry of solar energetic storm particle events - Voyagers 1 and 2

    NASA Technical Reports Server (NTRS)

    Sarris, E. T.; Decker, R. B.; Krimigis, S. M.

    1985-01-01

    It has been well established that solar flare shock waves, propagating through the interplanetary medium, accelerate ambient energetic particles, giving rise to the formation of energetic storm particle (ESP) intensity enhancements. However, the acceleration mechanism which is responsible for the generation of ESP events is still under investigation. In the present investigation, energetic proton observations during solar flare ESP events made with the aid of the Voyagers 1 and 2 deep space probes are employed as a basis to examine further the acceleration processes responsible for the generation of ESP events under different 'interplanetary magnetic field-shock front' configurations. It is found that large ESP proton intensity enhancements are superimposed on the ambient solar energetic particle population for solar flare sites to the east of the sun-spacecraft medidian.

  17. Searching for decaying dark matter in deep XMM-Newton observation of the Draco dwarf spheroidal

    NASA Astrophysics Data System (ADS)

    Ruchayskiy, Oleg; Boyarsky, Alexey; Iakubovskyi, Dmytro; Bulbul, Esra; Eckert, Dominique; Franse, Jeroen; Malyshev, Denys; Markevitch, Maxim; Neronov, Andrii

    2016-08-01

    We present results of a search for the 3.5 keV emission line in our recent very long (˜ 1.4 Ms) XMM-Newton observation of the Draco dwarf spheroidal galaxy. The astrophysical X-ray emission from such dark matter-dominated galaxies is faint, thus they provide a test for the dark matter origin of the 3.5 keV line previously detected in other massive, but X-ray bright objects, such as galaxies and galaxy clusters. We do not detect a statistically significant emission line from Draco; this constrains the lifetime of a decaying dark matter particle to τ > (7-9) × 1027 s at 95 per cent CL (combining all three XMM-Newton cameras; the interval corresponds to the uncertainty of the dark matter column density in the direction of Draco). The PN camera, which has the highest sensitivity of the three, does show a positive spectral residual (above the carefully modelled continuum) at E = 3.54 ± 0.06 keV with a 2.3σ significance. The two MOS cameras show less-significant or no positive deviations, consistently within 1σ with PN. Our Draco limit on τ is consistent with previous detections in the stacked galaxy clusters, M31 and the Galactic Centre within their 1 - 2σ uncertainties, but is inconsistent with the high signal from the core of the Perseus cluster (which has itself been inconsistent with the rest of the detections). We conclude that this Draco observation does not exclude the dark matter interpretation of the 3.5 keV line in those objects.

  18. RADIO AND DEEP CHANDRA OBSERVATIONS OF THE DISTURBED COOL CORE CLUSTER ABELL 133

    SciTech Connect

    Randall, S. W.; Nulsen, P. E. J.; Forman, W. R.; Murray, S. S.; Clarke, T. E.; Owers, M. S.; Sarazin, C. L.

    2010-10-10

    We present results based on new Chandra and multi-frequency radio observations of the disturbed cool core cluster Abell 133. The diffuse gas has a complex bird-like morphology, with a plume of emission extending from two symmetric wing-like features. The plume is capped with a filamentary radio structure that has been previously classified as a radio relic. X-ray spectral fits in the region of the relic indicate the presence of either high-temperature gas or non-thermal emission, although the measured photon index is flatter than would be expected if the non-thermal emission is from inverse Compton scattering of the cosmic microwave background by the radio-emitting particles. We find evidence for a weak elliptical X-ray surface brightness edge surrounding the core, which we show is consistent with a sloshing cold front. The plume is consistent with having formed due to uplift by a buoyantly rising radio bubble, now seen as the radio relic, and has properties consistent with buoyantly lifted plumes seen in other systems (e.g., M87). Alternatively, the plume may be a gas sloshing spiral viewed edge-on. Results from spectral analysis of the wing-like features are inconsistent with the previous suggestion that the wings formed due to the passage of a weak shock through the cool core. We instead conclude that the wings are due to X-ray cavities formed by displacement of X-ray gas by the radio relic. The central cD galaxy contains two small-scale cold gas clumps that are slightly offset from their optical and UV counterparts, suggestive of a galaxy-galaxy merger event. On larger scales, there is evidence for cluster substructure in both optical observations and the X-ray temperature map. We suggest that the Abell 133 cluster has recently undergone a merger event with an interloping subgroup, initialing gas sloshing in the core. The torus of sloshed gas is seen close to edge-on, leading to the somewhat ragged appearance of the elliptical surface brightness edge. We show

  19. The DEEP2 Galaxy Redshift Survey: AEGIS observations of a Dual AGNat z = 0.7

    SciTech Connect

    Gerke1, Brian F.; Newman, Jeffrey A.; Lotz, Jennifer; Yan,Renbin; Barmby, P.; Coil, Alison L.; Conselice, Christopher J.; Ivison,R.J.; Lin, Lihw ai; Koo, David C.; Nandra, Kirpal; Salim, Samir; Small,Todd; Weiner, Benjamin J.; Cooper, Michael C.; Davis, Marc; Faber, S.M.; Guhathakurta, Puragra

    2006-10-13

    We present evidence for a dual Active Galactic Nucleus (AGN) within an early-type galaxy at z = 0.709 in the Extended Groth Strip. The galaxy lies on the red sequence, with absolute magnitude M{sub B} = -21.0 ( AB, w , with h = 0 0.7) and rest-frame color U - B = 1.38. Its optical spectrum shows strong, double-peaked [O III] emission lines and weak H{beta} emission, with Seyfert-like line ratios. The two narrow peaks are separate by 630 km s-1 in velocity and arise from two distinct regions, spatially resolved in the DEIMOS spectrum, with a projected physical separation of 1.2 kpc. HST/ACS imaging shows an early-type (E/S0) galaxy with hints of disturbed structure, consistent with the remnant of a dissipationless merger. Multiwavelength photometric information from the AEGIS consortium confirm the identification of a dust-obscured AGN in an early-type galaxy, with detections in X-ray, optical, infrared and radio wavebands. These data are most readily explained as a single galaxy harboring two AGN--the first such system to be observed in an otherwise typical early-type galaxy.

  20. Numerical spherical aberration correction method using spatial light modulator under deep-part fluorescence observation

    NASA Astrophysics Data System (ADS)

    Takiguchi, Yu; Takamoto, Hisayoshi; Kanada, Masamitsu; Inoue, Takashi; Matsumoto, Naoya; Terakawa, Susumu

    2014-03-01

    We have developed a confocal fluorescence laser scanning microscopy (CFLSM) incorporating a liquid crystal on silicon spatial light modulator (LCOS-SLM). To achieve high-resolution and high-contrast imaging for deeper part of the tissue with CFLSM, high numerical aperture objective lenses are required to tightly focus excitation light to meet Rayleigh limit(criterion) for the specimens. However, mismatch of refractive index at the boundary of interfacing materials, such as atmosphere, glass cover, and biological tissues, causes spherical aberration. Recently, we proposed a numerical method for correcting spherical aberration. In this method a pre-distorted wavefront pattern for aberration correction is calculated by ray tracing from a hypothetical focal point inside a specimen to the pupil plane. The resulting microscope can correct such spherical aberration. We observed 6.0μm fluorescent micro-beads dispersed three-dimensionally in agarose gel to confirm effectiveness of aberration correction. We reconstructed a three-dimensional image by taking 20 images by changing the depth with 1 μm interval and stacking them. It was apparent that the longitudinal/depth resolution was improved and that the intensity of fluorescence image was increased with aberration correction. While this method is applicable to other laser scanning microscopes, it has potential to enhance the signals for various super-resolution microscopic techniques, such as stimulated- emission-depletion (STED) fluorescence microscopy.

  1. HESS J1731-347: A new TeV gamma-ray and X-ray emitting supernova remnant

    NASA Astrophysics Data System (ADS)

    Puehlhofer, Gerd

    2012-10-01

    HESS J1731-347 is only the third known TeV-emitting SNR with a pure nonthermal X-ray spectrum. Together with RX J1713.7-3946 and RX J0852.0-4622, the sources are outstanding because of their TeV luminosity and their synchrotron-only X-ray emission. These SNRs are considered prime candidates for hadronic cosmic ray acceleration. But currently, it is highly debated if the TeV emission is really tracing hadronic cosmic rays, or if X-rays and TeV photons are emitted basically just by the same cosmic ray electron population. With this proposal, we ask for 55 ksec of XMM-Newton observing time on the western part of the HESS J1731-347 shell, in order to resolve the synchrotron-emitting filaments in this part of the remnant and to bring the high resolution X-ray mapping of the source to near completion.

  2. HESS J1731-347: A new TeV gamma-ray and X-ray emitting supernova remnant

    NASA Astrophysics Data System (ADS)

    Puehlhofer, Gerd

    2011-10-01

    HESS J1731-347 is only the third known TeV-emitting SNR with a pure nonthermal X-ray spectrum. Together with RX J1713.7-3946 and RX J0852.0-4622, the sources are outstanding because of their TeV luminosity and their synchrotron-only X-ray emission. These SNRs are considered prime candidates for hadronic cosmic ray acceleration. But currently, it is highly debated if the TeV emission is really tracing hadronic cosmic rays, or if X-rays and TeV photons are emitted basically just by the same cosmic ray electron population. With this proposal, we ask for 55 ksec of XMM-Newton observing time on the western part of the HESS J1731-347 shell, in order to resolve the synchrotron-emitting filaments in this part of the remnant and to bring the high resolution X-ray mapping of the source to near completion.

  3. Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations

    NASA Astrophysics Data System (ADS)

    Lundgren, P.; Samsonov, S. V.; López, C. M.; Ordoñez, M.

    2015-12-01

    Nevado del Ruiz (NRV) is part of a large volcano complex in the northern Andes of Colombia with a large glacier that erupted in 1985, generating a lahar killing over 23,000 people in the city of Armero and 2,000 people in the town of Chinchina. NRV is the most active volcano in Colombia and since 2012 has generated small eruptions, with no casualties, and constant gas and ash emissions. Interferometric synthetic aperture radar (InSAR) observations from ascending and descending track RADARSAT-2 data show a large (>20 km) wide inflation pattern apparently starting in late 2011 to early 2012 and continuing to the time of this study in early 2015 at a LOS rate of over 3-4 cm/yr (Fig. 1). Volcano pressure volume models for both a point source (Mogi) and a spheroidal (Yang) source find solutions over 14 km beneath the surface, or 10 km below sea level, and centered 10 km to the SW of Nevado del Ruiz volcano. The spheroidal source has a roughly horizontal long axis oriented parallel to the Santa Isabel - Nevado del Ruiz volcanic line and perpendicular to the ambient compressive stress direction. Its solution provides a statistically significant improvement in fit compared to the point source, though consideration of spatially correlated noise sources may diminish this significance. Stress change computations do not favor one model over the other but show that propagating dikes would become trapped in sills, leading to a more complex pathway to the surface and possibly explaining the significant lateral distance between the modeled sources and Nevado del Ruiz volcano.

  4. [Hospitals in Hesse in the view of enlightened travellers].

    PubMed

    Vanja, Christina

    2006-01-01

    The "Hohen Hospitäler", hospitals founded by landgrave Philipp dem Grossmütigen during the years 1533-1542, were seen as an expression of greatest caritas in Early Modern times. These protestant institutions for the poor and sick underlings of Hesse were appreciated as charitable shelters by noblemen and commoners. This situation changed dramatically at the end of the 18th century. The first critics were travelling philosophers of the Enlightenment, who visited the "mad houses" of Hesse as well as other oddities. They published their experiences in travel reports. Although the hospitals as integrated institutions still cared for both psychiatric and somatic patients, these authors only concentrated on the mad inmates. The fact that these were kept in "dark and dirty cloistral corridors" was the central point of criticism. This negative situation was confronted by the travellers not only with a demand for more hygiene but also with a call for an academically trained physician. Furthermore, they claimed for dissecting deceased patients in order to explore the nature of madness. A comparison of these travel reports with the first psychiatric publications of the early 19th century discloses a literary discourse. It leads from the reports of travellers with a general interest to specialist literature of early psychiatry. Obviously it had a formative influence on the self-conception of this new medical field, which benefited from the criticism concerning the allegedly inhumane conditions in the old hospitals. Three questions follow from this statement: 1. Which were the images produced or reproduced by the travellers in their reports? 2. Which were the standards against which the critics measured their reports? 3. In how far were the philanthropic aims of the enlightened travellers related to the self-conception of the hospitals and their inmates? Travelling reports are compared with the circumstances in the hospitals. This comparison throws light in the "invention" of

  5. The Anisotropy of the Microwave Background to l = 3500: Deep Field Observations with the Cosmic Background Imager

    NASA Technical Reports Server (NTRS)

    Mason, B. S.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.; Sievers, J.; Udomprasert, P. S.; Cartwright, J. K.; Farmer, A. J.; Padin, S.; Myers, S. T.; Six, N. Frank (Technical Monitor)

    2002-01-01

    We report measurements of anisotropy in the cosmic microwave background radiation over the multipole range l approximately 200 (right arrow) 3500 with the Cosmic Background Imager based on deep observations of three fields. These results confirm the drop in power with increasing l first reported in earlier measurements with this instrument, and extend the observations of this decline in power out to l approximately 2000. The decline in power is consistent with the predicted damping of primary anisotropies. At larger multipoles, l = 2000-3500, the power is 3.1 sigma greater than standard models for intrinsic microwave background anisotropy in this multipole range, and 3.5 sigma greater than zero. This excess power is not consistent with expected levels of residual radio source contamination but, for sigma 8 is approximately greater than 1, is consistent with predicted levels due to a secondary Sunyaev-Zeldovich anisotropy. Further observations are necessary to confirm the level of this excess and, if confirmed, determine its origin.

  6. A Deep Chandra Observation of NGC 1404: the Best Constraints on the Transport Processes in the Intracluster Medium

    NASA Astrophysics Data System (ADS)

    Kraft, Ralph P.; Su, Yuanyuan; Nulsen, Paul; Roediger, Elke; Forman, William R.; Churazov, Eugene; Jones, Christine; Randall, Scott W.; Machacek, Marie E.

    2016-04-01

    The intracluster medium, as a magnetized and highly ionized fluid, provides an ideal laboratory to study plasma physics. We present results from the Chandra X-ray observation of NGC 1404, a bright elliptical galaxy falling through the ICM of the Fornax Cluster. The hot, gaseous corona surrounding NGC 1404 is characterized by a sharp upstream edge and a downstream gaseous tail. We resolve the scales of contact discontinuities down to an unprecedented level due to the combination of the proximity of NGC 1404, the superb spatial resolution of Chandra, and a very deep (670 ksec) exposure. We observed Kelvin-Helmholtz instability (KHI) rolls and put an upper limit on the viscosity of hot cluster plasma. We also observed a mixing between the hot cluster gas and the cold galaxy gas in the downstream stripped tail, providing further support of a low viscosity plasma. Across the upstream front, we measured a discontinuity smaller than the mean free path. The magnetic field is strong enough to suppress electron diffusions but weak enough to allow KHI rolls unsuppressed. Our simulation, tailored to the specific scenario, will provide further insight into the details of the transport process.

  7. Aircraft observations of biomass burning emissions in the lower stratosphere during the Deep Convective Clouds and Chemistry Experiment (DC3)

    NASA Astrophysics Data System (ADS)

    Knapp, D. J.; Montzka, D.; Campos, T. L.; Flocke, F. M.; Stechman, D.; Farris, C.; Rooney, M.; Pan, L.; Apel, E. C.; Hornbrook, R. S.; Riemer, D. D.; Chen, D.; Huey, L. G.; Brock, C. A.; Froyd, K. D.; Liao, J.; Murphy, D. M.; Ryerson, T. B.; Dibb, J. E.; Scheuer, E. M.; Diskin, G. S.; Sachse, G. W.; Gao, R.; Langridge, J. M.; Hair, J. W.; Butler, C. F.; Fenn, M. A.; Fromm, M. D.; Lindsey, D.; Weinheimer, A. J.

    2012-12-01

    During test flights for the Deep Convective Clouds and Chemistry Experiment conducted in May and June of 2012, clear indications of biomass burning (BB) were observed in the Lower Stratosphere (LS). Enhancements in CO, aerosols, and CH3CN substantiate the impact of BB effluents on the studied air mass. A large complex of fires southwest of Lake Baikal in Russia had been observed to flare up significantly on May 7, 2012, leading to a strong Aerosol Index signature. The aerosol plume was tracked using AURA Ozone Monitoring Instrument (OMI) and Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observations (CALIPSO) curtains from the Baikal area, over Northern Siberia, the Aleutian Islands, South Western Canada and ultimately to the DC3 flight study area on May 14, 2012. BB tracers were sampled from the NASA DC8 and the NSF GV aircraft over a lateral range of 600km and an altitude of approximately 11.7 km which is approximately 0.5 km to 1.0 km above the local cold point tropopause.

  8. Ocean deep convection in the Mediterranean sea: 2012-2013 case study in the Gulf of Lions, from observations to multi-scale modelling.

    NASA Astrophysics Data System (ADS)

    Waldman, Robin; Somot, Samuel; Herrmann, Marine; Sevault, Florence; Caniaux, Guy; Giordani, Hervé; Testor, Pierre; Estournel, Claude

    2015-04-01

    Ocean deep convection is a major process of interaction between surface and deep ocean, it indeed plays a major role in ocean heat and CO2 uptake in a warming climate, sea level rise and nutrient storage for marine biology. In this study, ocean deep convection is investigated in the Gulf of Lions, the main deep water formation (DWF) site in the Western Mediterranean sea. Recent observations in the frame of MOOSE, HyMeX and Mermex programmes allow for a thorough analysis of 2012-2013 convective year. The Mediterranean sea model NEMOMED12 ( 6km resolution) with its grid refinement ( 2km) is used as a numerical tool to characterize and understand ocean deep convection in 2012-2013. The model is initialized on august 1st 2012 using an ensemble of gridded reanalyses based on in situ observations (MOOSE 2012 ship cruise). The atmospheric forcing ALADIN-Climate is a dynamical downscaling of the ERA-INTERIM reanalysis at 12km and 3hr resolution over the 2012-2013 period. Near-Atlantic ocean conditions are damped towards ORAS4 reanalysis and river and Black Sea freshwater inflows are prescribed from climatologies. An assessment of large-scale convection is done for 2012-2013 year in NEMOMED12 and observations, allowing for a characterization of its chronology, intensity, location as well as the hydrology of the main water masses involved. This study addresses the respective impacts of atmospheric forcing, ocean preconditionning and mesoscale resolution to deep convection.

  9. Faint submillimeter galaxies revealed by multifield deep ALMA observations: number counts, spatial clustering, and a dark submillimeter line emitter

    SciTech Connect

    Ono, Yoshiaki; Ouchi, Masami; Momose, Rieko; Kurono, Yasutaka

    2014-11-01

    We present the statistics of faint submillimeter/millimeter galaxies (SMGs) and serendipitous detections of a submillimeter/millimeter line emitter (SLE) with no multi-wavelength continuum counterpart revealed by the deep ALMA observations. We identify faint SMGs with flux densities of 0.1-1.0 mJy in the deep Band-6 and Band-7 maps of 10 independent fields that reduce cosmic variance effects. The differential number counts at 1.2 mm are found to increase with decreasing flux density down to 0.1 mJy. Our number counts indicate that the faint (0.1-1.0 mJy, or SFR{sub IR} ∼ 30-300 M {sub ☉} yr{sup –1}) SMGs contribute nearly a half of the extragalactic background light (EBL), while the remaining half of the EBL is mostly contributed by very faint sources with flux densities of <0.1 mJy (SFR{sub IR} ≲ 30 M {sub ☉} yr{sup –1}). We conduct counts-in-cells analysis with multifield ALMA data for the faint SMGs, and obtain a coarse estimate of galaxy bias, b {sub g} < 4. The galaxy bias suggests that the dark halo masses of the faint SMGs are ≲ 7 × 10{sup 12} M {sub ☉}, which is smaller than those of bright (>1 mJy) SMGs, but consistent with abundant high-z star-forming populations, such as sBzKs, LBGs, and LAEs. Finally, we report the serendipitous detection of SLE-1, which has no continuum counterparts in our 1.2 mm-band or multi-wavelength images, including ultra deep HST/WFC3 and Spitzer data. The SLE has a significant line at 249.9 GHz with a signal-to-noise ratio of 7.1. If the SLE is not a spurious source made by the unknown systematic noise of ALMA, the strong upper limits of our multi-wavelength data suggest that the SLE would be a faint galaxy at z ≳ 6.

  10. Wet scavenging of soluble gases in DC3 deep convective storms using WRF-Chem simulations and aircraft observations

    NASA Astrophysics Data System (ADS)

    Bela, Megan M.; Barth, Mary C.; Toon, Owen B.; Fried, Alan; Homeyer, Cameron R.; Morrison, Hugh; Cummings, Kristin A.; Li, Yunyao; Pickering, Kenneth E.; Allen, Dale J.; Yang, Qing; Wennberg, Paul O.; Crounse, John D.; St. Clair, Jason M.; Teng, Alex P.; O'Sullivan, Daniel; Huey, L. Gregory; Chen, Dexian; Liu, Xiaoxi; Blake, Donald R.; Blake, Nicola J.; Apel, Eric C.; Hornbrook, Rebecca S.; Flocke, Frank; Campos, Teresa; Diskin, Glenn

    2016-04-01

    We examine wet scavenging of soluble trace gases in storms observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. We conduct high-resolution simulations with the Weather Research and Forecasting model with Chemistry (WRF-Chem) of a severe storm in Oklahoma. The model represents well the storm location, size, and structure as compared with Next Generation Weather Radar reflectivity, and simulated CO transport is consistent with aircraft observations. Scavenging efficiencies (SEs) between inflow and outflow of soluble species are calculated from aircraft measurements and model simulations. Using a simple wet scavenging scheme, we simulate the SE of each soluble species within the error bars of the observations. The simulated SEs of all species except nitric acid (HNO3) are highly sensitive to the values specified for the fractions retained in ice when cloud water freezes. To reproduce the observations, we must assume zero ice retention for formaldehyde (CH2O) and hydrogen peroxide (H2O2) and complete retention for methyl hydrogen peroxide (CH3OOH) and sulfur dioxide (SO2), likely to compensate for the lack of aqueous chemistry in the model. We then compare scavenging efficiencies among storms that formed in Alabama and northeast Colorado and the Oklahoma storm. Significant differences in SEs are seen among storms and species. More scavenging of HNO3 and less removal of CH3OOH are seen in storms with higher maximum flash rates, an indication of more graupel mass. Graupel is associated with mixed-phase scavenging and lightning production of nitrogen oxides (NOx), processes that may explain the observed differences in HNO3 and CH3OOH scavenging.

  11. H.E.S.S. Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center

    NASA Astrophysics Data System (ADS)

    Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Hahn, J.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Liu, R.; Lohse, T.; Lorentz, M.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morâ, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Öttl, S.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tluczykont, M.; Trichard, C.; Tuffs, R.; van der Walt, J.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.; H. E. S. S. Collaboration

    2016-10-01

    A search for dark matter linelike signals iss performed in the vicinity of the Galactic Center by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis iss developed to improve the sensitivity to linelike signals. The upgraded analysis along with newer data extend the energy coverage of the previous measurement down to 100 GeV. The 18 h of data collected with the H.E.S.S. array allow one to rule out at 95% C.L. the presence of a 130 GeV line (at l =-1.5 ° , b =0 ° and for a dark matter profile centered at this location) previously reported in Fermi-LAT data. This new analysis overlaps significantly in energy with previous Fermi-LAT and H.E.S.S. results. No significant excess associated with dark matter annihilations was found in the energy range of 100 GeV to 2 TeV and upper limits on the gamma-ray flux and the velocity weighted annihilation cross section are derived adopting an Einasto dark matter halo profile. Expected limits for present and future large statistics H.E.S.S. observations are also given.

  12. HST/ACS Observations of RR Lyrae Stars in Six Ultra-Deep Fields of M31

    NASA Technical Reports Server (NTRS)

    Jeffery, E. J.; Smith, E.; Brown, T. M.; Sweigart, A. V.; Kalirai, J. S.; Ferguson, H. C.; Guhathakurta, P.; Renzini, A.; Rich, R. M.

    2010-01-01

    We present HST/ACS observations of RR Lyrae variable stars in six ultra deep fields of the Andromeda galaxy (M31), including parts of the halo, disk, and giant stellar stream. Past work on the RR Lyrae stars in M31 has focused on various aspects of the stellar populations that make up the galaxy s halo, including their distances and metallicities. This study builds upon this previous work by increasing the spatial coverage (something that has been lacking in previous studies) and by searching for these variable stars in constituents of the galaxy not yet explored. Besides the 55 RR Lyrae stars we found in our initial field located 11kpc from the galactic nucleus, we find additional RR Lyrae stars in four of the remaining five ultra deep fields as follows: 21 in the disk, 24 in the giant stellar stream, 3 in the halo field 21kpc from the galactic nucleus, and 5 in one of the halo fields at 35kpc. No RR Lyrae were found in the second halo field at 35kpc. The RR Lyrae populations of these fields appear to mostly be of Oosterhoff I type, although the 11kpc field appears to be intermediate or mixed. We will discuss the properties of these stars including period and reddening distributions. We calculate metallicities and distances for the stars in each of these fields using different methods and compare the results, to an extent that has not yet been done. We compare these methods not just on RR Lyrae in our M31 fields, but also on a data set of Milky Way field RR Lyrae stars.

  13. Shallow-to-Deep Transition of Madden-Julian Oscillation Convection as Observed by TRMM and GPM

    NASA Astrophysics Data System (ADS)

    Xu, W.; Rutledge, S. A.

    2015-12-01

    This study uses TRMM and GPM data to study the evolution of Madden-Julian Oscillation (MJO) convection over the Indian Ocean (IO). Radar observations from the 2011-2012 DYNAMO field campaign in the central IO have provided rich information on the 3D structure of MJO convection, including the transition from shallow to deep convection during the MJO onset. However, DYNAMO radar measurements are limited to only three MJO events and three radar sites. In this study, the shallow to deep transition (SDT) problem and lifecycle evolution of MJO events over the IO is revisited using longer term, larger-scale TRMM and GPM data. Our analysis indicates that the TRMM and GPM satellite is able to capture the evolution of individual MJO events (e.g., precipitation) on the daily and regional (e.g., 2000 km x 2000 km) scale. We have investigated the evolution and properties of ~40 prominent MJO events in terms of precipitation amounts, three-dimensional radar reflectivity, microwave ice scattering signatures, cloud top brightness temperature, and lightning flash rates. We track the SDT time scale and lifecycle evolution of each MJO using these multiple parameters, instead of composites in previous TRMM studies. MJO events have also been examined as a function of the MJO type (e.g., duration of MJO lifecycles and MJO strength). Preliminary results show that the SDT is on the scale of 7-10 days with small variations among different MJO types. SDT trends are less well-defined by the 20 dBZ (TRMM PR) echo top height compared to lower thresholds. In contrast, the satellite IR brightness temperature (TRMM VIRS), the 12 dBZ (GPM DPR Ka-band) echo top heights, and lightning flash rate (TRMM LIS) depict the STD rather well.

  14. HST/ACS OBSERVATIONS OF RR LYRAE STARS IN SIX ULTRA-DEEP FIELDS OF M31

    SciTech Connect

    Jeffery, E. J.; Smith, E.; Brown, T. M.; Kalirai, J. S.; Ferguson, H. C.; Sweigart, A. V.; Rich, R. M.

    2011-05-15

    We present HST/ACS observations of RR Lyrae variable stars in six ultra-deep fields of the Andromeda galaxy (M31), including parts of the halo, disk, and giant stellar stream. Past work on the RR Lyrae stars in M31 has focused on various aspects of the stellar populations that make up the galaxy's halo, including their distances and metallicities. This study builds upon this previous work by increasing the spatial coverage (something that has been lacking in previous studies) and by searching for these variable stars in constituents of the galaxy not yet explored. Besides the 55 RR Lyrae stars we found in our initial field located 11 kpc from the galactic nucleus, we find additional RR Lyrae stars in four of the remaining five ultra-deep fields as follows: 21 in the disk, 24 in the giant stellar stream, three in the halo field 21 kpc from the galactic nucleus, and five in one of the halo fields at 35 kpc. No RR Lyrae stars were found in the second halo field at 35 kpc. The RR Lyrae populations of these fields appear to be mostly of Oosterhoff I type, although the 11 kpc field appears to be intermediate or mixed. We will discuss the properties of these stars including period and reddening distributions. We calculate metallicities and distances for the stars in each of these fields using different methods and compare the results, to an extent that has not yet been done. We compare these methods not just on RR Lyrae stars in our M31 fields, but also on a data set of Milky Way field RR Lyrae stars.

  15. [Sauna deaths in Hesse, Germany, between 1994 and 2014].

    PubMed

    Plenzig, Stefanie; Birngruber, Christoph G; Kettner, Mattias; Held, Hannelore; Verhoff, Marcel A

    2015-01-01

    Due to the high ambient temperature, sauna deaths show a few confounding particularities, such as an accelerated onset of the postmortem changes, that can make correct assessment of the manner of death difficult and severely constrain the accuracy of post- mortem interval estimates. This retrospective study, performed at the medicolegal institutes in Hesse, Germany, reviewed all autopsy reports from the years 1994-2014 for sauna-related deaths. 9 relevant cases were found involving one woman and eight men aged between 52 and 80 years (mean and median value: 67 years). Of the individuals who had died of a natural cause, four were found to have had coronary heart disease, which, in the setting of heart hypertrophy and exposure to high temperatures, ultimately led to cardiac failure. In three other cases, a non-natural cause of death had been diagnosed; however, all were attributable to accidents. In two of these, blood alcohol concentrations (BAC) of over two per mil were found. In our opinion, the manner of death should be classified as undetermined in sauna-related fatalities. Such cases require a court-ordered autopsy to reliably identify the actual cause of death.

  16. Search for photon-linelike signatures from dark matter annihilations with H.E.S.S.

    PubMed

    Abramowski, A; Acero, F; Aharonian, F; Akhperjanian, A G; Anton, G; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Becker Tjus, J; Bernlöhr, K; Birsin, E; Biteau, J; Bochow, A; Boisson, C; Bolmont, J; Bordas, P; Brucker, J; Brun, F; Brun, P; Bulik, T; Carrigan, S; Casanova, S; Cerruti, M; Chadwick, P M; Chaves, R C G; Cheesebrough, A; Colafrancesco, S; Cologna, G; Conrad, J; Couturier, C; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; deWilt, P; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Egberts, K; Eger, P; Espigat, P; Fallon, L; Farnier, C; Fegan, S; Feinstein, F; Fernandes, M V; Fernandez, D; Fiasson, A; Fontaine, G; Förster, A; Füßling, M; Gajdus, M; Gallant, Y A; Garrigoux, T; Gast, H; Giebels, B; Glicenstein, J F; Glück, B; Göring, D; Grondin, M-H; Häffner, S; Hague, J D; Hahn, J; Hampf, D; Harris, J; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hillert, A; Hinton, J A; Hofmann, W; Hofverberg, P; Holler, M; Horns, D; Jacholkowska, A; Jahn, C; Jamrozy, M; Jung, I; Kastendieck, M A; Katarzyński, K; Katz, U; Kaufmann, S; Khélifi, B; Klepser, S; Klochkov, D; Kluźniak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lefaucheur, J; Lemoine-Goumard, M; Lenain, J-P; Lennarz, D; Lohse, T; Lopatin, A; Lu, C-C; Marandon, V; Marcowith, A; Masbou, J; Maurin, G; Maxted, N; Mayer, M; McComb, T J L; Medina, M C; Méhault, J; Menzler, U; Moderski, R; Mohamed, M; Moulin, E; Naumann, C L; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nguyen, N; Niemiec, J; Nolan, S J; Ohm, S; de Oña Wilhelmi, E; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Paz Arribas, M; Pekeur, N W; Pelletier, G; Perez, J; Petrucci, P-O; Peyaud, B; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raue, M; Reimer, A; Reimer, O; Renaud, M; de Los Reyes, R; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sheidaei, F; Skilton, J L; Sol, H; Spengler, G; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Szostek, A; Tavernet, J-P; Terrier, R; Tluczykont, M; Trichard, C; Valerius, K; van Eldik, C; Vasileiadis, G; Venter, C; Viana, A; Vincent, P; Völk, H J; Volpe, F; Vorobiov, S; Vorster, M; Wagner, S J; Ward, M; White, R; Wierzcholska, A; Wouters, D; Zacharias, M; Zajczyk, A; Zdziarski, A A; Zech, A; Zechlin, H-S

    2013-01-25

    Gamma-ray line signatures can be expected in the very-high-energy (E(γ)>100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical γ-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. Using data collected with the H.E.S.S. γ-ray instrument, upper limits on linelike emission are obtained in the energy range between ∼ 500 GeV and ∼ 25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic γ-ray line emission, flux limits of (2 × 10(-7) -2 × 10(-5)) m(-2) s(-1) sr(-1) and (1 × 10(-8) -2 × 10(-6)) m(-2) s(-1)sr(-1) are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section ⟨σv⟩(χχ → γγ) reach ∼ 10(-27) cm(3)s(-1), based on the Einasto parametrization of the Galactic DM halo density profile.

  17. The W49 region as seen by H.E.S.S.

    NASA Astrophysics Data System (ADS)

    Brun, F.; de Naurois, M.; Hofmann, W.; Carrigan, S.; Djannati-Ataï, A.; Ohm, S.

    2011-12-01

    The W49 region hosts a star forming region (W49A) and a supernova remnant interacting with molecular clouds (W49B). The 10^6 M_{⊙} Giant Molecular Cloud W49A is one of the most luminous giant radio H II region in our Galaxy and hosts several active, high-mass star formation sites. The mixed-morphology supernova remnant W49B has one of the highest radio surface brightness of all the SNRs of this class in our Galaxy. Infrared observations evidenced that W49B is interacting with molecular clouds and Fermi recently reported the detection of a coincident bright, high-energy gamma-ray source. Observations by the H.E.S.S. telescope array resulted in the significant detection of VHE gamma-ray emission from the W49 region, compatible with gamma-ray emission from the SNR W49B. The results, the morphology and the origin of the VHE gamma-ray emission are presented in the multi-wavelength context and the implications on the origin of the signal are discussed.

  18. Search for photon-linelike signatures from dark matter annihilations with H.E.S.S.

    PubMed

    Abramowski, A; Acero, F; Aharonian, F; Akhperjanian, A G; Anton, G; Balenderan, S; Balzer, A; Barnacka, A; Becherini, Y; Becker Tjus, J; Bernlöhr, K; Birsin, E; Biteau, J; Bochow, A; Boisson, C; Bolmont, J; Bordas, P; Brucker, J; Brun, F; Brun, P; Bulik, T; Carrigan, S; Casanova, S; Cerruti, M; Chadwick, P M; Chaves, R C G; Cheesebrough, A; Colafrancesco, S; Cologna, G; Conrad, J; Couturier, C; Dalton, M; Daniel, M K; Davids, I D; Degrange, B; Deil, C; deWilt, P; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubus, G; Dutson, K; Dyks, J; Dyrda, M; Egberts, K; Eger, P; Espigat, P; Fallon, L; Farnier, C; Fegan, S; Feinstein, F; Fernandes, M V; Fernandez, D; Fiasson, A; Fontaine, G; Förster, A; Füßling, M; Gajdus, M; Gallant, Y A; Garrigoux, T; Gast, H; Giebels, B; Glicenstein, J F; Glück, B; Göring, D; Grondin, M-H; Häffner, S; Hague, J D; Hahn, J; Hampf, D; Harris, J; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hillert, A; Hinton, J A; Hofmann, W; Hofverberg, P; Holler, M; Horns, D; Jacholkowska, A; Jahn, C; Jamrozy, M; Jung, I; Kastendieck, M A; Katarzyński, K; Katz, U; Kaufmann, S; Khélifi, B; Klepser, S; Klochkov, D; Kluźniak, W; Kneiske, T; Komin, Nu; Kosack, K; Kossakowski, R; Krayzel, F; Krüger, P P; Laffon, H; Lamanna, G; Lefaucheur, J; Lemoine-Goumard, M; Lenain, J-P; Lennarz, D; Lohse, T; Lopatin, A; Lu, C-C; Marandon, V; Marcowith, A; Masbou, J; Maurin, G; Maxted, N; Mayer, M; McComb, T J L; Medina, M C; Méhault, J; Menzler, U; Moderski, R; Mohamed, M; Moulin, E; Naumann, C L; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Nguyen, N; Niemiec, J; Nolan, S J; Ohm, S; de Oña Wilhelmi, E; Opitz, B; Ostrowski, M; Oya, I; Panter, M; Parsons, R D; Paz Arribas, M; Pekeur, N W; Pelletier, G; Perez, J; Petrucci, P-O; Peyaud, B; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raue, M; Reimer, A; Reimer, O; Renaud, M; de Los Reyes, R; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Rulten, C B; Sahakian, V; Sanchez, D A; Santangelo, A; Schlickeiser, R; Schulz, A; Schwanke, U; Schwarzburg, S; Schwemmer, S; Sheidaei, F; Skilton, J L; Sol, H; Spengler, G; Stawarz, L; Steenkamp, R; Stegmann, C; Stinzing, F; Stycz, K; Sushch, I; Szostek, A; Tavernet, J-P; Terrier, R; Tluczykont, M; Trichard, C; Valerius, K; van Eldik, C; Vasileiadis, G; Venter, C; Viana, A; Vincent, P; Völk, H J; Volpe, F; Vorobiov, S; Vorster, M; Wagner, S J; Ward, M; White, R; Wierzcholska, A; Wouters, D; Zacharias, M; Zajczyk, A; Zdziarski, A A; Zech, A; Zechlin, H-S

    2013-01-25

    Gamma-ray line signatures can be expected in the very-high-energy (E(γ)>100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical γ-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. Using data collected with the H.E.S.S. γ-ray instrument, upper limits on linelike emission are obtained in the energy range between ∼ 500 GeV and ∼ 25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic γ-ray line emission, flux limits of (2 × 10(-7) -2 × 10(-5)) m(-2) s(-1) sr(-1) and (1 × 10(-8) -2 × 10(-6)) m(-2) s(-1)sr(-1) are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section ⟨σv⟩(χχ → γγ) reach ∼ 10(-27) cm(3)s(-1), based on the Einasto parametrization of the Galactic DM halo density profile. PMID:25166149

  19. Long-period (12sec) Volcanic Tremor Observed at Usu 2000 Eruption: Seismological Detection of a Deep Magma Plumbing system

    NASA Astrophysics Data System (ADS)

    KAWAKATSU, H.; YAMAMOTO, M.

    2001-12-01

    Mt. Usu is a dacitic stratovolcano located in southwestern Hokkaido, Japan, and has erupted repeatedly (in 1910, 1943-45, and 1977-78). In the end of March 2000, after twenty some years of quiescence, Usu volcano began its activity with an intensive earthquake swarm. After several days of the earthquake swarm, on March 31, 2000, the eruption began at the northwest foot of the volcano. We have installed five broadband seismometers around the volcano, and detected long period (12 sec) tremors (hereafter called LPTs) which are continually emitted from the volcano. Although these LPTs are continually observed at an interval of a few minutes, there exist no corresponding surface activities such as eruptions. The source of these LPTs are located relatively deep at a depth of 5 km, and their amplitude variation well correlates with the uplift rate of the eruption area. We thus attribute these LPTs to the flow induced vibration of a magma chamber and its outlet located around the source region of the LPTs. The estimated moment tensor for LPTs shows a reversed polarity for the isotropic and CLVD components. This is consistent with a combination of a deflating spherical source and an inflating crack which opens northwestern direction toward the eruption site. The volumetric magma flow rate may be estimated from the observed RMS amplitude of LPT through a seismic moment rate, and turns out to be around 3*E5 m3 per day. Geodetic observations report the volume change of the order of 107 m3 within the first few days. It appears that the volume flow rate estimated from LPTs is about one order of magnitude smaller than that of the actual flow rate. This may be reasonable if we consider that through seismic waves we are observing a fluctuating part of the magma flow. This may be the first seismological detection of dynamics of a main magma plumbing system beneath volcanos directly related to eruption activities.

  20. GALAXY EVOLUTION EXPLORER OBSERVATIONS OF CS AND OH EMISSION IN COMET 9P/TEMPEL 1 DURING DEEP IMPACT

    SciTech Connect

    Feldman, Paul D.; McCandliss, Stephan R.; Morgenthaler, Jeffrey P.; Lisse, Carey M.; Weaver, Harold A.; A'Hearn, Michael F.

    2010-03-10

    Galaxy Evolution Explorer (GALEX) observations of comet 9P/Tempel 1 using the near-ultraviolet (NUV) objective grism were made before, during and after the Deep Impact event that occurred on 2005 July 4 at 05:52:03 UT when a 370 kg NASA spacecraft was maneuvered into the path of the comet. The NUV channel provides usable spectral information in a bandpass covering 2000-3400 A with a point source spectral resolving power of R {approx} 100. The primary spectral features in this range include solar continuum scattered from cometary dust and emissions from OH and CS molecular bands centered near 3085 and 2575 A, respectively. In particular, we report the only cometary CS emission detected during this event. The observations allow the evolution of these spectral features to be tracked over the period of the encounter. In general, the NUV emissions observed from Tempel 1 are much fainter than those that have been observed by GALEX from other comets. However, it is possible to derive production rates for the parent molecules of the species detected by GALEX in Tempel 1 and to determine the number of these molecules liberated by the impact. The derived quiescent production rates are Q(H{sub 2}O) = 6.4 x 10{sup 27} molecules s{sup -1} and Q(CS{sub 2}) = 6.7 x 10{sup 24} molecules s{sup -1}, while the impact produced an additional 1.6 x 10{sup 32} H{sub 2}O molecules and 1.3 x 10{sup 29} CS{sub 2} molecules, a similar ratio as in quiescent outgassing.

  1. Observations of in situ deep-sea marine bioluminescence with a high-speed, high-resolution sCMOS camera

    NASA Astrophysics Data System (ADS)

    Phillips, Brennan T.; Gruber, David F.; Vasan, Ganesh; Roman, Christopher N.; Pieribone, Vincent A.; Sparks, John S.

    2016-05-01

    Observing and measuring marine bioluminescence in situ presents unique challenges, characterized by the difficult task of approaching and imaging weakly illuminated bodies in a three-dimensional environment. To address this problem, a scientific complementary-metal-oxide-semiconductor (sCMOS) microscopy camera was outfitted for deep-sea imaging of marine bioluminescence. This system was deployed on multiple platforms (manned submersible, remotely operated vehicle, and towed body) in three oceanic regions (Western Tropical Pacific, Eastern Equatorial Pacific, and Northwestern Atlantic) to depths up to 2500 m. Using light stimulation, bioluminescent responses were recorded at high frame rates and in high resolution, offering unprecedented low-light imagery of deep-sea bioluminescence in situ. The kinematics of light production in several zooplankton groups was observed, and luminescent responses at different depths were quantified as intensity vs. time. These initial results signify a clear advancement in the bioluminescent imaging methods available for observation and experimentation in the deep-sea.

  2. A Deep Herschel/PACS Observation of CO(40-39) in NGC 1068: A Search for the Molecular Torus

    NASA Astrophysics Data System (ADS)

    Janssen, A. W.; Bruderer, S.; Sturm, E.; Contursi, A.; Davies, R.; Hailey-Dunsheath, S.; Poglitsch, A.; Genzel, R.; Graciá-Carpio, J.; Lutz, D.; Tacconi, L.; Fischer, J.; González-Alfonso, E.; Sternberg, A.; Veilleux, S.; Verma, A.; Burtscher, L.

    2015-10-01

    Emission from high-J CO lines in galaxies has long been proposed as a tracer of X-ray dominated regions (XDRs) produced by active galactic nuclei (AGNs). Of particular interest is the question of whether the obscuring torus, which is required by AGN unification models, can be observed via high-J CO cooling lines. Here we report on the analysis of a deep Herschel/PACS observation of an extremely high-J CO transition (40-39) in the Seyfert 2 galaxy NGC 1068. The line was not detected, with a derived 3σ upper limit of 2× {10}-17 {{W}} {{{m}}}-2. We apply an XDR model in order to investigate whether the upper limit constrains the properties of a molecular torus in NGC 1068. The XDR model predicts the CO spectral line energy distributions for various gas densities and illuminating X-ray fluxes. In our model, the CO(40-39) upper limit is matched by gas with densities of ˜ {10}6-{10}7 {{cm}}-3, located at 1.6-5 pc from the AGN, with column densities of at least {10}25 {{cm}}-2. At such high column densities, however, dust absorbs most of the CO(40-39) line emission at λ =65.69 μ {{m}}. Therefore, even if NGC 1068 has a molecular torus that radiates in the CO(40-39) line, the dust can attenuate the line emission to below the PACS detection limit. The upper limit is thus consistent with the existence of a molecular torus in NGC 1068. In general, we expect that the CO(40-39) is observable in only a few AGN nuclei (if at all), because of the required high gas column density, and absorption by dust.

  3. Constraining parameters of the neutron star in the supernova remnant HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Klochkov, D.; Suleimanov, V.; Puehlhofer, G.; Werner, K.; Santangelo, A.

    2014-07-01

    The Central Compact Object (CCO) in HESS J1731-347, presumably a neutron star, is one of the brightest sources in this class. Like other CCOs, it potentially provides an "undisturbed" view of thermal radiation generated at the neutron star surface. The shape and normalization of the corresponding X-ray spectrum depends on the emitting area, surface redshift, and gravity acceleration. Thus, its modeling under certain assumptions allows the mass and radius of the neutron star to be constrained. In our analysis, we model the spectrum of the CCO accumulated with XMM-Newton over ˜100 ksec exposure time in three observations. The exposure time has increased by a factor of five since our previous analysis of the source. For the spectral fitting, we use our hydrogen and carbon atmosphere models calculated assuming hydrostatic and radiative equilibria and taking into account pressure ionization and the presence of spectral lines (in case of carbon). We present the resulting constraints on the mass, radius, distance, and temperature of the neutron star.

  4. Observations of comet 19P/Borrelly by the miniature integrated camera and spectrometer aboard deep space 1

    USGS Publications Warehouse

    Soderblom, L.A.; Becker, T.L.; Bennett, G.; Boice, D.C.; Britt, D.T.; Brown, R.H.; Buratti, B.J.; Isbell, C.; Giese, B.; Hare, T.; Hicks, M.D.; Howington-Kraus, E.; Kirk, R.L.; Lee, M.; Nelson, R.M.; Oberst, J.; Owen, T.C.; Rayman, M.D.; Sandel, B.R.; Stern, S.A.; Thomas, N.; Yelle, R.V.

    2002-01-01

    The nucleus of the Jupiter-family comet 19P/Borrelly was closely observed by the Miniature Integrated Camera and Spectrometer aboard the Deep Space 1 spacecraft on 22 September 2001. The 8-kilometer-long body is highly variegated on a scale of 200 meters, exhibiting large albedo variations (0.01 to 0.03) and complex geologic relationships. Short-wavelength infrared spectra (1.3 to 2.6 micrometers) show a slope toward the red and a hot, dry surface (???345 kelvin, with no trace of water ice or hydrated minerals), consistent with ???10% or less of the surface actively sublimating. Borrelly's coma exhibits two types of dust features: fans and highly collimated jets. At encounter, the near-nucleus coma was dominated by a prominent dust jet that resolved into at least three smaller jets emanating from a broad basin in the middle of the nucleus. Because the major dust jet remained fixed in orientation, it is evidently aligned near the rotation axis of the nucleus.

  5. Using Observations of Deep Convective Systems to Constrain Atmospheric Column Absorption of Solar Radiation in the Optically Thick Limit

    NASA Technical Reports Server (NTRS)

    Dong, Xiquan; Wielicki, Bruce A.; Xi, Baike; Hu, Yongxiang; Mace, Gerald G.; Benson, Sally; Rose, Fred; Kato, Seiji; Charlock, Thomas; Minnis, Patrick

    2008-01-01

    Atmospheric column absorption of solar radiation A(sub col) is a fundamental part of the Earth's energy cycle but is an extremely difficult quantity to measure directly. To investigate A(sub col), we have collocated satellite-surface observations for the optically thick Deep Convective Systems (DCS) at the Department of Energy Atmosphere Radiation Measurement (ARM) Tropical Western Pacific (TWP) and Southern Great Plains (SGP) sites during the period of March 2000 December 2004. The surface data were averaged over a 2-h interval centered at the time of the satellite overpass, and the satellite data were averaged within a 1 deg X 1 deg area centered on the ARM sites. In the DCS, cloud particle size is important for top-of-atmosphere (TOA) albedo and A(sub col) although the surface absorption is independent of cloud particle size. In this study, we find that the A(sub col) in the tropics is approximately 0.011 more than that in the middle latitudes. This difference, however, disappears, i.e., the A(sub col) values at both regions converge to the same value (approximately 0.27 of the total incoming solar radiation) in the optically thick limit (tau greater than 80). Comparing the observations with the NASA Langley modified Fu_Liou 2-stream radiative transfer model for optically thick cases, the difference between observed and model-calculated surface absorption, on average, is less than 0.01, but the model-calculated TOA albedo and A(sub col) differ by 0.01 to 0.04, depending primarily on the cloud particle size observation used. The model versus observation discrepancies found are smaller than many previous studies and are just within the estimated error bounds. We did not find evidence for a large cloud absorption anomaly for the optically thick limit of extensive ice cloud layers. A more modest cloud absorption difference of 0.01 to 0.04 cannot yet be ruled out. The remaining uncertainty could be reduced with additional cases, and by reducing the current

  6. Deep 3-GHz observations of the Lockman Hole North with the Very Large Array - I. Source extraction and uncertainty analysis

    NASA Astrophysics Data System (ADS)

    Vernstrom, T.; Scott, Douglas; Wall, J. V.; Condon, J. J.; Cotton, W. D.; Perley, R. A.

    2016-09-01

    This is the first of two papers describing the observations and cataloguing of deep 3-GHz observations of the Lockman Hole North using the Karl G. Jansky Very Large Array. The aim of this paper is to investigate, through the use of simulated images, the uncertainties and accuracy of source-finding routines, as well as to quantify systematic effects due to resolution, such as source confusion and source size. While these effects are not new, this work is intended as a particular case study that can be scaled and translated to other surveys. We use the simulations to derive uncertainties in the fitted parameters, as well as bias corrections for the actual catalogue (presented in Paper II). We compare two different source-finding routines, OBIT and AEGEAN, and two different effective resolutions, 8 and 2.75 arcsec. We find that the two routines perform comparably well, with OBIT being slightly better at de-blending sources, but slightly worse at fitting resolved sources. We show that 30-70 per cent of sources are missed or fit inaccurately once the source size becomes larger than the beam, possibly explaining source count errors in high-resolution surveys. We also investigate the effect of blending, finding that any sources with separations smaller than the beam size are fit as single sources. We show that the use of machine-learning techniques can correctly identify blended sources up to 90 per cent of the time, and prior-driven fitting can lead to a 70 per cent improvement in the number of de-blended sources.

  7. H.E.S.S. discovery of VHE γ-rays from the quasar PKS 1510-089

    NASA Astrophysics Data System (ADS)

    H.E.S.S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Behera, B.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chaves, R. C. G.; Cheesebrough, A.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Menzler, U.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nguyen, N.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H. S.

    2013-06-01

    The quasar PKS 1510-089 (z = 0.361) was observed with the H.E.S.S. array of imaging atmospheric Cherenkov telescopes during high states in the optical and GeV bands, to search for very high energy (VHE, defined as E ≥ 0.1 TeV) emission. VHE γ-rays were detected with a statistical significance of 9.2 standard deviations in 15.8 h of H.E.S.S. data taken during March and April 2009. A VHE integral flux of I(0.15 TeV < E < 1.0 TeV)= (1.0 ± 0.2stat ± 0.2sys) × 10-11 cm-2 s-1 is measured. The best-fit power law to the VHE data has a photon index of Γ = 5.4 ± 0.7stat ± 0.3sys. The GeV and optical light curves show pronounced variability during the period of H.E.S.S. observations. However, there is insufficient evidence to claim statistically significant variability in the VHE data. Because of its relatively high redshift, the VHE flux from PKS 1510-089 should suffer considerable attenuation in the intergalactic space due to the extragalactic background light (EBL). Hence, the measured γ-ray spectrum is used to derive upper limits on the opacity due to EBL, which are found to be comparable with the previously derived limits from relatively-nearby BL Lac objects. Unlike typical VHE-detected blazars where the broadband spectrum is dominated by nonthermal radiation at all wavelengths, the quasar PKS 1510-089 has a bright thermal component in the optical to UV frequency band. Among all VHE detected blazars, PKS 1510-089 has the most luminous broad line region. The detection of VHE emission from this quasar indicates a low level of γ - γ absorption on the internal optical to UV photon field.

  8. 78 FR 20910 - Hess Energy Marketing, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... Energy Regulatory Commission Hess Energy Marketing, LLC; Supplemental Notice That Initial Market-Based... above-referenced proceeding, of Hess Energy Marketing, LLC's application for market-based rate authority... at http://www.ferc.gov . To facilitate electronic service, persons with Internet access who will...

  9. Weaving Colors into a White Landscape: Unpacking the Silences in Karen Hesse's Children's Novel "Out of the Dust"

    ERIC Educational Resources Information Center

    Simon, Lisa

    2008-01-01

    The children's novel "Out of the Dust" (Hesse, 1997) is an evocative portrayal of the drought and dust storms that devastated Midwestern farms in the 1930s. Through the voice of her 13-year-old narrator, Karen Hesse intertwines history and free verse poetry to create what many readers find to be a moving depiction of the Oklahoma Dustbowl…

  10. Multi-platform observation of submesoscale vortices formed by deep vertical mixing: characterization and role for the general circulation of the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Bosse, Anthony; Testor, Pierre; Mortier, Laurent; Houpert, Loïc

    2015-04-01

    Since 2010, an intense effort in the collection of in-situ observations has been carried out in the Northwestern Mediterranean Sea thanks to gliders, regular cruises and a highly instrumented mooring line. This integrated observing system enabled a year-to-year monitoring of the deep water formation that occurred in the Gulf of Lions area during the 4 consecutive winters of the study period (2010-2013). Vortical structures remnant of wintertime deep vertical mixing events were regularly sampled by different platforms. They are isolated Submesoscale Coherent Vortices (SCVs) characterized by a small radius (~5km), strong depth-intensified azimutal velocities (~10-15cm/s) with a weaker surface signature, high Rossby (~0.5) and Burger (~1) numbers. Anticyclones are found to transport mode and newly formed deep waters resulting from vertical mixing characterized by intermediate (~300-500m) to deep (~2000m) mixing. Cyclones are characterized by a weakly stratified core of newly formed Western Mediterranean Deep Waters (or Dense Shelf Waters that cascaded from the shelf of the Gulf of Lions in 2012) extending from ~500-1000m depth to the bottom (~2300m). The formation of the cyclones might be favoured by bottom-reaching convection or cascading events reaching the abyssal plain. This study confirms the prominent role anticyclonic SCVs and shed light into the role of cyclonic SCVs in the spreading of newly formed deep waters out of an open-ocean deep convection area. They could also potentially impact vertical mixing during the the following winter through a local preconditioning effect.

  11. Spectral study of the HESS J1745-290 gamma-ray source as dark matter signal

    NASA Astrophysics Data System (ADS)

    Cembranos, J. A. R.; Gammaldi, V.; Maroto, A. L.

    2013-04-01

    We study the main spectral features of the gamma-ray fluxes observed by the High Energy Stereoscopic System (HESS) from the J1745-290 Galactic Center source during the years 2004, 2005 and 2006. In particular, we show that these data are well fitted as the secondary gamma-rays photons generated from dark matter annihilating into Standard Model particles in combination with a simple power law background. We present explicit analyses for annihilation in a single standard model particle-antiparticle pair. In this case, the best fits are obtained for the uū and dbar d quark channels and for the W+W- and ZZ gauge bosons, with background spectral index compatible with the Fermi-Large Area Telescope (LAT) data from the same region. The fits return a heavy WIMP, with a mass above ~ 10 TeV, but well below the unitarity limit for thermal relic annihilation.

  12. Search for TeV emission from the region around PSR B1706-44 with the HESS experiment

    NASA Astrophysics Data System (ADS)

    Aharonian, F.; Akhperjanian, A. G.; Aye, K.-M.; Bazer-Bachi, A. R.; Beilicke, M.; Benbow, W.; Berge, D.; Berghaus, P.; Bernlöhr, K.; Boisson, C.; Bolz, O.; Borgmeier, C.; Braun, I.; Breitling, F.; Brown, A. M.; Bussons Gordo, J.; Chadwick, P. M.; Chounet, L.-M.; Cornils, R.; Costamante, L.; Degrange, B.; Djannati-Ataï, A.; O'C. Drury, L.; Dubus, G.; Ergin, T.; Espigat, P.; Feinstein, F.; Fleury, P.; Fontaine, G.; Fuchs, Y.; Funk, S.; Gallant, Y. A.; Giebels, B.; Gillessen, S.; Goret, P.; Hadjichristidis, C.; Hauser, M.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Holleran, M.; Horns, D.; de Jager, O. C.; Jung, I.; Khélifi, B.; Komin, Nu.; Konopelko, A.; Latham, I. J.; Le Gallou, R.; Lemière, A.; Lemoine, M.; Leroy, N.; Lohse, T.; Marcowith, A.; Masterson, C.; McComb, T. J. L.; de Naurois, M.; Nolan, S. J.; Noutsos, A.; Orford, K. J.; Osborne, J. L.; Ouchrif, M.; Panter, M.; Pelletier, G.; Pita, S.; Pühlhofer, G.; Punch, M.; Raubenheimer, B. C.; Raue, M.; Raux, J.; Rayner, S. M.; Redondo, I.; Reimer, A.; Reimer, O.; Ripken, J.; Rob, L.; Rolland, L.; Rowell, G.; Sahakian, V.; Saugé, L.; Schlenker, S.; Schlickeiser, R.; Schuster, C.; Schwanke, U.; Siewert, M.; Sol, H.; Steenkamp, R.; Stegmann, C.; Tavernet, J.-P.; Terrier, R.; Théoret, C. G.; Tluczykont, M.; Vasileiadis, G.; Venter, C.; Vincent, P.; Visser, B.; Völk, H. J.; Wagner, S. J.

    2005-03-01

    The region around PSR B1706-44 has been observed with the HESS imaging atmospheric Cherenkov telescopes in 2003. No evidence for γ-ray emission in the TeV range was found at the pulsar position or at the radio arc which corresponds to the supernova remnant G 343.1-2.3. The 99% confidence level flux upper limit at the pulsar position is Ful(E>350 GeV) = 1.4 × 10-12 s-1 cm-2 assuming a power law (dN/dE ∝ E-Γ) with photon index of Γ = 2.5 and Ful(E > 500 GeV) = 1.3 × 10-12 s-1 cm-2 without an assumption on the spectral shape. The reported upper limits correspond to 8% of the flux from an earlier detection by the CANGAROO experiment.

  13. Spectral study of the HESS J1745-290 gamma-ray source as dark matter signal

    SciTech Connect

    Cembranos, J.A.R.; Gammaldi, V.; Maroto, A.L. E-mail: vivigamm@ucm.es

    2013-04-01

    We study the main spectral features of the gamma-ray fluxes observed by the High Energy Stereoscopic System (HESS) from the J1745-290 Galactic Center source during the years 2004, 2005 and 2006. In particular, we show that these data are well fitted as the secondary gamma-rays photons generated from dark matter annihilating into Standard Model particles in combination with a simple power law background. We present explicit analyses for annihilation in a single standard model particle-antiparticle pair. In this case, the best fits are obtained for the uū and d d-bar quark channels and for the W{sup +}W{sup −} and ZZ gauge bosons, with background spectral index compatible with the Fermi-Large Area Telescope (LAT) data from the same region. The fits return a heavy WIMP, with a mass above ∼ 10 TeV, but well below the unitarity limit for thermal relic annihilation.

  14. Chandra Deep X-ray Observation of a Typical Galactic Plane Region and Near-Infrared Identification

    NASA Technical Reports Server (NTRS)

    Ebisawa, K.; Tsujimoto, M.; Paizis, A.; Hamaguichi, K.; Bamba, A.; Cutri, R.; Kaneda, H.; Maeda, Y.; Sato, G.; Senda, A.

    2004-01-01

    Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l,b) approx. (28.5 deg,0.0 deg), where no discrete X-ray source has been reported previously. We have detected 274 new point X-ray sources (4 sigma confidence) as well as strong Galactic diffuse emission within two partidly overlapping ACIS-I fields (approx. 250 sq arcmin in total). The point source sensitivity was approx. 3 x 10(exp -15)ergs/s/sq cm in the hard X-ray band (2-10 keV and approx. 2 x 10(exp -16) ergs/s/sq cm in the soft band (0.5-2 keV). Sum of all the detected point source fluxes account for only approx. 10 % of the total X-ray fluxes in the field of view. In order to explain the total X-ray fluxes by a superposition of fainter point sources, an extremely rapid increase of the source population is required below our sensitivity limit, which is hardly reconciled with any source distribution in the Galactic plane. Therefore, we conclude that X-ray emission from the Galactic plane has truly diffuse origin. Only 26 point sources were detected both in the soft and hard bands, indicating that there are two distinct classes of the X-ray sources distinguished by the spectral hardness ratio. Surface number density of the hard sources is only slightly higher than observed at the high Galactic latitude regions, strongly suggesting that majority of the hard X-ray sources are active galaxies seen through the Galactic plane. Following the Chandra observation, we have performed a near-infrared (NIR) survey with SOFI at ESO/NTT to identify these new X-ray sources. Since the Galactic plane is opaque in NIR, we did not see the background extragalactic sources in NIR. In fact, only 22 % of the hard sources had NIR counterparts which are most likely to be Galactic origin. Composite X-ray energy spectrum of those hard X-ray sources having NIR counterparts exhibits a narrow approx. 6.7 keV iron emission line, which

  15. H.E.S.S. reveals a lack of TeV emission from the supernova remnant Puppis A

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E. O.; Backes, M.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Carrigan, S.; Casanova, S.; Chadwick, P. M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; O'C. Drury, L.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Grudzińska, M.; Hadasch, D.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2015-03-01

    Context. Puppis A is an interesting ~4 kyr-old supernova remnant (SNR) that shows strong evidence of interaction between the forward shock and a molecular cloud. It has been studied in detail from radio frequencies to high-energy (HE, 0.1-100 GeV) γ-rays. An analysis of the Fermi-LAT data has shown extended HE γ-ray emission with a 0.2-100 GeV spectrum exhibiting no significant deviation from a power law, unlike most of the GeV-emitting SNRs known to be interacting with molecular clouds. This makes it a promising target for imaging atmospheric Cherenkov telescopes (IACTs) to probe the γ-ray emission above 100 GeV. Aims: Very-high-energy (VHE, E ≥ 0.1 TeV) γ-ray emission from Puppis A has been, for the first time, searched for with the High Energy Stereoscopic System (H.E.S.S.). Methods: Stereoscopic imaging of Cherenkov radiation from extensive air showers is used to reconstruct the direction and energy of the incident γ-rays in order to produce sky images and source spectra. The profile likelihood method is applied to find constraints on the existence of a potential break or cutoff in the photon spectrum. Results: The analysis of the H.E.S.S. data does not reveal any significant emission towards Puppis A. The derived upper limits on the differential photon flux imply that its broadband γ-ray spectrum must exhibit a spectral break or cutoff. By combining Fermi-LAT and H.E.S.S. measurements, the 99% confidence-level upper limits on such a cutoff are found to be 450 and 280 GeV, assuming a power law with a simple exponential and a sub-exponential cutoff, respectively. It is concluded that none of the standard limitations (age, size, radiative losses) on the particle acceleration mechanism, assumed to be continuing at present, can explain the lack of VHE signal. The scenario in which particle acceleration has ceased some time ago is considered as an alternative explanation. The HE/VHE spectrum of Puppis A could then exhibit a break of non-radiative origin (as

  16. A deep Chandra observation of oxygen-rich supernova remnant B0049-73.6 in the Small Magellanic Cloud

    SciTech Connect

    Schenck, Andrew; Park, Sangwook; Burrows, David N.; Hughes, John P.; Lee, Jae-Joon; Mori, Koji

    2014-08-10

    We report on the initial results from our deep Chandra observation (450 ks) of O-rich supernova remnant (SNR) B0049-73.6 in the Small Magellanic Cloud. We detect small metal-rich ejecta features extending out to the outermost boundary of B0049-73.6, which were not seen in the previous data with a shorter exposure. The central nebula is dominated by emission from reverse-shocked ejecta material enriched in O, Ne, Mg, and Si. O-rich ejecta distribution is relatively smooth throughout the central nebula. In contrast, the Si-rich material is highly structured. These results suggest that B0049-73.6 was produced by an asymmetric core-collapse explosion of a massive star. The estimated abundance ratios among these ejecta elements are in plausible agreement with the nucleosynthesis products from the explosion of a 13-15 M{sub ☉} progenitor. The central ring-like (in projection) ejecta nebula extends to ∼9 pc from the SNR center. This suggests that the contact discontinuity may be located at a further distance from the SNR center than the previous estimate. We estimate the Sedov age of ∼17,000 yr and an explosion energy of E{sub 0} ∼1.7 × 10{sup 51} erg for B0049-73.6. We place a stringent upper limit on the 2-7 keV band luminosity of L{sub X} ∼ 8.5 × 10{sup 31} erg s{sup –1} for the embedded compact stellar remnant at the center of B0049-73.6.

  17. Halomonhystera disjuncta - a young-carrying nematode first observed for the Baltic Sea in deep basins within chemical munitions disposal sites

    NASA Astrophysics Data System (ADS)

    Grzelak, Katarzyna; Kotwicki, Lech

    2016-06-01

    Three deep basins in the Baltic Sea were investigated within the framework of the CHEMSEA project (Chemical Munitions Search & Assessment), which aims to evaluate the ecological impact of chemical warfare agents dumped after World War II. Nematode communities, which comprise the most numerous and diverse organisms in the surveyed areas, were investigated as a key group of benthic fauna. One of the most successful nematode species was morphologically identified as Halomonhystera disjuncta (Bastian, 1865). The presence of this species, which is an active coloniser that is highly resistant to disturbed environments, may indicate that the sediments of these disposal sites are characterised by toxic conditions that are unfavourable for other metazoans. Moreover, ovoviviparous reproductive behaviour in which parents carry their brood internally, which is an important adaptation to harsh environmental conditions, was observed for specimens from Gdansk Deep and Gotland Deep. This reproductive strategy, which is uncommon for marine nematodes, has not previously been reported for nematodes from the Baltic Sea sediment.

  18. An electromagnetic sounding experiment in Germany using the vertical gradient of geomagnetic variations observed in a deep borehole

    NASA Astrophysics Data System (ADS)

    Schmucker, Ulrich; Spitzer, Klaus; Steveling, Erich

    2009-09-01

    We have recorded for 13 d, geomagnetic variations simultaneously on the Earth's surface and in a borehole at 832 m depth straight below, with a sampling rate of 1 Hz. In addition, geoelectric variations were observed at the same site near Bad Königshofen in Frankonia, Germany. The penetrated moderately conductive Triassic sediments lie above highly resistive Permian deposits. A presumably crystalline basement begins at 1500-1900 m depth. The purpose of the experiment is to determine the skin effect of geomagnetic variations and to derive from it the equivalent to the magnetotelluric (MT) surface impedance, using the vertical gradient (VG) method of electromagnetic (EM) sounding. In this way, we were able to reproduce all four elements of the MT impedance tensor, except for an unexplained but consistent downward shift of VG phases against MT phases by roughly 15° for the two off-diagonal elements. Hence, our tensor evaluation goes beyond the common practice, to express the skin effect by a single VG transfer function in response to a layered structure. The otherwise good agreement of VG and MT results implies that at our test site, the MT impedance tensor is largely distortion-free and that, for example, its pronounced anisotropy should be regarded as a genuine characteristic of the EM response for a laterally non-uniform or possibly anisotropic deep structure. The drilling site lies within the range of a widespread induction anomaly. We have observed the resulting variations of the vertical magnetic component at the surface and in the borehole and found them to be identical. The thus established absence of a skin effect for the vertical component allows us to treat the sedimentary layer down to the depth of the borehole instrument as a thin sheet, and the pertinent thin-sheet approximation for EM induction forms the basis of our analysis. We have derived the required estimate of conductance from the skin effect of horizontal components, noting that this estimate

  19. Observations and Parameterizations of Particle Size Distributions in Deep Tropical Cirrus and Stratiform Precipitation Clouds: Results from In-Situ Observations in TRMM Field Campaigns

    NASA Technical Reports Server (NTRS)

    Heymsfield, Andrew J.; Bansemer, Aaron; Field, Paul R.; Durden, Stephen L.; Stith, Jeffrey L.; Dye, James E.; Hall, William; Grainger, Cedric A.

    2002-01-01

    In this study, we report on the evolution of particle size distributions (PSDs) and habits as measured during slow, Lagrangian-type spiral descents through deep subtropical and tropical cloud layers in Florida, Brazil, and Kwajalein, Marshall Islands, most of which were precipitating. The objective of the flight patterns was to learn more about how the PSDs evolved in the vertical and to obtain information of the vertical structure of microphysical properties. New instrumentation yielding better information on the concentrations of particles in the size (D) range between 0.2 and 2 cm, as well as improved particle imagery, produced more comprehensive observations for tropical stratiform precipitation regions and anvils than have been available previously. Collocated radar observations provided additional information on the vertical structure of the cloud layers sampled. Most of the spirals began at cloud top, with temperatures (T) as low as -50 C, and ended at cloud base or below the melting layer (ML). The PSDs broadened from cloud top towards cloud base, with the largest particles increasing in size from several millimeters at cloud top to one centimeter or larger towards cloud base. Some continued growth was noted in the upper part of the ML. Concentrations of particles less than 1 mm in size decreased with decreasing height. The result was a consistent change in the PSDs in the vertical. Similarly, systematic changes in the size dependence of the particle cross-sectional area was noted with decreasing height. Aggregation-as ascertained from both the changes in the PSDs and evolution of particle habits as observed in high detail with the cloud particle imager (CPI) probe-was responsible for these trends. The PSDs were generally well-represented by gamma distributions of the form N = N0 gamma D microns e- lambda gamma D that were fitted to the PSDs over 1-km horizontal intervals throughout the spirals. The intercept (N0 gamma), slope (lambda gamma), and dispersion

  20. X-RAY EMISSION FROM HESS J1731-347/SNR G353.6-0.7 AND CENTRAL COMPACT SOURCE XMMS J173203-344518

    SciTech Connect

    Tian, W. W.; Li, Z.; Leahy, D. A.; Yang, J.; Lu, D.; Yang, X. J.; Yamazaki, R. E-mail: wtian@ucalgary.c

    2010-04-01

    We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally be characterized by an absorbed power-law model, with a photon index of {approx}2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of {approx}0.5 keV plus a power-law tail with a photon index of {approx}5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the High Energy Stereoscopic System (HESS) source reveal a bright cloud component at -20 +- 4 km s{sup -1}, which is likely located at the same distance of {approx}3.2 kpc as the SNR. Based on the probable association between the X-ray and gamma-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.

  1. X-Ray Emission from HESS J1731-347/SNR G353.6-0.7 and Central Compact Source XMMS J173203-344518

    NASA Astrophysics Data System (ADS)

    Tian, W. W.; Li, Z.; Leahy, D. A.; Yang, J.; Yang, X. J.; Yamazaki, R.; Lu, D.

    2010-04-01

    We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally be characterized by an absorbed power-law model, with a photon index of ~2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of ~0.5 keV plus a power-law tail with a photon index of ~5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the High Energy Stereoscopic System (HESS) source reveal a bright cloud component at -20 ± 4 km s-1, which is likely located at the same distance of ~3.2 kpc as the SNR. Based on the probable association between the X-ray and γ-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.

  2. Observations and Parameterizations of Particle Size Distributions in Deep Tropical Cirrus and Stratiform Precipitating Clouds: Results from In Situ Observations in TRMM Field Campaigns.

    NASA Astrophysics Data System (ADS)

    Heymsfield, Andrew J.; Bansemer, Aaron; Field, Paul R.; Durden, Stephen L.; Stith, Jeffrey L.; Dye, James E.; Hall, William; Grainger, Cedric A.

    2002-12-01

    This study reports on the evolution of particle size distributions (PSDs) and habits as measured during slow, Lagrangian-type spiral descents through deep subtropical and tropical cloud layers in Florida, Brazil, and Kwajalein, Marshall Islands, most of which were precipitating. The objective of the flight patterns was to learn more about how the PSDs evolved in the vertical and to obtain information of the vertical structure of microphysical properties. New instrumentation yielding better information on the concentrations of particles in the size (D) range between 0.2 and 2 cm, as well as improved particle imagery, produced more comprehensive observations for tropical stratiform precipitation regions and anvils than have been available previously. Collocated radar observations provided additional information on the vertical structure of the cloud layers sampled.Most of the spirals began at cloud top, with temperatures (T) as low as 50°C, and ended at cloud base or below the melting layer (ML). The PSDs broadened from cloud top toward cloud base, with the largest particles increasing in size from several millimeters at cloud top, to 1 cm or larger toward cloud base. Some continued growth was noted in the upper part of the ML. Concentrations of particles less than 1 mm in size decreased with decreasing height. The result was a consistent change in the PSDs in the vertical. Similarly, systematic changes in the size dependence of the particle cross-sectional area was noted with decreasing height. Aggregation-as ascertained from both the changes in the PSDs and evolution of particle habits as observed in high detail with the cloud particle imager (CPI) probe-was responsible for these trends.The PSDs were generally well-represented by gamma distributions of the form N = N0DeD that were fitted to the PSDs over 1-km horizontal intervals throughout the spirals. The intercept (N0), slope (), and dispersion () values were derived for each PSD. Exponential curves (N = N0e

  3. Conscientisation in Castalia: A Freirean Reading of Hermann Hesse's "The Glass Bead Game"

    ERIC Educational Resources Information Center

    Roberts, Peter

    2007-01-01

    This paper considers Hermann Hesse's novel, "The Glass Bead Game," in the light of Paulo Freire's educational philosophy. "The Glass Bead Game" is set in Castalia, a "pedagogical province" of the 23rd century. It is argued that the central character in the book, Joseph Knecht, undergoes a complex process of conscientisation. Knecht develops an…

  4. Disease Management Project Breast Cancer in Hesse – 5-Year Survival Data

    PubMed Central

    Jackisch, C.; Funk, A.; König, K.; Lubbe, D.; Misselwitz, B.; Wagner, U.

    2014-01-01

    Introduction: The Disease Management Project Breast Cancer (DMP Breast Cancer) was first launched in Hesse in 2004. The project is supported by the health insurance companies in Hesse and the Professional Association of Gynaecologists in Hesse. The aim is to offer structured treatment programmes to all women diagnosed with breast cancer in Hesse by creating intersectoral cooperations between coordinating clinics, associated hospitals and gynaecologists in private practice who registered in the DMP programme. Method: Between 1 January 2005 and 30 June 2011, 13 973 women were enrolled in the DMP programme. Results: After data cleansing, survival rates were calculated for a total of 11 214 women. The 5-year overall survival (OS) rate was 86.3 %; survival rates according to tumour stage on presentation were 92.2 % (pT1) and 82.3 % (pT2), respectively. The impact of steroid hormone receptor status on survival (87.8 % for receptor-positive cancers vs. 78.9 % for receptor-negative cancers) and of age at first diagnosis on survival (≤ 35 years = 91 %) were calculated. Conclusion: The project showed that intersectoral cooperation led to significant improvements in the quality of treatment over time, as measured by quality indicators and outcomes after treatment. PMID:24882878

  5. Observations of oceanic crust and mantle structures at a deep ocean seismic array in the Eastern Mid Atlantic

    NASA Astrophysics Data System (ADS)

    Hannemann, Katrin; Krüger, Frank; Dahm, Torsten

    2016-04-01

    In 2011, twelve ocean bottom stations (OBS) were installed approximately 100 km North of the Gloria Fault during the DOCTAR project (Deep OCean Test ARray). This fault marks the plate boundary between the Eurasian and African plate in the North Eastern Mid Atlantic. The experiment took place in water depth of 4-6 km, 800 km West of the Portuguese coast. The stations were equipped with broad band seismometers which recorded for ten months. We employ P and S receiver functions (RF) to have a closer look at the structure of crust and mantle. The ocean is a quite noisy environment, therefore the number of usable events is low (around 20) compared to RF studies on land. We use several quality criteria (e.g. signal to noise ratio, relative spike position) to select proper processing parameters for the calculation of the RF and carefully reviewed all later on used RF. Despite the low number of events, the usage of an array of OBS with an aperture of 75 km allows us to investigate deeper discontinuities (e.g. in 410 and 660 km depth) compared to single station approaches which are usually employed for OBS. Furthermore, we increase the number of usable events by applying array methods. We use move out corrected and stacked RF to have a closer look at the mantle transition zone, and estimate average depth values for the Moho, the lithosphere asthenosphere boundary (LAB) and the base of the asthenosphere. The Moho lies at depth of 7 km, the LAB at approximately 50 km and the asthenosphere has an approximated thickness of 110 km. We observe a slight increase in the time difference of the mantle discontinuity conversion times compared to PREM. RF give just information regarding the impedance contrast at a discontinuity instead of velocities. We additionally use P wave polarization of teleseismic events to estimate absolute S velocities beneath the single stations. All in all, we use the information gained by the RF analysis, and the analysis of the P wave polarization to

  6. Deep MUSE observations in the HDFS. Morpho-kinematics of distant star-forming galaxies down to 108M⊙

    NASA Astrophysics Data System (ADS)

    Contini, T.; Epinat, B.; Bouché, N.; Brinchmann, J.; Boogaard, L. A.; Ventou, E.; Bacon, R.; Richard, J.; Weilbacher, P. M.; Wisotzki, L.; Krajnović, D.; Vielfaure, J.-B.; Emsellem, E.; Finley, H.; Inami, H.; Schaye, J.; Swinbank, M.; Guérou, A.; Martinsson, T.; Michel-Dansac, L.; Schroetter, I.; Shirazi, M.; Soucail, G.

    2016-06-01

    Aims: Whereas the evolution of gas kinematics of massive galaxies is now relatively well established up to redshift z ~ 3, little is known about the kinematics of lower mass (M⋆≤ 1010M⊙) galaxies. We use MUSE, a powerful wide-field, optical integral-field spectrograph (IFS) recently mounted on the VLT, to characterize this galaxy population at intermediate redshift. Methods: We made use of the deepest MUSE observations performed so far on the Hubble Deep Field South (HDFS). This data cube, resulting from 27 h of integration time, covers a one arcmin2 field of view at an unprecedented depth (with a 1σ emission-line surface brightness limit of 1 × 10-19 erg s-1 cm-2 arcsec-2) and a final spatial resolution of ≈0.7''. We identified a sample of 28 resolved emission-line galaxies, extending over an area that is at least twice the seeing disk, spread over a redshift interval of 0.2

  7. Pressure-induced shallow-to-deep donor-state transition in 119doped GaAs observed by Mössbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Gibart, P.; Williamson, D. L.; Moser, J.; Basmaji, P.

    1990-08-01

    The Sn DX center in GaAs, a deep donor state of Sn, has been observed by Mössbauer measurements at high pressure. The size of the pressure-induced Sn DX Mössbauer resonance compared to the net conduction-electron concentration at zero pressure provides evidence that the Sn DX center localizes two or three electrons in the ground state.

  8. Analyses of outcrop and sediment grains observed and collected from the Sirena Deep and Middle Pond of the Mariana Trench

    NASA Astrophysics Data System (ADS)

    Hand, K. P.; Bartlett, D. H.; Fryer, P.

    2012-12-01

    During a March 2012 expedition we recovered sediments from two locales within the Marina Trench - Middle Pond and Sirena Deep. Samples were recovered from a Niskin bottle deployed on a passive lander platform that released an arm after touching down on the seafloor. The impact of the arm holding the Niskin bottle caused sediments to enter the bottle; this process was seen in images and on video captured by the lander. The combination of imagery and preliminary analyses of the sediments indicates that the Sirena Deep locale is a region of serpentinization and active microbial communities. Images show several outcrops consistent with serpentinization, some of which are coated with filamentous microbial mats. Results and analyses of these samples will be presented.

  9. Vertical velocities associated with deep open-ocean convection in the Northwestern Mediterranean Sea as indirectly observed by gliders

    NASA Astrophysics Data System (ADS)

    Bosse, Anthony; Testor, Pierre; Legland, Guillaume; Mortier, Laurent; Houpert, Loïc; Prieur, Louis

    2014-05-01

    During winter 2012-2013, deep open-ocean convection occurred in the Gulf of Lions (Northwestern Mediterranean Sea) and has been thoroughly documented thanks to the deployment of several gliders at the same time, Argo profiling floats, dedicated ship cruises, and a mooring located within the mixed patch. The data collected represent an unprecedented density of profiles during a event of open-ocean deep convection. We applied a method able to infer the vertical velocity signal from the glider navigation data. During active phase of mixing, the gliders faced significant vertical velocities (upward and downward displacement stronger than 10cm/s). Moving along a saw-tooth trajectory between the surface and 1000m, they could cross small scale convective plumes (L~1km) over a dive or ascent (2km and 2h between the surface and maximum depth), while recording temperature and salinity, as well as biogeochemical properties (dissolved oxygen, fluorescence, turbidity, ...). Our study provides a comprehensive dataset to get a characterization of convective plumes and a deeper understanding of their role in deep open-ocean convection.

  10. Aerosol radiative effects over global arid and semi-arid regions based on MODIS Deep Blue satellite observations

    NASA Astrophysics Data System (ADS)

    Hatzianastassiou, Nikolaos; Papadimas, Christos D.; Gkikas, Antonis; Matsoukas, Christos; Sayer, Andrew M.; Hsu, N. Christina; Vardavas, Ilias

    2014-05-01

    Aerosols are a key parameter for several atmospheric processes related to weather and climate of our planet. Specifically, the aerosol impact on Earth's climate is exerted and quantified through their radiative effects, which are induced by their direct, indirect and semi-direct interactions with radiation, in particular at short wavelengths (solar). It is acknowledged that the uncertainty of present and future climate assessments is mainly associated with aerosols and that a better understanding of their physico-chemical, optical and radiative effects is needed. The contribution of satellites to this aim is important as a complementary tool to climate and radiative transfer models, as well as to surface measurements, since space observations of aerosol properties offer an extended spatial coverage. However, such satellite based aerosol properties and associated model radiation computations have suffered from unavailability over highly reflecting surfaces, namely polar and desert areas. This is also the case for MODIS which, onboard the Terra and Aqua satellites, has been providing high quality aerosol data since 2000 and 2002, respectively. These data, more specifically the aerosol optical depth (AOD) which is the most important optical property used in radiative and climate models, are considered to be of best quality. In order to address this problem, the MODIS Deep Blue (DB) algorithm has been developed which enables the retrieval of AOD above arid and semi-arid areas of the globe, including the major deserts. In the present study we make use of the FORTH detailed spectral radiative transfer model (RTM) with MODIS DB AOD data, supplemented with single scattering albedo (SSA) and asymmetry parameter (AP) aerosol data from the Global Aerosol DataSet (GADS) to estimate the aerosol DREs over the arid and semi-arid regions of the globe. The RTM is run using surface and atmospheric data from the ISCCP-D2 dataset and the NCEP global reanalysis project and computes the

  11. Optical properties of the deep brain in the red and NIR: changes observed under in-vivo, post-mortem, frozen and formalin-fixated conditions

    NASA Astrophysics Data System (ADS)

    Pitzschke, A.; Lovisa, B.; Seydoux, O.; Zellweger, M.; Pfleiderer, M.; Haenggi, M.; Oertel, M.; Tardy, Y.; Wagnières, G.

    2015-07-01

    Photobiomodulation (PBM) is a promising approach to treat Parkinson's disease (PD) symptoms in cellular or animal models. Unfortunately, little information is available on the optical parameters playing a role in the light dosimetry during PBM. We conducted a study to determine the effective attenuation coefficient μeff of PD-relevant human deep brain tissues at 671 and 808 nm, using a multichannel fluence rate-meter comprising sub-millimeter isotropic detectors. The first step involved measurements of tissue modifications induced by postmortem situation and tissue storage on rabbit brains. The parameter μeff was measured using various tissue conditions (in vivo, immediately after sacrifice, after six weeks' storage at -20°C or in 10 % formaldehyde solution) on eight female New Zealand white rabbits. In the second step, fluence rate was measured at various locations of a frozen human deep brain when the deep brain was illuminated from the sphenoidal sinus. The results were processed by an iterative Monte-Carlo algorithm to generate sets of optical parameters, and results collected on rabbit brains were used to extrapolate the μeff value that would be observed in human deep brain tissues in vivo. Under all tissue conditions, the value of μeff at 808 nm was smaller than that at 671 nm. After long-term storage for six weeks at -20°C, μeff decreased, on average by 15 to 25 % at all wavelengths, while it increased by 5 to 15 % at all wavelengths after storage in formaldehyde. Therefore, a reasonable estimate of in vivo human deep brain μeff values at 671 and 808 nm can be obtained by multiplying the data we report by 120 %.

  12. Fluid-rock interactions in the Rhine Graben: A thermodynamic model of the hydrothermal alteration observed in deep drilling

    NASA Astrophysics Data System (ADS)

    Komninou, A.; Yardley, B. W. D.

    1997-02-01

    Deep drilling at Soultz-sous-Forêts, France, on the western flanks of the Rhine Graben, has penetrated Hercynian granite underlying Mesozoic sediments. Veins are present throughout the drilled granite, and there are flows of warm water localized in fractures within the granite. Detailed mineralogical study of core material from the research drillhole EPS 1 has been carried out in order to assess the alteration history of the Soultz granite, part of the crystalline basement of the Rhine Graben. The results of the study have been used, in conjunction with analyses of present-day fluids from deep drilling in the Rhine Graben reported in the literature, to model thermodynamically the alteration process, and in particular to evaluate if it is likely to be continuing today. Reaction-path calculations show that if deep basinal brines, such as are known from sediments of the central Rhine Graben, react with Hercynian granite, they will form different alteration assemblages depending on both the path that the fluid follows (e.g., descending through sediments or through granite) and the extent of preexisting alteration of the granite. The calculations suggest that fluid now sampled from granite in EPS-1 achieved its peak temperature, c. 200°C, while within Permo-Triassic sandstone. The modeling also indicates that present-day fluids from the Rhine Graben system are capable of producing the vein quartz and possibly also the baryte veins, seen in the EPS 1 core. Much of the alteration present in the granite in the vicinity of veins and fractures may have been produced by a flow regime similar to that prevailing today.

  13. Observation of a novel relaxation process associated with electronic transitions from deep (D) defects in hydrogenated amorphous silicon

    NASA Astrophysics Data System (ADS)

    Cohen, J. David; Leen, Thomas M.; Rasmussen, Randall J.

    1992-12-01

    Junction capacitance transient measurements were employed to study the thermal emission of electrons trapped in deep (D) defects in lightly n-doped a-Si:H samples. We conclude that a novel defect relaxation process occurs upon a change of change state of the defect such that an electron's thermal release rate is inversely proportional to its residence time in the defect. Supplemental spin transient measurements indicate that both D-/D0 and D0/D+ transitions must be involved. A good fit to our data is obtained if we assume a non-Markovian process for the D0/D+ transition.

  14. Distributions of charged hadrons observed in deep-inelastic muon-deuterium scattering at 490 GeV

    NASA Astrophysics Data System (ADS)

    Adams, M. R.; Aïd, S.; Anthony, P. L.; Baker, M. D.; Bartlett, J.; Bhatti, A. A.; Braun, H. M.; Busza, W.; Conrad, J. M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S. K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Figiel, J.; Gebauer, H. J.; Geesaman, D. F.; Gilman, R.; Green, M. C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V. W.; Jackson, H. E.; Jaffe, D. E.; Jancso, G.; Jansen, D. M.; Kaufman, S.; Kennedy, R. D.; Kirk, T.; Kobrak, H. G. E.; Krzywdzinski, S.; Kunori, S.; Lord, J. J.; Lubatti, H. J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D. G.; Mohr, W.; Montgomery, H. E.; Morfin, J. G.; Nickerson, R. B.; O'Day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F. M.; Ramberg, E. J.; Röser, A.; Ryan, J. J.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schüler, K. P.; Seyerlein, H. J.; Skuja, A.; Snow, G. A.; Söldner-Rembold, S.; Steinberg, P. H.; Stier, H. E.; Stopa, P.; Swanson, R. A.; Talaga, R.; Tentindo-Repond, S.; Trost, H.-J.; Vidal, M.; Wilhelm, M.; Wilkes, J.; Venkataramania, H.; Wilson, Richard; Wittek, W.; Wolbers, S. A.; Zhao, T.

    1991-11-01

    Longitudinal and transverse momentum spectra of final state hadrons produced in deep-inelastic muon-deuterium scattering at incident muon energy of 490 GeV have been measured up to a hadronic center of mass energy of 30 GeV. The longitudinal distributions agree well with data from earlier muon-nucleon scattering experiments; these distributions tend to increase in steepness as the center of mass energy increases. Comparisons with e+e- data at comparable center of mass energies indicate slight differences. The transverse momentum distributions show an increase in mean pT2 with an increase in the center of mass energy.

  15. Shallow and Deep Latent Heating Modes Over Tropical Oceans Observed with TRMM PR Spectral Latent Heating Data

    NASA Technical Reports Server (NTRS)

    Takayabu, Yukari N.; Shige, Shoichi; Tao, Wei-Kuo; Hirota, Nagio

    2010-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of its formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the Tropics. Associated with this rainfall is a vast amount of heat, which is known as latent heat. It arises mainly due to the phase change of water vapor condensing into liquid droplets; three-fourths of the total heat energy available to the Earth's atmosphere comes from tropical rainfall. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. Three-dimensional distributions of latent heating estimated from Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR)utilizing the Spectral Latent Heating (SLH) algorithm are analyzed. Mass-weighted and vertically integrated latent heating averaged over the tropical oceans is estimated as approx.72.6 J/s (approx.2.51 mm/day), and that over tropical land is approx.73.7 J/s (approx.2.55 mm/day), for 30degN-30degS. It is shown that non-drizzle precipitation over tropical and subtropical oceans consists of two dominant modes of rainfall systems, deep systems and congestus. A rough estimate of shallow mode contribution against the total heating is about 46.7 % for the average tropical oceans, which is substantially larger than 23.7 % over tropical land. While cumulus congestus heating linearly correlates with the SST, deep mode is dynamically bounded by large-scale subsidence. It is notable that substantial amount of rain, as large as 2.38 mm day-1 in average, is brought from congestus clouds under the large-scale subsiding circulation. It is also notable that even in the region with SST warmer than 28 oC, large-scale subsidence effectively suppresses the deep convection, remaining the heating by congestus clouds. Our results support that the entrainment of mid-to-lower-tropospheric dry air, which accompanies the large

  16. New observations on the ultrastructure of mammalian conducting airway epithelium: application of liquid propane freezing, deep etching, and rotary shadowing techniques to freeze-fracture.

    PubMed

    Carson, J L; Collier, A M; Smith, C A

    1984-10-01

    Freshly isolated, viable hamster tracheal epithelium was rapidly frozen in a jet of liquid nitrogen-cooled propane followed by freeze-fracture, deep etching, and rotary shadowing. Examination of the replicas by transmission electron microscopy revealed characteristic features of both ciliated and nonciliated cells, profiles of tight junctional complexes, and two distinct types of membrane particle complexes. The findings of this study suggest that rapid freezing of viable biological specimens coupled with freeze-fracture, deep etching, and rotary shadowing may provide a useful approach to achieving some additional perspectives of cell structure and function. Since the experimental protocol avoided any use of chemical fixation and processing procedures generally employed in electron microscopy, this study also validates for airway epithelium the details of fine structure observed using more conventional ultrastructural methods. PMID:6544880

  17. Probing the extent of the non-thermal emission from the Vela X region at TeV energies with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Cologna, G.; Conrad, J.; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O.' C.; Dubois, F.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Grondin, M.-H.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Menzler, U.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nguyen, N.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2012-12-01

    Context. Vela X is a region of extended radio emission in the western part of the Vela constellation: one of the nearest pulsar wind nebulae, and associated with the energetic Vela pulsar (PSR B0833-45). Extended very-high-energy (VHE) γ-ray emission (HESS J0835-455) was discovered using the H.E.S.S. experiment in 2004. The VHE γ-ray emission was found to be coincident with a region of X-ray emission discovered with ROSAT above 1.5 keV (the so-called Vela X cocoon): a filamentary structure extending southwest from the pulsar to the centre of Vela X. Aims: A deeper observation of the entire Vela X nebula region, also including larger offsets from the cocoon, has been performed with H.E.S.S. This re-observation was carried out in order to probe the extent of the non-thermal emission from the Vela X region at TeV energies and to investigate its spectral properties. Methods: To increase the sensitivity to the faint γ-ray emission from the very extended Vela X region, a multivariate analysis method combining three complementary reconstruction techniques of Cherenkov-shower images is applied for the selection of γ-ray events. The analysis is performed with the On/Off background method, which estimates the background from separate observations pointing away from Vela X; towards regions free of γ-ray sources but with comparable observation conditions. Results: The γ-ray surface brightness over the large Vela X region reveals that the detection of non-thermal VHE γ-ray emission from the PWN HESS J0835-455 is statistically significant over a region of radius 1.2° around the position α = 08h35m00s, δ = -45°36'00'' (J2000). The Vela X region exhibits almost uniform γ-ray spectra over its full extent: the differential energy spectrum can be described by a power-law function with a hard spectral index Γ = 1.32 ± 0.06stat ± 0.12sys and an exponential cutoff at an energy of (14.0 ± 1.6stat ± 2.6sys) TeV. Compared to the previous H.E.S.S. observations of Vela X the

  18. Transition from bound to free excitons observed in deep- ultraviolet photoluminescence of AlN grown by MOCVD

    NASA Astrophysics Data System (ADS)

    Wang, Weiying; Jin, Peng; Tang, Ning; Liu, Yali; Fu, Lei; Xu, Fujun; Qin, Zhixin; Ge, Weikun; Shen, Bo

    2016-07-01

    The transition from bound exciton to free exciton and exciton-phonon interaction in an AlN epilayer have been investigated by time resolved deep ultraviolet photoluminescence spectroscopy. Based on the analysis of the energy position (S-shaped dependence with temperature), integrated intensity as well as decay time, the main X peak located at 6.06 eV at 7.7 K is assigned to originate from radiative recombination of excitons bound to some unintentionally doped Si or O impurities. While the other two peaks on the lower energy side should be from the bound exciton’s phonon replicas. The corresponding small Huang-Rhys factor indicates weak interaction between phonon and bound excitons, in comparison to the case of free exciton, for which our experimental results are in good agreement with the theoretical calculation of the Huang-Rhys factors.

  19. Anatomy of the Hesse photoreceptor cell axonal system in the central nervous system of amphioxus.

    PubMed

    Castro, Antonio; Becerra, Manuela; Manso, María Jesús; Sherwood, Nancy M; Anadón, Ramón

    2006-01-01

    The present study reports the organization of the Hesse cell axonal system in the central nervous system of the amphioxus, with the use of a polyclonal antiserum raised against lamprey gonadotropin-releasing hormone-I (GnRH-I). In the spinal cord, the rhabdomeric photoreceptor cells of the bicellular organs were well labeled with this antibody. These cells sent smooth, straight, lateral processes that bent and became beaded as they passed ventrally and crossed to the contralateral side of the cord. There, the processes of several cells aggregated to give rise to a longitudinal fiber bundle. Beaded collaterals of these processes were directed to ventral neuropil and did not appear to contact giant Rohde cell axons. The crossed projections of the Hesse photoreceptors are compared with those of vertebrate retinal ganglion cells. Other antisera raised against GnRH weakly labeled rhabdomeric photoreceptors located dorsally in the brain, the Joseph cells. The finding that GnRH antibodies label amphioxus photoreceptor cells and axons is not definitive proof that the photoreceptors contain GnRH. Regardless of whether the antibody recognizes amphioxus GnRH, which has not yet been identified by structure, the antibody has revealed the processes of the Hesse photoreceptor cells.

  20. HESS J1818-154, a new composite supernova remnant discovered in TeV gamma rays and X-rays

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-02-01

    Composite supernova remnants (SNRs) constitute a small subclass of the remnants of massive stellar explosions where non-thermal radiation is observed from both the expanding shell-like shock front and from a pulsar wind nebula (PWN) located inside of the SNR. These systems represent a unique evolutionary phase of SNRs where observations in the radio, X-ray, and γ-ray regimes allow the study of the co-evolution of both these energetic phenomena. In this article, we report results from observations of the shell-type SNR G 15.4+0.1 performed with the High Energy Stereoscopic System (H.E.S.S.) and XMM-Newton. A compact TeV γ-ray source, HESS J1818-154, located in the center and contained within the shell of G 15.4+0.1 is detected by H.E.S.S. and featurs a spectrum best represented by a power-law model with a spectral index of -2.3 ± 0.3stat ± 0.2sys and an integral flux of F(> 0.42 TeV) = (0.9 ± 0.3stat ± 0.2sys) × 10-12 cm-2 s-1. Furthermore, a recent observation with XMM-Newton reveals extended X-ray emission strongly peaked in the center of G 15.4+0.1. The X-ray source shows indications of an energy-dependent morphology featuring a compact core at energies above 4 keV and more extended emission that fills the entire region within the SNR at lower energies. Together, the X-ray and VHE γ-ray emission provide strong evidence of a PWN located inside the shell of G 15.4+0.1 and this SNR can therefore be classified as a composite based on these observations. The radio, X-ray, and γ-ray emission from the PWN is compatible with a one-zone leptonic model that requires a low average magnetic field inside the emission region. An unambiguous counterpart to the putative pulsar, which is thought to power the PWN, has been detected neither in radio nor in X-ray observations of G 15.4+0.1.

  1. Deep Chlorophyll Maximum distribution in the Alboran sea and its relationship with mesoscale and frontal features through syncronous glider observations.

    NASA Astrophysics Data System (ADS)

    Olita, Antonio; Ribotti, Alberto; Ruiz, Simon; Pascual, Ananda

    2015-04-01

    May 25 2014, two gliders were launched in the framework of the multiplatform and multidisciplinary experiment in the Alboran sea named ALBOREX (a PERSEUS project sampling) and of the JERICO TNA FRIPP project. The two instruments glided for 6 days, during which ADCP, ship based CTD, ARGO floats and surface drifters also sampled surface to deep waters allowing, togheter with bottle water samples, to collect a comprehensive dataset of oceanographic multidisciplinary quasi-synoptic data at (sub-)mesoscale. This preliminary work presents the results related to the two glider launched at approximatively 20 km each other. The two gliders intercepted in their pathway a frontal structure belonging to the northern margin of a quite large and strong anticyclonic structure originating by the meandering of Atlantic Waters entering in Mediterranean through Gibraltar. The vertical structure of Chlorophyll-a (as derived by fluorimeter measurements) shows the area of subsidence across the front and the deepening of isolines in the eddy interior. The analysis of the relatively low-cost glider data, combined with synoptic satellite measurements, shed light on the dynamics determining the re-distribution of the phytoplanktonic biomass and provide pretious hints, combined with dissolved oxygen data also collected by the unmanned autonomous vehicles, about the influence of such dynamical features on Primary Production.

  2. THERMAL-ENERGY STORAGE IN A DEEP SANDSTONE AQUIFER IN MINNESOTA: FIELD OBSERVATIONS AND THERMAL ENERGY-TRANSPORT MODELING.

    USGS Publications Warehouse

    Miller, R.T.

    1986-01-01

    A study of the feasibility of storing heated water in a deep sandstone aquifer in Minnesota is described. The aquifer consists of four hydraulic zones that are areally anisotropic and have average hydraulic conductivities that range from 0. 03 to 1. 2 meters per day. A preliminary axially symmetric, nonisothermal, isotropic, single-phase, radial-flow, thermal-energy-transport model was constructed to investigate the sensitivity of model simulation to various hydraulic and thermal properties of the aquifer. A three-dimensional flow and thermal-energy transport model was constructed to incorporate the areal anisotropy of the aquifer. Analytical solutions of equations describing areally anisotropic groundwater flow around a doublet-well system were used to specify model boundary conditions for simulation of heat injection. The entire heat-injection-testing period of approximately 400 days was simulated. Model-computed temperatures compared favorably with field-recorded temperatures, with differences of no more than plus or minus 8 degree C. For each test cycle, model-computed aquifer thermal efficiency, defined as total heat withdrawn divided by total heat injected, was within plus or minus 2% of the field-calculated values.

  3. Multiple Geophysical Observations by a newly developed multi-component borehole instrument at the Continental Deep Drilling Site of the CCSD, Donghai, China

    NASA Astrophysics Data System (ADS)

    Xu, J.; Zhao, Z.; Ishii, H.; Yamauchi, T.

    2004-12-01

    Multiple Geophysical Observations by a newly developed multi-component borehole instrument at the Continental Deep Drilling Site of the CCSD, Donghai, China Jiren Xu1 (+86-10-68992879; xujiren@ccsd.org.cn) Zhixin Zhao1 (+86-10-68999734; zhaozhixin@ccsd.org.cn) Hiroshi Ishii2 (+81-0572-67-3105; ishii@tries.gr.jp Tsuneo Yamauchi3 (+81-052-789-3045; yamauchi@seis.nagoya-u.ac.jp) 1 Institute of Geology, Chinese Academy of Geological Sciences, China 2 Tono Research Institute of Earthquake Science (TRIES), Japan 3 Graduate School of Environmental Studies, Nagoya University, Japan The Chinese Continental Scientific Drilling (CCSD) site is located in the Donghai area of the Dabie-Sulu belt, which is the largest UHPM belt in the world. The drilling of the main borehole with 5000m will finish in next year. Three satellite boreholes, PP1, PP2 and PP3 were drilled and various surveys have been performed in the Donghai area about 6 years ago. We are going to install a newly developed Multi-component Instrument for borehole observations in main hole near the large Tanlu fault, and establish a long-term underground observation laboratory, which is the first noiseless one in China. The seismic activity and various geophysical fields, viz. strain, geomagnetism, geothermy, tilt, pore pressure etc. will be investigated. Data from the underground laboratory will be open to scientific, engineering and public services. We will measure the initial stress in various depths of the borehole by overcoring method using a new developed wireless intelligent type strainmeter of in-situ stress. Establishing a long-term noiseless underground observation laboratory at deep borehole and investigating crustal movement in East China are important for observing the physical conditions of the earth¡_s interior and solving many social problems, such as resources, disasters and environment. Multiple geophysical observations and the study in deep borehole will speed up and develop the study on tectonics

  4. An intensely star-forming galaxy at z ∼ 7 with low dust and metal content revealed by deep ALMA and HST observations

    SciTech Connect

    Ouchi, Masami; Ono, Yoshiaki; Momose, Rieko; Ellis, Richard; Nakanishi, Kouichiro; Kohno, Kotaro; Tamura, Yoichi; Kurono, Yasutaka; Ashby, M. L. N.; Willner, S. P.; Fazio, G. G.; Shimasaku, Kazuhiro; Iono, Daisuke

    2013-12-01

    We report deep ALMA observations complemented by associated Hubble Space Telescope (HST) imaging for a luminous (m {sub UV} = 25) galaxy, 'Himiko', at a redshift of z = 6.595. The galaxy is remarkable for its high star formation rate, 100 M {sub ☉} yr{sup –1}, which has been securely estimated from our deep HST and Spitzer photometry, and the absence of any evidence for strong active galactic nucleus activity or gravitational lensing magnification. Our ALMA observations probe an order of magnitude deeper than previous IRAM observations, yet fail to detect a 1.2 mm dust continuum, indicating a flux of <52 μJy, which is comparable to or weaker than that of local dwarf irregulars with much lower star formation rates. We likewise provide a strong upper limit for the flux of [C II] 158 μm, L{sub [C} {sub II]}<5.4×10{sup 7} L{sub ⊙}, which is a diagnostic of the hot interstellar gas that is often described as a valuable probe for early galaxies. In fact, our observations indicate that Himiko lies off the local L{sub [C} {sub II]}-star formation rate scaling relation by a factor of more than 30. Both aspects of our ALMA observations suggest that Himiko is a unique object with a very low dust content and perhaps nearly primordial interstellar gas. Our HST images provide unique insight into the morphology of this remarkable source, highlighting an extremely blue core of activity and two less extreme associated clumps. Himiko is undergoing a triple major merger event whose extensive ionized nebula of Lyα emitting gas, discovered in our earlier work with Subaru, is powered by star formation and the dense circumgalactic gas. We are likely witnessing an early massive galaxy during a key period of its mass assembly close to the end of the reionization era.

  5. Cell and Microvesicle Urine microRNA Deep Sequencing Profiles from Healthy Individuals: Observations with Potential Impact on Biomarker Studies

    PubMed Central

    Ben-Dov, Iddo Z.; Whalen, Veronica M.; Goilav, Beatrice; Max, Klaas E. A.; Tuschl, Thomas

    2016-01-01

    Background Urine is a potential source of biomarkers for diseases of the kidneys and urinary tract. RNA, including microRNA, is present in the urine enclosed in detached cells or in extracellular vesicles (EVs) or bound and protected by extracellular proteins. Detection of cell- and disease-specific microRNA in urine may aid early diagnosis of organ-specific pathology. In this study, we applied barcoded deep sequencing to profile microRNAs in urine of healthy volunteers, and characterized the effects of sex, urine fraction (cells vs. EVs) and repeated voids by the same individuals. Results Compared to urine-cell-derived small RNA libraries, urine-EV-derived libraries were relatively enriched with miRNA, and accordingly had lesser content of other small RNA such as rRNA, tRNA and sn/snoRNA. Unsupervised clustering of specimens in relation to miRNA expression levels showed prominent bundling by specimen type (urine cells or EVs) and by sex, as well as a tendency of repeated (first and second void) samples to neighbor closely. Likewise, miRNA profile correlations between void repeats, as well as fraction counterparts (cells and EVs from the same specimen) were distinctly higher than correlations between miRNA profiles overall. Differential miRNA expression by sex was similar in cells and EVs. Conclusions miRNA profiling of both urine EVs and sediment cells can convey biologically important differences between individuals. However, to be useful as urine biomarkers, careful consideration is needed for biofluid fractionation and sex-specific analysis, while the time of voiding appears to be less important. PMID:26785265

  6. A new 2.5D representation for lymph node detection using random sets of deep convolutional neural network observations.

    PubMed

    Roth, Holger R; Lu, Le; Seff, Ari; Cherry, Kevin M; Hoffman, Joanne; Wang, Shijun; Liu, Jiamin; Turkbey, Evrim; Summers, Ronald M

    2014-01-01

    Automated Lymph Node (LN) detection is an important clinical diagnostic task but very challenging due to the low contrast of surrounding structures in Computed Tomography (CT) and to their varying sizes, poses, shapes and sparsely distributed locations. State-of-the-art studies show the performance range of 52.9% sensitivity at 3.1 false-positives per volume (FP/vol.), or 60.9% at 6.1 FP/vol. for mediastinal LN, by one-shot boosting on 3D HAAR features. In this paper, we first operate a preliminary candidate generation stage, towards -100% sensitivity at the cost of high FP levels (-40 per patient), to harvest volumes of interest (VOI). Our 2.5D approach consequently decomposes any 3D VOI by resampling 2D reformatted orthogonal views N times, via scale, random translations, and rotations with respect to the VOI centroid coordinates. These random views are then used to train a deep Convolutional Neural Network (CNN) classifier. In testing, the CNN is employed to assign LN probabilities for all N random views that can be simply averaged (as a set) to compute the final classification probability per VOI. We validate the approach on two datasets: 90 CT volumes with 388 mediastinal LNs and 86 patients with 595 abdominal LNs. We achieve sensitivities of 70%/83% at 3 FP/vol. and 84%/90% at 6 FP/vol. in mediastinum and abdomen respectively, which drastically improves over the previous state-of-the-art work.

  7. Deep Chandra Observations of the Compact Starburst Galaxy Henize 2–10: X-Rays from the Massive Black Hole

    NASA Astrophysics Data System (ADS)

    Reines, Amy E.; Reynolds, Mark T.; Miller, Jon M.; Sivakoff, Gregory R.; Greene, Jenny E.; Hickox, Ryan C.; Johnson, Kelsey E.

    2016-10-01

    We present follow-up X-ray observations of the candidate massive black hole (BH) in the nucleus of the low-mass, compact starburst galaxy Henize 2–10. Using new high-resolution observations from the Chandra X-ray Observatory totaling 200 ks in duration, as well as archival Chandra observations from 2001, we demonstrate the presence of a previously unidentified X-ray point source that is spatially coincident with the known nuclear radio source in Henize 2–10 (i.e., the massive BH). We show that the hard X-ray emission previously identified in the 2001 observation is dominated by a source that is distinct from the nucleus, with the properties expected for a high-mass X-ray binary. The X-ray luminosity of the nuclear source suggests the massive BH is radiating significantly below its Eddington limit (∼10{}-6 {L}{Edd}), and the soft spectrum resembles other weakly accreting massive BHs including Sagittarius A*. Analysis of the X-ray light curve of the nucleus reveals the tentative detection of a ∼9 hr periodicity, although additional observations are required to confirm this result. Our study highlights the need for sensitive high-resolution X-ray observations to probe low-level accretion, which is the dominant mode of BH activity throughout the universe.

  8. Geodetic observations of deep re-equilibration of magmatic systems accompanying the Hekla 2000 and Eyjafjallajökull 2010 eruptions, Iceland

    NASA Astrophysics Data System (ADS)

    Geirsson, Halldor; LaFemina, Peter; Sturkell, Erik; Ofeigsson, Benedikt; Arnadottir, Thora; Hreinsdottir, Sigrun; Hjaltadottir, Sigurlaug; Hooper, Andy; Lund, Bjorn; Schmidt, Peter; Sigmundsson, Freysteinn; Linde, Alan; Sacks, Selwyn

    2015-04-01

    Volcano geodesy most easily displays deformation from shallow deformation sources. However, with the expansion of geodetic networks and observations systems, there is growing evidence for far-field deformation at some volcanoes, indicating deeper processes within theses magmatic systems. We reflect here on crustal deformation from two recent eruptions in Iceland, the Hekla 2000 and Eyjafjallajokull 2010, which show signs of pressure changes at various crustal depths accompanying the eruptions. These eruptions were of similar eruptive volumes, approximately 0.2 km3, and were accompanied by crustal deformation relating to shallow dike and sill emplacements, in addition to more subtle and widespread crustal deformation caused by magma withdrawal. The crustal deformation associated with the Hekla 2000 eruption was captured by various geodetic methods, including continuous and episodic GPS, dry-tilt (i.e., short leveling lines), borehole strain, and InSAR. Continuous GPS data show deformation at >50 km from Hekla. We derive new deformation estimates from the episodic GPS network, and model the GPS displacements with previously published dry-tilt, InSAR, and borehole strain measurements in a formal joint inversion. While most of our data indicate a deep source of magma withdrawal (~20 km depth for a spherical source, or a pipe-like structure that reaches up to shallower depths), data from the borehole strain station closest to Hekla cannot be readily explained with a deep source. The borehole strain data at Hekla has good short-term resolution but poor long-term resolution, while the GPS, tilt, and InSAR measurements span a longer time interval. Therefore, we suggest the geodetic data from the Hekla 2000 eruption can best be interpreted with spatio-temporal progression of pressure changes in the magmatic system such that the co-eruptive signal was from a shallower (~10 km) source, which was followed by magma transport from deep to shallower depths before, during and

  9. Deep XMM observations of Draco rule out at the 99 per cent confidence level a dark matter decay origin for the 3.5 keV line

    NASA Astrophysics Data System (ADS)

    Jeltema, Tesla; Profumo, Stefano

    2016-06-01

    We searched for an X-ray line at energies around 3.5 keV in deep, ˜1.6 Ms XMM-Newton observations of the dwarf spheroidal galaxy Draco. No line was found in either the Metal Oxide Semi-conductor (MOS) or the p-type/n-type semiconductor (PN) detectors. The data in this energy range are completely consistent with a single, unfolded power-law modelling the particle background, which dominates at these energies, plus instrumental lines; the addition of a ˜3.5 keV line feature gives no improvement to the fit. The corresponding upper limit on the line flux rules out a dark matter decay origin for the 3.5 keV line found in observations of clusters of galaxies and in the Galactic Centre at greater than 99 per cent confidence level.

  10. Coronal and interplanetary propagation, interplanetary acceleration, cosmic-ray observations by deep space network and anomalous component

    NASA Technical Reports Server (NTRS)

    Ng, C. K.

    1986-01-01

    The purpose is to provide an overview of the contributions presented in sessions SH3, SH1.5, SH4.6 and SH4.7 of the 19th International Cosmic Ray Conference. These contributed papers indicate that steady progress continues to be made in both the observational and the theoretical aspects of the transport and acceleration of energetic charged particles in the heliosphere. Studies of solar and interplanetary particles have placed emphasis on particle directional distributions in relation to pitch-angle scattering and magnetic focusing, on the rigidity and spatial dependence of the mean free path, and on new propagation regimes in the inner and outer heliosphere. Coronal propagation appears in need of correlative multi-spacecraft studies in association with detailed observation of the flare process and coronal magnetic structures. Interplanetary acceleration has now gone into a consolidation phase, with theories being worked out in detail and checked against observation.

  11. Constraints on the progenitor system and the environs of SN 2014J from deep EVN and MERLIN radio observations

    NASA Astrophysics Data System (ADS)

    Perez-Torres, M.; Lundqvist, P.; Beswick, R. J.; Björnsson, C. I.; Muxlow, T. W. B.; Paragi, Z.; Ryder, S.; Alberdi, A.; Fransson, C.; Marcaide, J. M.; Ros, E.; Argo, M. K.; Guirado, J. C.

    We report the deepest radio interferometric observations of the closest Type Ia supernova in decades, SN 2014J, which exploded in the nearby galaxy M 82. These observations represent, together with radio observations of SNe 2011fe, the most sensitive radio studies of a Type Ia SN ever. We constrain the mass-loss rate from the progenitor system of SN 2014J to dM/dt &t;~ 7×10-10 M_sun/yr (for a wind speed of 100 km/s). Most single-degenerate scenarios, i.e., the wide family of progenitor systems where a red giant, main-sequence, or sub-giant star donates mass to a exploding white dwarf, are ruled out by our observations. On the contrary, our stringent upper limits to the radio emission from SN 2014 favor a double-degenerate scenario - involving two WD stars - for the progenitor system of SN 2014J, as such systems have less circumstellar gas than our upper limits. Thus, the evidence from SNe 2011fe and 2014J points in the direction of a double-degenerate scenario for both. Looking into the future, we note that the huge improvement in sensitivity of the SKA with respect to its predecessors will allow us to determine which progenitor scenario (single-degenerate vs. double-degenerate) applies to a large sample of nearby Type Ia SNe, thus unambiguously solving this issue.

  12. Transfer of metals in soil-grass ecosystems under long-term N, P, K fertilization in Hesse, Germany

    NASA Astrophysics Data System (ADS)

    Czarnecki, Sezin; Düring, Rolf-Alexander

    2015-04-01

    With this study focuses on the influence of long-term (14 years) fertilization on metal transition from soil to plants is presented. Accumulation of metals in plants due to long-term fertilization and predicting the bioavailability and transfer of metals in the soil-plant system is of great importance with regard to human health as plants represent the first compartment of the terrestrial food chain. Soil and plant (Lolio-Cynosuretum) samples were taken from a 14 years long-term fertilization field experiment which was carried out in Hesse, Germany. Correlation coefficients, transfer factors, and regression analysis was performed for Cd, Cu, Mn, Pb, and Zn to quantify the relative difference in bioavailability of metals to plants or to identify the capacity of plants to accumulate a given metal. Correlation coefficients between metals in soils and in plants show significant relationships (p<0.01) for selected metals. Metal bioavailability from soil to plant based on transfer factor (TF) was observed to decrease in the order Cd>Cu>Zn>Mn>Pb. Results of stepwise multiple linear regression analysis showed that Corg, CEC and bioavailable metal content are the most important predictors for plant metal uptake.

  13. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water.

    PubMed

    Darelius, E; Fer, I; Nicholls, K W

    2016-01-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing. PMID:27481659

  14. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water.

    PubMed

    Darelius, E; Fer, I; Nicholls, K W

    2016-01-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing.

  15. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water

    NASA Astrophysics Data System (ADS)

    Darelius, E.; Fer, I.; Nicholls, K. W.

    2016-08-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing.

  16. Observed vulnerability of Filchner-Ronne Ice Shelf to wind-driven inflow of warm deep water

    PubMed Central

    Darelius, E.; Fer, I.; Nicholls, K. W.

    2016-01-01

    The average rate of melting at the base of the large Filchner-Ronne Ice Shelf in the southern Weddell Sea is currently low, but projected to increase dramatically within the next century. In a model study, melt rates increase as changing ice conditions cause a redirection of a coastal current, bringing warm water of open ocean origin through the Filchner Depression and into the Filchner Ice Shelf cavity. Here we present observations from near Filchner Ice Shelf and from the Filchner Depression, which show that pulses of warm water already arrive as far south as the ice front. This southward heat transport follows the eastern flank of the Filchner Depression and is found to be directly linked to the strength of a wind-driven coastal current. Our observations emphasize the potential sensitivity of Filchner-Ronne Ice Shelf melt rates to changes in wind forcing. PMID:27481659

  17. Early science with the Large Millimetre Telescope: Deep LMT/AzTEC millimetre observations of ɛ Eridani and its surroundings

    NASA Astrophysics Data System (ADS)

    Chavez-Dagostino, M.; Bertone, E.; Cruz-Saenz de Miera, F.; Marshall, J. P.; Wilson, G. W.; Sánchez-Argüelles, D.; Hughes, D. H.; Kennedy, G.; Vega, O.; De la Luz, V.; Dent, W. R. F.; Eiroa, C.; Gómez-Ruiz, A. I.; Greaves, J. S.; Lizano, S.; López-Valdivia, R.; Mamajek, E.; Montaña, A.; Olmedo, M.; Rodríguez-Montoya, I.; Schloerb, F. P.; Yun, Min S.; Zavala, J. A.; Zeballos, M.

    2016-11-01

    ɛ Eridani is a nearby, young Sun-like star that hosts a ring of cool debris analogous to the Solar system's Edgeworth-Kuiper belt. Early observations at (sub-)mm wavelengths gave tentative evidence of the presence of inhomogeneities in the ring, which have been ascribed to the effect of a putative low eccentricity planet, orbiting close to the ring. The existence of these structures has been recently challenged by high-resolution interferometric millimetre observations. Here, we present the deepest single-dish image of ɛ Eridani at millimetre wavelengths, obtained with the Large Millimetre Telescope Alfonso Serrano (LMT). The main goal of these LMT observations is to confirm (or refute) the presence of non-axisymmetric structure in the disc. The dusty ring is detected for the first time along its full projected elliptical shape. The radial extent of the ring is not spatially resolved and shows no evidence, to within the uncertainties, of dust density enhancements. Additional features of the 1.1 mm map are: (i) the presence of significant flux in the gap between the ring and the star, probably providing the first exo-solar evidence of Poynting-Robertson drag, (ii) an unambiguous detection of emission at the stellar position with a flux significantly above that expected from ɛ Eridani's photosphere, and (iii) the identification of numerous unresolved sources which could correspond to background dusty star-forming galaxies.

  18. Biodiversity of the Deep-Sea Benthic Fauna in the Sangihe-Talaud Region, Indonesia: Observations from the INDEX-SATAL 2010 Expedition

    NASA Astrophysics Data System (ADS)

    Herrera, S.; Munro, C.; Nganro, N.; Tunnicliffe, V.; Wirasantosa, S.; Sibert, E.; Hammond, S. R.; Bors, E.; Butterfield, D.; Holden, J. F.; Baker, E. T.; Sherrin, J.; Makarim, S.; Troa, R.; Shank, T. M.

    2010-12-01

    The benthic ecosystems found in the deep-sea promontories of Sangihe Talaud region were explored, between June and August 2010, using the ROV Little Hercules aboard the NOAA ship Okeanos Explorer. The Sangihe-Talaud region is part of the Coral Triangle (CT) an area known for harboring the most biodiverse shallow-water coral reefs in the world. Notwithstanding the significant research efforts that have been undertaken to catalog and protect the biodiversity of the CT prior this expedition, virtually nothing was known about the life inhabiting the deep sea. The high-resolution imagery obtained from the 27 ROV dives revealed remarkably high abundances and diversity of animal species, many of which appear to be novel. On hard bottom substrates, cold-water corals were the dominant sessile macrofauna, in terms of biomass, followed by glass sponges (Hexactinellida) and sea lilies (Crinoidea). The coral taxa observed in this area represent six large orders of cnidarians: antipatharians (black corals), scleractinians (stony corals), zoanthideans (gold corals), alcyonaceans (octocorals), pennatulaceans (sea pens), and anthoathecates (hydrocorals). Most sessile species, independently of their size class or taxonomic affiliation, harbor a wide variety of associated fauna. Brittle stars (Ophiuroidea), squat lobsters (Galatheoidea), shrimp (Caridea), amphipods (Amphipoda), anemones (Actinaria), zanthideans, barnacles (Cirripedia), hydroids (Hydrozoa) and worms (Polychaeta) are the animal groups most commonly found forming these associations. In contrast, soft bottom habitats were dominated by stalked sponges, sea pens, sea cucumbers (Holothuroidea) and brittle stars. Other conspicuous fauna include fish, hermit crabs (Paguridae), urchins (Echinoidea) and octopuses (Cephalopoda). The abundance of habitats generated by the high number of geological and biological features and depth ranges present in the deep coral triangle (e.g., ridges, seamounts, island margins, plains, and rock

  19. Fermi-LAT Constraints on the Pulsar Wind Nebula Nature of HESS J1857+026

    NASA Technical Reports Server (NTRS)

    Rousseau, R.; Grondin, M.-H.; VanEtten, A.; Lemoine-Goumard, M.; Bogdanov, S.; Hessels, J. W. T.; Kaspi, V. M.; Arzoumanian, Z.; Camilo, F.; Casandjian, J. M.; Espinoza, C. M.; Johnston, S.; Lyne, A. G.; Smith, D. A.; Stappers, B. W.; Caliandro, G. A.

    2012-01-01

    Since its launch, the Fermi satellite has firmly identified 5 pulsar wind nebulae plus a large number of candidates, all powered by young and energetic pulsars. HESS J1857+026 is a spatially extended gamma-ray source detected by H.E.S.S. and classified as a possible pulsar wind nebula candidate powered by PSR J1856+0245. Aims. We search for -ray pulsations from PSR J1856+0245 and explore the characteristics of its associated pulsar wind nebula. Methods. Using a rotational ephemeris obtained from the Lovell telescope at Jodrell Bank Observatory at 1.5 GHz, we phase.fold 36 months of gamma-ray data acquired by the Large Area Telescope (LAT) aboard Fermi. We also perform a complete gamma-ray spectral and morphological analysis. Results. No pulsation was detected from PSR J1856+0245. However, significant emission is detected at a position coincident with the TeV source HESS J1857+026. The gamma-ray spectrum is well described by a simple power law with a spectral index of Gamma = 1.53 +/- 0.11(sub stat) +/- 0.55(sub syst) and an energy flux of G(0.1 C100 GeV) = (2.71 +/- 0.52(sub stat) +/- 1.51(sub syst) X 10(exp -11) ergs/ sq cm/s. This implies a gamma.ray efficiency of approx 5 %, assuming a distance of 9 kpc, the gamma-ray luminosity of L(sub gamma) (sub PWN) (0.1 C100 GeV) = (2.5 +/- 0.5(sub stat) +/- 1.5(sub syst)) X 10(exp 35)(d/(9kpc))(exp 2) ergs/s and E-dot = 4.6 X 10(exp 36) erg /s, in the range expected for pulsar wind nebulae. Detailed multi-wavelength modeling provides new constraints on its pulsar wind nebula nature.

  20. Fermi-LAT constraints on the pulsar wind nebula nature of HESS J1857+026

    NASA Astrophysics Data System (ADS)

    Rousseau, R.; Grondin, M.-H.; Van Etten, A.; Lemoine-Goumard, M.; Bogdanov, S.; Hessels, J. W. T.; Kaspi, V. M.; Arzoumanian, Z.; Camilo, F.; Casandjian, J. M.; Espinoza, C. M.; Johnston, S.; Lyne, A. G.; Smith, D. A.; Stappers, B. W.; Caliandro, G. A.

    2012-08-01

    Context. Since its launch, the Fermi satellite has firmly identified 5 pulsar wind nebulae plus a large number of candidates, all powered by young and energetic pulsars. HESS J1857 + 026 is a spatially extended γ-ray source detected by H.E.S.S. and classified as a possible pulsar wind nebula candidate powered by PSR J1856 + 0245. Aims: We search for γ-ray pulsations from PSR J1856+0245 and explore the characteristics of its associated pulsar wind nebula. Methods: Using a rotational ephemeris obtained from the Lovell telescope at Jodrell Bank Observatory at 1.5 GHz, we phase-fold 36 months of γ-ray data acquired by the Large Area Telescope (LAT) aboard Fermi. We also perform a complete γ-ray spectral and morphological analysis. Results: No γ-ray pulsations were detected from PSR J1856+0245. However, significant emission is detected at a position coincident with the TeV source HESS J1857 + 026. The γ-ray spectrum is well described by a simple power-law with a spectral index of Γ = 1.53 ± 0.11stat ± 0.55syst and an energy flux of G(0.1-100 GeV) = (2.71 ± 0.52stat ± 1.51syst) × 10-11 erg cm-2 s-1. The γ-ray luminosity is LPWNγ (0.1-100 GeV)=(2.5 ± 0.5stat ± 1.5syst) × 1035 (d/9 kpc)2 erg s-1, assuming a distance of 9 kpc. This implies a γ-ray efficiency of ~5% for Ė = 4.6 × 1036 erg s-1, in the range expected for pulsar wind nebulae. Detailed multi-wavelength modeling provides new constraints on its pulsar wind nebula nature.

  1. Does the worsening galactic cosmic radiation environment observed by CRaTER preclude future manned deep space exploration?

    NASA Astrophysics Data System (ADS)

    Schwadron, N. A.; Blake, J. B.; Case, A. W.; Joyce, C. J.; Kasper, J.; Mazur, J.; Petro, N.; Quinn, M.; Porter, J. A.; Smith, C. W.; Smith, S.; Spence, H. E.; Townsend, L. W.; Turner, R.; Wilson, J. K.; Zeitlin, C.

    2014-11-01

    The Sun and its solar wind are currently exhibiting extremely low densities and magnetic field strengths, representing states that have never been observed during the space age. The highly abnormal solar activity between cycles 23 and 24 has caused the longest solar minimum in over 80 years and continues into the unusually small solar maximum of cycle 24. As a result of the remarkably weak solar activity, we have also observed the highest fluxes of galactic cosmic rays in the space age and relatively small solar energetic particle events. We use observations from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter to examine the implications of these highly unusual solar conditions for human space exploration. We show that while these conditions are not a show stopper for long-duration missions (e.g., to the Moon, an asteroid, or Mars), galactic cosmic ray radiation remains a significant and worsening factor that limits mission durations. While solar energetic particle events in cycle 24 present some hazard, the accumulated doses for astronauts behind 10 g/cm2 shielding are well below current dose limits. Galactic cosmic radiation presents a more significant challenge: the time to 3% risk of exposure-induced death (REID) in interplanetary space was less than 400 days for a 30 year old male and less than 300 days for a 30 year old female in the last cycle 23-24 minimum. The time to 3% REID is estimated to be ˜20% lower in the coming cycle 24-25 minimum. If the heliospheric magnetic field continues to weaken over time, as is likely, then allowable mission durations will decrease correspondingly. Thus, we estimate exposures in extreme solar minimum conditions and the corresponding effects on allowable durations.

  2. A DEEP CHANDRA OBSERVATION OF THE GIANT H II REGION N11. I. X-RAY SOURCES IN THE FIELD

    SciTech Connect

    Nazé, Yaël; Wang, Q. Daniel; Chu, You-Hua; Gruendl, Robert; Oskinova, Lida

    2014-08-01

    A very sensitive X-ray investigation of the giant H II region N11 in the Large Megallanic Cloud was performed using the Chandra X-ray Observatory. The 300 ks observation reveals X-ray sources with luminosities down to 10{sup 32} erg s{sup –1}, increasing the number of known point sources in the field by more than a factor of five. Among these detections are 13 massive stars (3 compact groups of massive stars, 9 O stars, and one early B star) with log (L {sub X}/L {sub BOL}) ∼–6.5 to –7, which may suggest that they are highly magnetic or colliding-wind systems. On the other hand, the stacked signal for regions corresponding to undetected O stars yields log (L {sub X}/L {sub BOL}) ∼–7.3, i.e., an emission level comparable to similar Galactic stars despite the lower metallicity. Other point sources coincide with 11 foreground stars, 6 late-B/A stars in N11, and many background objects. This observation also uncovers the extent and detailed spatial properties of the soft, diffuse emission regions, but the presence of some hotter plasma in their spectra suggests contamination by the unresolved stellar population.

  3. Morphological, molecular, and in situ behavioral observations of the rare deep-sea anglerfish Chaunacops coloratus (Garman, 1899), order Lophiiformes, in the eastern North Pacific

    NASA Astrophysics Data System (ADS)

    Lundsten, Lonny; Johnson, Shannon B.; Cailliet, Gregor M.; DeVogelaere, Andrew P.; Clague, David A.

    2012-10-01

    In situ observations and collections of Chaunacops coloratus (Garman, 1899) from seamounts in the eastern North Pacific Ocean lend new behavioral, morphological and molecular data to an under-sampled, deep-sea group of fishes in the order Lophiiformes. Seven observations were made at Davidson Seamount, 130 km southwest of Monterey, CA, and from the Taney Seamount chain, 290 km west of Moss Landing, CA, from depths ranging from 2313 to 3297 m. Specimens were collected at both locations. Morphometric and meristic analyses were performed to identify individuals to the species level. These observations of C. coloratus provide greater latitude and depth distributions in the eastern North Pacific Ocean than previously known. Detailed habitat information indicated the fish occurred near manganese-encrusted volcanic talus slopes, a highly rugose habitat. Video observations revealed possible ontogenetic color changes in which small fish were blue and large fish were red. Video recorded rapid, vertical swimming as an escape response and maneuvering, or walking, with pectoral and pelvic fins and esca deployment. Phylogenetic analyses used here verify what has been known since Garman first described C. coloratus in 1899, that Chaunax and Chaunacops are closely related; molecular tools complement previous knowledge and genetic information created has been submitted to GenBank for further use by the scientific community.

  4. Tide-related variability of TAG hydrothermal activity observed by deep-sea monitoring system and OBSH

    NASA Astrophysics Data System (ADS)

    Fujioka, Kantaro; Kobayashi, Kazuo; Kato, Kazuhiro; Aoki, Misumi; Mitsuzawa, Kyohiko; Kinoshita, Masataka; Nishizawa, Azusa

    1997-12-01

    Hydrothermal activities were monitored by an ocean bottom seismometer with hydrophone (OBSH) and a composite measuring system (Manatee) including CTD, current meter, transmission meter and cameras at a small depression on the TAG hydrothermal mound in the Mid-Atlantic Ridge. Low-frequency pressure pulses detected by the hydrophone with semi-diurnal periodicity seem to correspond to cycles of hydrothermal upflow from a small and short-lived smoker vent close to the observing site. The peaks of pressure pulses are synchronous with the maximum gradient of areal strain decrease due to tidal load release. Microearthquakes with very near epicenters occur sporadically and do not appear to be directly correlatable to hydrothermal venting. Temporal variations in bottom water temperature also have semi-diurnal periodicity but are more complicated than the pressure events. Temperatures may be affected both by upwelling of hot water and by lateral flow of the bottom current changing its directions with ocean tide.

  5. Development of deep-seated gravitational slope deformation on a shale dip-slope: observations from high-quality drillcores

    NASA Astrophysics Data System (ADS)

    Chigira, Masahiro; Hariyama, Takehiro; Yamasaki, Shintaro

    2013-04-01

    The internal structures within a gravitationally deformed slope were observed using high-quality drillcores obtained from a dip slope of a series of shale-dominated sediments. This slope has dimple-like depressions and an overall gentle slope angle, but has no well-defined landslide scarp, suggesting that this area underwent gravitationally deformation but with no separation of the deformed portion from the surrounding area. Three drillcores, to a maximum depth of 96 m, were used during this study, with detailed observations of cut paraffin-impregnated core surfaces used to characterize gravitational deformation in the study area. This logging identified shear zones that consist of disintegrated (brecciated) and pulverized zones that were up to 88 and 19 cm thick, respectively. Disintegrated zone breccias have local jigsaw-fit textures, but other areas contain compositional trails formed by cataclastic flow, and rounded outlines formed by attrition. Pulverized zones underwent increased amounts of shearing, leading to the formation of more rounded fragments and increasing amounts of clayey matrix material, but still containing more than 30% of visible rock fragments. As such, these zones are still classified as breccias in terms of fault rock classification. Planar structures, such as R and Y shears, and P foliations, are not developed in the study area. Shear zones are intermittently located across the slope and have not formed a through-going master sliding zone. Incipient shear zones are present within the slope, including a pair of shear surfaces with a pull apart-like opening, and thin disintegrated or pulverized zones in intact rocks at 3-10 m below the base of the main area of gravitational deformation, suggesting that these shear zones propagate downward in a step-wise manner. This propagation may be related to the redistribution of stress induced by river incision.

  6. Deep observations of the Super-CLASS supercluster at 325 MHz with the GMRT: the low-frequency source catalogue

    NASA Astrophysics Data System (ADS)

    Riseley, C. J.; Scaife, A. M. M.; Hales, C. A.; Harrison, I.; Birkinshaw, M.; Battye, R. A.; Beswick, R. J.; Brown, M. L.; Casey, C. M.; Chapman, S. C.; Demetroullas, C.; Hung, C.-L.; Jackson, N. J.; Muxlow, T.; Watson, B.

    2016-10-01

    We present the results of 325 MHz Giant Metrewave Radio Telescope observations of a supercluster field, known to contain five Abell clusters at redshift z ˜ 0.2. We achieve a nominal sensitivity of 34 μJy beam-1 towards the phase centre. We compile a catalogue of 3257 sources with flux densities in the range 183 μ {Jy}-1.5 {Jy} within the entire ˜6.5 deg2 field of view. Subsequently, we use available survey data at other frequencies to derive the spectral index distribution for a sub-sample of these sources, recovering two distinct populations - a dominant population which exhibit spectral index trends typical of steep-spectrum synchrotron emission, and a smaller population of sources with typically flat or rising spectra. We identify a number of sources with ultrasteep spectra or rising spectra for further analysis, finding two candidate high-redshift radio galaxies and three gigahertz-peaked-spectrum radio sources. Finally, we derive the Euclidean-normalized differential source counts using the catalogue compiled in this work, for sources with flux densities in excess of 223 μJy. Our differential source counts are consistent with both previous observations at this frequency and models of the low-frequency source population. These represent the deepest source counts yet derived at 325 MHz. Our source counts exhibit the well-known flattening at mJy flux densities, consistent with an emerging population of star-forming galaxies; we also find marginal evidence of a downturn at flux densities below 308 μJy, a feature so far only seen at 1.4 GHz.

  7. ISOCAM observations in the Lockman Hole . II. The 14.3 μm deep survey: Data reduction, catalogue and source counts

    NASA Astrophysics Data System (ADS)

    Rodighiero, G.; Lari, C.; Fadda, D.; Franceschini, A.; Elbaz, D.; Cesarsky, C.

    2004-12-01

    We present a new analysis of the ISOCAM 14.3 μm deep survey in a 20 × 20 square arcmins area in the Lockman Hole. This survey is intermediate between the ultra-deep surveys and the shallow surveys in the ELAIS fields. The data have been analyzed with the method presented by Lari et al. (\\cite{Lar01}). We have produced a catalogue of 283 sources detected above the 5-σ threshold, with fluxes in the interval 0.1-8 mJy. The catalogue is 90% complete at 1 mJy. The positional accuracy, estimated from the cross-correlation of infrared and optical sources, is around 1.5 arcsec. The search for the optical counterparts of the sources in the survey is performed on a medium-deep r' band optical image (5σ depth of r'=25), making use of the radio detections when available. The photometry has been checked through simulations and by comparing the data with those presented in a shallower and more extended ISOCAM survey in the Lockman Hole, that we have presented in a companion paper. Only 15% of the 14.3 μm sources do not have an optical counterpart down to r'=25 mag. We use the 6.7/14.3 μm colour as a star/galaxy separator, together with a visual inspection of the optical image and an analysis of the observed Spectral Energy Distribution of the ISOCAM sources. The stars in the sample turn out to be only 6% of the sample. We discuss the 14.3 μm counts of extragalactic sources, combining our catalogue with that obtained from the shallower ISOCAM survey. The data in the two surveys are consistent, and our results fully support the claims in previous works for the existence of an evolving population of infrared galaxies, confirming the evident departure from non-evolutionary model predictions. Based on observations obtained with the Infrared Space Observatory, an ESA science mission with instruments and contributions funded by ESA Member States and the USA (NASA). Tables 2 and 3 are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130

  8. Low Latitude Gravity Wave Variances in the MLT Derived from Saber Temperature Observation and Compared with Model Simulations of Waves Generated By Deep Tropical Convection

    NASA Astrophysics Data System (ADS)

    Walterscheid, R. L.; Christensen, A. B.

    2014-12-01

    Equatorial regions are the scene of prolific generation of gravity waves by deep tropical convection. Waves generated by deep convection have appreciable energy at frequencies and spatial scales that are able to reach altitudes in the Middle Atmosphere and Lower Thermosphere (MLT) and above where they may attain significant amplitudes. A portion of these waves have scales and amplitudes large enough to be detected by space borne instruments. We have analyzed temperature data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) satellite for sub-tidal scale fluctuations. Filtering was applied both vertically and horizontally to extract wave variances. We have examined the variances at equatorial latitudes for the altitude region between 70 and 120 km and have have characterized them as a function of season, local time intervals, geographical location and altitude. We find large variances in locations of where convection is particularly prolific (e.g., western South Pacific) and at altitudes where wave trapping is known to be favored (e.g., the lower thermospheric duct). The locations of significant variances persist from year to year. Variances of on the order of a few tens of degrees are found. We have also performed simulations of the response to deep tropical convection with the The Aerospace Corporation Dynamical Model (ADM). This model is a time dependent, high-resolution fully compressible dynamical model that has been used to examine the MLT wave response to intense cellular convection in northern Australia. The background thermal structure for the present simulations was obtained from TIMED/SABER data averaged over low latitudes by season and local time. Our simulations give wave amplitudes that agree reasonably well with the observed amplitudes and show layering that is consistent with the observations. We will show the results of our analysis of

  9. Chandra Deep Observation of XDCP J0044.0-2033, a Massive Galaxy Cluster at z > 1.5

    NASA Astrophysics Data System (ADS)

    Tozzi, P.; Santos, J. S.; Jee, M. J.; Fassbender, R.; Rosati, P.; Nastasi, A.; Forman, W.; Sartoris, B.; Borgani, S.; Boehringer, H.; Altieri, B.; Pratt, G. W.; Nonino, M.; Jones, C.

    2015-01-01

    We report the analysis of the Chandra observation of XDCP J0044.0-2033, a massive, distant (z = 1.579) galaxy cluster discovered in the XDCP survey. The total exposure time of 380 ks with Chandra ACIS-S provides the deepest X-ray observation currently achieved on a massive, high-redshift cluster. Extended emission from the intra cluster medium (ICM) is detected at a very high significance level (S/N ~ 20) on a circular region with a 44'' radius, corresponding to R ext = 375 kpc at the cluster redshift. We perform an X-ray spectral fit of the ICM emission modeling the spectrum with a single-temperature thermal mekal model. Our analysis provides a global temperature kT=6.7+1.3-0.9 keV, and a iron abundance ZFe = 0.41-0.26+0.29ZFe_⊙ (error bars correspond to 1σ). We fit the background-subtracted surface brightness profile with a single β-model out to 44'', finding a rather flat profile with no hints of a cool core. We derive the deprojected electron density profile and compute the ICM mass within the extraction radius R ext = 375 kpc to be M ICM(r < R ext) = (1.48 ± 0.20) × 1013 M ⊙. Under the assumption of hydrostatic equilibrium and assuming isothermality within R ext, the total mass is M2500= 1.23-0.27+0.46 × 10 14 M_⊙ for R2500 = 240-20+30 kpc. Extrapolating the profile at radii larger than the extraction radius R ext we find M500 = 3.2-0.6+0.9 × 10 14 M_⊙ for R500 = 562-37+50 kpc. This analysis establishes the existence of virialized, massive galaxy clusters at redshift z ~ 1.6, paving the way to the investigation of the progenitors of the most massive clusters today. Given its mass and the XDCP survey volume, XDCP J0044.0-2033 does not create significant tension with the WMAP-7 ΛCDM cosmology.

  10. CHANDRA DEEP OBSERVATION OF XDCP J0044.0-2033, A MASSIVE GALAXY CLUSTER AT z > 1.5

    SciTech Connect

    Tozzi, P.; Santos, J. S.; Rosati, P.; Jee, M. J.; Fassbender, R.; Nastasi, A.; Forman, W.; Jones, C.; Sartoris, B.; Borgani, S.; Boehringer, H.; Altieri, B.; Pratt, G. W.; Nonino, M.

    2015-01-20

    We report the analysis of the Chandra observation of XDCP J0044.0-2033, a massive, distant (z = 1.579) galaxy cluster discovered in the XDCP survey. The total exposure time of 380 ks with Chandra ACIS-S provides the deepest X-ray observation currently achieved on a massive, high-redshift cluster. Extended emission from the intra cluster medium (ICM) is detected at a very high significance level (S/N ∼ 20) on a circular region with a 44'' radius, corresponding to R {sub ext} = 375 kpc at the cluster redshift. We perform an X-ray spectral fit of the ICM emission modeling the spectrum with a single-temperature thermal mekal model. Our analysis provides a global temperature kT=6.7{sub −0.9}{sup +1.3} keV, and a iron abundance Z{sub Fe}=0.41{sub −0.26}{sup +0.29}Z{sub Fe{sub ⊙}} (error bars correspond to 1σ). We fit the background-subtracted surface brightness profile with a single β-model out to 44'', finding a rather flat profile with no hints of a cool core. We derive the deprojected electron density profile and compute the ICM mass within the extraction radius R {sub ext} = 375 kpc to be M {sub ICM}(r < R {sub ext}) = (1.48 ± 0.20) × 10{sup 13} M {sub ☉}. Under the assumption of hydrostatic equilibrium and assuming isothermality within R {sub ext}, the total mass is M{sub 2500}=1.23{sub −0.27}{sup +0.46}×10{sup 14} M{sub ⊙} for R{sub 2500}=240{sub −20}{sup +30} kpc. Extrapolating the profile at radii larger than the extraction radius R {sub ext} we find M{sub 500}=3.2{sub −0.6}{sup +0.9}×10{sup 14} M{sub ⊙} for R{sub 500}=562{sub −37}{sup +50} kpc. This analysis establishes the existence of virialized, massive galaxy clusters at redshift z ∼ 1.6, paving the way to the investigation of the progenitors of the most massive clusters today. Given its mass and the XDCP survey volume, XDCP J0044.0-2033 does not create significant tension with the WMAP-7 ΛCDM cosmology.

  11. HESS Opinions "Topography driven conceptual modelling (FLEX-Topo)"

    NASA Astrophysics Data System (ADS)

    Savenije, H. H. G.

    2010-12-01

    Heterogeneity and complexity of hydrological processes offer substantial challenges to the hydrological modeller. Some hydrologists try to tackle this problem by introducing more and more detail in their models, or by setting-up more and more complicated models starting from basic principles at the smallest possible level. As we know, this reductionist approach leads to ever higher levels of equifinality and predictive uncertainty. On the other hand, simple, lumped and parsimonious models may be too simple to be realistic or representative of the dominant hydrological processes. In this commentary, a new approach is proposed that tries to find the middle way between complex distributed and simple lumped modelling approaches. Here we try to find the right level of simplification while avoiding over-simplification. Paraphrasing Einstein, the maxim is: make a model as simple as possible, but not simpler than that. The approach presented is process based, but not physically based in the traditional sense. Instead, it is based on a conceptual representation of the dominant physical processes in certain key elements of the landscape. The essence of the approach is that the model structure is made dependent on a limited number of landscape classes in which the topography is the main driver, but which can include geological, geomorphological or land-use classification. These classes are then represented by lumped conceptual models that act in parallel. The advantage of this approach over a fully distributed conceptualisation is that it retains maximum simplicity while taking into account observable landscape characteristics.

  12. HESS Opinions "Topography driven conceptual modelling (FLEX-Topo)"

    NASA Astrophysics Data System (ADS)

    Savenije, H. H. G.

    2010-07-01

    Heterogeneity and complexity of hydrological processes offer substantial challenges to the hydrological modeller. Some hydrologists try to tackle this problem by introducing more and more detail in their models, or by setting-up more and more complicated models starting from basic principles at the smallest possible level. As we know, this reductionist approach leads to ever higher levels of equifinality and predictive uncertainty. On the other hand, simple, lumped and parsimonious models may be too simple to be realistic or representative of the dominant hydrological processes. In this commentary, a new model approach is proposed that tries to find the middle way between complex distributed and simple lumped modelling approaches. Here we try to find the right level of simplification while avoiding over-simplification. Paraphrasing Einstein, the maxim is: make a model as simple as possible, but not simpler than that. The approach presented is process based, but not physically based in the traditional sense. Instead, it is based on a conceptual representation of the dominant physical processes in certain key elements of the landscape. The essence of the approach is that the model structure is made dependent on a limited number of landscape classes in which the topography is the main driver, but which can include geological, geomorphological or land-use classification. These classes are then represented by lumped conceptual models that act in parallel. The advantage of this approach over a fully distributed conceptualisation is that it retains maximum simplicity while taking into account observable landscape characteristics.

  13. PROBING THE NATURE OF THE UNIDENTIFIED TeV GAMMA-RAY SOURCE HESS J0632+057 WITH SWIFT

    SciTech Connect

    Falcone, A. D.; Stroh, M.; Grube, J.; Hinton, J.; Skilton, J.; Holder, J.; Maier, G.; Mukherjee, R.

    2010-01-01

    New generation TeV gamma-ray telescopes have discovered many new sources, including several enigmatic unidentified TeV objects. HESS J0632+057 is a particularly interesting unidentified TeV source since: it is a point source, it has a possible hard-spectrum X-ray counterpart and a positionally consistent Be star, it has evidence of long-term very high energy gamma-ray flux variability, and it is postulated to be a newly detected TeV/X-ray binary. We have obtained Swift X-ray telescope observations of this source from MJD 54857 to 54965, in an attempt to ascertain its nature and to investigate the hypothesis that it is a previously unknown X-ray/TeV binary. Variability and spectral properties similar to those of the other three known X-ray/TeV binaries have been observed, with measured flux increases by factors of {approx}3. X-ray variability is present on multiple timescales including days to months; however, no clear signature of periodicity is present on the timescales probed by these data. If binary modulation is present and dominating the measured variability, then the period of the orbit is likely to be {>=}54 days (half of this campaign), or it has a shorter period with a variable degree of flux modulation on successive high states. If the two high states measured to date are due to binary modulation, then the favored period is approximately 35-40 days. More observations are required to determine if this object is truly a binary system and to determine the extent that the measured variability is due to inter-orbit flaring effects or periodic binary modulation.

  14. Deep Chandra observations of HCG 16. II. The development of the intra-group medium in a spiral-rich group

    SciTech Connect

    O'Sullivan, E.; Vrtilek, J. M.; David, L. P.; Zezas, A.; Nulsen, P.; Giacintucci, S.; Ponman, T. J.; Raychaudhury, S.; Mamon, G. A.

    2014-10-01

    We use a combination of deep Chandra X-ray observations and radio continuum imaging to investigate the origin and current state of the intra-group medium (IGM) in the spiral-rich compact group HCG 16. We confirm the presence of a faint (L {sub X,} {sub bolo} = 1.87{sub −0.66}{sup +1.03}×10{sup 41} erg s{sup –1}), low-temperature (0.30{sub −0.05}{sup +0.07} keV) IGM extending throughout the ACIS-S3 field of view, with a ridge linking the four original group members and extending to the southeast, as suggested by previous ROSAT and XMM-Newton observations. This ridge contains 6.6{sub −3.3}{sup +3.9}× 10{sup 9} M {sub ☉} of hot gas and is at least partly coincident with a large-scale H I tidal filament, indicating that the IGM in the inner part of the group is highly multi-phase. We present evidence that the group is not yet virialized, and show that gas has probably been transported from the starburst winds of NGC 838 and NGC 839 into the surrounding IGM. Considering the possible origin of the IGM, we argue that material ejected by galactic winds may have played a significant role, contributing 20%-40% of the observed hot gas in the system.

  15. 10 Year Video Monitoring and its Implication to the Fluctuation Detected by Multi-disciplinary Observation on Deep Seafloor at Cold Seepage Site in Sagami Bay, Central Japan

    NASA Astrophysics Data System (ADS)

    Iwase, R.

    2004-12-01

    As a part of multidisciplinary real-time observation at cold seepage site on deep seafloor which faces swarm earthquake area at a depth of 1175 m off Hatsushima Island in Sagami Bay, central Japan, video monitoring has been carried out for about 10 years by a cabled observatory. Through the monitoring, both outbreak event such as mudflows caused by earthquakes and long-term phenomena such as sedimentation on seafloor associated not only with mudflow but also with the fluctuation of the amount of suspended particles were observed, along with spawning of clams or other biological events. Some of these video images provide important information on the fluctuation observed by other sensors of the observatory, such as seasonal changes in sub-bottom temperature and intensity of gamma-ray, indicating that those fluctuations were primarily related to such environmental changes on seafloor as sedimentation. On the other hand, extracting meaningful events or phenomena from a huge amount of stored video images needs tremendous time and effort. Effective methodology of scene detection and indexing is necessary to be developed.

  16. The European Fixed point Open Ocean Observatory network (FixO3): Multidisciplinary observations from the air-sea interface to the deep seafloor

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard; Cristini, Luisa; Alexiou, Sofia

    2015-04-01

    The Fixed point Open Ocean Observatory network (FixO3, http://www.fixo3.eu/ ) integrates 23 European open ocean fixed point observatories and improves access to these infrastructures for the broader community. These provide multidisciplinary observations in all parts of the oceans from the air-sea interface to the deep seafloor. Started in September 2013 with a budget of 7 Million Euros over 4 years, the project has 29 partners drawn from academia, research institutions and SME's coordinated by the National Oceanography Centre, UK. Here we present the programme's achievements in the 18 months and the activities of the 12 Work Packages which have the objectives to: • integrate and harmonise the current procedures and processes • offer free access to observatory infrastructures to those who do not have such access, and free and open data services and products • innovate and enhance the current capability for multidisciplinary in situ ocean observation Open ocean observation is a high priority for European marine and maritime activities. FixO3 provides important data and services to address the Marine Strategy Framework Directive and in support of the European Integrated Maritime Policy. FixO3 provides a strong integrated framework of open ocean facilities in the Atlantic from the Arctic to the Antarctic and throughout the Mediterranean, enabling an integrated, regional and multidisciplinary approach to understand natural and anthropogenic change in the ocean.

  17. Paleomagnetic constraints on deformation of superfast-spread oceanic crust exposed at Pito Deep Rift

    NASA Astrophysics Data System (ADS)

    Horst, A. J.; Varga, R. J.; Gee, J. S.; Karson, J. A.

    2011-12-01

    The uppermost oceanic crust produced at the superfast spreading (˜142 km Ma-1, full-spreading rate) southern East Pacific Rise (EPR) during the Gauss Chron is exposed in a tectonic window along the northeastern wall of the Pito Deep Rift. Paleomagnetic analysis of fully oriented dike (62) and gabbro (5) samples from two adjacent study areas yield bootstrapped mean remanence directions of 38.9° ± 8.1°, -16.7° ± 15.6°, n = 23 (Area A) and 30.4° ± 8.0°, -25.1° ± 12.9°, n = 44 (Area B), both are significantly distinct from the Geocentric Axial Dipole expected direction at 23° S. Regional tectonics and outcrop-scale structural data combined with bootstrapped remanence directions constrain models that involve a sequence of three rotations that result in dikes restored to subvertical orientations related to (1) inward-tilting of crustal blocks during spreading (Area A = 11°, Area B = 22°), (2) clockwise, vertical-axis rotation of the Easter Microplate (A = 46°, B = 44°), and (3) block tilting at Pito Deep Rift (A = 21°, B = 10°). These data support a structural model for accretion at the southern EPR in which outcrop-scale faulting and block rotation accommodates spreading-related subaxial subsidence that is generally less than that observed in crust generated at a fast spreading rate exposed at Hess Deep Rift. These data also support previous estimates for the clockwise rotation of crust adjacent to the Easter Microplate. Dike sample natural remanent magnetization (NRM) has an arithmetic mean of 5.96 A/m ± 3.76, which suggests that they significantly contribute to observed magnetic anomalies from fast- to superfast-spread crust.

  18. Deep Heterogeneous Structure and Earthquake Generating Properties in the Yamasaki Fault Zone Estimated from Dense Seismic Observation

    NASA Astrophysics Data System (ADS)

    Nishigami, K.; Shibutani, T.; Katao, H.; Yamaguchi, S.; Mamada, Y.

    2011-12-01

    The Yamasaki fault zone is a left-lateral, strike-slip active fault with a total length of about 80 km in southwest Japan. We deployed dense seismic observation network, which is composed of 32 stations with average spacing of 5-10 km, around the Yamasaki fault zone. We have been estimating detailed fault structure such as fault dip and shape, segmentation, and possible location of asperities and rupture initiation point, as well as generating properties of earthquakes in the fault zone, through analyses of accurate hypocenter distribution, focal mechanism, 3-D velocity tomography, coda wave inversion, and other waveform analyses. We also deployed a linear seismic array across the fault, composed of 20 stations with about 20 m spacing, in order to delineate the fault-zone structure in more detail using the seismic waves trapped inside the low velocity fault-zone. We also estimated resistivity structure at shallow depth of the fault zone by AMT (audio-frequency magnetotelluric) and MT surveys. In the scattering analysis of coda waves, we used the waveform data of dense temporary stations from 2008 to 2010 and also the routine stations in 2002 and 2003. Fig.1 shows an example of the result, 3-D distribution of relative scattering coefficients estimated around the Yamasaki fault zone. In this analysis, 2,391 waveforms recorded at 60 stations for 121 earthquakes were used. This result shows that microseismicity is high and scattering coefficient is relatively larger in the upper crust along the entire fault zone. The distribution of strong scatterers suggests that the Ohara and Hijima faults, which are the segments in the northwestern part of the Yamasaki fault zone, have almost vertical fault plane from surface to a depth of about 15 km. We will construct a fault structure model and discuss its relation to seismic activity in the Yamasaki fault zone. We used seismic network data operated by Univs., NIED, AIST, and JMA. This study is carried out as a part of the

  19. Deep Structure and Earthquake Generating Properties in the Yamasaki Fault Zone, Southwest Japan, Estimated from Dense Seismic Observation

    NASA Astrophysics Data System (ADS)

    Nishigami, K.; Shibutani, T.; Katao, H.; Yamaguchi, S.; Mamada, Y.

    2012-12-01

    The Yamasaki fault zone is a left-lateral, strike-slip active fault with a total length of about 80 km in southwest Japan. We deployed dense seismic observation network, which is composed of 32 stations with average spacing of 5-10 km, around the Yamasaki fault zone. We have been estimating detailed fault structure such as fault dip and shape, segmentation, and possible location of asperities and rupture initiation point, as well as generating properties of earthquakes in and around the fault zone, through analyses of accurate hypocenter distribution, focal mechanism, 3-D velocity tomography, coda wave inversion, and other waveform analyses. We also deployed a linear seismic array across the fault, composed of 20 stations with about 20 m spacing, in order to delineate the fault-zone structure in more detail using the seismic waves trapped inside the low velocity fault-zone. We also estimated detailed resistivity structure at shallow depth of the fault zone by AMT (audio-frequency magnetotelluric) surveys. In the scattering analysis of seismic coda waves, we used the waveform data of dense temporary stations from 2008 to 2010 and also the routine-stations data in 2002 and 2003, and estimated 3-D distribution of relative scattering coefficients around the Yamasaki fault zone. In this analysis, 3,033 waveforms recorded at 60 stations for 136 earthquakes were used. This result shows that microseismicity is high and scattering coefficient is relatively larger in the upper crust along the entire fault zone. The distribution of strong scatterers suggests that the Ohara and Hijima faults, which are the segments in the northwestern part of the Yamasaki fault zone, have almost vertical fault plane from surface to a depth of about 15 km. We will construct a fault structure model and discuss its relation to seismic activity in the Yamasaki fault zone. We used seismic network data operated by Universities, NIED, AIST, and JMA. This study has been carried out as a part of the

  20. Searches for particle dark matter with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    Brun, Pierre

    2015-08-01

    P. Brun, on behalf of the H.E.S.S. collaborationProbes of the matter budget of the universe at all scales indicate 84% of its mass is made of a new form of matter; this is the so-called dark matter problem. An appealing hypothesis is that it would be formed of new, yet undiscovered, stable particles of mass between a few GeV and hundreds of TeV. Having only weak interactions, hose would have been produced in the early hot phases of the universe, and their density would have been frozen at temperatures around 10^{15} K, 10^{-10} s after the big bang. The clustering of these particles would seed galaxy formation and their collisions within dense regions are expected to produce gamma rays with energies of the order of the above-mentioned mass. I will report here searches for dark matter particle collision-induced gamma rays with the H.E.S.S. array of ground-based gamma-ray telescopes. In the absence of convincing exotic signal, constraints on some parameters of the hypothesized dark matter particles will be presented.

  1. Using an autonomous passive acoustic observational system to monitor the environmental impact of the Gulf of Mexico oil spill on deep-diving marine mammals

    NASA Astrophysics Data System (ADS)

    Sidorovskaia, N.; Ackleh, A.; Ma, B.; Tiemann, C.; Ioup, J. W.; Ioup, G. E.

    2012-12-01

    The Littoral Acoustic Demonstration Center (LADC) is a consortium of scientists from four universities and the U.S. Navy, which performs acoustic measurements and analysis in littoral waters. For the present work, six passive autonomous broadband acoustic sensors were deployed by LADC in the vicinity of the Deep Water Horizon oil spill site in the Northern Gulf of Mexico in fall 2010. The objective of the project is to assess long-term impact of the spill on the deep-diving residential population of marine mammals, particularly, sperm and beaked whales. Collected data were processed to detect, extract, and count acoustic signals produced by different types of marine mammals. As a next step, a statistical model which uses acoustic inputs was developed to estimate residential populations of different types of marine mammals at different distances from the spill site. The estimates were compared to population estimates from years prior to the spill, using pre-spill collected data in the area by LADC from 2001, 2002, and 2007. The results indicate different responses from sperm and beaked whales in the first months following the spill. A recently published article by our research group (Ackleh et al., J. Acoust. Soc. Am. 131, 2306-2314) provides a comparison of 2007 and 2010 estimates showing a decrease in acoustic activity and abundance of sperm whales at the 9-mile distant site, whereas acoustic activity and abundance at the 25-mile distant site has clearly increased. This may indicate that some sperm whales have relocated farther away from the spill subject to food source availability. The beaked whale population appears to return to 2007 numbers after the spill even at the closest 9-mile distant site. Several acoustically observed changes in the animals' habitat associated with the spill, such as anthropogenic noise level, prey presence, etc., can be connected with the observed population trends. Preliminary results for interpreting observed population trends will

  2. Ammonia excitation imaging of shocked gas towards the W28 gamma-ray source HESS J1801-233

    NASA Astrophysics Data System (ADS)

    Maxted, Nigel I.; de Wilt, Phoebe; Rowell, Gavin P.; Nicholas, Brent P.; Burton, Michael. G.; Walsh, Andrew; Fukui, Yasuo; Kawamura, Akiko

    2016-10-01

    We present 12 mm Mopra observations of the dense (>103 cm-3) molecular gas towards the north-east of the W28 supernova remnant (SNR). This cloud is spatially well matched to the TeV gamma-ray source HESS J1801-233 and is known to be an SNR-molecular cloud interaction region. Shock-disruption is evident from broad NH3 (1,1) spectral linewidths in regions towards the W28 SNR, while strong detections of spatially extended NH3 (3,3), NH3(4,4) and NH3(6,6) inversion emission towards the cloud strengthen the case for the existence of high temperatures within the cloud. Velocity dispersion measurements and NH3(n,n)/(1,1) ratio maps, where n = 2, 3, 4 and 6, indicate that the source of disruption is from the side of the cloud nearest to the W28 SNR, suggesting that it is the source of cloud-disruption. Towards part of the cloud, the ratio of ortho to para-NH3 is observed to exceed 2, suggesting gas-phase NH3 enrichment due to NH3 liberation from dust-grain mantles. The measured NH3 abundance with respect to H2 is ˜(1.2 ± 0.5) × 10-9, which is not high, as might be expected for a hot, dense molecular cloud enriched by sublimated grain-surface molecules. The results are suggestive of NH3 sublimation and destruction in this molecular cloud, which is likely to be interacting with the W28 SNR shock.

  3. A DEEP CHANDRA OBSERVATION OF THE X-SHAPED RADIO GALAXY 4C +00.58: A CANDIDATE FOR MERGER-INDUCED REORIENTATION?

    SciTech Connect

    Hodges-Kluck, Edmund J.; Reynolds, Christopher S.; Miller, M. Coleman; Cheung, Chi C.

    2010-07-01

    Although rapid reorientation of a black hole spin axis (lasting less than a few megayears) has been suggested as a mechanism for the formation of wings in X-shaped radio galaxies (XRGs), to date no convincing case of reorientation has been found in any XRG. Alternative wing formation models such as the hydrodynamic backflow models are supported by observed trends indicating that XRGs form preferentially with jets aligned along the major axis of the surrounding medium and wings along the minor axis. In this Letter, we present a deep Chandra observation of 4C +00.58, an odd XRG with its jet oriented along the minor axis. By using the X-ray data in tandem with available radio and optical data, we estimate relevant timescales with which to evaluate wing formation models. The hydrodynamic models have difficulty explaining the long wings, whereas the presence of X-ray cavities (suggesting jet activity along a prior axis) and a potential stellar shell (indicating a recent merger) favor a merger-induced reorientation model.

  4. Astrometric and spectroscopic confirmation of a brown dwarf companion to GSC 08047-00232. VLT/NACO deep imaging and spectroscopic observations

    NASA Astrophysics Data System (ADS)

    Chauvin, G.; Lagrange, A.-M.; Lacombe, F.; Dumas, C.; Mouillet, D.; Zuckerman, B.; Gendron, E.; Song, I.; Beuzit, J.-L.; Lowrance, P.; Fusco, T.

    2005-02-01

    We report VLT/NACO imaging observations of the stars GSC 08047-00232 and HIP 6856, probable members of the large Tucana-Horologium association. During our previous ADONIS/SHARPII deep imaging survey, a substellar candidate companion was discovered around each star. Based on VLT/NACO astrometric measurements, we find that GSC 08047-00232 and the faint candidate companion near to it share the same proper motion with a significance of 3.1 σ. On the contrary, the candidate companion to HIP 6856 is probably a background object with a significance of 4.3 σ. We also detect a new fainter and closer candidate companion to HIP 6856, but which is likely a background object too with a significance of 4 σ. Recent VLT/NACO spectroscopic measurements of GSC 08047-00232 finally confirm the substellar nature of this young brown dwarf with a derived spectral type M 9.5±1. GSC 08047-00232 B, with an estimated mass of 25±10 MJup and an effective temperature of 2100±200 K, is presently the third substellar companion identified among young, nearby associations. Based on observations obtained at the VLT in ESO with programs 70.C-0677 and 072.C-0644.

  5. High ice water content at low radar reflectivity near deep convection - Part 1: Consistency of in situ and remote-sensing observations with stratiform rain column simulations

    NASA Astrophysics Data System (ADS)

    Fridlind, A. M.; Ackerman, A. S.; Grandin, A.; Dezitter, F.; Weber, M.; Strapp, J. W.; Korolev, A. V.; Williams, C. R.

    2015-06-01

    Occurrences of jet engine power loss and damage have been associated with flight through fully glaciated deep convection at -10 to -50 °C. Power loss events commonly occur during flight through radar reflectivity (Ze) less than 20-30 dBZ and no more than moderate turbulence, often overlying moderate to heavy rain near the surface. During 2010-2012 Airbus carried out flight tests seeking to characterize the highest ice water content (IWC) in such low-Ze regions of large, cold-topped storm systems in the vicinity of Cayenne, Darwin, and Santiago. Within the highest IWC regions encountered, at typical sampling elevations circa 11 km, the measured ice size distributions exhibit a notably narrow concentration of mass over area-equivalent diameters of 100-500 μm. Given substantial and poorly quantified measurement uncertainties, here we evaluate the consistency of the Airbus in situ measurements with ground-based profiling radar observations obtained under quasi-steady, heavy stratiform rain conditions in one of the Airbus-sampled locations. We find that profiler-observed radar reflectivities and mean Doppler velocities at Airbus sampling temperatures are generally consistent with those calculated from in situ size distribution measurements. We also find that column simulations using the in situ size distributions as an upper boundary condition are generally consistent with observed profiles of Ze, mean Doppler velocity, and retrieved rain rate. The results of these consistency checks motivate an examination of the microphysical pathways that could be responsible for the observed size distribution features in Part 2.

  6. High ice water content at low radar reflectivity near deep convection - Part 1: Consistency of in situ and remote-sensing observations with stratiform rain column simulations

    NASA Astrophysics Data System (ADS)

    Fridlind, A. M.; Ackerman, A. S.; Grandin, A.; Dezitter, F.; Weber, M.; Strapp, J. W.; Korolev, A. V.; Williams, C. R.

    2015-10-01

    Occurrences of jet engine power loss and damage have been associated with flight through fully glaciated deep convection at -10 to -50 °C. Power loss events commonly occur during flight through radar reflectivity (Ze) less than 20-30 dBZ and no more than moderate turbulence, often overlying moderate to heavy rain near the surface. During 2010-2012, Airbus carried out flight tests seeking to characterize the highest ice water content (IWC) in such low-Ze regions of large, cold-topped storm systems in the vicinity of Cayenne, Darwin, and Santiago. Within the highest IWC regions encountered, at typical sampling elevations (circa 11 km), the measured ice size distributions exhibit a notably narrow concentration of mass over area-equivalent diameters of 100-500 μm. Given substantial and poorly quantified measurement uncertainties, here we evaluate the consistency of the Airbus in situ measurements with ground-based profiling radar observations obtained under quasi-steady, heavy stratiform rain conditions in one of the Airbus-sampled locations. We find that profiler-observed radar reflectivities and mean Doppler velocities at Airbus sampling temperatures are generally consistent with those calculated from in situ size-distribution measurements. We also find that column simulations using the in situ size distributions as an upper boundary condition are generally consistent with observed profiles of Ze, mean Doppler velocity (MDV), and retrieved rain rate. The results of these consistency checks motivate an examination of the microphysical pathways that could be responsible for the observed size-distribution features in Ackerman et al. (2015).

  7. Evaluation of Cloud-resolving and Limited Area Model Intercomparison Simulations using TWP-ICE Observations. Part 1: Deep Convective Updraft Properties

    SciTech Connect

    Varble, A. C.; Zipser, Edward J.; Fridlind, Ann; Zhu, Ping; Ackerman, Andrew; Chaboureau, Jean-Pierre; Collis, Scott M.; Fan, Jiwen; Hill, Adrian; Shipway, Ben

    2014-12-27

    Ten 3D cloud-resolving model (CRM) simulations and four 3D limited area model (LAM) simulations of an intense mesoscale convective system observed on January 23-24, 2006 during the Tropical Warm Pool – International Cloud Experiment (TWP-ICE) are compared with each other and with observed radar reflectivity fields and dual-Doppler retrievals of vertical wind speeds in an attempt to explain published results showing a high bias in simulated convective radar reflectivity aloft. This high bias results from ice water content being large, which is a product of large, strong convective updrafts, although hydrometeor size distribution assumptions modulate the size of this bias. Snow reflectivity can exceed 40 dBZ in a two-moment scheme when a constant bulk density of 100 kg m-3 is used. Making snow mass more realistically proportional to area rather than volume should somewhat alleviate this problem. Graupel, unlike snow, produces high biased reflectivity in all simulations. This is associated with large amounts of liquid water above the freezing level in updraft cores. Peak vertical velocities in deep convective updrafts are greater than dual-Doppler retrieved values, especially in the upper troposphere. Freezing of large rainwater contents lofted above the freezing level in simulated updraft cores greatly contributes to these excessive upper tropospheric vertical velocities. Strong simulated updraft cores are nearly undiluted, with some showing supercell characteristics. Decreasing horizontal grid spacing from 900 meters to 100 meters weakens strong updrafts, but not enough to match observational retrievals. Therefore, overly intense simulated updrafts may partly be a product of interactions between convective dynamics, parameterized microphysics, and large-scale environmental biases that promote different convective modes and strengths than observed.

  8. Observation of persistent α-helical content and discrete types of backbone disorder during a molten globule to ordered peptide transition via deep-UV resonance Raman spectroscopy

    PubMed Central

    Brown, Mia C.; Mutter, Andrew; Koder, Ronald L.; JiJi, Renee D.; Cooley, Jason W.

    2016-01-01

    The molten globule state can aide in the folding of a protein to a functional structure and is loosely defined as an increase in structural disorder with conservation of the ensemble secondary structure content. Simultaneous observation of persistent secondary structure content with increased disorder has remained experimentally problematic. As a consequence, modeling how the molten globule state remains stable and how it facilitates proper folding remains difficult due to a lack of amenable spectroscopic techniques to characterize this class of partially unfolded proteins. Previously, deep-UV resonance Raman (dUVRR) spectroscopy has proven useful in the resolution of global and local structural fluctuations in the secondary structure of proteins. In this work, dUVRR was employed to study the molten globule to ordered transition of a model four-helix bundle protein, HP7. Both the average ensemble secondary structure and types of local disorder were monitored, without perturbation of the solvent, pH, or temperature. The molten globule to ordered transition is induced by stepwise coordination of two heme molecules. Persistent dUVRR spectral features in the amide III region at 1295–1301 and 1335–1338 cm−1 confirm previous observations that HP7 remains predominantly helical in the molten globule versus the fully ordered state. Additionally, these spectra represent the first demonstration of conserved helical content in a molten globule protein. With successive heme binding significant losses are observed in the spectral intensity of the amide III3 and S regions (1230–1260 and 1390 cm−1, respectively), which are known to be sensitive to local disorder. These observations indicate that there is a decrease in the structural populations able to explore various extended conformations, with successive heme binding events. DUVRR spectra indicate that the first heme coordination between two helical segments diminishes exploration of more elongated backbone structural

  9. High Ice Water Content at Low Radar Reflectivity near Deep Convection. Part I ; Consistency of In Situ and Remote-Sensing Observations with Stratiform Rain Column Simulations

    NASA Technical Reports Server (NTRS)

    Fridlind, A. M.; Ackerman, A. S.; Grandin, A.; Dezitter, F.; Weber, M.; Strapp, J. W.; Korolev, A. V.; Williams, C. R.

    2015-01-01

    Occurrences of jet engine power loss and damage have been associated with flight through fully glaciated deep convection at -10 to -50 degrees Centigrade. Power loss events commonly occur during flight through radar reflectivity (Zeta (sub e)) less than 20-30 decibels relative to Zeta (dBZ - radar returns) and no more than moderate turbulence, often overlying moderate to heavy rain near the surface. During 2010-2012, Airbus carried out flight tests seeking to characterize the highest ice water content (IWC) in such low-radar-reflectivity regions of large, cold-topped storm systems in the vicinity of Cayenne, Darwin, and Santiago. Within the highest IWC regions encountered, at typical sampling elevations (circa 11 kilometers), the measured ice size distributions exhibit a notably narrow concentration of mass over area-equivalent diameters of 100-500 micrometers. Given substantial and poorly quantified measurement uncertainties, here we evaluate the consistency of the Airbus in situ measurements with ground-based profiling radar observations obtained under quasi-steady, heavy stratiform rain conditions in one of the Airbus-sampled locations. We find that profiler-observed radar reflectivities and mean Doppler velocities at Airbus sampling temperatures are generally consistent with those calculated from in situ size-distribution measurements. We also find that column simulations using the in situ size distributions as an upper boundary condition are generally consistent with observed profiles of radar reflectivity (Ze), mean Doppler velocity (MDV), and retrieved rain rate. The results of these consistency checks motivate an examination of the microphysical pathways that could be responsible for the observed size-distribution features in Ackerman et al. (2015).

  10. Interstellar protons in the TeV γ-ray SNR HESS J1731-347: Possible evidence for the coexistence of hadronic and leptonic γ-rays

    SciTech Connect

    Fukuda, T.; Yoshiike, S.; Sano, H.; Torii, K.; Yamamoto, H.; Fukui, Y.; Acero, F.

    2014-06-10

    HESS J1731-347 (G353.6-0.7) is one of the TeV γ-ray supernova remnants (SNRs) that shows the shell-like morphology. We have made a new analysis of the interstellar protons toward the SNR by using both the {sup 12}CO(J = 1-0) and H I data sets. The results indicate that the TeV γ-ray shell shows significant spatial correlation with the interstellar protons at a velocity range from –90 km s{sup –1} to –75 km s{sup –1}. The total mass of the interstellar medium (ISM) protons is estimated to be 6.4 × 10{sup 4} M {sub ☉}, 25% of which is atomic gas, and the distance corresponding to the velocity range is ∼5.2 kpc, a factor of 2 larger than the previous figure, 3 kpc. We have identified the cold H I gas observed as self-absorption which shows significant correspondence with the northeastern γ-ray peak. While the good correspondence between the ISM protons and TeV γ-rays in the north of the SNR lends support to the hadronic scenario for the TeV γ-rays, the southern part of the shell shows a break in the correspondence; in particular, the southwestern rim of the SNR shell shows a significant decrease of the interstellar protons by a factor of two. We argue that this discrepancy can be explained due to leptonic γ-rays because this region coincides well with the bright shell that emits non-thermal radio continuum emission and non-thermal X-rays, suggesting that the γ-rays of HESS J1713-347 consist of both the hadronic and leptonic components. The leptonic contribution corresponds to ∼20% of the total γ-rays.

  11. Interstellar Protons in the TeV γ-Ray SNR HESS J1731-347: Possible Evidence for the Coexistence of Hadronic and Leptonic γ-Rays

    NASA Astrophysics Data System (ADS)

    Fukuda, T.; Yoshiike, S.; Sano, H.; Torii, K.; Yamamoto, H.; Acero, F.; Fukui, Y.

    2014-06-01

    HESS J1731-347 (G353.6-0.7) is one of the TeV γ-ray supernova remnants (SNRs) that shows the shell-like morphology. We have made a new analysis of the interstellar protons toward the SNR by using both the 12CO(J = 1-0) and H I data sets. The results indicate that the TeV γ-ray shell shows significant spatial correlation with the interstellar protons at a velocity range from -90 km s-1 to -75 km s-1. The total mass of the interstellar medium (ISM) protons is estimated to be 6.4 × 104 M ⊙, 25% of which is atomic gas, and the distance corresponding to the velocity range is ~5.2 kpc, a factor of 2 larger than the previous figure, 3 kpc. We have identified the cold H I gas observed as self-absorption which shows significant correspondence with the northeastern γ-ray peak. While the good correspondence between the ISM protons and TeV γ-rays in the north of the SNR lends support to the hadronic scenario for the TeV γ-rays, the southern part of the shell shows a break in the correspondence; in particular, the southwestern rim of the SNR shell shows a significant decrease of the interstellar protons by a factor of two. We argue that this discrepancy can be explained due to leptonic γ-rays because this region coincides well with the bright shell that emits non-thermal radio continuum emission and non-thermal X-rays, suggesting that the γ-rays of HESS J1713-347 consist of both the hadronic and leptonic components. The leptonic contribution corresponds to ~20% of the total γ-rays.

  12. The Search for Identity in Selected Novels of Hermann Hesse: A Thematic Study for the Secondary Schools.

    ERIC Educational Resources Information Center

    Miller, Jean Sawyer

    This study used four novels by Hermann Hesse as models to illustrate for secondary school English teachers a thematic analysis of the search for identity motif using the triadic view of individual growth. The novels are "Peter Camenzind,""Beneath the Wheel,""Demian," and "Siddhartha." In summary, this study (1) found that analysis of the question…

  13. Disease Management Project Breast Cancer in Hesse - 5-Year Survival Data: Successful Model of Intersectoral Communication for Quality Assurance.</