Science.gov

Sample records for herschel gasps open

  1. The Evolution of Gas in Protoplanetary Systems: The Herschel GASPS Open Time Key Programme

    NASA Technical Reports Server (NTRS)

    Roberge, A.; Dent, W.

    2010-01-01

    The Gas in Protoplanetary Systems (GASPS) Open Time Key Programme for the Herschel Space Observatory will be the first extensive, systematic survey of gas in circumstellar disks over the critical transition from gas-rich protoplanetary through to gas-poor debris. The brightest spectral lines from disks lie in the far-infrared and arise from radii spanning roughly 10 to 100 AU, where giant planets are expected to form. Herschel is uniquely able to observe this wavelength regime with the sensitivity to allow a large scale survey. We will execute a 2-phase study using the PACS instrument. Phase I is a spectroscopic survey about 250 young stars for fine structure emission lines of [CII] (at 157 microns) and [OI] (at 63 microns). In Phase II, the brightest sources will be followed up with additional PACS spectroscopy ([OI] at 145 microns and some rotational lines of water). We expect that the gas mass sensitivity will be more than an order of magnitude lower than that achieved by ISO and Spitzer or expected for SOFIA. We will also measure the dust continuum to an equivalent mass sensitivity. We will observe several nearby clusters with ages from 1 to 30 Myr, encompassing a wide range of disk masses and stellar luminosities. The sample covers disk evolution from protoplanetary disks through to young debris disks, i.e. the main epoch of planet formation. With this extensive dataset, the GASPS project will: 1) trace gas and dust in the planet formation region across a large multivariate parameter space, 2) provide the first definitive measurement of the gas dissipation timescale in disks, 3) elucidate the evolutionary link between protoplanetary and debris disks, 4) investigate water abundances in the planetforming regions of disks, and 5) provide a huge database of disk observations and models with long-lasting legacy value for follow-up studies.

  2. GASPS--A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

    NASA Technical Reports Server (NTRS)

    Dent, W.R.F.; Thi, W. F.; Kamp, I.; Williams, J. P.; Menard, F.; Andrews, S.; Ardila, D.; Aresu, G.; Augereau, J.-C.; Barrado y Navascues, D.; Brittain, S.; Carmona, A.; Ciardi, D.; Danchi, W.; Donaldson, J.; Duchene, G.; Eiroa, C.; Fedele, D.; Grady, C.; de Gregorio-Molsalvo, I.; Howard, C.; Huelamo, N.; Krivov, A.; Lebreton, J.; Roberge, A.

    2013-01-01

    We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted approx. 250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 micron the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 micron, [CII] at 157 µm, as well as several transitions of H2O and high-excitation CO lines at selected wavelengths between 78 and 180 micron. Additionally, GASPS included continuum photometry at 70, 100 and 160 micron, around the peak of the dust emission. The targets were SED Class II– III T Tauri stars and debris disks from seven nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy of the program. We summarize some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability. The [OI] line at 63 micron was the brightest line seen in almost all objects, by a factor of 10. Overall [OI] 63 micron detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI] 63 µm detection of approx.10(exp -5) Solar M.. Normalizing to a distance of 140 pc, 84% of objects with dust masses =10 (exp -5) Solar M can be detected in this line in the present survey; 32% of those of mass 10(exp -6) – 10 (exp -5) Solar M, and only a very small number

  3. The Herschel view of GAS in Protoplanetary Systems (GASPS). First comparisons with a large grid of models

    NASA Astrophysics Data System (ADS)

    Pinte, C.; Woitke, P.; Ménard, F.; Duchêne, G.; Kamp, I.; Meeus, G.; Mathews, G.; Howard, C. D.; Grady, C. A.; Thi, W.-F.; Tilling, I.; Augereau, J.-C.; Dent, W. R. F.; Alacid, J. M.; Andrews, S.; Ardila, D. R.; Aresu, G.; Barrado, D.; Brittain, S.; Ciardi, D. R.; Danchi, W.; Eiroa, C.; Fedele, D.; de Gregorio-Monsalvo, I.; Heras, A.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaïdi, C.; Mendigutía, I.; Montesinos, B.; Mora, A.; Morales-Calderon, M.; Nomura, H.; Pantin, E.; Pascucci, I.; Phillips, N.; Podio, L.; Poelman, D. R.; Ramsay, S.; Riaz, B.; Rice, K.; Riviere-Marichalar, P.; Roberge, A.; Sandell, G.; Solano, E.; Vandenbussche, B.; Walker, H.; Williams, J. P.; White, G. J.; Wright, G.

    2010-07-01

    The Herschel GASPS key program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of protoplanetary discs, we have combined the capabilities of the radiative transfer code MCFOST with the gas thermal balance and chemistry code ProDiMo to compute a grid of ≈300 000 disc models (DENT). We present a comparison of the first Herschel/GASPS line and continuum data with the predictions from the DENT grid of models. Our objective is to test some of the main trends already identified in the DENT grid, as well as to define better empirical diagnostics to estimate the total gas mass of protoplanetary discs. Photospheric UV radiation appears to be the dominant gas-heating mechanism for Herbig stars, whereas UV excess and/or X-rays emission dominates for T Tauri stars. The DENT grid reveals the complexity in the analysis of far-IR lines and the difficulty to invert these observations into physical quantities. The combination of Herschel line observations with continuum data and/or with rotational lines in the (sub-)millimetre regime, in particular CO lines, is required for a detailed characterisation of the physical and chemical properties of circumstellar discs. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  4. Correlations between the stellar and disc properties of Taurus PMS stars in the GASPS sample

    NASA Astrophysics Data System (ADS)

    Alonso-Martínez, Miguel; Riviere-Marichalar, Pablo; Pascual, Natalia; Montesinos, Benjamín; Howard, Christian D.; Sandell, Göran; Meeus, Gwendolyn; Eiroa, Carlos; Dent, Bill

    2013-07-01

    The Herschel Open Time Key Programme GASPS (P.I. B. Dent) has observed a large number of pre-main sequence TTauri stars in Taurus with PACS (photometry and spectroscopy). In addition, we have also carried out new ground-based optical and near-IR observations (photometry and spectroscopy) of most of the Taurus GASPS sample. In this poster, we present some preliminary results on correlations between the stellar and disc properties of this young stellar sample.

  5. The Herschel DUNES Open Time Key Programme

    NASA Technical Reports Server (NTRS)

    Danchi, William C.

    2009-01-01

    We will use the unique photometric capabilities provided by Herschel to perform a deep and systematic survey for faint, cold debris disks around nearby stars. Our sensitivity-limited Open Time Key Programme (OTKP) aims at finding and characterizing faint extrasolar analogues to the Edgeworth-Kuiper Belt (EKB) in an unbiased, statistically significant sample of nearby FGK main-sequence stars. Our target set spans a broad range of stellar ages (from 0.1 to 10 Gyr) and is volume-limited (distances < 20 pc). All stars with known extrasolar planets within this distance are included; additionally, some M- and A-type stars will be observed in collaboration with the Herschel DEBRIS OTKP, so that the entire sample covers a decade in stellar mass, from 0.2 to 2 solar masses. We will perform PACS and SPIRE photometric observations covering the wavelength range from 70 to 500 microns. The PACS observations at 100 microns have been designed to detect the stellar photospheres down to the confusion limit with a signal-to-noise ratio > 5. The observations in the other Herschel bands will allow us to characterize, model, and constrain the disks. As a result, it will be possible for us to reach fractional dust luminosities of a few times 10-7, close to the EKB level in the Solar System. This will provide an unprecedented lower limit to the fractional abundance of planetesimal systems and allow us to assess the presence of giant planets, which would play dynamical roles similar to those played by Jupiter and Neptune in the Solar System. The proposed observations will provide new and unique evidence for the presence of mature planetary systems in the solar neighbourhood and, in turn, will address the universality of planet/planetary system formation in disks around young stars.

  6. The Herschel Oxygen Project: Herschel Space Observatory Open Time Key Project

    NASA Technical Reports Server (NTRS)

    Goldsmith, Paul F.

    2008-01-01

    Topics include: Why oxygen and why at submillimeter wavelengths; gas phase chemistry for water, oxygen, and carbon monoxide is relatively simple; molecular oxygen structure; lower rotational levels and transitions of oxygen; oxygen abundance in interstellar clouds; SWAS spectra of terrestrial oxygen; what Herschel offers HOP; key regions for probing oxygen in the dense interstellar medium; HOP sources and strategy; and HOP data and analysis.

  7. THE HERSCHEL INVENTORY OF THE AGENTS OF GALAXY EVOLUTION IN THE MAGELLANIC CLOUDS, A HERSCHEL OPEN TIME KEY PROGRAM

    SciTech Connect

    Meixner, M.; Roman-Duval, J.; Seale, J.; Gordon, K.; Beck, T.; Boyer, M. L.; Panuzzo, P.; Hony, S.; Sauvage, M.; Okumura, K.; Chanial, P.; Babler, B.; Bernard, J.-P.; Bolatto, A.; Bot, C.; Carlson, L. R.; Clayton, G. C.; and others

    2013-09-15

    We present an overview of the HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds project, which is a Herschel Space Observatory open time key program. We mapped the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 100, 160, 250, 350, and 500 {mu}m with the Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS) instruments on board Herschel using the SPIRE/PACS parallel mode. The overriding science goal of HERITAGE is to study the life cycle of matter as traced by dust in the LMC and SMC. The far-infrared and submillimeter emission is an effective tracer of the interstellar medium (ISM) dust, the most deeply embedded young stellar objects (YSOs), and the dust ejected by the most massive stars. We describe in detail the data processing, particularly for the PACS data, which required some custom steps because of the large angular extent of a single observational unit and overall the large amount of data to be processed as an ensemble. We report total global fluxes for the LMC and SMC and demonstrate their agreement with measurements by prior missions. The HERITAGE maps of the LMC and SMC are dominated by the ISM dust emission and bear most resemblance to the tracers of ISM gas rather than the stellar content of the galaxies. We describe the point source extraction processing and the criteria used to establish a catalog for each waveband for the HERITAGE program. The 250 {mu}m band is the most sensitive and the source catalogs for this band have {approx}25,000 objects for the LMC and {approx}5500 objects for the SMC. These data enable studies of ISM dust properties, submillimeter excess dust emission, dust-to-gas ratio, Class 0 YSO candidates, dusty massive evolved stars, supernova remnants (including SN1987A), H II regions, and dust evolution in the LMC and SMC. All images and catalogs are delivered to the Herschel Science Center as part of the community support

  8. The HERschel Inventory of the Agents of Galaxy Evolution in the Magellanic Clouds, a HERschel Open Time Key Program

    NASA Technical Reports Server (NTRS)

    Meixner, Margaret; Panuzzo, P.; Roman-Duval, J.; Engelbracht, C.; Babler, B.; Seale, J.; Hony, S.; Montiel, E.; Sauvage, M.; Gordon, K.; Misselt, K.; Okumura, K.; Chanial, P.; Beck, T.; Bernard, J.-P.; Bolatto, A.; Bot, C.; Boyer, M. L.; Carlson, L. R.; Clayton, G. C.; Chen, C.-H. R.; Cormier, D.; Fukui, Y.; Galametz, M.; Galliano, F.

    2013-01-01

    We present an overview or the HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds project, which is a Herschel Space Observatory open time key program. We mapped the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 100, 160, 250, 350, and 500 micron with the Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS) instruments on board Herschel using the SPIRE/PACS parallel mode. The overriding science goal of HERITAGE is to study the life cycle of matter as traced by dust in the LMC and SMC. The far-infrared and submillimeter emission is an effective tracer of the interstellar medium (ISM) dust, the most deeply embedded young stellar objects (YSOs), and the dust ejected by the most massive stars. We describe in detail the data processing, particularly for the PACS data, which required some custom steps because of the large angular extent of a single observational unit and overall the large amount of data to be processed as an ensemble. We report total global fluxes for LMC and SMC and demonstrate their agreement with measurements by prior missions. The HERITAGE maps of the LMC and SMC are dominated by the ISM dust emission and bear most resemblance to the tracers of ISM gas rather than the stellar content of the galaxies. We describe the point source extraction processing and the critetia used to establish a catalog for each waveband for the HERITAGE program. The 250 micron band is the most sensitive and the source catalogs for this band have approx. 25,000 objects for the LMC and approx. 5500 objects for the SMC. These data enable studies of ISM dust properties, submillimeter excess dust emission, dust-to-gas ratio, Class 0 YSO candidates, dusty massive evolved stars, supemova remnants (including SN1987A), H II regions, and dust evolution in the LMC and SMC. All images and catalogs are delivered to the Herschel Science Center as part of the conummity support

  9. The Herschel Space Observatory, Opening the Far Infrared

    NASA Astrophysics Data System (ADS)

    Pearson, John C.

    2009-06-01

    The Herschel Space Observatory (Herschel) is a multi user observatory operated by the European Space Agency with a significant NASA contribution. Herschel features a passively cooled 3.5 meter telescope expected to operate near 78 Kelvin and three cryogenic instruments covering the 670 to 57 μm spectral region. The mission life time, determined by the consumption of 2500 liters of liquid helium, is expected to be at least 3.5 years with at least 3 years of operational lifetime in an L2 orbit. The three payload instruments are the Spectral and Photometric Imaging Receiver (SPIRE), Photodetector Array Camera and Spectrometer (PACS), and the Heterodyne Instrument for Far Infrared (HIFI). SPIRE covers 200-670 μm and is a three band bolometer based photometer and a two band imaging Martin-Puplett FTS with a spectral resolution of up to 600. PACS covers 57-200 μm and is a three band bolometer based photometer and a grating slit spectrometer illuminating photoconductor arrays in two bands with a resolution of up to 5000. HIFI covers 480-1272 GHz and 1440-1910 GHz and is a series of seven dual polarization heterodyne receivers with a spectral resolution up to 5×10^6. The observatory performance, selected science program and upcoming opportunities will be discussed.

  10. GASPS Photometry of the Tucana-Horologium Association

    NASA Technical Reports Server (NTRS)

    Roberge, Donaldson J.; Roberge, Aki

    2010-01-01

    The GASPS Open Time Key Programme on Herschel represents a new opportunity to sensitively probe protoplanetary and debris disks at far-IR wavelengths. We present preliminary PACS 70 and 160 micron photometry of eighteen stars in the 30 Myr-old Tucana-Horologium association. Of these eighteen, eight were detected in the 70 micron band. Four of these eight were also detected in the 160 micron band. We constructed SEDs for these systems using optical data from Hipparcos (B and V), near-IR data from 2MASS (J, H, and K), mid-IR data from IRAS and Spitzer MIPS (12 and 24 microns, respectively), and the new far-IR data from PACS. For the stars showing IR excess emission, we fit simple single-temperature blackbody curves to the IR excess in order to determine the rough dust abundances and temperatures. Dust observations at these wavelengths will also be important for comparison with upcoming Herschel PACS spectra that will search for gas in the disks. Our goal is to determine or limit the ever-allusive gas-to-dust ratio for these disk systems.

  11. Hypoxic apnea and gasping.

    PubMed Central

    Guntheroth, W G; Kawabori, I

    1975-01-01

    We have tested the hypothesis that severe lypoxia causes apnea, regardless of the arterial CO2 and pH, and that extreme hypoxia causes gasping. Acute experiments with airway occlusion and with low inspired oxygen (FIo2) were performed on anesthetized adult dogs and monkeys. Arterial oxygen saturation was recorded continuously with fiberoptic oximetry, and Pco2 by an electrode catheter. In addition, blood samples were obtained for Po2, Pco2, and pH. Apnea was induced regularly when the Pao2 fell below 10 torr, whether the Paco2 was high with asphyxia (63 torr) or low (26 torr) with low FIo2. Similarly, the Pao2 at apnea was the same whether the pH was 7.17 with asphyxic hypoxia or 7.46 with hypoxic hypoxia. Gasping occurred at even lower Pao2 (below 5 torr) after 1 or 2 min of apnea. Gasping promptly restored the Pao2 to levels of moderate hypoxia (over 30 torr) which permitted resumption of regular respiration, with gradual elimination of the gasping. Fetal monkeys at term were studied in a similar manner from the moment of cord clamping. Their blood gases with apnea were quite similar to adult values in the narrow range of Pao2 and the wide range of Paco2 and pH. In the fetus, gasping was less immediately effective in improving arterial oxygen, but more persistent than in the adult. Regular respirations would not develop in the absence of oxygen in either the fetus or adult animal. Images PMID:811688

  12. Pheochromocytoma: Gasping for Air.

    PubMed

    Jochmanová, Ivana; Zhuang, Zhengping; Pacak, Karel

    2015-12-01

    There has been increasing evidence that pseudohypoxia--a phenomenon that we refer to as "gasping for air"--along with mitochondrial enzyme dysregulation play a crucial role in tumorigenesis, particularly in several hereditary pheochromocytomas (PHEOs) and paragangliomas (PGLs). Alterations in key tricarboxylic acids (TCA) cycle enzymes (SDH, FH, MDH2) have been shown to induce pseudohypoxia via activation of the hypoxia-inducible transcription factor (HIF) signaling pathway that is involved in tumorigenesis, invasiveness, and metastatic spread, including an association with resistance to various cancer therapies and worse prognosis. This review outlines the ongoing story of the pathogenesis of hereditary PHEOs/PGLs, showing the unique and most updated evidence of TCA cycle dysregulation that is tightly linked to hypoxia signaling. PMID:26138106

  13. The Herschel ATLAS

    NASA Technical Reports Server (NTRS)

    Eales, S.; Dunne, L.; Clements, D.; Cooray, A.; De Zotti, G.; Dye, S.; Ivison, R.; Jarvis, M.; Lagache, G.; Maddox, S.; Negrello, M.; Serjeant, S.; Thompson, M. A.; Van Kampen, E.; Amblard, A.; Andreani, P.; Baes, M.; Beelen, A.; Bendo, G. J.; Bertoldi, F.; Benford, D.; Bock, J.

    2010-01-01

    The Herschel ATLAS is the largest open-time key project that will be carried out on the Herschel Space Observatory. It will survey 570 sq deg of the extragalactic sky, 4 times larger than all the other Herschel extragalactic surveys combined, in five far-infrared and submillimeter bands. We describe the survey, the complementary multiwavelength data sets that will be combined with the Herschel data, and the six major science programs we are undertaking. Using new models based on a previous submillimeter survey of galaxies, we present predictions of the properties of the ATLAS sources in other wave bands.

  14. GASP- GENERAL AVIATION SYNTHESIS PROGRAM

    NASA Technical Reports Server (NTRS)

    Galloway, T. L.

    1994-01-01

    The General Aviation Synthesis Program, GASP, was developed to perform tasks generally associated with the preliminary phase of aircraft design. GASP gives the analyst the capability of performing parametric studies in a rapid manner during preliminary design efforts. During the development of GASP, emphasis was placed on small fixed-wing aircraft employing propulsion systems varying from a single piston engine with a fixed pitch propeller through twin turboprop/turbofan systems as employed in business or transport type aircraft. The program is comprised of modules representing the various technical disciplines of design, integrated into a computational flow which ensures that the interacting effects of design variables are continuously accounted for in the aircraft sizing procedures. GASP provides a useful tool for comparing configurations, assessing aircraft performance and economics, and performing tradeoff and sensitivity studies. By utilizing GASP, the impact of various aircraft requirements and design factors may be studied in a systematic manner, with benefits being measured in terms of overall aircraft performance and economics. The GASP program consists of a control module and six "technology" submodules which perform the various independent studies required in the design of general aviation or small transport type aircraft. The six technology modules include geometry, aerodynamics, propulsion, weight and balance, mission analysis, and economics. The geometry module calculates the dimensions of the synthesized aircraft components based on such input parameters as number of passengers, aspect ratio, taper ratio, sweep angles, and thickness of wing and tail surfaces. The aerodynamics module calculates the various lift and drag coefficients of the synthesized aircraft based on inputs concerning configuration geometry, flight conditions, and type of high lift device. The propulsion module determines the engine size and performance for the synthesized aircraft

  15. Regulation of GDF-11 and myostatin activity by GASP-1 and GASP-2.

    PubMed

    Lee, Yun-Sil; Lee, Se-Jin

    2013-09-24

    Myostatin (MSTN) and growth and differentiation factor-11 (GDF-11) are highly related TGF-β family members that have distinct biological functions. MSTN is expressed primarily in skeletal muscle and acts to limit muscle growth. GDF-11 is expressed more widely and plays multiple roles, including regulating axial skeletal patterning during development. Several MSTN and GDF-11 binding proteins have been identified, including GDF-associated serum protein-1 (GASP-1) and GASP-2, which are capable of inhibiting the activities of these ligands. Here, we show that GASP-1 and GASP-2 act by blocking the initial signaling event (namely, the binding of the ligand to the type II receptor). Moreover, we show that mice lacking Gasp1 and Gasp2 have phenotypes consistent with overactivity of MSTN and GDF-11. Specifically, we show that Gasp2(-/-) mice have posteriorly directed transformations of the axial skeleton, which contrast with the anteriorly directed transformations seen in Gdf11(-/-) mice. We also show that both Gasp1(-/-) and Gasp2(-/-) mice have reductions in muscle weights, a shift in fiber type from fast glycolytic type IIb fibers to fast oxidative type IIa fibers, and impaired muscle regeneration ability, which are the reverse of what are seen in Mstn(-/-) mice. All of these findings suggest that both GASP-1 and GASP-2 are important modulators of GDF-11 and MSTN activity in vivo. PMID:24019467

  16. Rapid Antibiotic Resistance Evolution of GASP Mutants

    NASA Astrophysics Data System (ADS)

    Zhang, Qiucen; Kim, Hyunsung; Pourmand, Nader; Austin, Robert

    2012-02-01

    The GASP phenotype in bacteria is due to a mutation which enables the bacteria to grow under high stress conditions where other bacteria stop growing. We probe using our Death Galaxy microenvironment how rapidly the GASP mutant can evolve resistance to mutagenic antibiotics compared to wild-type bacteria, and explore the genomic landscape changes due to the evolution of resistance.

  17. Code enhancements and validation of GASP

    NASA Astrophysics Data System (ADS)

    Walters, Robert W.; Cinnella, P.; Slack, D. C.

    1990-03-01

    Enhancements to GASP and the validation test cases that were investigated to date are described. GASP is a computational fluid dynamics computer code that solves the integral form of the governing equations, which includes the full Reynolds-averaged Navier-Stokes (NS) equations, the Thin Layer NS equations, the Parabolized NS equations, and the Euler equations. GASP contains a generalized chemistry model and both equilibrium and non-equilibrium thermodynamics models for simulating a wide range of conditions. GASP is highly vectorized and contains a variety of time integration schemes for both steady-state and time-accurate calculations. Additional capabilities including boundary condition options, chemistry models incorporated, and memory management techniques are reviewed in outline format.

  18. GASP/WFIKKN proteins: evolutionary aspects of their functions.

    PubMed

    Monestier, Olivier; Brun, Caroline; Cocquempot, Olivier; Petit, Daniel; Blanquet, Véronique

    2012-01-01

    Growth and differentiation factor Associated Serum Protein (GASP) 1 and 2 are proteins known to be involved in the control of myostatin activity at least in vitro. Most deuterostome GASPs share a modular organization including WAP, follistatin/kazal, IGc2, two kunitz, and NTR domains. Based on an exon shuffling model, we performed independent phylogenetic analyses on these modules and assessed that papilin is probably a sister sequence to GASP with a divergence date estimated from the last common ancestor to bilateria. The final organization was acquired by the addition of the FS domain in early deuterostomes. Our study revealed that Gasp genes diverged during the first round of genome duplication in early vertebrates. By evaluating the substitution rate at different sites on the proteins, we showed a better conservation of the follistatin/kazal domain of GASP1 than GASP2 in mammals, suggesting a stronger interaction with myostatin. We also observed a progressive increase in the conservation of follistatin and kunitz domains from the ancestor of Ciona to early vertebrates. In situ hybridization performed on mouse embryos showed a weak Gasp1 expression in the formed somites at 10.5 dpc and in limb buds from embryonic E10.0 to E12.5. Similar results were obtained for zebrafish embryos. We propose a synthetic view showing possible interactions between GASP1 and myostatin and highlighting the role of the second kunitz domain in preventing myostatin proteolysis. PMID:22937083

  19. Structural lineaments of Gaspe from ERTS imagery

    NASA Technical Reports Server (NTRS)

    Steffensen, R.

    1973-01-01

    A test study was conducted to assess the value of ERTS images for mapping geologic features of the Gaspe Peninsula, Quebec. The specific objectives of the study were: 1) to ascertain the best procedure to follow in order to obtain valuable geologic data as a result of interpretation; and 2) to indicate in which way these data could relate to mineral exploration. Of the four spectral bands of the Multispectral scanner, the band from 700 to 800 nanometers, which seems to possess the best informational content for geologic study, was selected for analysis. The original ERTS image at a scale of 1:3,700,000 was enlarged about 15 times and reproduced on film. Geologically meaningful lines, called structural lineaments, were outlined and classified according to five categories: morpho-lithologic boundaries, morpho-lithologic lineaments, fault traces, fracture zones and undefined lineaments. Comparison with the geologic map of Gaspe shows that morpho-lithologic boundaries correspond to contacts between regional stratigraphic units. Morpholithologic lineaments follow bedding trends, whereas fracture traces appear as sets of parallel lineaments, intersecting at high angles the previous category of lineaments. Fault traces mark more precisely the location of faults already mapped and spot the presence of presumable faults, not indicated on the geologic map.

  20. The Herschels and Modern Astronomy

    NASA Astrophysics Data System (ADS)

    Clerke, Agnes Mary

    2010-05-01

    Preface; 1. Early life of William Herschel; 2. The King's astronomer; 3. The explorer of the heavens; 4. Herschel's special investigations; 5. The influence of Herschel's career on modern astronomy; 6. Caroline Herschel; 7. Sir John Herschel at Cambridge and Slough; 8. Expedition to the Cape; 9. Life at Collingwood; 10. Writings and experimental investigations; Index.

  1. An analysis of the first two years of GASP data

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Nastrom, G. D.; Falconer, P. D.

    1977-01-01

    Distributions of mean ozone levels from the first two years of data from the NASA Global Atmospheric Sampling Program (GASP) show spatial and temporal variations in agreement with previous measurements. The standard deviations of these distributions reflect the large natural variability of ozone levels in the altitude range of the GASP measurements. Monthly mean levels of ozone below the tropopause show an annual cycle with a spring maximum which is believed to result from transport from the stratosphere. Correlations of ozone with independent meteorological parameters, and meteorological parameters obtained by the GASP systems show that this transport occurs primarily through cyclogenesis at mid-latitudes.

  2. HERSCHEL OBSERVATIONS OF GAS AND DUST IN THE UNUSUAL 49 Ceti DEBRIS DISK

    SciTech Connect

    Roberge, A.; Kamp, I.; Montesinos, B.; Dent, W. R. F.; Meeus, G.; Eiroa, C.; Donaldson, J. K.; Olofsson, J.; Moor, A.; Augereau, J.-C.; Thi, W.-F.; Ardila, D. R.; Woitke, P.

    2013-07-01

    We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space Observatory PACS and SPIRE instruments, largely as part of the ''Gas in Protoplanetary Systems'' (GASPS) Open Time Key Programme. Disk dust emission is detected in images at 70, 160, 250, 350, and 500 {mu}m; 49 Cet is significantly extended in the 70 {mu}m image, spatially resolving the outer dust disk for the first time. Spectra covering small wavelength ranges centered on eight atomic and molecular emission lines were obtained, including [O I] 63 {mu}m and [C II] 158 {mu}m. The C II line was detected at the 5{sigma} level-the first detection of atomic emission from the disk. No other emission lines were seen, despite the fact that the O I line is the brightest one observed in Herschel protoplanetary disk spectra. We present an estimate of the amount of circumstellar atomic gas implied by the C II emission. The new far-IR/sub-mm data fills in a large gap in the previous spectral energy distribution (SED) of 49 Cet. A simple model of the new SED confirms the two-component structure of the disk: warm inner dust and cold outer dust that produces most of the observed excess. Finally, we discuss preliminary thermochemical modeling of the 49 Cet gas/dust disk and our attempts to match several observational results simultaneously. Although we are not yet successful in doing so, our investigations shed light on the evolutionary status of the 49 Cet gas, which might not be primordial gas but rather secondary gas coming from comets.

  3. Herschel Observations of Gas and Dust in the Unusual 49 Ceti Debris Disk

    NASA Technical Reports Server (NTRS)

    Roberge, A.; Kamp, I.; Montesinos, B.; Dent, W. R. F.; Meeus, G.; Donaldson, J. K.; Olofsson, J.; Moor, A.; Augereau, J.-C.; Howard, C.; Eiroa, C.; Thi, W.-F.; Ardila, D. R.; Sandell, G.; Woitke, P.

    2013-01-01

    We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space Observatory PACS and SPIRE instruments, largely as part of the “Gas in Protoplanetary Systems” (GASPS) Open Time Key Programme. Disk dust emission is detected in images at 70, 160, 250, 350, and 500 micron; 49 Cet is significantly extended in the 70 micron image, spatially resolving the outer dust disk for the first time. Spectra covering small wavelength ranges centered on eight atomic and molecular emission lines were obtained, including [O i] 63 micron and [C ii] 158 micron. The C ii line was detected at the 5 sigma level—the first detection of atomic emission from the disk. No other emission lines were seen, despite the fact that the Oi line is the brightest one observed in Herschel protoplanetary disk spectra. We present an estimate of the amount of circumstellar atomic gas implied by the C ii emission. The new far-IR/sub-mm data fills in a large gap in the previous spectral energy distribution (SED) of 49 Cet. A simple model of the new SED confirms the two-component structure of the disk: warm inner dust and cold outer dust that produces most of the observed excess. Finally, we discuss preliminary thermochemical modeling of the 49 Cet gas/dust disk and our attempts to match several observational results simultaneously. Although we are not yet successful in doing so, our investigations shed light on the evolutionary status of the 49 Cet gas, which might not be primordial gas but rather secondary gas coming from comets.

  4. Overview of the GASP project; Field applications and economics

    SciTech Connect

    Sarshar, M.M.; Lovie, P.M. )

    1992-03-01

    This paper reports that the aim of the Goodfellow Assocs. subsea production (GASP) project was to develop a subsea production system for use in the development of marginal oil fields. The project was divided into three phases that culminated in testing a prototype system in a dry dock. The GASP system enables manifolding of products, separation of gas from produced liquids, and transportation of gas and liquids, and transportation of gas and liquids through separate lines. The produced liquids are pumped with a single-phase pumping system that is highly modularized for ease of installation and retrieval of key components. GASP is suitable for deepwater application and development of marginal fields far from the host platform. The economics were assessed with probabilistic methods to weigh the uncertainties. Developing marginal fields with the GASP system looks attractive, offering a development cost of $2.50 to $5.50 per barrel in many typical instances.

  5. The Herschel Science Archive

    NASA Astrophysics Data System (ADS)

    Verdugo, Eva

    2015-12-01

    The Herschel mission required a Science Archive able to serve data to very different users: The own Data Analysis Software (both Pipeline and Interactive Analysis), the consortia of the different instruments and the scientific community. At the same time, the KP consortia were committed to deliver to the Herschel Science Centre, the processed products corresponding to the data obtained as part of their Science Demonstration Phase and the Herschel Archive should include the capability to store and deliver them. I will explain how the current Herschel Science Archive is designed to cover all these requirements.

  6. Herschel's Interference Demonstration.

    ERIC Educational Resources Information Center

    Perkalskis, Benjamin S.; Freeman, J. Reuben

    2000-01-01

    Describes Herschel's demonstration of interference arising from many coherent rays. Presents a method for students to reproduce this demonstration and obtain beautiful multiple-beam interference patterns. (CCM)

  7. A characterization of the respiratory pattern of gasping.

    PubMed

    St John, W M; Knuth, K V

    1981-05-01

    The purpose of this investigation was to compare the respiratory pattern of gasping with eupnea and apneusis. Decerebrate, cerebellectomized, vagotomized, paralyzed and ventilated cats were used. The ventilatory pattern, assessed by phrenic nerve activity, was reversibly altered from eupnea to apneusis or gasping by use of a cooling-for, thermode positioned inm the rostral pons or through the pontomedullary junction, respectively. Irreversible apneusis or gasping resulted from brain stem lesions or freezing at appropriate loci. Analysis of phrenic activity revealed that the rates of onset and rise of the gasp were much greater than those of the eupneic or apneustic inspiration. Moreover, in contrast to eupnea or apneusis, neither the frequency nor the intensity of gasps was altered by hypercapnia, hypocapnia, or carotid chemoreceptor stimulation by sodium cyanide. Although hypoxia caused an increase in gasping frequency, this response was transient and not dependent on carotid chemoreceptor mechanisms. These results provide no support for the concept that common mechanisms localized in medulla, underlie the neurogenesis of all automatic ventilatory patterns. PMID:6785267

  8. John Herschel's Graphical Method

    NASA Astrophysics Data System (ADS)

    Hankins, Thomas L.

    2011-01-01

    In 1833 John Herschel published an account of his graphical method for determining the orbits of double stars. He had hoped to be the first to determine such orbits, but Felix Savary in France and Johann Franz Encke in Germany beat him to the punch using analytical methods. Herschel was convinced, however, that his graphical method was much superior to analytical methods, because it used the judgment of the hand and eye to correct the inevitable errors of observation. Line graphs of the kind used by Herschel became common only in the 1830s, so Herschel was introducing a new method. He also found computation fatiguing and devised a "wheeled machine" to help him out. Encke was skeptical of Herschel's methods. He said that he lived for calculation and that the English would be better astronomers if they calculated more. It is difficult to believe that the entire Scientific Revolution of the 17th century took place without graphs and that only a few examples appeared in the 18th century. Herschel promoted the use of graphs, not only in astronomy, but also in the study of meteorology and terrestrial magnetism. Because he was the most prominent scientist in England, Herschel's advocacy greatly advanced graphical methods.

  9. Development and application of GASP 2.0

    NASA Technical Reports Server (NTRS)

    Mcgrory, W. D.; Huebner, L. D.; Slack, D. C.; Walters, R. W.

    1992-01-01

    GASP 2.0 represents a major new release of the computational fluid dynamics code in wide use by the aerospace community. The authors have spent the last two years analyzing the strengths and weaknesses of the previous version of the finite-rate chemistry, Navier Stokes solution algorithm. What has resulted is a completely redesigned computer code that offers two to four times the performance of previous versions while requiring as little as one quarter of the memory requirements. In addition to the improvements in efficiency over the original code, Version 2.0 contains many new features. A brief discussion of the improvements made to GASP, and an application using GASP 2.0 which demonstrates some of the new features are presented.

  10. Variability of cloudiness at airline cruise altitudes from GASP measurements

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastrom, G. D.; Davis, R. E.; Holdeman, J. D.

    1985-01-01

    Additional statistics relating to the climatology of cloud cover at airline cruise altitudes are presented. The data were obtained between 1975 and 1979 from commercial airliners participating in the Global Atmospheric Sampling Program (GASP). The statistics describe the seasonal, latitudinal and altitudinal variation in cloudiness parameters as well as differences in the high-altitude cloud structure attributed to cyclone and convective-cloud generation processes. The latitudinal distribution of cloud cover derived form the GASP data was found to agree with high-altitude satellite observations. The relationships between three different measures of cloudiness and the relative vorticity at high altitudes is also discussed.

  11. SCHOOL SCHEDULING BY COMPUTER, THE STORY OF GASP.

    ERIC Educational Resources Information Center

    MURPHY, JUDITH; SUTTER, ROBERT

    GENERALIZED ACADEMIC SIMULATION PROGRAMS (GASP) IS SCHOOL SCHEDULING BY COMPUTER. THE PUBLICATION COMPARES THE MANUAL METHOD OF DEVELOPING A SCHOOL SCHEDULE WITH THE NEW METHOD OF COMPUTER PROGRAMING. A MAJOR ADVANTAGE OF COMPUTER PROGRAMING IS THAT IT RELIEVES THE ADMINISTRATOR OF THIS BUSY WORK SO THAT HE CAN DEVOTE HIS ENERGIES AND TIME TO MORE…

  12. School Scheduling by Computer, the Story of GASP.

    ERIC Educational Resources Information Center

    Murphy, Judith; Sutter, Robert

    Generalized academic simulation programs (GASP) is school scheduling by computer. The publication compares the manual method of developing a school schedule with the new method of computer programing. A major advantage of computer programing is that it relieves the administrator of this busy work so that he can devote his energies and time to more…

  13. A Debris Disk Case Study: 49 Ceti with Herschel

    NASA Technical Reports Server (NTRS)

    Roberge, Aki

    2011-01-01

    Gas-poor debris disks represent a fundamentally different class of circumstellar disk than gas-rich protoplanetary disks. Their gas probably originates from the same source as the dust, i.e. planetesimal destruction, but the low gas densities make it difficult to detect. So far, Herschel has detected far-IR gas emission from one debris disk, Beta Pictoris. Here I discuss a well-known debris disk system in the GASPS survey, 49 Ceti. It serves as a case study for modeling low-density gas in optically thin disks. The dust disk appears to be spatially resolved at 70 um. Most interestingly, there appears to be a hint of ClI 158 urn emission at the roughly 2 sigma level. Preliminary modeling suggests that reconciling the sub-mm CO emission from this system with the weak or non-existent far-IR atomic lines may require an unusual chemical composition in the gas of this disk.

  14. The accretion/ejection paradigm in young stellar objects: from HST and Herschel to JWST

    NASA Astrophysics Data System (ADS)

    Podio, Linda

    2012-07-01

    Stellar jets and molecular outflows are observed in association with young accreting stars and are believed to play a key role in the star formation process. In this talk I will show how current and future space missions are of crucial importance to investigate the origin of stellar jets and their link to the accretion process. Thanks to its high angular (˜0.1") resolution, HST has been the first telescope allowing us to investigate the jet physics at optical/UV wavelengths down to the heart of the launching mechanism. We recently analysed a datacube of the jet emitted by the T Tauri star DG Tau obtaining spatio-kinematical maps of the hot atomic gas in the jet and of its physical conditions (Maurri et al., submitted). These data confirm the predictions of theoretical models including the fact that jets may extract the excess angular momentum from the system. In the last two years Herschel has further improved our comprehension of the ejection process observing the far infrared counterpart of fast and collimated atomic jets. PACS and HIFI observations, acquired within the GASPS (GAS in Protoplanetary Systems) Open Time Key Project (PI: B. Dent), show that T Tauri stars driving optical jets are also associated with a warm gas component emitting not only atomic ([OI], [CII]) but also molecular (high-J CO, H_2O, OH) lines. The comparison with Class 0 outflows highlights a clear evolutionary trend: the emission associated with evolved Class I/II sources is fainter and more compact and the estimated mass loss rates and lines cooling are one to two orders of magnitudes lower (Podio et al., to be submitted). The arrival of JWST will fill-in the gap between HST and Herschel opening a new window in the near and mid-infrared range at unprecedented angular resolution (down to 0.03"). This will allow resolving the emission in both atomic (e.g., [FeII]) and molecular (e.g., H_2) lines and understanding if the molecular gas is entrained by the atomic jet or launched with it

  15. A Unique Gas-Rich Debris Disk: Herschel Imaging and Spectroscopy of 49 Ceti

    NASA Technical Reports Server (NTRS)

    Roberge, Aki

    2012-01-01

    Gas-poor debris disks represent a fundamentally different class of circumstellar disk than gas-rich protoplanetary disks. Their gas probably originates from the same source as the dust, i.e. planetesimal destruction, but the low gas densities make it difficult to detect. So far, Herschel has detected far-IR gas emission from only one or two debris disks, Beta Pictoris being one of them. Here we present Herschel GASPS observations of a well-known debris disk system, 49 Ceti. The dust disk is spatially resolved in thermal emission at 70 _m. Most interestingly, weak far-IR gas emission is detected. Preliminary modeling suggests that reconciling the sub-mm CO emission seen from this system with the far-IR gas detection and upper limits requires a low gas-to-dust ratio and possibly an unusual gas composition.

  16. Support of Herschel Key Programme Teams at the NASA Herschel Science Center

    NASA Astrophysics Data System (ADS)

    Shupe, David L.; Appleton, P. N.; Ardila, D.; Bhattacharya, B.; Mei, Y.; Morris, P.; Rector, J.; NHSC Team

    2010-01-01

    The first science data from the Herschel Space Observatory were distributed to Key Programme teams in September 2009. This poster describes a number of resources that have been developed by the NASA Herschel Science Center (NHSC) to support the first users of the observatory. The NHSC webpages and Helpdesk serve as the starting point for information and queries from the US community. Details about the use of the Herschel Common Science Software can be looked up in the Helpdesk Knowledgebase. The capability of real-time remote support through desktop sharing has been implemented. The NHSC continues to host workshops on data analysis and observation planning. Key Programme teams have been provided Wiki sites upon request for their team's private use and for sharing information with other teams. A secure data storage area is in place for troubleshooting purposes and for use by visitors. The NHSC draws upon close working relationships with Instrument Control Centers and the Herschel Science Center in Madrid in order to have the necessary expertise on hand to assist Herschel observers, including both Key Programme teams and respondents to upcoming open time proposal calls.

  17. Modularization and installation, maintenance, and repair aspects of GASP technology

    SciTech Connect

    Dick, P. )

    1992-03-01

    This paper reports that the Goodfellow Assocs. Susbsea Processing (GASP) project addressed most of the major problem posed by the development of remote, small, marginal, or satellite oil and natural gas fields in deep waters. It considered a number of field development scenarios and , in particular, reviewed cases for fields situated up to 30 km from a platform- or shore-based processing facility. During the design of the resultant modularized GASP system, it was determined that an inspection, maintenance, and repair (IMR) philosophy needed to be developed. The number of field development scenarios involved, the different module dimensions and weights, and the remote driverless activities required in deeper waters resulted in a separate project, Maintenance and Retrieval Equipment (MARE).

  18. Variability of Cloudiness at Airline Cruise Altitudes from GASP Measurements.

    NASA Astrophysics Data System (ADS)

    Jasperson, William H.; Nastrom, Gregory D.; Davis, Richard E.; Holdeman, James D.

    1985-01-01

    A climatology of high-altitude cloud encounters using data obtained between 1975 and 1979 from commercial airliners participating in the Global Atmospheric Sampling Program (GASP) is presented. The statistics are based on three different measures of cloudiness derived from the GASP data set. This climatology depicts the seasonal, latitudinal and altitudinal variation in the cloudiness parameters, as well as differences in the high-altitude cloud structure attributed to cyclone- and convective cloud-generation mechanisms. A qualitative agreement was found between the latitudinal distribution of cloud cover derived from the GASP data and satellite-derived high-altitude cloud statistics available in the literature. Relationships between the three different measures of cloudiness and the relative vorticity at high altitudes, stratified by season, latitude and distance from the tropopause are also presented. In midlatitudes, for example, the average cloudiness, when stratified by the sign of the relative vorticity, exhibits a seasonal cycle with the 1argest differences occurring in the layer 0-1.5 km below the tropopause. Seasonal and latitudinal patterns can also be seen in the other cloudiness parameters.

  19. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0003

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1976-01-01

    Atmospheric ozone, and related flight and meteorological data for May 1975, obtained during 49 flights of a Pan American World Airways 747, are available as GASP tape VL0003 from the National Climatic Center, Asheville, North Carolina. In addition to the GASP data, tropopause pressure fields obtained from NMC archives for the dates of the GASP flights are included on the data tape. Flight routes and dates, instrumentation, data processing procedures, and data tape specifications are described.

  20. G-protein coupled receptor-associated sorting protein 1 (GASP-1), a ubiquitous tumor marker.

    PubMed

    Zheng, Xiaoyi; Chang, Frank; Zhang, Xinmin; Rothman, Vicki L; Tuszynski, George P

    2012-08-01

    Using an innovative "2-D high performance liquid electrophoresis" (2-D HPLE) technology we identified that a specific fragment of G-protein coupled receptor-associated sorting protein 1 (GASP-1) was present in the sera of breast cancer patients and was over-expressed in early and late stage breast tumors (Tuszynski, G.P. et al., 2011). In this study we further investigated the significance of GASP-1 as a tumor marker by investigating the expression GASP-1 in different kinds of tumors as well as in the sera of patients with various cancers. Over expression of GASP-1 was detected in brain, pancreatic, and breast cancers as compared to their respective normal tissues as assessed by immunohistochemical staining of tissue arrays using a "peptide specific" GASP-1 antibody. We found that across these cancers, GASP-1 was expressed approximately 10 fold more in the cancer as compared to normal tissue. The increase in GASP-1 expression was also seen in hyperplastic and inflammatory lesions of breast and pancreatic cancers as compared to normal tissue. GASP-1 was primarily expressed in the tumor epithelium of the epithelial-derived cancers and in the transformed glial cells of the brain tumors. Using a sensitive "competitive ELISA" for GASP-1, we found that sera from patients with brain, liver, breast and lung cancers expressed 4-7 fold more GASP-1 peptide than sera from normal healthy individuals. These studies identify GASP-1 as a potential new serum and tumor biomarker for several cancers and suggest that GASP-1 may be a novel target for development of cancer therapeutics. PMID:22483848

  1. Ozone in the upper troposphere from Gasp measurements

    NASA Technical Reports Server (NTRS)

    Nastrom, G. D.

    1979-01-01

    Several aspects of tropospheric ozone variations are examined by using ozone measurements made from commercial airliners (Gasp data). Through visual inspection of the autocorrelation function it is shown that the east-west variations of ozone have a predominant wavelength near 2400 km, while temperature and wind have predominant wavelengths near 3300 km. Distance-lagged correlation functions of ozone with temperature and wind show a definite periodicity with wavelengths near 2400 km. Attention is given to the tropical tropospheric ozone values above 100 parts per billion by volume, which appear to be associated with meridional transport from middle latitudes, and in some cases, relatively large tropical ozone values are coincident with clouds.

  2. Cloud encounter and particle density variabilities from GASP data

    NASA Technical Reports Server (NTRS)

    Nastrom, G. D.; Holdeman, J. D.; Davis, R. E.

    1981-01-01

    Summary statistics and variability studies are presented for cloud encounter and particle number density data as part of the NASA Global Atmospheric Sampling Program (GASP) aboard commercial Boeing 747 airliners. On the average, cloud encounter is shown on about 15% of the 52,164 data samples available; this value varies with season, latitude, synoptic weather situation, and distance from the tropopause. The number density of particles (diameter greater than 3 microns) also varies with time and location, and depends on the horizontal extent of cloudiness.

  3. Impaired striatum-dependent behavior in GASP-1-knock-out mice.

    PubMed

    Mathis, C; Bott, J-B; Candusso, M-P; Simonin, F; Cassel, J-C

    2011-04-01

    G protein-coupled receptor (GPCR) associated sorting protein-1 (GASP-1) is suspected to play a key role in recycling and degradation of several GPCRs. In a previous study, we have shown that GASP-1-knock-out (GASP-1-KO) mice displayed deficits in acquiring a cocaine self-administration task, associated with an exacerbated down-regulation of striatal dopaminergic and cholinergic receptors. Among several possibilities, GASP-1 deficiency could have impaired memory processes underlying the acquisition of the operant conditioning task. Therefore, the present study investigated cognitive performances of GASP-1-KO mice and their wild-type littermates (WT) in a broad variety of memory tasks. Consistent with a deficit in procedural memory, GASP-1-KO mice showed delayed acquisition of a food-reinforced bar-press task. During water-maze training in hidden- or visible-platform paradigms, mutant and WT mice acquired the tasks at the same rate. However, GASP-1 mice exhibited persistent thigmotaxic swimming, longer distance to the platform, and reduced swim speed. There was no deficit in several tasks requiring simple behavioral responses (Barnes maze, object recognition and passive avoidance tasks). Thus, the ability to acquire and/or express complex responses seems affected in GASP-1-deficient mice. Hippocampal functions were preserved, as the retention of an acquired memory in spatial tasks remained unaffected. The pattern of behavioral deficits observed in GASP-1-KO mice is coherent with current knowledge on the role of striatal GPCRs in acquisition/expression of skilled behavior and in motivation. Together with the previous findings, the so far established phenotype of GASP-1-KO mice makes them a potentially exciting tool to study striatal functions. PMID:21091868

  4. Dunes of Herschel

    NASA Technical Reports Server (NTRS)

    2005-01-01

    4 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-toned sand dunes on the floor of the large martian impact crater, Herschel, located in the Terra Cimmeria region of Mars. The winds responsible for these dunes blew from the northeast (upper right).

    Location near: 15.7oS, 228.6oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  5. Herschel and the Molecular Universe

    NASA Technical Reports Server (NTRS)

    Tielens, A. G. G. M.; Helmich, F. P.

    2006-01-01

    Over the next decade, space-based missions will open up the universe to high spatial and spectral resolution studies at infrared and submillimeter wavelengths. This will allow us to study, in much greater detail, the composition and the origin and evolution of molecules in space. Moreover, molecular transitions in these spectral ranges provide a sensitive probe of the dynamics and the physical and chemical conditions in a wide range of objects at scales ranging from budding planetary systems to galactic and extragalactic sizes. Hence, these missions provide us with the tools to study key astrophysical and astrochemical processes involved in the formation and evolution of planets, stars, and galaxies. These new missions can be expected to lead to the detection of many thousands of new spectral features. Identification, analysis and interpretation of these features in terms of the physical and chemical characteristics of the astronomical sources will require detailed astronomical modeling tools supported by laboratory measurements and theoretical studies of chemical reactions and collisional excitation rates on species of astrophysical relevance. These data will have to be made easily accessible to the scientific community through web-based data archives. In this paper, we will review the Herschel mission and its expected impact on our understanding of the molecular universe.

  6. Measurements of atmospheric ozone made from a GASP-equipped 747 airliner Mid-March, 1975

    NASA Technical Reports Server (NTRS)

    Falconer, P. D.; Holdeman, J. D.

    1976-01-01

    This paper presents data on the ozone mixing ratio, static air temperature, wind speed, and wind direction obtained at altitudes from 8 to 12 km during several flights of a commercial airliner equipped with a fully automated air-sampling system developed for the NASA Global Atmospheric Sampling Program (GASP). The objectives of GASP are reviewed, and the data-gathering techniques are described. Two data sets are discussed which illustrate variations of the upper-tropospheric and lower-stratospheric ozone mixing ratios as a function of geographical location and aircraft altitude. Good agreement is found between the GASP data and the tropopause height obtained from National Meteorological Center gridded data.

  7. Optical outburst of 4C 38.41 (1633+382) observed by the GASP

    NASA Astrophysics Data System (ADS)

    Raiteri, C. M.; Villata, M.; Ehgamberdiev, Sh. A.; Mirzaqulov, D. O.; Holikov, Sh.

    2011-07-01

    The GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) reports on the recent observation of a strong optical brightening of the gamma-loud quasar 4C 38.41. This is one of the 28 blazars for which the GASP performs a long-term, multiwavelength monitoring. In the current optical observing season, the source has shown multiwavelength activity (see also ATels #3238, #3333, #3335, #3360), so that the GASP has intensified the observations with a dedicated campaign (contact person: C.

  8. nGASP - the nematode genome annotation assessment project

    SciTech Connect

    Coghlan, A; Fiedler, T J; McKay, S J; Flicek, P; Harris, T W; Blasiar, D; Allen, J; Stein, L D

    2008-12-19

    While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets for 10 Mb of the C. elegans genome. Predictions were compared to reference gene sets consisting of confirmed or manually curated gene models from WormBase. The most accurate gene-finders were 'combiner' algorithms, which made use of transcript- and protein-alignments and multi-genome alignments, as well as gene predictions from other gene-finders. Gene-finders that used alignments of ESTs, mRNAs and proteins came in second place. There was a tie for third place between gene-finders that used multi-genome alignments and ab initio gene-finders. The median gene level sensitivity of combiners was 78% and their specificity was 42%, which is nearly the same accuracy as reported for combiners in the human genome. C. elegans genes with exons of unusual hexamer content, as well as those with many exons, short exons, long introns, a weak translation start signal, weak splice sites, or poorly conserved orthologs were the most challenging for gene-finders. While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets for 10 Mb of the C. elegans genome

  9. GASP cloud encounter statistics - Implications for laminar flow control flight

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastrom, G. D.; Davis, R. E.; Holdeman, J. D.

    1984-01-01

    The cloud observation archive from the NASA Global Atmospheric Sampling Program (GASP) is analyzed in order to derive the probability of cloud encounter at altitudes normally flown by commercial airliners, for application to a determination of the feasability of Laminar Flow Control (LFC) on long-range routes. The probability of cloud encounter is found to vary significantly with season. Several meteorological circulation features are apparent in the latitudinal distribution of cloud cover. The cloud encounter data are shown to be consistent with the classical midlatitude cyclone model with more clouds encountered in highs than in lows. Aircraft measurements of route-averaged time-in-clouds fit a gamma probability distribution model which is applied to estimate the probability of extended cloud encounter, and the associated loss of LFC effectiveness along seven high-density routes. The probability is demonstrated to be low.

  10. Science with Herschel: Results from the HERITAGE project

    NASA Astrophysics Data System (ADS)

    Meixner, M.; Seale, J.; Roman-Duval, J.; Gordon, K.; HERITAGE Team

    The Herschel Space Observatory completed its last observation on 2013 April 29 after completing 35 000 astronomical observations resulting in numerous discoveries. In this review, we describe the capabilities and general scope of the Herschel mission. In particular, we review the science results from one of the open time key programs, the HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds. The HERITAGE project mapped the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 100, 160, 250, 350, and 500 μm using the SPIRE/PACS parallel mode. The total global fluxes for the LMC and SMC agree with measurements by other missions, including Planck. The HERITAGE maps of the LMC and SMC are dominated by the ISM dust emission and bear most resemblance to the tracers of ISM gas rather than the stellar content of the galaxies. The overriding science goal of HERITAGE is to study the life cycle of matter as traced by dust in the LMC and SMC. The far-infrared and submillimeter emission is an effective tracer of the interstellar medium (ISM) dust, the most deeply embedded young stellar objects (YSOs) and the dust ejected by the most massive stars which are discussed briefly in this review. The HERITAGE team has delivered the maps and source catalogs created for each of the 5 bands to the Herschel Science Center archive which will hold the legacy of Herschel.

  11. Laboratory Astrophysics Needs of the Herschel Space Observatory

    NASA Technical Reports Server (NTRS)

    Pearson, J. C.

    2002-01-01

    The science teams of the Herschel Space Observatory have identified a number of areas where laboratory study is required for proper interpretation of Herschel observational data. The most critical is the collection and compilation of laboratory data on spectral line frequencies, transition probabilities and energy levels for the known astrophysical atomic and molecular species in 670 to 57 micron wavelength range of Herschel. The second most critical need is the compilation of collisional excitation cross sections for the species known to dominate the energy balance in the ISM and the temperature dependent chemical reaction rates. On the theoretical front, chemical and radiative transfer models need to be prepared in advance to assess calibration and identify instrument anomalies. In the next few years there will be a need to incorporate spectroscopists and theoretical chemists into teams of astronomers so that the spectroscopic surveys planned can he properly calibrated and rapidly interpreted once the data becomes available. The science teams have also noted that the enormous prospects for molecular discovery will be greatly handicapped by the nearly complete lack of spectroscopic data for anything not already well known in the ISM. As a minimum, molecular species predicted to exist by chemical models should be subjected to detailed laboratory study to ensure conclusive detections. This has the greatest impact on any astrobiology program that might be proposed for Herschel. Without a significant amount of laboratory work in the very near future Herschel will not be prepared for many planned observations, much less addressing the open questions in molecular astrophysics.

  12. Laboratory Astrophysics Needs of the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Pearson, J. C.

    2002-11-01

    The science teams of the Herschel Space Observatory have identified a number of areas for laboratory study required for proper interpretation of Herschel observational data. The most critical is the collection and compilation of laboratory data on spectral line frequencies, transition probabilities and energy levels for the known astrophysical atomic and molecular species in 670 to 57 micron wavelength range of Herschel. The second most critical need is the compilation of collisional excitation cross sections for the species known to dominate the energy balance in the ISM and the temperature dependent chemical reaction rates. On the theoretical front chemical and radiative transfer models need to be prepared in advance to assess calibration and identify instrument anomalies. In the next few years there will be a need to incorporate spectroscopists and theoretical chemists into teams of astronomers so that the spectroscopic surveys planned can be properly calibrated and rapidly interpreted once the data becomes available. The science teams have also noted that the enormous prospects for molecular discovery will be greatly handicapped by the nearly complete lack of spectroscopic data for anything not already well known in the ISM. As a minimum, molecular species predicted to exist by chemical models should be subjected to detailed laboratory study to ensure conclusive detections. This has the greatest impact on any astrobiology program that might be proposed for Herschel. Without a significant amount of laboratory work in the very near future Herschel will not be prepared for many planned observations, much less addressing the open questions in molecular astrophysics.

  13. Charles Darwin and John Herschel

    NASA Astrophysics Data System (ADS)

    Warner, B.

    2009-11-01

    The influence of John Herschel on the philosophical thoughts of Charles Darwin, both through the former's book, Natural Philosophy, and through their meeting in 1836 at the Cape of Good Hope, is discussed. With Herschel having himself speculated on evolution just a few months before he met Darwin, it is probable that he stimulated at least the beginnings of the latter's lifelong work on the subject.

  14. An analysis of the first two years of GASP data. [Global Atmospheric Sampling Program

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Nastrom, G. D.; Falconer, P. D.

    1978-01-01

    Distributions of mean ozone levels from the first two years of data from the NASA Global Atmospheric Sampling Program (GASP) show spatial and temporal variations in agreement with previous measurements. The standard deviations of these distributions reflect the large natural variability of ozone levels in the altitude range of the GASP measurements. Monthly mean levels of ozone below the tropopause show an annual cycle with a spring maximum which is believed to result from transport from the stratosphere. Correlations of ozone with independent meteorological parameters, and meteorological parameters obtained by the GASP systems show that this transport occurs primarily through cyclogenesis at mid-latitudes. The GASP water vapor data, analyzed with respect to the location of the tropopause, correlates well with the simultaneously obtained ozone and cloud data.

  15. NASA Global Atmospheric Sampling Program (GASP) data report for tapes VL0007 and VL0008

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Gauntner, D. J.; Humenik, F. M.; Briehl, D.

    1977-01-01

    The Global Atmospheric Sampling Program (GASP) is obtaining measurements of atmospheric trace constituents in the upper troposphere and lower stratosphere using fully automated air sampling systems on board the NASA CV-990 research aircraft and four commerical B-747 aircraft in routine airline service. In-situ measurements of atmospheric ozone and water vapor, data from laboratory analysis of filters exposed in flight, and related flight and meteorological data obtained from September 1976 through January 1977 are reported. These data are now available on GASP tapes VL0007 & VL0008 from the National Climatic Center, Asheville, North Carolina. In addition to the GASP data, tropopause pressure fields obtained from NMC archives for the dates of the GASP flights are included on the data tape. Flight routes and dates, instrumentation, data processing procedures, and data tape specifications are described.

  16. Alternative binding modes identified for growth and differentiation factor-associated serum protein (GASP) family antagonism of myostatin.

    PubMed

    Walker, Ryan G; Angerman, Elizabeth B; Kattamuri, Chandramohan; Lee, Yun-Sil; Lee, Se-Jin; Thompson, Thomas B

    2015-03-20

    Myostatin, a member of the TGF-β family of ligands, is a strong negative regulator of muscle growth. As such, it is a prime therapeutic target for muscle wasting disorders. Similar to other TGF-β family ligands, myostatin is neutralized by binding one of a number of structurally diverse antagonists. Included are the antagonists GASP-1 and GASP-2, which are unique in that they specifically antagonize myostatin. However, little is known from a structural standpoint describing the interactions of GASP antagonists with myostatin. Here, we present the First low resolution solution structure of myostatin-free and myostatin-bound states of GASP-1 and GASP-2. Our studies have revealed GASP-1, which is 100 times more potent than GASP-2, preferentially binds myostatin in an asymmetrical 1:1 complex, whereas GASP-2 binds in a symmetrical 2:1 complex. Additionally, C-terminal truncations of GASP-1 result in less potent myostatin inhibitors that form a 2:1 complex, suggesting that the C-terminal domains of GASP-1 are the primary mediators for asymmetric complex formation. Overall, this study provides a new perspective on TGF-β antagonism, where closely related antagonists can utilize different ligand-binding strategies. PMID:25657005

  17. Alternative Binding Modes Identified for Growth and Differentiation Factor-associated Serum Protein (GASP) Family Antagonism of Myostatin*

    PubMed Central

    Walker, Ryan G.; Angerman, Elizabeth B.; Kattamuri, Chandramohan; Lee, Yun-Sil; Lee, Se-Jin; Thompson, Thomas B.

    2015-01-01

    Myostatin, a member of the TGF-β family of ligands, is a strong negative regulator of muscle growth. As such, it is a prime therapeutic target for muscle wasting disorders. Similar to other TGF-β family ligands, myostatin is neutralized by binding one of a number of structurally diverse antagonists. Included are the antagonists GASP-1 and GASP-2, which are unique in that they specifically antagonize myostatin. However, little is known from a structural standpoint describing the interactions of GASP antagonists with myostatin. Here, we present the First low resolution solution structure of myostatin-free and myostatin-bound states of GASP-1 and GASP-2. Our studies have revealed GASP-1, which is 100 times more potent than GASP-2, preferentially binds myostatin in an asymmetrical 1:1 complex, whereas GASP-2 binds in a symmetrical 2:1 complex. Additionally, C-terminal truncations of GASP-1 result in less potent myostatin inhibitors that form a 2:1 complex, suggesting that the C-terminal domains of GASP-1 are the primary mediators for asymmetric complex formation. Overall, this study provides a new perspective on TGF-β antagonism, where closely related antagonists can utilize different ligand-binding strategies. PMID:25657005

  18. GASPS: A time-dependent, one-dimensional, planar gas dynamics computer code

    SciTech Connect

    Pierce, R.E.; Sutton, S.B.; Comfort, W.J. III

    1986-12-05

    GASP is a transient, one-dimensional planar gas dynamic computer code that can be used to calculate the propagation of a shock wave. GASP, developed at LLNL, solves the one-dimensional planar equations governing momentum, mass and energy conservation. The equations are cast in an Eulerian formulation where the mesh is fixed in space, and material flows through it. Thus it is necessary to account for convection of material from one cell to its neighbor.

  19. The Newly-named "Herschel Space Observatory" revisits its science goals

    NASA Astrophysics Data System (ADS)

    2000-12-01

    In science, new answers often trigger new questions. And in astronomy, new questions often mean new instruments. The ESA 'Herschel Space Observatory', formerly called 'Far Infrared and Submillimetre Telescope' (FIRST), is the instrument that inherits many of the questions triggered by its predecessor, ESA's Infrared Space Observatory (ISO). 200 astronomers from all over the world met last week in Toledo, Spain, to discuss how to insert these new questions in Herschel's 'scientific agenda'. Thus, Herschel will study the origin of stars and galaxies -its main goals-, but it will also keep on searching for water in space -as ISO did-, and will help us to understand the formation of our own Solar System through detailed observations of comets and of the poorly known 'transneptunian objects'. A new name for 'FIRST' The new name for FIRST, 'Herschel Space Observatory', or 'Herschel', was announced at the opening of the Toledo conference by ESA's Director of Science, Roger Bonnet. William Herschel was an Anglo-German astronomer who discovered infrared light in 1800. Thanks to his discovery, astronomers can now observe a facet of the Universe that remains hidden to other telescopes. ESA's Herschel is the first space observatory covering a major part of the far-infrared and submillimetre waveband (from 57 to 670 microns) and its new name honours Herschel on the 200th anniversary of his discovery. Roger Bonnet explained: "It strikes me that we are at a key scientific conference devoted to the next ESA infrared space mission, gathering many 'infrared pioneers', 200 years after a famous musician and astronomer discovered that by placing a thermometer in the remote part of the solar spectrum, where apparently there was no light, he could detect heat. What we call now infrared radiation. This meeting marks two events: the beginning of a very promising utilisation of FIRST, and the adoption of a new name for the telescope: the Herschel Space Observatory". Roger Bonnet also

  20. The REAL Caroline Herschel

    NASA Astrophysics Data System (ADS)

    Hoskin, M. A.

    2003-12-01

    Caroline Herschel (1750-1848) is famous as the discoverer of eight comets, and the author of an Index to Flamsteed's British Catalogue of Stars, which the Royal Society published at its own expense. She was the devoted collaborator of her brother William during the twenty years he spent 'sweeping' for nebulae; and in old age she reorganized William's 2500 nebulae into a zone catalog that enabled his son John to re-examine these objects systematically, a work for which she was awarded a Gold Medal of the RAS. Nevertheless, study of her autobiographies and other manuscripts shows that her attitude to astronomy was ambivalent. William had rescued her from drudgery in Hanover, and her primary concern was to express her gratitude to him, even when his interests turned from music to astronomy and as a result she was required to abandon her career as a singer. Yet although the decision was hers, she often resented the sacrifice she had made. She emerges as a complex and often troubled personality, very different from the serene observer of legend.

  1. Results from the Herschel Oxygen Project

    NASA Astrophysics Data System (ADS)

    Goldsmith, Paul; Herschel Oxygen Project HOP Team

    2011-01-01

    Oxygen is the third most abundant element in the cosmos. In the gas phase, oxygen can be ionized, atomic, or in molecular, and it is also incorporated into grains. Gas-phase chemistry models predict molecular oxygen (O2) to be almost as abundant as carbon monoxide (CO). A number of searches for molecular oxygen have been carried out, including ground-based searches for the isotopologue 16O18O and searches for O2 in redshifted galaxies. Searches for Galactic O2 carried out with the SWAS and Odin spacecraft have yielded upper limits on the abundance of molecular oxygen typically 1 to 2 orders of magnitude below those predicted by gas-phase models. There has been a fairly clear detection of O2 in one source, again indicating a low abundance. A variety of explanations have been proposed to explain this low abundance. Some of these are based on depletion of atomic oxygen onto dust grains, resulting in incorporation of this species into water that remains on the grain surface. Available gas-phase oxygen is largely incorporated into CO, leaving little for gas-phase O2. Other models involve circulation of material between UV-irradiated and well-shielded regions. The Herschel Open Time Key Project HOP (Herschel Oxygen Project) addresses this important problem in astrochemistry, exploiting the high angular resolution and sensitivity of the Herschel HIFI instrument to observe 3 rotational transitions of O2 in a broad sample of molecular clouds. The sensitivity and angular resolution of HIFI is a dramatic improvement over anything previously available at these frequencies. These data should, whether yielding detections or significantly improved upper limits, provide critical information about interstellar chemistry and the structure of these varied molecular regions. We will discuss the HOP observations to date including exceptionally low upper limits to the abundance of O2 as well as some provocative, tentative positive results.

  2. John Herschel and astronomy: a bicentennial appraisal.

    NASA Astrophysics Data System (ADS)

    Hoskin, M. A.

    An assessment is given of John Herschel's overall contributions to nineteenth century astronomy. John Herschel built on his pioneering father William Herschel's foundations, with revisions and extensions to the southern hemisphere. His work, incorporated into his general treatises on astronomy, had a major influence on the direction of astronomical progress.

  3. John Herschel: Britain's first modern physical scientist.

    NASA Astrophysics Data System (ADS)

    Crowe, M. J.

    The author presents a sketch of the life and contributions to science of Sir John F. W. Herschel (1792 - 1871). One of the theses he develops is that John Herschel can meaningfully be described as Britain's first modern physical scientist. In addition to developing this thesis, the author makes some remarks about lesser known aspects of Herschel's life.

  4. HERSCHEL/PACS SURVEY OF PROTOPLANETARY DISKS IN TAURUS/AURIGA—OBSERVATIONS OF [O I] AND [C II], AND FAR-INFRARED CONTINUUM

    SciTech Connect

    Howard, Christian D.; Sandell, Göran; Vacca, William D.; Duchêne, Gaspard; Mathews, Geoffrey; Augereau, Jean-Charles; Ménard, Francois; Pinte, Christophe; Podio, Linda; Thi, Wing-Fai; Dent, William R. F.; Eiroa, Carlos; Meeus, Gwendolyn; Grady, Carol; Roberge, Aki; Kamp, Inga; Vicente, Silvia; Williams, Jonathan P.

    2013-10-10

    The Herschel Space Observatory was used to observe ∼120 pre-main-sequence stars in Taurus as part of the GASPS Open Time Key project. Photodetector Array Camera and Spectrometer was used to measure the continuum as well as several gas tracers such as [O I] 63 μm, [O I] 145 μm, [C II] 158 μm, OH, H{sub 2}O, and CO. The strongest line seen is [O I] at 63 μm. We find a clear correlation between the strength of the [O I] 63 μm line and the 63 μm continuum for disk sources. In outflow sources, the line emission can be up to 20 times stronger than in disk sources, suggesting that the line emission is dominated by the outflow. The tight correlation seen for disk sources suggests that the emission arises from the inner disk (<50 AU) and lower surface layers of the disk where the gas and dust are coupled. The [O I] 63 μm is fainter in transitional stars than in normal Class II disks. Simple spectral energy distribution models indicate that the dust responsible for the continuum emission is colder in these disks, leading to weaker line emission. [C II] 158 μm emission is only detected in strong outflow sources. The observed line ratios of [O I] 63 μm to [O I] 145 μm are in the regime where we are insensitive to the gas-to-dust ratio, neither can we discriminate between shock or photodissociation region emission. We detect no Class III object in [O I] 63 μm and only three in continuum, at least one of which is a candidate debris disk.

  5. Herschel - PACS Survey Of Protoplanetary Disks In Taurus - Auriga Observations Of [O I] And [C Ii], And Far-Infrared Continuum

    NASA Technical Reports Server (NTRS)

    Howard, Christian; Sandell, Goeran; Vacca, William D.; Duchene, Gaspard; Matthews, Geoffrey; Augereau, Jean-Charles; Barbado, David; Dent, William R. F.; Eiroa, Carlos; Grady, Carol; Kamp, Inga; Meeus, Gwendolyn; Menard, Francois; Pinte, Christophe; Podio, Linda; Riviere-Marichalar, Pablo; Roberge, Aki; Thi,, Wing-Fai; Vicente, Silvia; Williams, Jonathan P.

    2013-01-01

    The Herschel Space Observatory was used to observe approx. 120 pre-main-sequence stars in Taurus as part of the GASPS Open Time Key project. Photodetector Array Camera and Spectrometer was used to measure the continuum as well as several gas tracers such as [O I] 63 micron, [O I] 145 micron, [C II] 158, micron OH, H2O, and CO. The strongest line seen is [O I] at 63 micron. We find a clear correlation between the strength of the [O I] 63 micron line and the 63 micron continuum for disk sources. In outflow sources, the line emission can be up to 20 times stronger than in disk sources, suggesting that the line emission is dominated by the outflow. The tight correlation seen for disk sources suggests that the emission arises from the inner disk (<50 AU) and lower surface layers of the disk where the gas and dust are coupled. The [O I] 63 micron is fainter in transitional stars than in normal Class II disks. Simple spectral energy distribution models indicate that the dust responsible for the continuum emission is colder in these disks, leading to weaker line emission. [C II] 158 micron emission is only detected in strong outflow sources. The observed line ratios of [O I] 63 micron to [O I] 145 micron are in the regime where we are insensitive to the gas-to-dust ratio, neither can we discriminate between shock or photodissociation region emission. We detect no Class III object in [O I] 63 micron and only three in continuum, at least one of which is a candidate debris disk.

  6. Exploring New Spectral Windows with the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Bergin, Edwin A.

    2011-10-01

    The Herschel Space Observatory, an ESA cornerstone mission with NASA participation, has been in operation for over a year. I will briefly outline the overall capabilities of Herschel which has both photometric and spectroscopic coverage from 63 to 610 microns. Herschel offers unprecedented sensitivity as well as continuous spectral coverage across the gaps imposed by the atmosphere, opening up a largely unexplored wavelength regime to high resolution spectroscopy. In particular, I will present and discuss the most complete molecular spectrum of star-forming gas ever obtained in the spectrum of Orion KL and the galactic center molecular cloud Sagittarius B2. These spectra have over 1.4 THz of bandwidth and a resolution of 1 MHz. We estimate that there are over 100,000 spectral lines alone in the Orion KL spectrum with numerous lines of water vapor, ammonia, sulfur-bearing molecules, and numerous organics. I will demonstrate the power of molecular spectroscopy in characterizing the physical state of dense gas near massive stars through the perspective offered by observations of hundreds of lines of a single molecule and our new ability to peer through the Milky Way to reveal a hidden molecular phase. I will show how the spectra provide a near complete chemical assay and cooling census of star-forming gas. Ultimately the gains from Herschel have tremendous potential to extend our understanding of the physics of star birth and feedback while informing on the origin of water and organics in space.

  7. Carotid chemoreceptors do not mediate hypoxic-induced gasping and autoresuscitation in newborn rats.

    PubMed

    Lun, Rongzhi; Zhang, Chunfen; Fewell, James E

    2015-07-01

    Experiments were carried out on 48, 5-6-day-old rat pups to investigate the influence of carotid denervation on their time to last gasp during a single period of hypoxia, and on their ability to autoresuscitate from primary apnea during repeated hypoxic challenge. One group of pups was studied with intact carotid chemoreceptors and one group was studied following surgical denervation of the carotid chemoreceptors. Carotid denervation eliminated the early tachypneic phase during exposure to hypoxia and delayed the time to arousal/excitement but did not alter the time to primary apnea, the time to last gasp or the total number of gasps during exposure to a single period of unrelenting hypoxia. Furthermore, carotid denervation did not alter the number of successful autoresuscitations from primary apnea during repeated hypoxic exposure. Thus, the carotid chemoreceptors are not essential for the initiation or maintenance of gasping nor are they are integral to gasping effecting successful autoresuscitation from hypoxic-induced apnea in newborn rats. PMID:25907031

  8. The Herschel knighthoods under scrutiny

    NASA Astrophysics Data System (ADS)

    Hoskin, Michael

    2013-06-01

    William Herschel and his son John, respectively the first and fourth Presidents of the Royal Astronomical Society, were each "knights" of the Royal Hanoverian Guelphic Order and were (and are) commonly referred to as "Sir". But, as Michael Hoskin explains, the Guelphic Order, being foreign, in fact conferred no title on British holders.

  9. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0005

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Humenik, F. M.

    1977-01-01

    Atmospheric ozone, water vapor, and related flight and meteorological data were obtained during 214 flights of a United Airlines B-747 and two Pan American World Airways B-747's from March through June 1976. In addition, trichlorofluoromethane data obtained from laboratory analysis of two whole air samples collected in flight are reported. These data are available on GASP tape VL0005 from the National Climatic Center, Asheville, North Carolina. In addition to the GASP data, tropopause pressure fields obtained from NMC archives for the dates of the GASP flights are included on the data tape. Flight routes and dates, instrumentation, data processing procedures, and data tape specifications are described in this report. Selected analyses including ozone and sample bottle data are also presented.

  10. NASA Global Atmospheric Sampling Program (GASP) data report for tapes VL0010 and VL0012

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Dudzinski, T. J.; Tiefermann, M. W.; Nyland, T. W.

    1979-01-01

    The GASP atmospheric trace constituent data currently available are considered. Included on tapes are in-situ measurements of atmospheric ozone, carbon monoxide, water vapor, and clouds, data from laboratory analysis of filters exposed in flight, and related flight and meteorological data. Measurements of ozone levels within the first class cabin of these aircraft are also reported. In addition to the GASP data, tropopause pressures obtained from time and space interpolation of NMC archived data for the dates of the flights are included. Reported herein are the flight routes and dates, instrumentation, data processing procedures, data tape specifications, and analyses of the cabin ozone measurements.

  11. Subsea processing and control system in the GASP project; Testing of the prototype system

    SciTech Connect

    Nordvik, H.S. )

    1992-03-01

    The subsea production and processing system developed under the Goodfellow Assocs. Subsea Production (GASP) project involved two stages of separation that led to the production of exportable-quality crude oil by pipeline. The produced gas is transported along a separate line. This paper described key elements of the subsea process system. A prototype system was developed during the second phase of the project. The system was tested under dry and submerged conditions in a dry dock. Key features of the prototype system and the tests carried out are described. Prototype testing proved the viability of the GASP system and helped identify areas requiring particular attention and improvement for future applications.

  12. Ozone contamination in aircraft cabins: Results from GASP data and analyses

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Nastrom, G. D.

    1981-01-01

    The global atmospheric sampling program pertaining to the problem of ozone contamination in commercial airplane cabins is described. Specifically, analyses of GASP data have: confirmed the occurrence of high ozone levels in aircraft cabins and documented the ratio of ozone inside and outside the cabins of two B747 airliners, including the effects of air conditioning modifications on that ratio; defined ambient ozone climatology at commercial airplane cruise altitudes, including tabulation of encounter frequency data which were not available before GASP; and outlined procedures for estimating the frequency of flights encountering high cabin ozone levels using climatological ambient ozone data, and verified these procedures against cabin measurements.

  13. Ozone contamination in aircraft cabins - Results from GASP data and analyses

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Nastrom, G. D.

    1981-01-01

    The paper reviews results from the NASA Global Atmospheric Sampling Program (GASP) pertaining to the problem of ozone contamination in commercial aircraft cabins. Specifically, analyses of GASP data have (1) confirmed the high ozone levels in aircraft cabins and documented the ratio of ozone inside and outside the cabins of two B747 airliners, including the effects of air conditioning modifications on that ratio; (2) defined ambient ozone climatology at commercial aircraft cruise altitudes, including tabulation of encounter frequency data; and (3) outlined procedures for estimating the frequency of flights encountering high cabin ozone levels using climatological ambient ozone data and verified these procedures against cabin measurements.

  14. A comparison of the pharmacophore identification programs: Catalyst, DISCO and GASP.

    PubMed

    Patel, Yogendra; Gillet, Valerie J; Bravi, Gianpaolo; Leach, Andrew R

    2002-01-01

    Three commercially available pharmacophore generation programs, Catalyst/HipHop, DISCO and GASP, were compared on their ability to generate known pharmacophores deduced from protein-ligand complexes extracted from the Protein Data Bank. Five different protein families were included Thrombin, Cyclin Dependent Kinase 2, Dihydrofolate Reductase, HIV Reverse Transcriptase and Thermolysin. Target pharmacophores were defined through visual analysis of the data sets. The pharmacophore models produced were evaluated qualitatively through visual inspection and according to their ability to generate the target pharmacophores. Our results show that GASP and Catalyst outperformed DISCO at reproducing the five target pharmacophores. PMID:12602956

  15. The Cosmology of William Herschel

    NASA Astrophysics Data System (ADS)

    Hoskin, M.

    2009-08-01

    William Herschel was an amateur astronomer for half his life, until his discovery of Uranus earned him a royal pension. He then set himself to study "the construction of the heavens" with great reflectors, and discovered over 2,500 nebulae and star clusters. Clusters had clearly formed by the action of gravity, and so scattered clusters would in time become ever more compressed: scattered clusters were young, compressed clusters old. This marked the end of the 'clockwork' universe of Newton and Leibniz.

  16. Herschel flight models sorption coolers

    NASA Astrophysics Data System (ADS)

    Duband, L.; Clerc, L.; Ercolani, E.; Guillemet, L.; Vallcorba, R.

    2008-03-01

    The Herschel and Planck satellites will be jointly launched on an ARIANE 5 in 2008. The Herschel payload consists of three instruments built by international scientific consortia, heterodyne instrument for first (HIFI), photo-conductor array camera and spectrometer (PACS) and spectral and photometric imaging receiver (SPIRE). The spacecraft provides the environment for astronomical observations in the infrared and sub-millimeter wavelength range requiring cryogenic temperatures for the cold focal plane units. The spectral and photometric imaging receiver (SPIRE) will cover the 200-670 μm spectral range using bolometric detectors, as the photo-conductor array camera and spectrometer (PACS) will cover the 60-210 μm spectral range. Both instruments SPIRE and PACS feature detectors operating at 300 mK. This cooling will be effected by two helium sorption coolers developed at the Service des Basses Températures of the Commissariat à l'Energie Atomique (CEA-SBT). These coolers based on an evaporative cooling cycle features no moving parts and can be recycled indefinitely pending the availability of a cold heat sink at temperature below 3 K. Several models were developed in the course of the Herschel program and this paper deals with the design, manufacturing and qualification of the flight model coolers.

  17. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0009

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Dudzinski, T. J.; Nyland, T. W.; Tiefermann, M. W.

    1978-01-01

    The GASP atmospheric trace constituent data cover atmospheric ozone, carbon monoxide, condensation nuclei, clouds, and related meteorological and flight information obtained during October 28-31, 1977. Reported herein are flight routes and dates, instrumentation, data processing procedures, and data tape specifications.

  18. GASP - THERMODYNAMIC AND TRANSPORT PROPERTIES OF HELIUM, METHANE, NEON, NITROGEN, CARBON MONOXIDE, CARBON DIOXIDE, OXYGEN, AND ARGON

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.

    1994-01-01

    A computer program, GASP, has been written to calculate the thermodynamic and transport properties of argon, carbon dioxide, carbon monoxide, fluorine, methane, neon, nitrogen, and oxygen. GASP accepts any two of pressure, temperature, or density as input. In addition, entropy and enthalpy are possible inputs. Outputs are temperature, density, pressure, entropy, enthalpy, specific heats, expansion coefficient, sonic velocity, viscosity, thermal conductivity, and surface tension. A special technique is provided to estimate the thermal conductivity near the thermodynamic critical point. GASP is a group of FORTRAN subroutines. The user typically would write a main program that invoked GASP to provide only the described outputs. Subroutines are structured so that the user may call only those subroutines needed for his particular calculations. Allowable pressures range from 0.l atmosphere to 100 to l,000 atmospheres, depending on the fluid. Similarly, allowable pressures range from the triple point of each substance to 300 degrees K to 2000 degrees K, depending on the substance. The GASP package was developed to be used with heat transfer and fluid flow applications. It is particularly useful in applications of cryogenic fluids. Some problems associated with the liquefication, storage, and gasification of liquefied natural gas and liquefied petroleum gas can also be studied using GASP. This program is written in FORTRAN IV for batch execution and is available for implementation on IBM 7000 series computers. GASP was developed in 1971.

  19. The Herschel Point Source Catalogue

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Schulz, Bernhard; Altieri, Bruno; Calzoletti, Luca; Kiss, Csaba; Lim, Tanya; Lu, Nanyao; Paladini, Roberta; Papageorgiou, Andreas; Pearson, Chris; Rector, John; Shupe, David; Valtchanov, Ivan; Verebélyi, Erika; Xu, Kevin

    2015-08-01

    The Herschel Space Observatory was the fourth cornerstone mission in the European Space Agency (ESA) science programme with excellent broad band imaging capabilities in the submillimetre and far-infrared part of the spectrum. Although the spacecraft finished its observations in 2013, it left a large legacy dataset that is far from having been fully scrutinized and still has potential for new scientific discoveries. This is specifically true for the photometric observations of the PACS and SPIRE instruments that scanned >10% of the sky at 70, 100, 160, 250, 350 and 500 microns. Some source catalogs have already been produced by individual observing programs, but there are many observations that would never be analyzed for their full source content. To maximize the science return of the SPIRE and PACS data sets, our international team of instrument experts is in the process of building the Herschel Point Source Catalog (HPSC) from all scan map observations. Our homogeneous source extraction enables a systematic and unbiased comparison of sensitivity across the different Herschel fields that single programs will generally not be able to provide. The extracted point sources will contain individual YSOs of our Galaxy, unresolved YSO clusters in resolved nearby galaxies and unresolved galaxies of the local and distant Universe that are related to star formation. Such a huge dataset will help scientists better understand the evolution from interstellar clouds to individual stars. Furthermore the analysis of stellar clusters and the star formation on galactic scales will add more details to the understanding of star formation laws through time.We present our findings on comparison of different source detection and photometric tools. First results of the extractions are shown along with the description of our pipelines and catalogue entries. We also provide an additional science product, the structure noise map, that is used for the quality assessment of the catalogue in

  20. The Spectral and Photometric Imaging Receiver for Herschel

    NASA Astrophysics Data System (ADS)

    Lu, Nanyao Y.; Schulz, B.; Shupe, D.; Xu, C. K.; Schwartz, A.; Zhang, L.; ICC, SPIRE

    2010-01-01

    The Spectral and Photometric Imaging REceiver (SPIRE) is one of the three instruments on board the European Space Agency's Herschel Space Observatory launched on May 14, 2009. SPIRE features an imaging photometer with passbands centered at 250, 350 and 500 microns, and an imaging Fourier transform spectrometer covering the wavelength range between 194 and 672 microns. In view of its latest performance verification results, we describe the updated SPIRE instrumental capabilities, and its scientific potential. The instrument was developed by a consortium of European and American scientists, led by P.I. Prof. M. Griffin of Cardiff University (UK). The US is playing a crucial role in SPIRE, by providing its bolometer arrays (developed by Dr. J. Bock at JPL), participating in SPIRE's ground and in-flight commissioning and calibration, and in the development of the Herschel Common Science System (HCSS) data reduction software. Support for both Key and Open Time Programs of US astronomers is provided by the NASA Herschel Science Center (NHSC) at the Infrared Processing and Analysis Center (IPAC).

  1. Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets

    NASA Astrophysics Data System (ADS)

    Podio, L.; Kamp, I.; Flower, D.; Howard, C.; Sandell, G.; Mora, A.; Aresu, G.; Brittain, S.; Dent, W. R. F.; Pinte, C.; White, G. J.

    2012-09-01

    Context. Observations of the atomic and molecular line emission associated with jets and outflows emitted by young stellar objects provide sensitive diagnostics of the excitation conditions, and can be used to trace the various evolutionary stages they pass through as they evolve to become main sequence stars. Aims: To understand the relevance of atomic and molecular cooling in shocks, and how accretion and ejection efficiency evolves with the evolutionary state of the sources, we will study the far-infrared counterparts of bright optical jets associated with Class I and II sources in Taurus (T Tau, DG Tau A, DG Tau B, FS Tau A+B, and RW Aur). Methods: We have analysed Herschel/PACS observations of a number of atomic ([O i]63 μm, 145 μm, [C ii]158 μm) and molecular (high-J CO, H2O, OH) lines, collected within the open time key project GASPS (PI: W. R. F. Dent). To constrain the origin of the detected lines we have compared the obtained FIR emission maps with the emission from optical-jets and millimetre-outflows, and the measured line fluxes and ratios with predictions from shock and disk models. Results: All of the targets are associated with extended emission in the atomic lines; in particular, the strong [O i] 63 μm emission is correlated with the direction of the optical jet/mm-outflow. The line ratios suggest that the atomic lines can be excited in fast dissociative J-shocks occurring along the jet. The molecular emission, on the contrary, originates from a compact region, that is spatially and spectrally unresolved, and lines from highly excited levels are detected (e.g., the o-H2O 818-707 line, and the CO J = 36-35 line). Disk models are unable to explain the brightness of the observed lines (CO and H2O line fluxes up to 10-15-6 × 10-16 W m-2). Slow C- or J-shocks with high pre-shock densities reproduce the observed H2O and high-J CO lines; however, the disk and/or UV-heated outflow cavities may contribute to the observed emission. Conclusions

  2. Time- and age-dependent effects of serotonin on gasping and autoresuscitation in neonatal mice.

    PubMed

    Chen, Jianping; Magnusson, Jennifer; Karsenty, Gerard; Cummings, Kevin J

    2013-06-15

    The role of brain stem serotonin (5-hydroxytryptamine, 5-HT) in autoresuscitation in neonatal life is unclear. We hypothesized that a specific loss of 5-HT would compromise gasping and autoresuscitation mainly in the second postnatal week and that acute restoration of 5-HT would reverse the defects. We exposed postnatal day (P)4-5, P8-9, and P11-12 tryptophan-hydroxylase-2 knockout (TPH2(-/-)) and wild-type littermates (WT) to 10 episodes of anoxia (97% N2, 3% CO2), measuring survival, gasp latency, gasp frequency (fB), and the time required to restore eupnea and heart rate. We also tested P8-9 TPH2(-/-) mice after restoring 5-HT with a single injection of 5-hydroxytryptophan (5-HTP) 1-2 h before testing or with multiple injections beginning 24 h before testing. At P4-5 and P8-9, but not at P11-12, gasp latency and the recovery of eupnea were delayed ~2- to 3-fold in TPH2(-/-) pups compared with WT (P < 0.001). At all ages, TPH2(-/-) pups displayed reduced gasp fB (~20-30%; P < 0.001) and delayed heart rate recovery (~60%; P = 0.002) compared with WT littermates. TPH2(-/-) survival was reduced compared with WT (P < 0.001), especially at P8-9 and P11-12 (P = 0.004). Whereas 1-2 h of 5-HTP treatment improved the gasp latency and fB of P8-9 TPH2(-/-) pups, improved cardiorespiratory recovery and survival required 24 h of treatment. Our data suggest that 5-HT operates over a long time span (24 h) to improve survival during episodic severe hypoxia. Early in development (P4-9), 5-HT is critical for both respiratory and cardiovascular components of autoresuscitation; later (P11-12), it is critical mainly for cardiovascular components. Nevertheless, the effect of 5-HT deficiency on survival is most striking from P8 to P12. PMID:23558391

  3. HERSCHEL OBSERVATIONS OF CATACLYSMIC VARIABLES

    SciTech Connect

    Harrison, Thomas E.; Hamilton, Ryan T.; Tappert, Claus; Hoffman, Douglas I.; Campbell, Ryan K. E-mail: rthamilt@nmsu.edu E-mail: dhoffman@ipac.caltech.edu

    2013-01-01

    We have used the PACS instrument on the Herschel Space Observatory to observe eight cataclysmic variables at 70 and 160 {mu}m. Of these eight objects, only AM Her was detected. We have combined the Herschel results with ground-based, Spitzer, and WISE observations to construct spectral energy distributions for all of the targets. For the two dwarf novae in the sample, SS Cyg and U Gem, we find that their infrared luminosities are completely dominated by their secondary stars. For the two highly magnetic 'polars' in our survey, AM Her and EF Eri, we find that their mid-infrared excesses, previously attributed to circumbinary dust emission, can be fully explained by cyclotron emission. The WISE light curves for both sources show large, orbitally modulated variations that are identically phased to their near-IR light curves. We propose that significant emission from the lowest cyclotron harmonics (n {<=} 3) is present in EF Eri and AM Her. Previously, such emission would have been presumed to be optically thick, and not provide significant orbitally modulated flux. This suggests that the accretion onto polars is more complicated than assumed in the simple models developed for these two sources. We develop a model for the near-/mid-IR light curves for WZ Sge with an L2 donor star that shows that the ellipsoidal variations from its secondary star are detected. We conclude that none of the targets surveyed have dusty circumbinary disks.

  4. Cirrus cloud spectra and layers observed during the FIRE and GASP projects

    NASA Technical Reports Server (NTRS)

    Flatau, Piotr J.; Gultepe, I.; Nastrom, G.; Cotton, William R.; Heymsfield, A. J.

    1990-01-01

    A general characterization is developed for cirrus clouds in terms of their spectra, shapes, optical thicknesses, and radiative properties for use in numerical models. Data sets from the Global Atmospheric Sampling Project (GASP) of the upper troposphere and the First ISCCP Regional Experiment (FIRE) are combined and analyzed to study general traits of cirrus clouds. A definition is given for 2D turbulence, and the GASP and FIRE data sets are examined with respect to cirrus layers and entrainment and to dominant turbulent scales. The approach employs conditional sampling in cloudy and clear air, power-spectral analysis, and mixing-line-type diagrams. Evidence is given for a well mixed cloud deck and for the tendency of cirrus to be formed in multilayer structures. The results are of use in mesoscale and global circulation models which predict cirrus, in small-scale cirrus modeling, and in studying the role of gravity waves in the horizontal structure of upper tropospheric clouds.

  5. Temperature histories of commercial flights at severe conditions from GASP data

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastrom, G. D.

    1983-01-01

    The thermal environment of commercial aircraft from a data set gathered during the Global Atmospheric Sampling Program (GASP) is studied. The data set covers a four-year period of measurements. The report presents plots of airplane location and speed and atmospheric temperature as functions of elapsed time for 35 extreme-condition flights, selected by minimum values of several temperature parameters. One of these parameters, the severity factor, is an approximation of the in-flight wing-tank temperature. Representative low-severity-factor flight histories may be useful for actual temperature-profile inputs to design and research studies. Comparison of the GASP atmospheric temperatures to interpolated temperatures from National Meteorological Center and Global Weather Central analysis fields shows that the analysis temperatures are slightly biased toward warmer than actual temperatures, particularly over oceans and at extreme conditions.

  6. Simultaneous measurements of carbon monoxide and ozone in the NASA Global Atmospheric Sampling Program (GASP)

    NASA Technical Reports Server (NTRS)

    Newell, R. E.; Wu, M.-F.

    1985-01-01

    It is noted that the Global Atmospheric Sampling Program (GASP) was intended to establish global baseline values of selected atmospheric constituents that could be used for studies of the dynamics of the sampled region as well as for modeling purposes. Instrument packages were carried on four Boeing 747 aircraft in routine commercial service. Carbon monoxide and ozone data were collected simultaneously from early 1977 to early 1979 when GASP terminated. CO was measured with an infrared absorption analyzer using dual isotope fluorescence. Ozone was measured via absorption of UV light. Correlations between the CO and the O3 are tabulated; they are clearly negative for both troposphere and stratosphere in middle latitudes, indicating that transport processes between the stratosphere and troposphere (discussed) dominate. But in the low latitude troposphere the correlations are positive, indicating the possible influence of photochemical effects.

  7. Near-IR brightening of the blazar CTA 102 (2230+114) observed by the GASP

    NASA Astrophysics Data System (ADS)

    Carnerero, M. I.; Acosta-Pulido, J. A.; Arevalo, M. J.; Bueno, A.; Gonzalez, A. I.; Puerto-Gimenez, I.; Raiteri, C. M.; Villata, M.; GASP Collaboration

    2012-06-01

    The GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) reports on the recent observation of a strong near-IR brightening of the gamma-loud quasar CTA 102. This is one of the 28 blazars for which the GASP performs a long-term, multiwavelength monitoring. Observations performed at the Teide Observatory on 2012 June 5.2 UT revealed J = 14.02 +/- 0.02, H = 13.19 +/- 0.02, and Ks = 12.36 +/- 0.02, compared to J = 15.42 +/- 0.04, H = 14.99 +/- 0.04, and Ks = 14.30 +/- 0.06 measured on 2011 December 5.9 UT.

  8. Recent results at the N = Z line with GASP and EUROBALL

    SciTech Connect

    Farnea, E.

    2004-02-27

    Valuable information on the validity of the isospin symmetry was obtained by studying nuclei close to the N = Z line with the GASP and EUROBALL {gamma}-ray spectrometres coupled to ancillary devices. Here a few selected results on the study of mirror nuclei are presented, together with an estimate of the isospin mixing probability through the measurement of a forbidden E1 transition in 64Ge.

  9. Introducing the GASP scale: a new measure of guilt and shame proneness.

    PubMed

    Cohen, Taya R; Wolf, Scott T; Panter, A T; Insko, Chester A

    2011-05-01

    Although scholars agree that moral emotions are critical for deterring unethical and antisocial behavior, there is disagreement about how 2 prototypical moral emotions--guilt and shame--should be defined, differentiated, and measured. We addressed these issues by developing a new assessment--the Guilt and Shame Proneness scale (GASP)--that measures individual differences in the propensity to experience guilt and shame across a range of personal transgressions. The GASP contains 2 guilt subscales that assess negative behavior-evaluations and repair action tendencies following private transgressions and 2 shame subscales that assess negative self-evaluations (NSEs) and withdrawal action tendencies following publically exposed transgressions. Both guilt subscales were highly correlated with one another and negatively correlated with unethical decision making. Although both shame subscales were associated with relatively poor psychological functioning (e.g., neuroticism, personal distress, low self-esteem), they were only weakly correlated with one another, and their relationships with unethical decision making diverged. Whereas shame-NSE constrained unethical decision making, shame-withdraw did not. Our findings suggest that differentiating the tendency to make NSEs following publically exposed transgressions from the tendency to hide or withdraw from public view is critically important for understanding and measuring dispositional shame proneness. The GASP's ability to distinguish these 2 classes of responses represents an important advantage of the scale over existing assessments. Although further validation research is required, the present studies are promising in that they suggest the GASP has the potential to be an important measurement tool for detecting individuals susceptible to corruption and unethical behavior. PMID:21517196

  10. Theory, design, and simulation of GASP: A block data flow architecture for gallium arsenide supercomputers

    SciTech Connect

    Fouts, D.J.

    1990-01-01

    The advantages and disadvantages of using high-speed gallium arsenide (GaAs) logic for implementing digital systems are reviewed. A set of design guidelines is presented for systems that will be constructed with high-speed technologies such as GaAs and silicon emitter coupled logic (ECL). A new class of computer and digital system architectures, known as functionally modular architectures, is defined and explained. Functionally modular architectures are ideal for implementation in GaAs because they adhere to the design guidelines. GASP, a new, functionally modular, block data flow computer architecture is then described. SPICE simulations indicate that if constructed with existing GaAs IC technology, parts of GASP could run at a clock speed of 1 GHz, with the rest of the architecture using a 500 MHz clock. The new architecture uses data flow techniques at a program block level, which allows efficient execution of parallel programs while maintaining reasonably good performance on sequential programs. A simulation study of the architecture's best case and worst case performance is presented. Simulations of GASP executing a highly parallel program indicate that an instruction execution rate of over 30,000 MIPS can be attained with a 65 processor system.

  11. Summary of the GASP code application and evaluation effort for scramjet combustor flowfields

    NASA Technical Reports Server (NTRS)

    Srinivasan, Shivakumar; Bittner, Robert D.; Bobskill, Glenn J.

    1993-01-01

    Numerical simulations of 3D turbulent mixing and reacting flows have been systematically evaluated by comparison with experimental data and other numerical solutions to provide confidence in the General Aerodynamic Simulation Program (GASP) code version 1.3. Specifically, the GASP flow solver has been used to model high speed flow through scram jet combustors. Unit injector problems evaluated include (1) UVA staged sonic normal injection of air into Mach 2 air stream, (2) the VPI Mach 1.7 low angled (15 deg) flush wall helium injection into an unconfined Mach 6 'cold air' stream, and (3) the HYPULSE angled (30 deg) flush wall hydrogen injection into a Mach 6, high enthalpy (flight Mach 17 simulation) nitrogen and air test gases. Results of the numerical simulation for the first two test cases have been compared with detailed in-stream measurements and with SPARK CFD solutions. The results for the last two cases have been compared with measured wall pressure and heat flux data and with SPARK CFD solutions. The present GASP solutions compare favorably with both the experimental data and the SPARK solutions.

  12. Caroline Herschel: 'the unquiet heart'.

    PubMed

    Hoskin, Michael

    2005-03-01

    Caroline Herschel was famous in her own time as the discoverer of eight comets, but of even greater significance was the help she gave her brother William in his exploration of 'the construction of the heavens'. She acted as his amanuensis during night watches, wrote up neat copies of their observing records and prepared his papers for publication. She also compiled an index to John Flamsteed's Star Catalogue, which was published by the Royal Society at its own expense, and after William's death she reorganized his catalogues of nebulae so that his son John could revise his father's work. Yet Caroline's was a hard and largely loveless life, for which she found the recognition that came her way a scant consolation. PMID:15749149

  13. Change in network connectivity during fictive-gasping generation in hypoxia: prevention by a metabolic intermediate

    PubMed Central

    Nieto-Posadas, Andrés; Flores-Martínez, Ernesto; Lorea-Hernández, Jonathan-Julio; Rivera-Angulo, Ana-Julia; Pérez-Ortega, Jesús-Esteban; Bargas, José; Peña-Ortega, Fernando

    2014-01-01

    The neuronal circuit in charge of generating the respiratory rhythms, localized in the pre-Bötzinger complex (preBötC), is configured to produce fictive-eupnea during normoxia and reconfigures to produce fictive-gasping during hypoxic conditions in vitro. The mechanisms involved in such reconfiguration have been extensively investigated by cell-focused studies, but the actual changes at the network level remain elusive. Since a failure to generate gasping has been linked to Sudden Infant Death Syndrome (SIDS), the study of gasping generation and pharmacological approaches to promote it may have clinical relevance. Here, we study the changes in network dynamics and circuit reconfiguration that occur during the transition to fictive-gasping generation in the brainstem slice preparation by recording the preBötC with multi-electrode arrays and assessing correlated firing among respiratory neurons or clusters of respiratory neurons (multiunits). We studied whether the respiratory network reconfiguration in hypoxia involves changes in either the number of active respiratory elements, the number of functional connections among elements, or the strength of these connections. Moreover, we tested the influence of isocitrate, a Krebs cycle intermediate that has recently been shown to promote breathing, on the configuration of the preBötC circuit during normoxia and on its reconfiguration during hypoxia. We found that, in contrast to previous suggestions based on cell-focused studies, the number and the overall activity of respiratory neurons change only slightly during hypoxia. However, hypoxia induces a reduction in the strength of functional connectivity within the circuit without reducing the number of connections. Isocitrate prevented this reduction during hypoxia while increasing the strength of network connectivity. In conclusion, we provide an overview of the configuration of the respiratory network under control conditions and how it is reconfigured during fictive-gasping

  14. Herschel evidence for disk flattening or gas depletion in transitional disks

    SciTech Connect

    Keane, J. T.; Pascucci, I.; Espaillat, C.; Woitke, P.; Andrews, S.; Kamp, I.; Thi, W.-F.; Meeus, G.; Dent, W. R. F.

    2014-06-01

    Transitional disks are protoplanetary disks characterized by reduced near- and mid-infrared emission, with respect to full disks. This characteristic spectral energy distribution indicates the presence of an optically thin inner cavity within the dust disk believed to mark the disappearance of the primordial massive disk. We present new Herschel Space Observatory PACS spectra of [O I] 63.18 μm for 21 transitional disks. Our survey complements the larger Herschel GASPS program ({sup G}as in Protoplanetary Systems{sup )} by quadrupling the number of transitional disks observed with PACS in this wavelength. [O I] 63.18 μm traces material in the outer regions of the disk, beyond the inner cavity of most transitional disks. We find that transitional disks have [O I] 63.18 μm line luminosities ∼2 times fainter than their full disk counterparts. We self-consistently determine various stellar properties (e.g., bolometric luminosity, FUV excess, etc.) and disk properties (e.g., disk dust mass, etc.) that could influence the [O I] 63.18 μm line luminosity, and we find no correlations that can explain the lower [O I] 63.18 μm line luminosities in transitional disks. Using a grid of thermo-chemical protoplanetary disk models, we conclude that either transitional disks are less flared than full disks or they possess lower gas-to-dust ratios due to a depletion of gas mass. This result suggests that transitional disks are more evolved than their full disk counterparts, possibly even at large radii.

  15. Caroline Herschel as an Observer

    NASA Astrophysics Data System (ADS)

    Hoskin, M. A.

    2005-08-01

    Caroline Herschel (1750-1848) made an immense contribution to astronomy as amanuensis to her brother William during his sweeps for nebulae that resulted in catalogues of 2507 nebulae and clusters, but she was also an observer on her own account. From their arrival near Windsor in the fall of 1782 until William required her services at the beginning of 1784, she was free to observe when she so wished. During this time she discovered a number of nebulae, and, more importantly, demonstrated to William that nebulae were there in such numbers that even an amateur with a primitive refractor could find them. There then followed years when William's need for her help limited the time for her own observing, but in 1786, during his absence abroad, she discovered her first comet. In the period between William's marriage in 1788 (which relieved her of household duties) and her inexplicable move into lodgings in 1797, she found seven more, including Encke's Comet. In my paper I assess her work as an observer and discuss the objects she found.

  16. Debris disks as seen by Herschel/DUNES

    NASA Astrophysics Data System (ADS)

    Löhne, T.; Eiroa, C.; Augereau, J.-C.; Ertel, S.; Marshall, J. P.; Mora, A.; Absil, O.; Stapelfeldt, K.; Thébault, P.; Bayo, A.; del Burgo, C.; Danchi, W.; Krivov, A. V.; Lebreton, J.; Letawe, G.; Magain, P.; Maldonado, J.; Montesinos, B.; Pilbratt, G. L.; White, G. J.; Wolf, S.

    2012-06-01

    The far-infrared excesses produced by debris disks are common features of stellar systems. These disks are thought to contain solids ranging from micron-sized dust to planetesimals. Naturally, their formation and evolution are linked to those of potential planets. With this motivation, the Herschel open time key programme DUNES (DUst around NEarby Stars) aims at further characterising known debris disks and discovering new ones in the regime explored by the Herschel space observatory. On the one hand, in their survey of 133 nearby FGK stars, DUNES discovered a class of extremely cold and faint debris disks, different from well-known disks such as the one around Vega in that their inferred typical grain sizes are rather large, indicating low dynamical excitation and low collision rates. On the other hand, for the more massive disk around the sun-like star HD 207129, well-resolved PACS images confirmed the ring-liked structure seen in HST images and provided valuable information for an in-depth study and benchmark for models. Employing both models for power-law fitting and collisional evolution we found the disk around HD 207129 to feature low collision rates and large grains, as well. Transport by means of Poynting-Robertson drag likely plays a role in replenishing the dust seen closer to the star, inside of the ring. The inner edge is therefore rather smooth and the contribution from the extended halo of barely bound grains is small. Both slowly self-stirring and planetary perturbations could potentially have formed and shaped this disk. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  17. On the insignificance of Herschel's sunspot correlation

    USGS Publications Warehouse

    Love, Jeffrey J.

    2013-01-01

    We examine William Herschel's hypothesis that solar-cycle variation of the Sun's irradiance has a modulating effect on the Earth's climate and that this is, specifically, manifested as an anticorrelation between sunspot number and the market price of wheat. Since Herschel first proposed his hypothesis in 1801, it has been regarded with both interest and skepticism. Recently, reports have been published that either support Herschel's hypothesis or rely on its validity. As a test of Herschel's hypothesis, we seek to reject a null hypothesis of a statistically random correlation between historical sunspot numbers, wheat prices in London and the United States, and wheat farm yields in the United States. We employ binary-correlation, Pearson-correlation, and frequency-domain methods. We test our methods using a historical geomagnetic activity index, well known to be causally correlated with sunspot number. As expected, the measured correlation between sunspot number and geomagnetic activity would be an unlikely realization of random data; the correlation is “statistically significant.” On the other hand, measured correlations between sunspot number and wheat price and wheat yield data would be very likely realizations of random data; these correlations are “insignificant.” Therefore, Herschel's hypothesis must be regarded with skepticism. We compare and contrast our results with those of other researchers. We discuss procedures for evaluating hypotheses that are formulated from historical data.

  18. On the insignificance of Herschel's sunspot correlation

    NASA Astrophysics Data System (ADS)

    Love, Jeffrey J.

    2013-08-01

    We examine William Herschel's hypothesis that solar-cycle variation of the Sun's irradiance has a modulating effect on the Earth's climate and that this is, specifically, manifested as an anticorrelation between sunspot number and the market price of wheat. Since Herschel first proposed his hypothesis in 1801, it has been regarded with both interest and skepticism. Recently, reports have been published that either support Herschel's hypothesis or rely on its validity. As a test of Herschel's hypothesis, we seek to reject a null hypothesis of a statistically random correlation between historical sunspot numbers, wheat prices in London and the United States, and wheat farm yields in the United States. We employ binary-correlation, Pearson-correlation, and frequency-domain methods. We test our methods using a historical geomagnetic activity index, well known to be causally correlated with sunspot number. As expected, the measured correlation between sunspot number and geomagnetic activity would be an unlikely realization of random data; the correlation is "statistically significant." On the other hand, measured correlations between sunspot number and wheat price and wheat yield data would be very likely realizations of random data; these correlations are "insignificant." Therefore, Herschel's hypothesis must be regarded with skepticism. We compare and contrast our results with those of other researchers. We discuss procedures for evaluating hypotheses that are formulated from historical data.

  19. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0014

    NASA Technical Reports Server (NTRS)

    Briehl, D.; Dudzinski, T. J.; Liu, D. C.

    1980-01-01

    The data currently available from GASP, including flight routes and dates, instrumentation, data processing procedures, and data tape specifications are described. Measurements of atmospheric ozone, cabin ozine, carbon monoxide, water vapor, particles, clouds, condensation nuclei, filter samples and related meteorological and flight information obtained during 562 flights of aircraft N533PA, N4711U, N655PA, and VH-EBE from October 3, 1977 through January 5, 1978 are reported. Data representing tropopause pressures obtained from time and space interpolation of National Meteorological Center archived data for the dates of the flights are included.

  20. Mapping the Milky Way: William Herschel's Star Gages

    ERIC Educational Resources Information Center

    Timberlake, Todd

    2013-01-01

    William Herschel (Fig. 1) is rightfully known as one of the greatest astronomers of all time. Born in Hanover (in modern Germany) in 1738, Herschel immigrated to England in 1757 and began a successful career as a professional musician. Later in life Herschel developed a strong interest in astronomy. He began making his own reflecting telescopes in…

  1. Herschel-detected LBGs at 2

    NASA Astrophysics Data System (ADS)

    Wojno, Jennifer L.; Nichols, M. T.; Haberzettl, L.; Williger, G. M.; Leist, B.

    2014-01-01

    Lyman-break galaxies (LBGs) are well-known indicators of star formation. By analyzing the dust of moderate redshift ( 2) LBGs, we can further investigate the properties of these strongly star forming galaxies at an epoch when global star formation is expected to peak. Using data observed by Herschel and publicly available via PEP (PACS Evolutionary Probe) and the HerMES (Herschel Multi-tiered Extragalactic Survey) surveys, we derive far-infrared fluxes for our color-selected sample of 73 LBGs in the GOODS-S field. This sample includes a subsample of 14 infrared-luminous LBGs (ILLBGs). Measuring fluxes in the 70, 100, and 160 µm PACS bands, as well as the 250, 350, 500 µm SPIRE bands, we fit modified Planck curves and model spectral energy distributions (SEDs) to make estimations for dust temperatures and masses for our Herschel-detected LBGs.

  2. Mirror Figuring Techniques of Sir William Herschel

    NASA Astrophysics Data System (ADS)

    Albin, E. F.

    2004-05-01

    Between the years 1773 to 1818, Sir William Herschel constructed dozens of speculum telescope mirrors, with diameters ranging from 6 - 48 inches. Very little, if any, detailed information has ever been published on the specifics of his mirror figuring efforts. The reason for this certainly relates to his desire to closely guard mirror production trade secrets. Upon Herschel's death, all telescope-making documents were passed on to his only son, Sir John Herschel. These materials are now in the possession of the British RAS and primarily consist of: a) a four volume series entitled "Experiments on the Construction of Specula," b) a 129 page treaty called "On the Construction of Specula," and c) a 179 page manuscript entitled "Results of Experiments on the Construction of Mirrors." It is suggested that publication was further delayed and then eventually abandoned due to silver-coated glass mirrors coming into favor. A recent investigation by the author, of the unpublished manuscripts on the construction of specula, suggests that Herschel's mirror figuring techniques did not involve any guess work; in fact, his methods were highly refined -- never leaving to chance the evolution of a spherical surface into the required paraboloid. At the heart of Herschel's figuring techniques were a series of aperture diaphragms (similar to the Couder masks used by modern telescope makers) that were placed over the mirror, which allowed for the precise determination of its curvature at various predefined zones. With this information, Herschel was able to vary his figuring strokes with his polishing tool accordingly. In addition, all mirrors were subsequently "star tested," sometimes with aperture diaphragms in place, allowing for field examination of the mirror's "distinctness" or performance. Double stars and the planet Saturn were favorite targets used to analyze and then correct a mirror's figure.

  3. HERSCHEL OBSERVATIONS OF INTERSTELLAR CHLORONIUM

    SciTech Connect

    Neufeld, David A.; Indriolo, Nick; Roueff, Evelyne; Le Bourlot, Jacques; Le Petit, Franck; Snell, Ronald L.; Lis, Dariusz; Monje, Raquel; Phillips, Thomas G.; Benz, Arnold O.; Bruderer, Simon; Black, John H.; Larsson, Bengt; De Luca, Massimo; Gerin, Maryvonne; Goldsmith, Paul F.; Gupta, Harshal; Melnick, Gary J.; Menten, Karl M.; Nagy, Zsofia; and others

    2012-03-20

    Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have observed para-chloronium (H{sub 2}Cl{sup +}) toward six sources in the Galaxy. We detected interstellar chloronium absorption in foreground molecular clouds along the sight lines to the bright submillimeter continuum sources Sgr A (+50 km s{sup -1} cloud) and W31C. Both the para-H{sup 35}{sub 2}Cl{sup +} and para-H{sup 37}{sub 2}Cl{sup +} isotopologues were detected, through observations of their 1{sub 11}-0{sub 00} transitions at rest frequencies of 485.42 and 484.23 GHz, respectively. For an assumed ortho-to-para ratio (OPR) of 3, the observed optical depths imply that chloronium accounts for {approx}4%-12% of chlorine nuclei in the gas phase. We detected interstellar chloronium emission from two sources in the Orion Molecular Cloud 1: the Orion Bar photodissociation region and the Orion South condensation. For an assumed OPR of 3 for chloronium, the observed emission line fluxes imply total beam-averaged column densities of {approx}2 Multiplication-Sign 10{sup 13} cm{sup -2} and {approx}1.2 Multiplication-Sign 10{sup 13} cm{sup -2}, respectively, for chloronium in these two sources. We obtained upper limits on the para-H{sup 35}{sub 2}Cl{sup +} line strengths toward H{sub 2} Peak 1 in the Orion Molecular cloud and toward the massive young star AFGL 2591. The chloronium abundances inferred in this study are typically at least a factor {approx}10 larger than the predictions of steady-state theoretical models for the chemistry of interstellar molecules containing chlorine. Several explanations for this discrepancy were investigated, but none has proven satisfactory, and thus the large observed abundances of chloronium remain puzzling.

  4. William Herschel, the First Observational Cosmologist

    ScienceCinema

    Lemonick, Michael [Princeton University and Time Magazine, Princeton, New Jersey, United States

    2010-01-08

    In the late 1700s, a composer, orchestra director and soloist named William Herschel became fascinated with astronomy, and, having built his own reflecting telescope, went out in his garden in Bath, England, one night and discovered Uranus?the first planet in human history ever found by an individual. The feat earned him a lifetime pension from King George III. But Herschel considered the discovery to be relatively unimportant in comparison to his real work: understanding the composition, structure and evolution of the universe. In pursuing that work, he became the first observational cosmologist.

  5. William Herschel, the First Observational Cosmologist

    SciTech Connect

    Lemonick, Michael

    2008-11-12

    In the late 1700s, a composer, orchestra director and soloist named William Herschel became fascinated with astronomy, and, having built his own reflecting telescope, went out in his garden in Bath, England, one night and discovered Uranus—the first planet in human history ever found by an individual. The feat earned him a lifetime pension from King George III. But Herschel considered the discovery to be relatively unimportant in comparison to his real work: understanding the composition, structure and evolution of the universe. In pursuing that work, he became the first observational cosmologist.

  6. William Herschel, the First Observational Cosmologist

    SciTech Connect

    Lemonick, Michael

    2008-11-12

    In the late 1700s, a composer, orchestra director and soloist named William Herschel became fascinated with astronomy, and, having built his own reflecting telescope, went out in his garden in Bath, England, one night and discovered Uranus - the first planet in human history ever found by an individual. The feat earned him a lifetime pension from King George III. But Herschel considered the discovery to be relatively unimportant in comparison to his real work: understanding the composition, structure and evolution of the universe. In pursuing that work, he became the first observational cosmologist.

  7. Modeling IR SED of AGN with Spitzer and Herschel data

    NASA Astrophysics Data System (ADS)

    Feltre, A.

    2012-12-01

    One of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst (SB) activity. What is, in this picture, the role played by the obscur- ing dust around the nucleus and what do the state of the art AGN torus models have to say? Can the IR data provided by Spitzer and Herschel help us in extensively investigate both phenomena and, if so, how and with what limitations? In this paper we present our contribution to the efforts of answering these questions. We show some of the main results coming from a comparative study of various AGN SED modeling approaches, focusing mostly on the much-debated issue about the morphology of the dust distribution in the toroidal structure surrounding the AGN. We found that the properties of dust in AGN as measured by matching observations (be it broad band IR photometry or IR spectra) with models, strongly depend on the choice of the dust distribution. Then, we present the spec- tral energy distribution (SED) fitting procedure we developed, making make the best use of Spitzer and Herschel SPIRE mid- and far-IR observations, to dig into the role played by the possible presence of an AGN on the host galaxy's properties.

  8. Finger microvascular responses to deep inspiratory gasp assessed and quantified using wavelet analysis.

    PubMed

    Allen, John; Di Maria, Costanzo; Mizeva, Irina; Podtaev, Sergey

    2013-07-01

    The physiological changes following a deep inspiratory gasp (DIG) manoeuvre have been described in the literature. However, the lack of a reliable signal processing technique to visualize and quantify these physiological changes has so far limited the applicability of the test to the clinical setting. The main aim of this study was to assess the feasibility of using wavelet analysis to quantify the pulse arrival time (PAT) and its changes during the DIG manoeuvre. Vascular responses were extracted from cardiac (electrocardiogram, ECG) and peripheral pulse (photoplethysmography, PPG) waveforms. Wavelet analysis characterized their cardiovascular responses in healthy adult subjects in the time-frequency space, and for the ECG-PPG inter-relationship in terms of the PAT. PAT showed a characteristic biphasic response to gasp, with an increase of 59 ± 59 ms (p = 0.001) compared to the maximum value reached during quiet breathing, and a decrease of -38 ± 55 ms (p < 0.01) compared to the minimum value during quiet breathing. The response measures were repeatable. This pilot study has successfully shown the feasibility of using wavelet analysis to characterize the cardiovascular waveforms and quantify their changes with DIG. PMID:23771176

  9. Infrared properties of blazars: putting the GASP-WEBT sources into context

    NASA Astrophysics Data System (ADS)

    Raiteri, C. M.; Villata, M.; Carnerero, M. I.; Acosta-Pulido, J. A.; Larionov, V. M.; D'Ammando, F.; Arévalo, M. J.; Arkharov, A. A.; Bueno Bueno, A.; Di Paola, A.; Efimova, N. V.; González-Morales, P. A.; Gorshanov, D. L.; Grinon-Marin, A. B.; Lázaro, C.; Manilla-Robles, A.; Pastor Yabar, A.; Puerto Giménez, I.; Velasco, S.

    2014-07-01

    The infrared properties of blazars can be studied from the statistical point of view with the help of sky surveys, like that provided by the Wide-field Infrared Survey Explorer and the Two Micron All Sky Survey. However, these sources are known for their strong and unpredictable variability, which can be monitored for a handful of objects only. In this paper, we consider the 28 blazars (14 BL Lac objects and 14 flat-spectrum radio quasars, FSRQs) that are regularly monitored by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope since 2007. They show a variety of infrared colours, redshifts, and infrared-optical spectral energy distributions (SEDs), and thus represent an interesting mini-sample of bright blazars that can be investigated in more detail. We present near-IR light curves and colours obtained by the GASP from 2007 to 2013, and discuss the infrared-optical SEDs. These are analysed with the aim of understanding the interplay among different emission components. BL Lac SEDs are accounted for by synchrotron emission plus an important contribution from the host galaxy in the closest objects, and dust signatures in 3C 66A and Mrk 421. FSRQ SEDs require synchrotron emission with the addition of a quasar-like contribution, which includes radiation from a generally bright accretion disc (νLν up to ˜4 × 1046 erg s-1), broad-line region, and a relatively weak dust torus.

  10. Valid garnet biotite (GB) geothermometry and garnet aluminum silicate plagioclase quartz (GASP) geobarometry in metapelitic rocks

    NASA Astrophysics Data System (ADS)

    Wu, Chun-Ming; Cheng, Ben-He

    2006-06-01

    At present there are many calibrations of both the garnet-biotite (GB) thermometer and the garnet-aluminum silicate-plagioclase-quartz (GASP) barometer that may confuse geologists in choosing a reliable thermometer and/or barometer. To test the accuracy of the GB thermometers we have applied the various GB thermometers to reproduce the experimental data and data from natural metapelitic rocks of various prograde sequences, inverted metamorphic zones and thermal contact aureoles. We have concluded that the four GB thermometers (Perchuk, L.L., Lavrent'eva, I.V., 1983. Experimental investigation of exchange equilibria in the system cordierite-garnet-biotite. In: Saxena, S.K. (ed.) Kinetics and equilibrium in mineral reactions. Springer-Verlag New York, Berlin, Heidelberg. pp. 199-239.; Kleemann, U., Reinhardt, J., 1994. Garnet-biotite thermometry revised: the effect of Al VI and Ti in biotite. European Journal of Mineralogy 6, 925-941.; Holdaway, M.J., 2000. Application of new experimental and garnet Margules data to the garnet-biotite geothermometer. American Mineralogist 85, 881-892., Model 6AV; Kaneko, Y., Miyano, T., 2004. Recalibration of mutually consistent garnet-biotite and garnet-cordierite geothermometers. Lithos 73, 255-269. Model B) are the most valid and reliable of this kind of thermometer. More specifically, we prefer the Holdaway (Holdaway, M.J., 2000. Application of new experimental and garnet Margules data to the garnet-biotite geothermometer. American Mineralogist 85, 881-892.) and the Kleemann and Reinhardt (Kleemann, U., Reinhardt, J., 1994. Garnet-biotite thermometry revised: the effect of Al VI and Ti in biotite. European Journal of Mineralogy 6, 925-941.) calibrations due to their small errors in reproducing the experimental temperatures and good accuracy in successfully discerning the systematic temperature changes of the different sequences. In addition, after applying the GASP barometer to 335 natural metapelitic samples containing one kind

  11. Revised list of Sir William Herschel's Fields of Diffuse Nebulosity

    NASA Astrophysics Data System (ADS)

    Latusseck, A.

    2008-12-01

    William Herschel's catalogue of more than 2500 nonstellar celestial objects is without doubt one of the great astronomical achievements of this exceptional astronomer. Largely unknown, however, is a list containing fifty-two fields of extensive nebulosity, which Herschel published in 1811 as a supporting argument to his nebular hypothesis (Herschel, 1811: 275-276), all of which were observed as a by-product of his sweeps between 1783 and 1802. For the purpose of a final revision of Herschel's objects, his sister Caroline's copies of the eight observing books containing the results of his decade-long sweeps (Herschel, Herschel and Herschel, 2004) were analyzed. As a result, a number of errors and inaccuracies were found and corrected. Furthermore, the terminology used to describe the observed nebulosities--which differed widely from that used by Herschel to describe non-stellar objects in his better-known catalogues of nebulae--was investigated in order to obtain a clearer impression of the appearance of Herschel's objects. The resulting revised list, being one principal result of the review of Herschel's list of fifty-two nebulosities, contains corrected physical information on each of the nebulosities. It further gives estimates on the reliability of Herschel's observations and finally summarizes all of the noticed peculiarities in a separate column.

  12. The HERSCHEL/PACS early Data Products

    NASA Astrophysics Data System (ADS)

    Wieprecht, E.; Wetzstein, M.; Huygen, R.; Vandenbussche, B.; De Meester, W.

    2006-07-01

    ESA's Herschel Space Observatory to be launched in 2007, is the first space observatory covering the full far-infrared and submillimeter wavelength range (60 - 670 microns). The Photodetector Array Camera & Spectrometer (PACS) is one of the three science instruments. It contains two Ge:Ga photoconductor arrays and two bolometer arrays to perform imaging line spectroscopy and imaging photometry in the 60 - 210 micron wavelength band. The HERSCHEL ground segment (Herschel Common Science System - HCSS) is implemented using JAVA technology and written in a common effort by the HERSCHEL Science Center and the three instrument teams. The PACS Common Software System (PCSS) is based on the HCSS and used for the online and offline analysis of PACS data. For telemetry bandwidth reasons PACS science data are partially processed on board, compressed, cut into telemetry packets and transmitted to the ground. These steps are instrument mode dependent. We will present the software model which allows to reverse the discrete on board processing steps and evaluate the data. After decompression and reconstruction the detector data and instrument status information are organized in two main PACS Products. The design of these JAVA classes considers the individual sampling rates, data formats, memory and performance optimization aspects and comfortable user interfaces.

  13. A challenge for probing the statistics of interstellar magnetic fields: beyond the Planck resolution with Herschel

    NASA Astrophysics Data System (ADS)

    Bracco, Andrea; André, Philippe; Boulanger, Francois

    2015-08-01

    The recent Planck results in polarization at sub-mm wavelengths allow us to gain insight into the Galactic magnetic field topology, revealing its statistical correlation with matter, from the diffuse interstellar medium (ISM), to molecular clouds (MCs) (Planck intermediate results. XXXII, XXXIII, XXXV). This correlation has a lot to tell us about the dynamics of the turbulent ISM, stressing the importance of considering magnetic fields in the formation of structures, some of which eventually undergo gravitational collapse producing new star-forming cores.Investigating the early phases of star formation has been a fundamental scope of the Herschel Gould Belt survey collaboration (http://gouldbelt-herschel.cea.fr), which, in the last years, has thoroughly characterized, at a resolution of few tens of arcseconds, the statistics of MCs, such as their filamentary structure, kinematics and column density.Although at lower angular resolution, the Planck maps of dust emission at 353GHz, in intensity and polarization, show that all MCs are complex environments, where we observe a non-trivial correlation between the magnetic field and their density structure. This result opens new perspectives on their formation and evolution, which we have started to explore.In this talk, I will present first results of a comparative analysis of the Herschel-Planck data, where we combine the high resolution Herschel maps of some MCs of the Gould Belt with the Planck polarization data, which sample the structure of the field weighted by the density.In particular, I will discuss the large-scale envelopes of the selected MCs, and, given the correlation between magnetic field and matter, I will show how to make use of the high resolution information of the density structure provided by Herschel to investigate the statistics of interstellar magnetic fields in the Planck data.

  14. Flight summaries and temperature climatology at airliner cruise altitudes from GASP (Global Atmospheric Sampling Program) data

    NASA Technical Reports Server (NTRS)

    Nastrom, G. D.; Jasperson, W. H.

    1983-01-01

    Temperature data obtained by the Global Atmospheric Sampling Program (GASP) during the period March 1975 to July 1979 are compiled to form flight summaries of static air temperature and a geographic temperature climatology. The flight summaries include the height and location of the coldest observed temperature and the mean flight level, temperature and the standard deviation of temperature for each flight as well as for flight segments. These summaries are ordered by route and month. The temperature climatology was computed for all statistically independent temperture data for each flight. The grid used consists of 5 deg latitude, 30 deg longitude and 2000 feet vertical resolution from FL270 to FL430 for each month of the year. The number of statistically independent observations, their mean, standard deviation and the empirical 98, 50, 16, 2 and .3 probability percentiles are presented.

  15. GASP- General Aviation Synthesis Program. Volume 1: Main program. Part 1: Theoretical development

    NASA Technical Reports Server (NTRS)

    Hague, D.

    1978-01-01

    The General Aviation synthesis program performs tasks generally associated with aircraft preliminary design and allows an analyst the capability of performing parametric studies in a rapid manner. GASP emphasizes small fixed-wing aircraft employing propulsion systems varying froma single piston engine with fixed pitch propeller through twin turboprop/ turbofan powered business or transport type aircraft. The program, which may be operated from a computer terminal in either the batch or interactive graphic mode, is comprised of modules representing the various technical disciplines integrated into a computational flow which ensures that the interacting effects of design variables are continuously accounted for in the aircraft sizing procedure. The model is a useful tool for comparing configurations, assessing aircraft performance and economics, performing tradeoff and sensitivity studies, and assessing the impact of advanced technologies on aircraft performance and economics.

  16. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0004

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Humenik, F. M.; Lezberg, E. A.

    1976-01-01

    The NASA Global Atmospheric Sampling Program (GASP) is obtaining measurements of atmospheric trace constituents in the upper troposphere and lower stratosphere using fully automated air sampling systems on board several commercial B-747 aircraft in routine airline service. Atmospheric ozone, water vapor, and related flight and meteorological data were obtained during 139 flights of a United Airlines B-747 and a Pan American World Airways B-747 from December 1975 through March 1976. In addition, sample bottles were exposed during three flights and analyzed for trichlorofluoromethane, and filter samples were exposed during five flights and analyzed for sulfates, nitrates, and chlorides. Flight routes and dates, instrumentation, data processing procedures, data tape specifications, and selected analyses are discussed.

  17. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0006

    NASA Technical Reports Server (NTRS)

    Gauntner, D. J.; Holdeman, J. D.; Humenik, F. M.

    1977-01-01

    The NASA Global Atmospheric Sampling Program (GASP) is obtaining measurements of atmospheric trace constituents in the upper troposphere and lower stratosphere using fully automated air sampling systems on board several commercial B-747 aircraft in routine airline service. Atmospheric ozone, and related flight and meteorological data were obtained during 245 flights of a Qantas Airways of Australia B-747 and two Pan American World Airways B-747s from July 1976 through September 1976. In addition, whole air samples, obtained during three flights, were analyzed for trichlorofluoromethane, and filter samples, obtained during four flights, were analyzed for sulfates, nitrates, fluorides, and chlorides. Flight routes and dates, instrumentation, data processing procedures, data tape specifications, and selected analyses are discussed.

  18. GASP-PL/I Simulation of Integrated Avionic System Processor Architectures. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Brent, G. A.

    1978-01-01

    A development study sponsored by NASA was completed in July 1977 which proposed a complete integration of all aircraft instrumentation into a single modular system. Instead of using the current single-function aircraft instruments, computers compiled and displayed inflight information for the pilot. A processor architecture called the Team Architecture was proposed. This is a hardware/software approach to high-reliability computer systems. A follow-up study of the proposed Team Architecture is reported. GASP-PL/1 simulation models are used to evaluate the operating characteristics of the Team Architecture. The problem, model development, simulation programs and results at length are presented. Also included are program input formats, outputs and listings.

  19. Forecasting method of ice blocks fall by logistic model and melting degree-days calculation: a case study in northern Gaspésie, Québec, Canada.

    NASA Astrophysics Data System (ADS)

    Gauthier, Francis; Hétu, Bernard; Allard, Michel

    2013-04-01

    Ice blocks fall is a serious natural hazard that frequently happens in mountainous cold region. The ice blocks result from the melting and collapse of rockwall icings (ice walls or frozen waterfalls). Environment Canada weather data were analysed for 440 cases of ice blocks fall events reported in northern Gaspésie by the "Ministère des Transports du Québec" (M.T.Q.). The analysis shows that the ice blocks fall are mainly controlled by an increase of the air temperature above 0oC. The melting degree-days (DDmelt) can be used to follow the temperature variations and the heat transfer into the ice bodies. Furthermore, large daily temperature changes, especially drastic drops of temperatures and freeze-thaw cycles, can induce enough mechanical stress to favour the opening of cracks and possibly cause the collapse of unstable ice structures such as freestanding ice formations. By following the evolution of the DDmelt and the best logistic model, it is possible to forecast the collapse of some of the most problematic rockwall icings and target the most hazardous periods along the northern Gaspésie roads.

  20. Gaspé Belt subsurface geometry in the northern Québec Appalachians as revealed by an integrated geophysical and geological study: 2 — Seismic interpretation and potential field modelling results

    NASA Astrophysics Data System (ADS)

    Pinet, Nicolas

    2013-03-01

    Geological information, seismic reflection profiles and potential field data are used to study the geometry of the Middle Paleozoic Gaspé Belt (eastern Canada) that has been interpreted in various ways in the past. On the western edge of the Gaspé Belt, in the Matapédia area, growth strata are imaged on seismic profiles and testify of normal (or transtensional) motion during the period spanning the Silurian (and possibly Late Ordovician) to earliest Devonian along several faults, including the Shickshock-Sud Fault. In this area, Acadian deformation during the Middle to Late Devonian is associated with relatively modest shortening (less than 20%) accommodated by broad open folds, steeply-dipping neo-formed faults and inversion of previously formed faults. Neo-formed faults cut the entire Middle Paleozoic succession and offset the Ordovician Taconian unconformity suggesting that no sedimentary interval acted as an efficient décollement level. Toward the SE, the Sainte-Florence Fault divides rock assemblages with different paleogeographic settings and structural styles. Increase in tectonic complexity and amount of shortening to the south of the fault is interpreted as resulting of a vise effect between two basement blocks.

  1. Quality-Enhanced Legacy Products in the Herschel Science Archive

    NASA Astrophysics Data System (ADS)

    Teyssier, D.

    2016-05-01

    There is on-going effort within the Herschel Ground Segment to improve the data quality and science readiness of the Herschel standard Products. These Highly-Processed Data Products will focus both on dedicated data post-processing, and source and line catalogue generation. Eventually they shall be stored and served by the Herschel Science Archive. We present here an overview of the work packages contemplated in this effort.

  2. IRAC Snapshot Imaging of Red Herschel Galaxies

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha; Nayyeri, Hooshang; Wardlow, Julie; Ivison, Rob; Perez-Fournon, Ismael; Riechers, Dominik; Clements, David; Oliver, Seb; Oteo, Ivan

    2016-08-01

    Wide-field submillimeter surveys with Herschel have produced large samples of rare populations, which provide some of the most stringent constraints on galaxy formation theories. In this proposal we request IRAC observations of 'red' Herschel sources, which are the most extreme DSFGs at z>4. The proposed snapshot IRAC 3.6 and 4.5um data will probe the stellar emission from these systems - complementary data to the far-infrared dust emission that led to their identification. We will use these data to extend the SEDs into the near-IR regime and measure more reliable stellar masses than otherwise available. They will be combined with existing survey data and dedicated follow-up programs to map the evolution of DSFGs as a function of redshift, stellar mass and far-IR luminosity.

  3. Herschel Observations of Debris Disks from WISE

    NASA Technical Reports Server (NTRS)

    Padgett, D. L.; Stapelfeldt, K. R.; Liu, W.; Leisawitz, D. T.; Fajardo-Acosta, S.

    2012-01-01

    The \\Vide Field Infrared Survey Explorer (WISE) has just completed a sensitive all-sky survey in photometric bands at 3.4, 4.6,12 and 22 microns. We report on a study of main sequence Hipparcos and Tycho catalog stars within 120 pc with WISE 22 micron emission in excess of photospheric levels. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets and is preferentially found in young systems with ages < 1 Gyr. Nearly a hundred of the WISE new warm debris disk candidates detected among FGK stars are being observed by Herschel/PACS to characterize circumstellar dust. Preliminary results indicate 70 micron detection rates in excess of 80% for these targets, suggesting that most of these systems have both warm and cool dust in analogy to our asteroid and Kuiper belts. In this contribution, we will discuss the WISE debris disk survey and latest results from Herschel observations of these sources.

  4. John Herschel on the Discovery of Neptune

    NASA Astrophysics Data System (ADS)

    Kollerstrom, Nicholas

    2006-12-01

    The letters of John Herschel that concern the discovery of the planet Neptune have not been greatly discussed by historians of science. I have transcribed these in the course of archiving the British Neptune-discovery documents. Herschel tends to be depicted as a background figure in narrations of the story of Neptune's discovery, whereas the present account focuses upon his evolving view of the topic: the rival merits of the two main protagonists, and the startling manner in which an obscure branch of mathematics (perturbation theory) was able to pinpoint the position of a new sphere in the sky. As the son of the man who found Uranus, his views have a special relevance. Also, I suggest that his eloquent prose style may still be enjoyed today.

  5. The Herschel Planetary Nebula Survey (HerPlaNS)

    NASA Astrophysics Data System (ADS)

    Ueta, T.; Ladjal, D.; HerPlaNS Team

    2012-12-01

    The Herschel Planetary Nebula Survey (HerPlaNS, PI: T. Ueta) is one of the largest Herschel Open Time 1 program in which we explore the far-infrared aspects of 11 planetary nebulae (PNs) with the Herschel Space Observatory, exploiting its unprecedented capabilities in broadband photometry mapping, spectral mapping, and integral-field spectroscopy. We perform (1) deep PACS/SPIRE broadband mapping to account for the coldest dust component of the nebulae and determine the spatial distribution of the dusty haloes in the target PNs, (2) exhaustive PACS/SPIRE line mapping in far-IR atomic and molecular lines in two representative PNs to diagnose the energetics of the nebulae as a function of location in the nebulae, and (3) PACS/SPIRE spectral-energy-distribution spectroscopy at several positions in the target PNs to understand variations in the physical conditions as a function of location in the nebulae, to build a more complete picture of the interplay between the dust and gas components as a function of location in the nebulae. The HerPlaNS survey is distinguished from the existing guaranteed-time Key Program (KPGT), "Mass Loss of Evolved StarS" (MESS, PI: M. Groenewegen, including 10 PNs) by the extra dimension added by spectral mapping and integral-field spatio-spectroscopy that permit simultaneous probing of the gas and dust component in the target PNs. Through these investigations, we will consider the energetics of the entire gas-dust system as a function of location in the nebulae, which is a novel approach that has rarely been taken previously. HerPlaNS is conducted in collaboration with the Chandra Planetary Survey (ChanPlaNS, PI: J.H. Kastner) to furnish substantial PN data resources that would allow us—a community of PN astronomers—to tackle a multitude of unanswered issues in PN physics, from the shaping mechanisms of the nebulae to the energetics of the multi-phased gas-dust system surrounding the central white dwarf. These PN surveys, combined with

  6. A Herschel-PACS view of 16 Centaurs

    NASA Astrophysics Data System (ADS)

    Duffard, Rene; Pinilla-Alonso, N.; Santos-Sanz, P.; Vilenius, E.; Ortiz, J.; Mueller, T.; Fornasier, S.; Lellouch, E.; Mommert, M.; Pal, A.; Kiss, C.; Mueller, M.; Stansberry, J.; Delsanti, A.; Peixinho, N.

    2013-10-01

    The goal of this work is to characterize a set of Centaurs in terms of their size, albedo, and thermal properties. The Herschel open time key program "TNOs are Cool!'' observed 130 Centaurs and TNOs in 2009-2012. In this particular work we use Herschel/PACS three-band photometry to obtain monochromatic flux densities at 70, 100 and 160 μm. Additionally, we also incorporate Spitzer/MIPS flux densities at 24 and 70 μm when available. We use a consistent method for data reduction and aperture photometry to finally determine sizes and albedos of 16 Centaurs using radiometric techniques. We study the correlations between the size and albedo resulting from our models and other physical (i.e spectral slope) and orbital parameters using a more extended sample (obtained from literature). The final sample comprises 36 objects: 18 Centaurs observed with Herschel/PACS; 10 observed only with Spitzer and 8 SDOs. The first conclusion is that the albedo of the Centaurs is not determined by their orbit. Similarly we do not find any correlation between diameter and orbital parameters. We also find that most of the objects in our sample are dark (pv < 7%) and most of them are small (D < 120km). However, we do not find any correlation between albedo and diameter, in particular for the group of the small objects we can find albedo values homogeneously distributed from 4 - 15%. When it comes to correlation with the color of the objects, we find that the red objects are all small (mean diameter 65 km), while the gray ones are either small or large (mean diameter 120 km). Also, the gray objects seem to be darker, with a mean value of 5.6%, while for the red objects the albedo can vary from 5 to 15%, with a mean value of 8.5%. All of this shows that there are other physical properties (size and albedo distribution) that make differences between the gray and red objects, even if we do not yet have a physical explanation for the origin of this bimodality.

  7. The Herschels: A very fashionable scientific family

    NASA Astrophysics Data System (ADS)

    Winterburn, Emily

    2011-01-01

    What is special about the Herschel family? It is a family that has attracted the attention of historians of science for many years and has done so for a number of reasons. Some simply marvel at the family's ability to have produced generations upon generation of great men and women of science. Others have highlighted the work of individuals within the family and how their work changed the way astronomy was done, what it was about, and then later did the same for science as a whole. The unusually high status enjoyed by Herschel women, Caroline Herschel in particular, has not escaped notice, though I will here question some of the conclusions drawn about her motivations. Most of all, however I will argue in this paper, they should be interesting to a modern audience for the way in which they managed time and again, generation on generation, to make science fashionable and popular. In this paper I will look at three generations of this family - from William and Caroline discovering comets and planets in the late eighteenth century, through John and his claim that society needs science to be properly civilised, to John and Margaret's children and their varied takes on the relationship between astronomy, science and the public. I will look at the role astronomy played in each of their lives, how they were taught and taught each other and how in each generation they managed to make their work the talk of the town.

  8. The HERSCHEL/PACS Spectrometer Pipeline

    NASA Astrophysics Data System (ADS)

    Schreiber, J.; Wieprecht, E.; de Jong, J.; Wetzstein, M.; Jacobson, J.; Huygen, R.; Appleton, P.; Bouwman, J.; Contursi, A.; Fadda, D.; Jean, C.; Klaas, U.; Royer, P.; Vandenbussche, B.

    2009-09-01

    ESA's Herschel Space Observatory, to be launched in 2009, is the first space observatory covering the full far-infrared and sub-millimeter wavelength range (60 - 670 micron). The Photodetector Array Camera & Spectrometer (PACS) is one of the three science instruments. It employs two Ge:Ga photoconductor arrays and two bolometer arrays to perform integral field spectroscopy and imaging photometry in the 60 - 210 micron wavelength band. The interactive PACS Spectrometer and Photometer \\citep{wieprecht09} Data Reduction Pipeline is integrated in the Herschel Data Processing System. The DP is implemented using Java technology and written in a common effort by the HERSCHEL Science Center (HSC) and the three instrument teams. We overview the concept and status of the PACS Spectrometer Data Reduction Pipeline. Additionally, we address the instrument mode-dependent data processing and the definition of the products of the different processing levels. Finally, we show first results by applying the pipeline on flight model instrument level test data.

  9. Observations of Luminous Infrared Galaxies with Herschel

    NASA Astrophysics Data System (ADS)

    Armus, Lee

    2014-01-01

    A major result of the IRAS survey was the discovery of a large population of luminous infrared galaxies (LIRGs) which emit a significant fraction of their bolometric luminosity in the far-infrared. LIRGs cover the full range of morphologies from isolated disk galaxies, to advanced mergers, exhibiting enhanced star-formation rates and a higher fraction of Active Galactic Nuclei (AGN) compared to less luminous galaxies. A detailed study of low-redshift LIRGs is critical for our understanding of the cosmic evolution of galaxies and black holes, since LIRGs comprise the bulk of the cosmic far-infrared background and dominate the star-formation between 0.5 < z < 1. With ISO, it was possible to measure the full suite of infrared diagnostic lines in local normal and luminous infrared galaxies for the first time, but samples were small and observations challenging. With Herschel, we have been able to study large samples of low-redshift LIRGs, and even probe the physical conditions in poweful starburst galaxies out to significant redshifts. By combining the Herschel data with those from Spitzer, it is now possible to understand the heating and cooling of the dust and gas in complete samples of LIRGs for the first time. I will review recent results from a number of GTO, OTKP and GO programs in an attempt to summarize the advances we have made in understanding star formation and black hole accretion in LIRGs as a direct result of the Herschel mission.

  10. Constraining the properties of transitional discs in Chamaeleon I with Herschel

    NASA Astrophysics Data System (ADS)

    Ribas, Á.; Bouy, H.; Merín, B.; Duchêne, G.; Rebollido, I.; Espaillat, C.; Pinte, C.

    2016-05-01

    Transitional discs are protoplanetary discs with opacity gaps/cavities in their dust distribution, a feature that may be linked to planet formation. We perform Bayesian modelling of the three transitional discs SZ Cha, CS Cha, and T25 including photometry from the Herschel Space Observatory to quantify the improvements added by these new data. We find disc dust masses between 2 × 10-5 and 4 × 10-4 M⊙ and gap radii in the range of 7-18 au, with uncertainties of ˜ one order of magnitude and ˜4 au, respectively. Our results show that adding Herschel data can significantly improve these estimates with respect to mid-infrared data alone, which have roughly twice as large uncertainties on both disc mass and gap radius. We also find weak evidence for different density profiles with respect to full discs. These results open exciting new possibilities to study the distribution of disc masses for large samples of discs.

  11. Herschel and ALMA observations of AGB star envelopes

    NASA Astrophysics Data System (ADS)

    Katrien Els Decin, Leen

    2015-08-01

    The stellar winds of evolved (super)giant stars are known to be the prime birthplaces for the interstellar material in our galaxy. Fusion in the stellar interiors creates carbon, nitrogen, oxygen, and for more massive stars elements such as magnesium, sulphur etc. are synthesized. Thanks to dredge-ups in the stellar atmosphere and subsequent extensive mass loss through a stellar wind this material is injected into the interstellar medium (ISM).These stellar winds are really unique chemical laboratories in which various gas-phase and gas-dust processes create and destroy gas and dust species and hence manufacture the pristine building blocks of the ISM. The efficiency and working of these various chemical processes is ultimately linked to the dynamical processes which establish the morpho-kinematical structure of the wind. Unraveling the intriguing coupling between these macro-scale dynamical and micro-scale chemical processes is a real challenge to which recent advances in instrumentation, theoretical modeling, and laboratory experiments have contributed a lot. Thanks to their unprecedented sensitivity, spatial resolution and wavelength coverage, Herschel and ALMA have proven to be two key instruments in solving some enigmas related to AGB stellar winds. In this talk, I will give a review of some of the most recent results in the field of AGB stellar winds based on Herschel and ALMA data and I will discuss some open questions that I hope will be answered in the next decade thanks to a combined effort between instrumentation and laboratory specialists and theoretical astrophysicists.

  12. Tabulations of ambient ozone data obtained by GASP (Global Air Sampling Program) airliners, March 1975 to July 1979

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Holdeman, J. D.

    1984-01-01

    Tabulations are given of GASP ambient ozone mean, standard deviation, median, 84th percentile, and 98th percentile values, by month, flight level, and geographical region. These data are tabulated to conform to the temporal and spatial resolution required by FAA Advisory Circular 120-38 (monthly by 2000 ft in altitude by 5 deg in latitude) for climatological data used to show compliance with cabin ozone regulations. In addition seasonal x 10 deg latitude tabulations are included which are directly comparable to and supersede the interim GASP ambient ozone tabulations given in appendix B of FAA-EE-80-43 (NASA TM-81528). Selected probability variations are highlighted to illustrate the spatial and temporal variability of ambient ozone and to compare results from the coarse and fine grid analyses.

  13. Mapping the Milky Way: William Herschel's Star Gages

    NASA Astrophysics Data System (ADS)

    Timberlake, Todd

    2013-01-01

    William Herschel (Fig. 1) is rightfully known as one of the greatest astronomers of all time. Born in Hanover (in modern Germany) in 1738, Herschel immigrated to England in 1757 and began a successful career as a professional musician. Later in life Herschel developed a strong interest in astronomy. He began making his own reflecting telescopes in 1774, and soon his telescopes were recognized as the finest in the world. It was through one of his homemade telescopes, a Newtonian reflector with a focal length of seven feet and an aperture of 6.2 inches, that Herschel first spotted the planet Uranus in 1781. The discovery of a new planet catapulted Herschel to fame and secured him a position as personal astronomer to King George III.

  14. Panchromatic spectral energy distributions of Herschel sources

    NASA Astrophysics Data System (ADS)

    Berta, S.; Lutz, D.; Santini, P.; Wuyts, S.; Rosario, D.; Brisbin, D.; Cooray, A.; Franceschini, A.; Gruppioni, C.; Hatziminaoglou, E.; Hwang, H. S.; Le Floc'h, E.; Magnelli, B.; Nordon, R.; Oliver, S.; Page, M. J.; Popesso, P.; Pozzetti, L.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Roseboom, I.; Scott, D.; Symeonidis, M.; Valtchanov, I.; Viero, M.; Wang, L.

    2013-03-01

    Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S, and COSMOS fields, it is possible to sample the 8-500 μm spectral energy distributions (SEDs) of galaxies with at least 7-10 bands. Extending to the UV, optical, and near-infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected restframe ten colors space, based on this rich data-set, using a superposition of multivariate Gaussian modes. We use this model to classify galaxies and build median SEDs of each class, which are then fitted with a modified version of the magphys code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an active galactic nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6-9 classes, spanning a large range of far- to near-infrared luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z ~ 1 Ly-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eightother popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10-20%, the scatter being dominated more by fine tuning of the codes, rather than by the choice of

  15. Herschel's 20ft Telescope at the Smithsonian

    NASA Astrophysics Data System (ADS)

    DeVorkin, David H.

    2011-01-01

    The tube and one of the mirrors from the original Herschel 20-foot telescope have been on display at the National Air and Space Museum since September 12, 2001. Approximately 3,000 visitors walk past it each day, inspecting how William and Caroline jointly operated the telescope in their garden. This presentation will recount how the telescope was brought to NASM, and prepared for exhibition. We will also discuss a bit of what we've learned about the telescope's history from developing this display.

  16. The Safety System of the Herschel Cryostat

    NASA Astrophysics Data System (ADS)

    Langfermann, M.; Jahn, G.; Hohn, R.; Ruehe, W.; Jewell, C.

    2004-06-01

    The cryostat for the `Herschel Space Observatory' for the European Space Agency (ESA) science program, planned for a launch with Ariane 5 in 2007, is designed for 6 days ground hold time and 3.5 years lifetime in orbit. The system comprises two tanks containing about 346 kg of liquid and superfluid Helium, with two cryogenic cold safety valves and burst disks, surrounded by three vapor cooled shields and a vacuum vessel. The safety system is two faults tolerant with three independent paths for pressure relief. The analyses of failure modes and resulting mass flows and the safety elements of the cryogenic system will be discussed.

  17. Prostaglandin E2 differentially modulates the central control of eupnoea, sighs and gasping in mice

    PubMed Central

    Koch, Henner; Caughie, Cali; Elsen, Frank P; Doi, Atsushi; Garcia, Alfredo J; Zanella, Sebastien; Ramirez, Jan-Marino

    2015-01-01

    Prostaglandins are important regulators of autonomic functions in the mammalian organism. Here we demonstrate in vivo that prostaglandin E2 (PGE2) can differentially increase the frequency of eupnoea (normal breathing) and sighs (augmented breaths) when injected into the preBötzinger complex (preBötC), a medullary area that is critical for breathing. Low concentrations of PGE2 (100–300 nm) increased the sigh frequency, while higher concentrations (1–2 μm) were required to increase the eupnoeic frequency. The concentration-dependent effects were similarly observed in the isolated preBötC. This in vitro preparation also revealed that riluzole, a blocker of the persistent sodium current (INap), abolished the modulatory effect on sighs, while flufenamic acid, an antagonist for the calcium-activated non-selective cation conductance (ICAN) abolished the effect of PGE2 on fictive eupnoea at higher concentrations. At the cellular level PGE2 significantly increased the amplitude and frequency of intrinsic bursting in inspiratory neurons. By contrast PGE2 affected neither excitatory nor inhibitory synaptic transmission. We conclude that PGE2 differentially modulates sigh, gasping and eupnoeic activity by differentially increasing INap and ICAN currents in preBötC neurons. PMID:25556802

  18. The evolution of temperature extremes in the Gaspé Peninsula, Quebec, Canada (1974-2013)

    NASA Astrophysics Data System (ADS)

    Fortin, Guillaume; Acquaotta, Fiorella; Fratianni, Simona

    2016-07-01

    The majority of natural hazards that affect Canadian territory are the result of extreme climate and weather conditions. Among these weather hazards, some can be calculated from the application of thresholds for minimum and maximum temperatures at a daily or monthly timescale. These thermal indices allowed the prediction of extreme conditions that may have an impact on the human population by affecting, for example, health, agriculture, and water resources. In this article, we discuss the methods used (RHtestsV4, SPLIDHOM, ClimPACT) then describe the steps followed to calculate the indices, including how we dealt with the problem of missing data and the necessity to identify a common methodology to analyze the time series. We also present possible solutions for ensuring the quality of meteorological data. We then present an overview of the results, namely the main trends and variability of extreme temperature for seven stations located in the Gaspé Peninsula from 1974 to 2013. Our results indicate some break points in time series and positive trends for most indices related to the rise of the temperatures but indicate a negative trend for the indices related to low temperatures for most stations during the study period.

  19. HERSCHEL PACS OBSERVATIONS AND MODELING OF DEBRIS DISKS IN THE TUCANA-HOROLOGIUM ASSOCIATION

    SciTech Connect

    Donaldson, J. K.; Roberge, A.; Chen, C. H.; Augereau, J.-C.; Menard, F.; Eiroa, C.; Meeus, G.; Krivov, A. V.; Mathews, G. S.; Riviere-Marichalar, P.; Sandell, G.

    2012-07-10

    We present Herschel PACS photometry of 17 B- to M-type stars in the 30 Myr old Tucana-Horologium Association. This work is part of the Herschel Open Time Key Programme 'Gas in Protoplanetary Systems'. 6 of the 17 targets were found to have infrared excesses significantly greater than the expected stellar IR fluxes, including a previously unknown disk around HD30051. These six debris disks were fitted with single-temperature blackbody models to estimate the temperatures and abundances of the dust in the systems. For the five stars that show excess emission in the Herschel PACS photometry and also have Spitzer IRS spectra, we fit the data with models of optically thin debris disks with realistic grain properties in order to better estimate the disk parameters. The model is determined by a set of six parameters: surface density index, grain size distribution index, minimum and maximum grain sizes, and the inner and outer radii of the disk. The best-fitting parameters give us constraints on the geometry of the dust in these systems, as well as lower limits to the total dust masses. The HD105 disk was further constrained by fitting marginally resolved PACS 70 {mu}m imaging.

  20. The far-infrared behaviour of Herbig Ae/Be discs: Herschel PACS photometry

    NASA Astrophysics Data System (ADS)

    Pascual, N.; Montesinos, B.; Meeus, G.; Marshall, J. P.; Mendigutía, I.; Sandell, G.

    2016-02-01

    Herbig Ae/Be objects are pre-main sequence stars surrounded by gas- and dust-rich circumstellar discs. These objects are in the throes of star and planet formation, and their characterisation informs us of the processes and outcomes of planet formation processes around intermediate mass stars. Here we analyse the spectral energy distributions of disc host stars observed by the Herschel open time key programme "Gas in Protoplanetary Systems". We present Herschel/PACS far-infrared imaging observations of 22 Herbig Ae/Bes and 5 debris discs, combined with ancillary photometry spanning ultraviolet to sub-millimetre wavelengths. From these measurements we determine the diagnostics of disc evolution, along with the total excess, in three regimes spanning near-, mid-, and far-infrared wavelengths. Using appropriate statistical tests, these diagnostics are examined for correlations. We find that the far-infrared flux, where the disc becomes optically thin, is correlated with the millimetre flux, which provides a measure of the total dust mass. The ratio of far-infrared to sub-millimetre flux is found to be greater for targets with discs that are brighter at millimetre wavelengths and that have steeper sub-millimetre slopes. Furthermore, discs with flared geometry have, on average, larger excesses than flat geometry discs. Finally, we estimate the extents of these discs (or provide upper limits) from the observations. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. Deep Herschel PACS point spread functions

    NASA Astrophysics Data System (ADS)

    Bocchio, M.; Bianchi, S.; Abergel, A.

    2016-06-01

    The knowledge of the point spread function (PSF) of imaging instruments represents a fundamental requirement for astronomical observations. The Herschel PACS PSFs delivered by the instrument control centre are obtained from observations of the Vesta asteroid, which provides a characterisation of the central part and, therefore, excludes fainter features. In many cases, however, information on both the core and wings of the PSFs is needed. With this aim, we combine Vesta and Mars dedicated observations and obtain PACS PSFs with an unprecedented dynamic range (~106) at slow and fast scan speeds for the three photometric bands. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.FITS files of our PACS PSFs (Fig. 2) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A117

  2. Vibrationally excited molecular hydrogen near Herschel 36

    SciTech Connect

    Rachford, Brian L.; Snow, Theodore P.; Ross, Teresa L.

    2014-05-10

    We present the first high resolution UV spectra toward Herschel 36, a Trapezium-like system of high-mass stars contained within the Lagoon Nebula (M8, NGC 6523). The spectra reveal extreme rovibrational excitation of molecular hydrogen in material at a single velocity or very small range of velocities, with this component presumably lying near the star system and undergoing fluorescent excitation. The overall H{sub 2} excitation is similar to, but apparently larger than, that seen toward HD 37903 which previously showed the largest vibrationally excited H{sub 2} column densities seen in UV absorption spectra. While the velocities of the highly excited H{sub 2} lines are consistent within each observation, it appears that they underwent a ∼60 km s{sup –1} redshift during the 3.6 yr between observations. In neither case does the velocity of the highly excited material match the velocity of the bulk of the line-of-sight material which appears to mostly be in the foreground of M8. Recent work shows unusually excited CH and CH{sup +} lines and several unusually broad diffuse interstellar bands toward Herschel 36. Along with the H{sub 2} excitation, all of these findings appear to be related to the extreme environment within ∼0.1 pc of the massive young stellar system.

  3. William Herschel and the 'garnet' stars: μ Cephei and more

    NASA Astrophysics Data System (ADS)

    Steinicke, Wolfgang

    2015-07-01

    Although William Herschel's 'Garnet Star' (μ Cephei) is a prominent object, the story of the discovery of this famous red star is not well documented. Prior to and after Herschel, the identification of this star was the subject of confusion in various catalogues and atlases. The case is complex and involves other stars in southern Cepheus, including double stars, found by Herschel in the course of his star surveys. It is also fascinating to learn that μ Cephei is not the only star called 'garnet' by him. This study reveals that there are 21 in all, resulting in a 'Herschel Catalogue of Garnet Stars' - the first historical catalogue of red stars. Among them are prominent objects, which in the literature are credited to later observers. This misconception is corrected here, for Herschel was the true discoverer of all of them. The most interesting cases are Hind's 'Crimson Star', Secchi's 'La Superba', John Herschel's 'Ruby Star' and Schmidt's V Aquilae. Finally, we discussed whether Herschel speculated about the physical nature of his garnet stars, many of which are now known to be variable.

  4. The European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP)--a sentinel approach in the European Union (EU)/European Economic Area (EEA).

    PubMed

    Spiteri, Gianfranco; Cole, Michelle; Unemo, Magnus; Hoffmann, Steen; Ison, Catherine; van de Laar, Marita

    2013-12-01

    Antimicrobial resistance in Neisseria gonorrhoeae is monitored in the European Union/European Economic Area through the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) coordinated by the European Centre for Disease Prevention and Control. Euro-GASP includes a sentinel surveillance programme which aims to detect in a timely manner changes in resistance patterns and inform treatment guidelines. The programme aims to test a representative number of isolates from each European Union/European Economic Area member state per year for a range of therapeutically relevant antimicrobials through a biannual hybrid centralised/decentralised system. Testing is supported by an External Quality Assurance programme and a laboratory training programme. Participation in the programme has increased to 21 countries in 2012. Euro-GASP has been able to detect the rapid spread of isolates with decreased susceptibility to cefixime across Europe in 2010 and 2011. Results from the programme have informed changes in European treatment guidelines for gonorrhoea and led to the development of the 'Response plan to control and manage the threat of multidrug resistant gonorrhoea in Europe'. Future challenges for Euro-GASP include supporting countries to participate in Euro-GASP through decentralised testing, improving timeliness and epidemiological data quality, and increasing participation from Eastern Europe. PMID:24243874

  5. An investigation of the Eigenvalue Calibration Method (ECM) using GASP for non-imaging and imaging detectors

    NASA Astrophysics Data System (ADS)

    Kyne, Gillian; Lara, David; Hallinan, Gregg; Redfern, Michael; Shearer, Andrew

    2016-02-01

    Polarised light from astronomical targets can yield a wealth of information about their source radiation mechanisms, and about the geometry of the scattered light regions. Optical observations, of both the linear and circular polarisation components, have been impeded due to non-optimised instrumentation. The need for suitable observing conditions and the availability of luminous targets are also limiting factors. The science motivation of any instrument adds constraints to its operation such as high signal-to-noise (SNR) and detector readout speeds. These factors in particular lead to a wide range of sources that have yet to be observed. The Galway Astronomical Stokes Polarimeter (GASP) has been specifically designed to make observations of these sources. GASP uses division of amplitude polarimeter (DOAP) (Compain and Drevillon Appl. Opt. 37, 5938-5944, 1998) to measure the four components of the Stokes vector (I, Q, U and V) simultaneously, which eliminates the constraints placed upon the need for moving parts during observation, and offers a real-time complete measurement of polarisation. Results from the GASP calibration are presented in this work for both a 1D detector system, and a pixel-by-pixel analysis on a 2D detector system. Following Compain et al. (Appl. Opt. 38, 3490-3502 1999) we use the Eigenvalue Calibration Method (ECM) to measure the polarimetric limitations of the instrument for each of the two systems. Consequently, the ECM is able to compensate for systematic errors introduced by the calibration optics, and it also accounts for all optical elements of the polarimeter in the output. Initial laboratory results of the ECM are presented, using APD detectors, where errors of 0.2 % and 0.1° were measured for the degree of linear polarisation (DOLP) and polarisation angle (PA) respectively. Channel-to-channel image registration is an important aspect of 2-D polarimetry. We present our calibration results of the measured Mueller matrix of each sample

  6. GASP: A Performance Analysis Tool Interface for Global AddressSpace Programming Models, Version 1.5

    SciTech Connect

    Leko, Adam; Bonachea, Dan; Su, Hung-Hsun; George, Alan D.; Sherburne, Hans; George, Alan D.

    2006-09-14

    Due to the wide range of compilers and the lack of astandardized performance tool interface, writers of performance toolsface many challenges when incorporating support for global address space(GAS) programming models such as Unified Parallel C (UPC), Titanium, andCo-Array Fortran (CAF). This document presents a Global Address SpacePerformance tool interface (GASP) that is flexible enough to be adaptedinto current global address space compiler and runtime infrastructureswith little effort, while allowing performance analysis tools to gathermuch information about the performance of global address spaceprograms.

  7. Proteomics analysis of a long-term survival strain of Escherichia coli K-12 exhibiting a growth advantage in stationary-phase (GASP) phenotype.

    PubMed

    Gagliardi, Assunta; Lamboglia, Egidio; Bianchi, Laura; Landi, Claudia; Armini, Alessandro; Ciolfi, Silvia; Bini, Luca; Marri, Laura

    2016-03-01

    The aim of this work was the functional and proteomic analysis of a mutant, W3110 Bgl(+) /10, isolated from a batch culture of an Escherichia coli K-12 strain maintained at room temperature without addition of nutrients for 10 years. When the mutant was evaluated in competition experiments in co-culture with the wild-type, it exhibited the growth advantage in stationary phase (GASP) phenotype. Proteomes of the GASP mutant and its parental strain were compared by using a 2DE coupled with MS approach. Several differentially expressed proteins were detected and many of them were successful identified by mass spectrometry. Identified expression-changing proteins were grouped into three functional categories: metabolism, protein synthesis, chaperone and stress responsive proteins. Among them, the prevalence was ascribable to the "metabolism" group (72%) for the GASP mutant, and to "chaperones and stress responsive proteins" group for the parental strain (48%). PMID:26711811

  8. NASA Global Atmospheric Sampling Program (GASP). Data report for tape VL0001. [data management and data retrieval of information from environmental surveys

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.; Lezberg, E. A.

    1976-01-01

    Atmospheric trace constituents in the upper troposphere and lower stratosphere are now being measured as part of the NASA Global Atmospheric Sampling Program (GASP), using fully automated air sampling systems on board commercial 747 aircraft in routine airline service. Measurements of atmospheric ozone and related meteorological and flight information obtained during several GASP flights in March 1975 are now available from the National Climatic Center, Asheville, North Carolina. In addition to the data from the aircraft, tropopause pressure data obtained from the National Meteorological Center (NMC) archives for the dates of the flights are included. This report is the first of a series of reports which describes the data currently available from GASP, including flight routes and dates, instrumentation, the data processing procedure used, and data tape specifications.

  9. The neutral diffuse ISM after Herschel

    NASA Astrophysics Data System (ADS)

    Neufeld, David A.

    2015-08-01

    Observations with the Herschel Space Observatory have greatly enhanced our understanding of neutral diffuse material in the interstellar medium. In particular, high-resolution absorption line spectroscopy at THz frequencies has led to the discovery of several new interstellar molecules - including SH+, OH+, H2O, H2Cl+, HCl+, and ArH+ (the first known astrophysical molecule containing a noble gas atom) - and has enabled astrochemical studies in which the abundances of multiple species are measured and modeled. Because of the different chemical pathways responsible for their formation and destruction, different molecules probe specific aspects of the interstellar environment. Carefully interpreted, they provide unique information about the cosmic ray density, the molecular fraction, the ultraviolet radiation field, and the dissipation of energy within the turbulent interstellar medium. Future spectroscopic observations with ALMA and SOFIA promise to extend further our understanding of fundamental physical and chemical processes the neutral diffuse ISM.

  10. Caroline Herschel: agency and self-presentation

    PubMed Central

    Winterburn, Emily

    2015-01-01

    Caroline Herschel was rare among her female contemporaries in gaining public recognition for her work in science, yet her role in this process and her role in designing her training have never previously been studied. We know that access to education and participation in science was different for men and women in the eighteenth century. However, drawing on feminist, pedagogical and biographical approaches to history, I argue that although access depended on a variety of factors, a more consistent gender divide came in lessons on how to learn, and in what was regarded as appropriate behaviour. Caroline's skill—so often misunderstood—was to be aware of the differences and to use them to her own advantage. PMID:26489184

  11. CAROLINE HERSCHEL: AGENCY AND SELF-PRESENTATION.

    PubMed

    Winterburn, Emily

    2015-03-20

    Caroline Herschel was rare among her female contemporaries in gaining public recognition for her work in science, yet her role in this process and her role in designing her training have never previously been studied. We know that access to education and participation in science was different for men and women in the eighteenth century. However, drawing on feminist, pedagogical and biographical approaches to history, I argue that although access depended on a variety of factors, a more consistent gender divide came in lessons on how to learn, and in what was regarded as appropriate behaviour. Caroline's skill--so often misunderstood--was to be aware of the differences and to use them to her own advantage. PMID:26489184

  12. First Observations Of Titan With Herschel Spire

    NASA Astrophysics Data System (ADS)

    Courtin, Regis D.; Swinyard, B. M.; Fulton, T.; Lellouch, E.; Moreno, R.; Hartogh, P.; Jarchow, C.; Rengel, M.; HssO Team

    2010-10-01

    A Titan spectrum was recorded on June 22, 2010 with the SPIRE instrument of the Herschel Space Observatory as part of the guaranteed time key programme "Water and related chemistry in the Solar System" (KP-GT HssO). This initial spectrum, corresponding to an exposure time of 1322s, was designed as a test of the full 10h Titan observation performed on July 16, 2010. It covers the 14.6-51.8 cm-1 interval with a unapodized spectral resolution of 0.04 cm-1. Despite the limited integration time, numerous transitions are detected, notably those of CH4, CO, HCN, and of the isotopologues 13CO, C18O, H13CN, and HC15N. The analysis of this set of observations will provide new determinations of the abundances of these species, and hence new contraints on the isotopic ratios 12C/13C, 14N/15N and 16O/18O in Titan's atmosphere.

  13. An image display package for Herschel DP based on Jsky

    NASA Astrophysics Data System (ADS)

    Meester, W. D.; Huygen, R.

    2006-07-01

    The Data Processing software for ESA's Herschel Space Observatory is written in JAVA as a joint effort of ESA and the three instrument teams. The observers as well as the instrument specialists will use a jython environment to reduce the science observations and to analyse the calibration measurements of the instrument. We describe the development of an image display package for Herschel DP (Data Processing) based on JSky, which is being developed as part of the Gemini Observing Tool and the difficulties we encountered in adapting the JSky library to the needs of Herschel DP. We give insights in the adaption to the Herschel DP data structures and the possibility to display both two- and three dimensional arrays and images. We describe the power of using Jython as a frontend and the possibility to use this image display in GUI's written by or for observers.

  14. Herschel Dust Measurements of SDSS Supernovae Host Galaxies

    NASA Astrophysics Data System (ADS)

    Trinh, Donald; Cooray, Asantha R.; Nayyeri, Hooshang; Herschel Hermes and h-atlas Collaboration

    2016-01-01

    We use Herschel Spectral and Photometric Imaging Receiver (SPIRE) far-infrared observations of Supernova host galaxies to study the cosmological distant measurement from Hubble diagrams. We investigate the dust content of SN host galaxy from the Sloan Digital Sky Survery (SDSS) using the far-infrared stacks of Herschel in the Equatorial Stripe using , Herschel Multi-Tiered Extragalactic Survey (HELMS), and the Herschel Stripe 82 Survey (HERS). Cosmic dust may contribute to much more obscuring of standard candles than previously thought. Measuring the average flux values of stacks from dim Type-Ia supernovae provides a measure of the dust content of galaxies as a function of deviation of those sources from the Hubble diagram given a standard cosmology. Using the optical to far infrared stacked data of the galaxies we also measure the physical properties of the standard candles as a function of dust content.

  15. Sir William Herschel's notebooks - Abstracts of solar observations

    NASA Technical Reports Server (NTRS)

    Hoyt, Douglas V.; Schatten, Kenneth H.

    1992-01-01

    An introduction to the background of Sir William Herschel's notebooks and the historical context within which his observations were made are provided. The observations have relevance in reconstructing solar behavior, as discussed in a separate analysis paper by Hoyt and Schatten (1992), and in understanding active features on the sun such as faculae. The text of Herschel's notebooks with modern terms used throughout forms the body of this paper. The complete text has not previously been published and is not easily accessible to scholars. Herschel used different words for solar features than are used today, and thus, for clarity, his terminology is changed on two occasions. A glossary explains the terminology changed. In the text of the notebooks, several contemporaries are mentioned; a brief description of Herschel's colleagues is provided.

  16. Herschel Measurements of Molecular Oxygen in Orion

    NASA Astrophysics Data System (ADS)

    Goldsmith, Paul F.; Liseau, René; Bell, Tom A.; Black, John H.; Chen, Jo-Hsin; Hollenbach, David; Kaufman, Michael J.; Li, Di; Lis, Dariusz C.; Melnick, Gary; Neufeld, David; Pagani, Laurent; Snell, Ronald; Benz, Arnold O.; Bergin, Edwin; Bruderer, Simon; Caselli, Paola; Caux, Emmanuel; Encrenaz, Pierre; Falgarone, Edith; Gerin, Maryvonne; Goicoechea, Javier R.; Hjalmarson, Åke; Larsson, Bengt; Le Bourlot, Jacques; Le Petit, Franck; De Luca, Massimo; Nagy, Zsofia; Roueff, Evelyne; Sandqvist, Aage; van der Tak, Floris; van Dishoeck, Ewine F.; Vastel, Charlotte; Viti, Serena; Yıldız, Umut

    2011-08-01

    We report observations of three rotational transitions of molecular oxygen (O2) in emission from the H2 Peak 1 position of vibrationally excited molecular hydrogen in Orion. We observed the 487 GHz, 774 GHz, and 1121 GHz lines using the Heterodyne Instrument for the Far Infrared on the Herschel Space Observatory, having velocities of 11 km s-1 to 12 km s-1 and widths of 3 km s-1. The beam-averaged column density is N(O2) = 6.5 × 1016 cm-2, and assuming that the source has an equal beam-filling factor for all transitions (beam widths 44, 28, and 19''), the relative line intensities imply a kinetic temperature between 65 K and 120 K. The fractional abundance of O2 relative to H2 is (0.3-7.3) × 10-6. The unusual velocity suggests an association with a ~5'' diameter source, denoted Peak A, the Western Clump, or MF4. The mass of this source is ~10 M sun and the dust temperature is >=150 K. Our preferred explanation of the enhanced O2 abundance is that dust grains in this region are sufficiently warm (T >= 100 K) to desorb water ice and thus keep a significant fraction of elemental oxygen in the gas phase, with a significant fraction as O2. For this small source, the line ratios require a temperature >=180 K. The inferred O2 column density sime5 × 1018 cm-2 can be produced in Peak A, having N(H2) ~= 4 × 1024 cm-2. An alternative mechanism is a low-velocity (10-15 km s-1) C-shock, which can produce N(O2) up to 1017 cm-2. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  17. GASP cloud- and particle-encounter statistics and their application to LPC aircraft studies. Volume 1: Analysis and conclusions

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastrom, G. D.; Davis, R. E.; Holdeman, J. D.

    1984-01-01

    Summary studies are presented for the entire cloud observation archieve from the NASA Global Atmospheric Sampling Program (GASP). Studies are also presented for GASP particle concentration data gathered concurrently with the cloud observations. Cloud encounters are shown on about 15 percent of the data samples overall, but the probability of cloud encounter is shown to vary significantly with altitude, latitude, and distance from the tropopause. Several meteorological circulation features are apparent in the latitudinal distribution of cloud cover, and the cloud encounter statistics are shown to be consistent with the classical mid-latitude cyclone model. Observations of clouds spaced more closely than 90 minutes are shown to be statistically dependent. The statistics for cloud and particle encounter are utilized to estimate the frequency of cloud encounter on long range airline routes, and to assess the probability and extent of laminar flow loss due to cloud or particle encounter by aircraft utilizing laminar flow control (LFC). It is shown that the probability of extended cloud encounter is too low, of itself, to make LFC impractical.

  18. GASP cloud- and particle-encounter statistics and their application to LFC aircraft studies. Volume 2: Appendixes

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastron, G. D.; Davis, R. E.; Holdeman, J. D.

    1984-01-01

    Summary studies are presented for the entire cloud observation archive from the NASA Global Atmospheric Sampling Program (GASP). Studies are also presented for GASP particle-concentration data gathered concurrently with the cloud observations. Cloud encounters are shown on about 15 percent of the data samples overall, but the probability of cloud encounter is shown to vary significantly with altitude, latitude, and distance from the tropopause. Several meteorological circulation features are apparent in the latitudinal distribution of cloud cover, and the cloud-encounter statistics are shown to be consistent with the classical mid-latitude cyclone model. Observations of clouds spaced more closely than 90 minutes are shown to be statistically dependent. The statistics for cloud and particle encounter are utilized to estimate the frequency of cloud encounter on long-range airline routes, and to assess the probability and extent of laminaar flow loss due to cloud or particle encounter by aircraft utilizing laminar flow control (LFC). It is shown that the probability of extended cloud encounter is too low, of itself, to make LFC impractical. This report is presented in two volumes. Volume I contains the narrative, analysis, and conclusions. Volume II contains five supporting appendixes.

  19. Vertical and horizontal fluxes of ozone at the tropopause from the first year of GASP data. [Global Atmospheric Sampling Program

    NASA Technical Reports Server (NTRS)

    Nastrom, G. D.

    1977-01-01

    Ozone measurements taken from commercial airlines (GASP data) are used to estimate the vertical and horizontal fluxes of ozone near the tropopause. The annual average flux of O3 into the troposphere at 30 to 50 deg N is nearly the same as indirect estimates based on surface O3 data, thus supporting the hypothesis that the amount of ozone in the troposphere is essentially controlled by injection from the stratosphere. The present GASP estimates of the total flux of O3 into the troposphere verify the model results of Cunnold et al. (1975), although the distribution of flux between mean motions and diffusion is different and suggests that models with coarse horizontal resolution must continue to parameterize much vertical transport by diffusion coefficients. A significant variation in the east-west spatial autocorrelation function of O3 near the tropopause is found to be about 1900 km. Monthly estimates of the horizontal transient eddy flux of ozone are generally smaller than seasonal or yearly results based on ozonesonde data. This is perhaps because the present estimates are made over monthly periods to reduce the influence of correlation between the annual variations in ozone and meridional wind. The available data support the hypothesis that transient eddy fluxes of O3 have large longitudinal variations.

  20. Geophysical astrophysical spectral-element adaptive refinement (GASpAR): Object-oriented h-adaptive fluid dynamics simulation

    NASA Astrophysics Data System (ADS)

    Rosenberg, Duane; Fournier, Aimé; Fischer, Paul; Pouquet, Annick

    2006-06-01

    An object-oriented geophysical and astrophysical spectral-element adaptive refinement (GASpAR) code is introduced. Like most spectral-element codes, GASpAR combines finite-element efficiency with spectral-method accuracy. It is also designed to be flexible enough for a range of geophysics and astrophysics applications where turbulence or other complex multiscale problems arise. The formalism accommodates both conforming and non-conforming elements. Several aspects of this code derive from existing methods, but here are synthesized into a new formulation of dynamic adaptive refinement (DARe) of non-conforming h-type. As a demonstration of the code, several new 2D test cases are introduced that have time-dependent analytic solutions and exhibit localized flow features, including the 2D Burgers equation with straight, curved-radial and oblique-colliding fronts. These are proposed as standard test problems for comparable DARe codes. Quantitative errors are reported for 2D spatial and temporal convergence of DARe.

  1. The Herschel Lensing Survey (HLS): HST Frontier Field Coverage

    NASA Astrophysics Data System (ADS)

    Egami, Eiichi

    2015-08-01

    The Herschel Lensing Survey (HLS; PI: Egami) is a large Far-IR/Submm imaging survey of massive galaxy clusters using the Herschel Space Observatory. Its main goal is to detect and study IR/Submm galaxies that are below the nominal confusion limit of Herschel by taking advantage of the strong gravitational lensing power of massive galaxy clusters. HLS has obtained deep PACS (100/160 um) and SPIRE (250/350/500 um) images for 54 cluster fields (HLS-deep) as well as shallower but nearly confusion-limited SPIRE-only images for 527 cluster fields (HLS-snapshot) with a total observing time of ~420 hours. Extensive multi-wavelength follow-up studies are currently on-going with a variety of observing facilities including ALMA.Here, I will focus on the analysis of the deep Herschel PACS/SPIRE images obtained for the 6 HST Frontier Fields (5 observed by HLS-deep; 1 observed by the Herschel GT programs). The Herschel/SPIRE maps are wide enough to cover the Frontier-Field parallel pointings, and we have detected a total of ~180 sources, some of which are strongly lensed. I will present the sample and discuss the properties of these Herschel-detected dusty star-forming galaxies (DSFGs) identified in the Frontier Fields. Although the majority of these Herschel sources are at moderate redshift (z<3), a small number of extremely high-redshift (z>6) candidates can be identified as "Herschel dropouts" when combined with longer-wavelength data. We have also identified ~40 sources as likely cluster members, which will allow us to study the properties of DSFGs in the dense cluster environment.A great legacy of our HLS project will be the extensive multi-wavelength database that incorporates most of the currently available data/information for the fields of the Frontier-Field, CLASH, and other HLS clusters (e.g., HST/Spitzer/Herschel images, spectroscopic/photometric redshifts, lensing models, best-fit SED models etc.). Provided with a user-friendly GUI and a flexible search engine, this

  2. A Herschel study of NGC 650

    NASA Astrophysics Data System (ADS)

    van Hoof, P. A. M.; Van de Steene, G. C.; Exter, K. M.; Barlow, M. J.; Ueta, T.; Groenewegen, M. A. T.; Gear, W. K.; Gomez, H. L.; Hargrave, P. C.; Ivison, R. J.; Leeks, S. J.; Lim, T. L.; Olofsson, G.; Polehampton, E. T.; Swinyard, B. M.; Van Winckel, H.; Waelkens, C.; Wesson, R.

    2013-12-01

    As part of the Herschel guaranteed time key project Mass loss of Evolved StarS (MESS) we have imaged a sample of planetary nebulae. In this paper we present the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) images of the classical bipolar planetary nebula NGC 650. We used these images to derive a temperature map of the dust. We also constructed a photoionization and dust radiative transfer model using the spectral synthesis code Cloudy. To constrain this model, we used the PACS and SPIRE fluxes and combined them with hitherto unpublished International Ultraviolet Explorer (IUE) and Spitzer InfraRed Spectrograph (IRS) spectra as well as various other data from the literature. A temperature map combined with a photoionization model were used to study various aspects of the central star, the nebula, and in particular the dust grains in the nebula. The central star parameters are determined to be Teff = 208 kK and L = 261 L⊙ assuming a distance of 1200 pc. The stellar temperature is much higher than previously published values. We confirm that the nebula is carbon-rich with a C/O ratio of 2.1. The nebular abundances are typical for a type IIa planetary nebula. With the photoionization model we determined that the grains in the ionized nebula are large (assuming single-sized grains, they would have a radius of 0.15 μm). Most likely these large grains were inherited from the asymptotic giant branch phase. The PACS 70/160 μm temperature map shows evidence of two radiation components heating the grains. The first component is direct emission from the central star, while the second component is diffuse emission from the ionized gas (mainly Lyα). We show that previous suggestions of a photo-dissociation region surrounding the ionized region are incorrect. The neutral material resides in dense clumps inside the ionized region. These may also harbor stochastically heated very small grains in addition to the large

  3. Irish America at the Crossroads: A New Beginning or the Last Gasp of Irish Immigration in the Twenty-First Century?

    ERIC Educational Resources Information Center

    Sarbaugh, Timothy J.

    1991-01-01

    Demographic patterns of immigration to the United States from Ireland are examined, and a scenario is projected for Irish immigration in the twenty-first century. It is argued that the wave of Irish immigration of the 1980s will prove to be a last gasp of a 200-year-old tradition. (SLD)

  4. A bright near-IR state of the blazar 4C 38.41 (1633+382) observed by the GASP

    NASA Astrophysics Data System (ADS)

    Carnerero, M. I.; Raiteri, C. M.; Villata, M.; Acosta-Pulido, J. A.; Velasco, S.; Gonzalez-Morales, Pedro A.

    2013-07-01

    The flat-spectrum radio quasar 4C 38.41 (1633+382) is one of the 28 blazars for which the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) performs a long-term, multiwavelength monitoring.

  5. Observations of ammonia in comets with Herschel

    NASA Astrophysics Data System (ADS)

    Biver, N.; Bockelée-Morvan, D.; Hartogh, P.; Crovisier, J.; de Val-Borro, M.; Kidger, M.; Küppers, M.; Lis, D.; Moreno, R.; Szutowicz, S.; HssO Team

    2014-07-01

    Ammonia is the most abundant nitrogen bearing species in comets. However, it has been scarcely observed in comets due to the weakness of the lines observable from the ground at infrared and centimetre wavelengths. Nevertheless, its main photodissociation product NH_2 has been observed in several comets in the visible. The fundamental rotational J_{K}=(1_0-0_0) transition of NH_3 at 572.5 GHz has been observed in comets since 2004, with the Odin satellite (Biver et al. 2007). In the frame of the Herschel guaranteed time key program ''HssO'' (Hartogh et al. 2009), ammonia was detected with the HIFI instrument in comets 10P/Tempel 2 (Biver et al. 2012), 45P/Honda- Mrkos-Pajdusakova, 103P/Hartley 2, and C/2009 P1 (Garradd). The hyperfine structure of the line is resolved. We have built a complete excitation model to interpret these observations, including the radial distribution in comet 103P. The derived abundances relative to water are on the order of 0.5 %, similar to the values inferred from visible observations of NH_2.

  6. New results from the Herschel Reference Survey

    NASA Astrophysics Data System (ADS)

    Boselli, A.

    2013-11-01

    The Herschel Reference Survey is a SPIRE guaranteed time key project aimed at studying the properties of the interstellar medium of a K-band selected, volume-limited (15 ≤ D ≤ 25 Mpc) complete sample of 322 galaxies spanning a large range in morphological type and stellar mass. We study the far infrared colours of the late-type galaxies of the cluster with the purpose of tracing with an empirical approach the relationships between the shape of the observed spectral energy distribution (SED) and different physical parameters such as the star formation rate, the birthrate parameter (or specific star formation rate), here taken as a tracer of the hardness of the inciding radiation, the intensity of the ionising and non ionising radiation, the metallicity and the Hα and FUV attenuation. We also show that the far infrared shape of the SED cannot be fitted with a modified black body with a fixed grain emissivity parameter β. All this analysis is a brief summary of a work presented in Boselli_etal. (2012).

  7. Herschel far-infrared observations of the Carina Nebula complex. II. The embedded young stellar and protostellar population

    NASA Astrophysics Data System (ADS)

    Gaczkowski, B.; Preibisch, T.; Ratzka, T.; Roccatagliata, V.; Ohlendorf, H.; Zinnecker, H.

    2013-01-01

    -mass and intermediate-mass stars, but no massive (M ≳ 20 M⊙) stars. The characteristic spatial configuration of the YSOs provides support to the picture that the formation of this latest stellar generation is triggered by the advancing ionization fronts. The Herschel data described in this paper have been obtained in the open time project OT1_tpreibis1 (PI: T. Preibisch). Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables A.1, B.1, C.1, and D.1 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/549/A67

  8. OverPlotter: A Utility for Herschel Data Processing

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Mei, Y.; Schulz, B.

    2008-08-01

    The OverPlotter utility is a GUI tool written in Java to support interactive data processing (DP) and analysis for the Herschel Space Observatory within the framework of the Herschel Common Science System (HCSS)(Wieprecht et al 2004). The tool expands upon the capabilities of the TableViewer (Zhang & Schulz 2005), providing now also the means to create additional overlays of several X/Y scatter plots within the same display area. These layers can be scaled and panned, either individually, or together as one graph. Visual comparison of data with different origins and units becomes much easier. The number of available layers is not limited, except by computer memory and performance. Presentation images can be easily created by adding annotations, labeling layers and setting colors. The tool will be very helpful especially in the early phases of Herschel data analysis, when a quick access to contents of data products is important.

  9. A concert of music by Sir William Herschel

    NASA Astrophysics Data System (ADS)

    Hessman, F. V.; Hammer, C.

    2002-01-01

    The Orchester Göttinger Musikfreunde presented an evening of music in the magnificent Aula of the University as one of the social events of the conference. The astronomical highlights of the concert were two symphonic works by Sir William Herschel, including an oboe solo by a member of the LOC (W. Glatzel). This is the text from the concert programme. A recording of the concert is included in this proceedings. Programme --------- Sir William Herschel (1738-1822): Symphony No. 13 in D Major (1762) W. A. Mozart (1756-1791): Piano Concerto No. 27 in B Major (KV 595), C. Hammer (piano) Sir William Herschel (1738-1822): Fragment of an Oboe Concerto in C Major (MS790), W. Glatzel (oboe) J. Haydn (1732-1809): Symphony No. 91 E-flat Major We would like to acknowledge the Sparkasse Göttingen and the Versicherungsgesellschaft Hannover for generously making this concert possible.

  10. Interstellar dust on the eve of Herschel and Planck

    NASA Astrophysics Data System (ADS)

    Miville-Deschênes, M.-A.

    2008-11-01

    In this contribution I review some of the key scientific questions that animate the interstellar dust community a few months before the launch of Herschel and Planck. Great progress have been made in the past 25 years on the subject of interstellar dust using infrared observations from space. With the advent of sub-millimeter and millimeter observations with Herschel and Planck, new scientific challenges are coming and exciting discoveries are to be expected. In particular Herschel and Planck will bring key information 1) on the growth process of dust grains, the first step toward the formation of planetesimals, 2) on the structure of the interstellar medium and its link with interstellar turbulence, 3) on the physical conditions of the Galactic halo clouds which are thought to have some cold dust, 4) on the properties of the interstellar magnetic field and 5) on the interstellar PAHs using their spinning dust emission in the millimeter.

  11. Enhancing the Legacy of Spitzer and Herschel with the MOSFIRE Deep Evolution Field Survey

    NASA Astrophysics Data System (ADS)

    Reddy, Naveen

    The next frontier for comprehensive galaxy surveys is the epoch at z~1.5-3.5, the peak of star formation and black hole activity. Despite the new windows that Spitzer and Herschel have opened up into the stellar and dust emission of distant galaxies and AGN during this key epoch, these studies have been limited by the lack of spectroscopic redshifts and the unknown physical conditions (e.g., metallicities, ionization) within the targeted galaxies. To realize the full potential of Spitzer and Herschel, we require a large spectroscopic survey that will: (a) efficiently assemble spectroscopic redshifts for large samples of galaxies at z=1.4-3.8; (b) yield the physical conditions, including the ionization and metallicities of these galaxies; and (c) easily obtain spectroscopic redshifts even for very dusty/confused galaxies. To this end, our team has been allocated a large program of 47 Keck nights with the multi-object near-IR spectrograph MOSFIRE to carry out the MOSFIRE Deep Evolution Field Survey (MOSDEF) in three of the Hubble CANDELS fields. MOSDEF will obtain rest-optical spectra of ~1500 galaxies at redshifts z=1.4-3.8, targeting many of the optical nebular emission lines and continuum features (e.g., [OII], [OIII], H-beta, H-alpha, [NII], [SII], 4000 Angstrom break, Ca H and K, and Mbg) that until now have been inaccessible for large samples of distant galaxies, but which are routinely used to measure the SFRs, dust attenuation, metal and gas content, and ionization and dynamical properties in nearby galaxies. MOSDEF spectroscopy provides a critical supporting role for the analysis of Spitzer and Herschel observations of distant galaxies. With this transformative dataset, we will perform the following analyses. First, we will use Spitzer and Herschel imaging, aided with spectroscopic redshifts from MOSDEF, to construct individual and mean dust SEDs for galaxies at redshifts 1.4

  12. Herschel far-infrared observations of the Carina Nebula complex. I. Introduction and global cloud structure

    NASA Astrophysics Data System (ADS)

    Preibisch, T.; Roccatagliata, V.; Gaczkowski, B.; Ratzka, T.

    2012-05-01

    the strong feedback from numerous massive stars and the corresponding cloud dispersal processes that are going on since several million years, there are still several 10 000 M⊙ of cool cloud material present at column-densities sufficient for further star formation. Comparison of our total gas mass estimates to molecular cloud masses derived from CO line mapping suggests that as much as about 75% of all the gas is in atomic rather than molecular form. The Herschel data described in this paper have been obtained in the open time project OT1_tpreibis1 (PI: T. Preibisch). Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix A is available in electronic form at http://www.aanda.org

  13. Infrared study of transitional disks in Ophiuchus with Herschel

    NASA Astrophysics Data System (ADS)

    Rebollido, Isabel; Merín, Bruno; Ribas, Álvaro; Bustamante, Ignacio; Bouy, Hervé; Riviere-Marichalar, Pablo; Prusti, Timo; Pilbratt, Göran L.; André, Philippe; Ábrahám, Péter

    2015-09-01

    Context. Observations of nearby star-forming regions with the Herschel Space Observatory complement our view of the protoplanetary disks in Ophiuchus with information about the outer disks. Aims: The main goal of this project is to provide new far-infrared fluxes for the known disks in the core region of Ophiuchus and to identify potential transitional disks using data from Herschel. Methods: We obtained PACS and SPIRE photometry of previously spectroscopically confirmed young stellar objects (YSO) in the region and analysed their spectral energy distributions. Results: From an initial sample of 261 objects with spectral types in Ophiuchus, we detect 49 disks in at least one Herschel band. We provide new far-infrared fluxes for these objects. One of them is clearly a new transitional disk candidate. Conclusions: The data from Herschel Space Observatory provides fluxes that complement previous infrared data and that we use to identify a new transitional disk candidate. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Final reduced Herschel maps are 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/581/A30Appendix A is available in electronic form at http://www.aanda.orgAll tables are also 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/581/A30

  14. Galaxy formation from deep surveys with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Lutz, D.

    2011-11-01

    Deep far-infrared photometric surveys studying galaxy evolution and the nature of the cosmic infrared background are a key strength of the Herschel mission. The PACS Evolutionary Probe (PEP) guaranteed time key program obtains deep photometric surveys of some of the key extragalactic multiwavelength fields at wavelengths between 70 and 160 μm. This contribution gives an overview of first science results, illustrating the potential of Herschel in providing calorimetric star formation rates for various high redshift galaxy populations, thus testing and superseding previous extrapolations from other wavelengths, and enabling a wide range of galaxy evolution studies.

  15. Herschel Discovery of a New Class of Cold, Faint Debris Discs

    NASA Technical Reports Server (NTRS)

    Eiroal, C.; Marshall, J. P.; Mora, A.; Krivov, A. V.; Montesinos, B.; Absil, O.; Ardila, D.; Arevalo, M.; Augereau, J.-Ch.; Bayo, A.; Danchi, W.; del Burgo, C.; Ertel, S.; Fridlund, M.; Gonzalez-Garcia, B. M.; Heras, A. M.; Lebreton, J.; Liseau, R.; Maldonado, J.; Meeus, G.; Montes, D.; Pilbratt, G. L.; Roberge, A.; Sanz-Forcada, J.; Stapelfeldt, K.

    2011-01-01

    We present Herschel PACS 100 and 160 micron observations of the solar-type stars alpha Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel Open Time Key Programme (OTKP) DUNES (DUst around NEarby Stars). Our observations show small infrared excesses at 160 m for all three stars. HD 210277 also shows a small excess at 100 micron, while the 100 micron fluxes of alpha Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. alpha Men and HD 88230 are spatially resolved in the PACS 160 m images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from approx 115 to <= 250 AU. The estimated black body temperatures from the 100 and 160 micron fluxes are approx < 22 K, while the fractional luminosity of the cold dust is L(sub dust) / L(*) approx 10 (exp 6) close to the luminosity of the Solar-System's Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars and cannot easily be explained by invoking "classical" debris disc models.

  16. Herschel Discovery of a New class of Cold, Faint Debris Discs

    NASA Technical Reports Server (NTRS)

    Eiroa, C.; Marshall, J. P.; Mora, A.; Krivov, A. V.; Montesinos, B.; Absil, O.; Ardila, D.; Arevalo, M.; Augereau, J. -Ch.; Bayo, A.; Danchi, W.; del Burgo, C.; Ertel, S.; Fridlund, M.; Gonzalez-Garcia, B. M.; Heras, A. M.; Lebreton, J.; Liseau, R.; Maldonado, J.; Meeus, G.; Montes, D.; Pilbratt, G. L.; Roberge, A.; Sanz-Forcada, J.; Stapelfeldt, K.

    2012-01-01

    We present Herschel PACS 100 and 160 micron observations of the solar-type stars alpha Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel Open Time Key Programme (OTKP) DUNES (DUst around NEarby Stars). Our observations show small infrared excesses at 160 micron for all three stars. HD 210277 also shows a small excess at 100 micron. while the 100 micron fluxes of a Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. alpha Men and HD 88230 are spatially resolved in the PACS 160 micron images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from approximately 115 to <= 250 AU. The estimated black body temperatures from the 100 and 160 micron fluxes are approximately < 22 K, while the fractional luminosity of the cold dust is L(dust)/ L(star) approximates 10(exp -6), close to the luminosity of the Solar-System's Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars and cannot easily be explained by invoking "classical" debris disc models.

  17. A Portrait of the Centaur 2060 Chiron: new results from groundbased and Herschel observations

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lellouch, E.; Müller, T.; Panuzzo, P.; Kiss, C.; Lim, T.; Mommert, M.; Bockelée-Morvan, D.; Vilenius, E.; Tozzi, G. P.; Mottola, S.; Duffard, R.; Barucci, M. A.

    2013-09-01

    The Herschel Open Time Key Program entitled "TNOs are Cool: A survey of the trans-Neptunian region" has been awarded 373 hours to investigate the albedo, size distribution and thermal properties of TNOs and Centaurs [1]. In this work we present the results of the combined SPIRE and PACS instruments observations over 6 bands of the Centaur 2060 Chiron, together with groundbased observations used to constrain its absolute magnitude, to investigate possible cometary activity and its surface composition. The estimated nuclear HV magnitude during the Herschel observations is 5.81±0.08, indicating a high flux from the Centaur comparable to that of its activity peak during 1989. Using this HV value, our Chiron's best size estimation, from NEATM and TPM modelling, is 218±20 km, with an albedo of 16±3 %, a value higher than previous Chiron's albedo estimation. Chiron shows the strongest decrease in the emissivity versus wavelength in the TNOs and Centaurs sample investigated with the PACS and SPIRE instruments. The results on the cometary activity analysis both in the visual and far infrared images will also be presented.

  18. Communicating Herschel Key Programs in Solar System Studies to the Public

    NASA Astrophysics Data System (ADS)

    Rengel, M.; Hartogh, P.; Müller, T.

    2011-10-01

    The Herschel Space Observatory, one of the cornerstone missions of the European Space Agency (ESA) with participation from NASA, is delivering a wealth of far-infrared and sub-millimeter observations of the cold Universe. A considerable part of the observing time for the nominal three year mission lifetime has been awarded in the form of Key Programs. Between the 42 key programs (guaranteed and open times), only two key programs are dedicated to study the Solar System: "Water and Related Chemistry in the Solar System", also known as Herschel Solar System Observations (HssO) project [1], and "TNOs are Cool: A Survey of the Transneptunian Region" [2]. In the framework of these Programs, a serie of public outreach activities and efforts of its results are being carried out. We present some of the outreach strategies developed (e.g. press releases, web pages, logos, public lectures, exhibitions, interviews, reports, etc.) and some plans in this direction. Our activities introduce people to knowledge and beauty of solar system research and wider the opportunities for the public to become more involved in topics like solar system studies, specially in the times of frequent exo-planet discoveries.

  19. HERSCHEL MEASUREMENTS OF MOLECULAR OXYGEN IN ORION

    SciTech Connect

    Goldsmith, Paul F.; Chen, Jo-Hsin; Li Di; Liseau, Rene; Black, John H.; Bell, Tom A.; Hollenbach, David; Kaufman, Michael J.; Lis, Dariusz C.; Melnick, Gary; Neufeld, David; Pagani, Laurent; Encrenaz, Pierre; Snell, Ronald; Benz, Arnold O.; Bruderer, Simon; Bergin, Edwin; Caselli, Paola; Caux, Emmanuel; Falgarone, Edith

    2011-08-20

    We report observations of three rotational transitions of molecular oxygen (O{sub 2}) in emission from the H{sub 2} Peak 1 position of vibrationally excited molecular hydrogen in Orion. We observed the 487 GHz, 774 GHz, and 1121 GHz lines using the Heterodyne Instrument for the Far Infrared on the Herschel Space Observatory, having velocities of 11 km s{sup -1} to 12 km s{sup -1} and widths of 3 km s{sup -1}. The beam-averaged column density is N(O{sub 2}) = 6.5 x 10{sup 16} cm{sup -2}, and assuming that the source has an equal beam-filling factor for all transitions (beam widths 44, 28, and 19''), the relative line intensities imply a kinetic temperature between 65 K and 120 K. The fractional abundance of O{sub 2} relative to H{sub 2} is (0.3-7.3) x 10{sup -6}. The unusual velocity suggests an association with a {approx}5'' diameter source, denoted Peak A, the Western Clump, or MF4. The mass of this source is {approx}10 M{sub sun} and the dust temperature is {>=}150 K. Our preferred explanation of the enhanced O{sub 2} abundance is that dust grains in this region are sufficiently warm (T {>=} 100 K) to desorb water ice and thus keep a significant fraction of elemental oxygen in the gas phase, with a significant fraction as O{sub 2}. For this small source, the line ratios require a temperature {>=}180 K. The inferred O{sub 2} column density {approx_equal}5 x 10{sup 18} cm{sup -2} can be produced in Peak A, having N(H{sub 2}) {approx_equal} 4 x 10{sup 24} cm{sup -2}. An alternative mechanism is a low-velocity (10-15 km s{sup -1}) C-shock, which can produce N(O{sub 2}) up to 10{sup 17} cm{sup -2}.

  20. Footprint Database and web services for the Herschel space observatory

    NASA Astrophysics Data System (ADS)

    Verebélyi, Erika; Dobos, László; Kiss, Csaba

    2015-08-01

    Using all telemetry and observational meta-data, we created a searchable database of Herschel observation footprints. Data from the Herschel space observatory is freely available for everyone but no uniformly processed catalog of all observations has been published yet. As a first step, we unified the data model for all three Herschel instruments in all observation modes and compiled a database of sky coverage information. As opposed to methods using a pixellation of the sphere, in our database, sky coverage is stored in exact geometric form allowing for precise area calculations. Indexing of the footprints allows for very fast search among observations based on pointing, time, sky coverage overlap and meta-data. This enables us, for example, to find moving objects easily in Herschel fields. The database is accessible via a web site and also as a set of REST web service functions which makes it usable from program clients like Python or IDL scripts. Data is available in various formats including Virtual Observatory standards.

  1. John Herschel's position in the post-Neptune discovery debates.

    NASA Astrophysics Data System (ADS)

    Kollerstrom, N.

    2005-08-01

    In the course of archiving Britain's Neptune correspondence I have transcribed letters by Herschel (from the Royal Society Library) that have been little appreciated by scholars. The great polemical debates took place chiefly within the RAS but also affecting the Royal Society and the British Association, and Herschel was very much at the centre of things. His views become especially interesting once the sceptical American view started to be heard some months after the discovery, that because the real Neptune was so very different in its motions from that predicted by Adams and LeVerrier, and because the 2:1 resonance between Uranus and Neptune is such a large effect and yet was wholly unknown to these two, the prediction had to have been a mere happy coincidence. Herschel's view that the synchrony involved was beneficial for public understanding of science remains of relevance today. During these intense debates, Herschel was completing his bestseller 'Outlines of Astronomy' that was to go through twelve editions.

  2. Who Invented the Word Asteroid: William Herschel or Stephen Weston?

    NASA Astrophysics Data System (ADS)

    Cunningham, Clifford J.; Orchiston, Wayne

    2011-11-01

    William Herschel made the first serious study of 1 Ceres and 2 Pallas in the year 1802. He was moved by their dissimilarities to the other planets to coin a new term to distinguish them. For this purpose he enlisted the aid of his good friends William Watson and Sir Joseph Banks. Watson gave him a long list of possible names, which Herschel rejected. With a lifetime of experience classifying and naming newly found objects in nature, Banks became the man both Erasmus Darwin (in 1781) and William Herschel (in 1802) turned to for sage advice in developing a new descriptive language. In the case of Ceres and Pallas, Banks turned the task over to his friend, the noted philologist Stephen Weston, FRS. It has recently been stated by a noted British historian that it was Weston - not Herschel - who coined the term 'asteroid' to collectively describe Ceres and Pallas. This claim is investigated, and parallels are drawn in the use of neologism in astronomy and botany.

  3. Identification of new transitional disk candidates in Lupus with Herschel

    NASA Astrophysics Data System (ADS)

    Bustamante, I.; Merín, B.; Ribas, Á.; Bouy, H.; Prusti, T.; Pilbratt, G. L.; André, Ph.

    2015-06-01

    Context. New data from the Herschel Space Observatory are broadening our understanding of the physics and evolution of the outer regions of protoplanetary disks in star-forming regions. In particular they prove to be useful for identifying transitional disk candidates. Aims: The goals of this work are to complement the detections of disks and the identification of transitional disk candidates in the Lupus clouds with data from the Herschel Gould Belt Survey. Methods: We extracted photometry at 70, 100, 160, 250, 350, and 500 μm of all spectroscopically confirmed Class II members previously identified in the Lupus regions and analyzed their updated spectral energy distributions. Results: We have detected 34 young disks in Lupus in at least one Herschel band, from an initial sample of 123 known members in the observed fields. Using recently defined criteria, we have identified five transitional disk candidates in the region. Three of them are new to the literature. Their PACS-70 μm fluxes are systematically higher than those of normal T Tauri stars in the same associations, as already found in T Cha and in the transitional disks in the Chamaeleon molecular cloud. Conclusions: Herschel efficiently complements mid-infrared surveys for identifying transitional disk candidates and confirms that these objects seem to have substantially different outer disks than the T Tauri stars in the same molecular clouds. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables 5-7 and Figs. 3 and 4 are available in electronic form at http://www.aanda.org

  4. NASA Global Atmospheric Sampling Program (GASP) data report for tape VL0015, VL0016, VL0017, VL0018, VL0019, and VL0020

    NASA Technical Reports Server (NTRS)

    Papthakos, L. C.; Briehl, D.

    1981-01-01

    This is the twelfth of a series of reports which describes the data currently available from GASP, including flight routes and dates, instrumentation, data processing procedures, and data tape specifications. In-situ measurements of atmospheric ozone, cabin ozone, carbon monoxide, water vapor, particles, clouds, condensation nuclei, filter samples and related meteorological and flight information obtained during 1732 flights of aircraft N533PA, N4711U, N655PA, and VH-EBE from January 5, 1978 through October 9, 1978 are reported. These data are now available from the National Climatic Center, Asheville, NC, 22801. In addition to the GASP data, tropopause pressures obtained from time ans space interpolation of National Meteorological Center archived data for the dates of the flights are included.

  5. "Heart" of Herschel to be presented to media

    NASA Astrophysics Data System (ADS)

    2007-09-01

    The Herschel mission, equipped with the largest telescope ever launched in space (3.5 m diameter), will give astronomers their best capability yet to explore the universe at far-infrared and sub-millimetre wavelengths. By measuring the light at these wavelengths, scientists see the ‘cold’ universe. Herschel will give them an unprecedented view, allowing them to see deep into star forming regions, galactic centres and planetary systems. In order to achieve its objectives and to be able to detect the faint radiation coming from the coolest objects in the cosmos, otherwise ‘invisible’, Herschel’s detectors must operate at very low and stable temperatures. The spacecraft is equipped so as to cool them close to absolute zero (-273.15 ºC), ranging from -271 ºC to only a few tenths of a degree above absolute zero. To have achieved this particular feature alone is a remarkable accomplishment for European industry and science. The final integration of the various components of the Herschel spacecraft - payload module, cryostat, service module, telescope and solar arrays - will be completed in the next few months. This phase will be followed by a series of tests to get the spacecraft ready for launch at the end of July 2008. Herschel will be launched into space on an Ariane 5 ECA rocket. The launch is shared with Planck, ESA’s mission to study relic radiation from the Big Bang. Media interested to attend the press event are invited to fill in the reply form below. Note for editors The Prime Contractor for the Herschel spacecraft is Thales Alenia Space (Cannes, France). It leads a consortium of industrial partners with Astrium (Germany) responsible for the Extended Payload Module (EPLM, including the Herschel cryostat), Astrium (France) responsible for the telescope, and the Thales Alenia Space industry branch of Torino, Italy, responsible for the Service Module (SVM). There is also a host of subcontractors spread throughout Europe. The three Herschel

  6. Astronomy from Space: The Hubble, Herschel and James Webb Space Telescopes

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2009-01-01

    Space-based astronomy is going through a renaissance, with three Great Observatories currently flying: Hubble in the visible and ultraviolet, Spitzer in the infrared and Chandra in X-rays. The future looks equally bright. The final servicing mission to Hubble will take place in February 2009 and promises to make the observatory more capable than ever with two new cameras, and refurbishment that will allow it to last at least five years. The upcoming launch of the Herschel Space Telescope will open the far-infrared to explore the cool and dusty Universe. Finally, we look forward to the launch of the James Webb Space Telescope in 2013, which wil provide a successor to both Hubble and Spitzer. In this talk, the author discusses some of the highlights of scientific discovery in the last 10 years and reveals the promise to the next 10 years.

  7. Downregulation of 5-HT7 Serotonin Receptors by the Atypical Antipsychotics Clozapine and Olanzapine. Role of Motifs in the C-Terminal Domain and Interaction with GASP-1.

    PubMed

    Manfra, Ornella; Van Craenenbroeck, Kathleen; Skieterska, Kamila; Frimurer, Thomas; Schwartz, Thue W; Levy, Finn Olav; Andressen, Kjetil Wessel

    2015-07-15

    The human 5-HT7 serotonin receptor, a G-protein-coupled receptor (GPCR), activates adenylyl cyclase constitutively and upon agonist activation. Biased ligands differentially activate 5-HT7 serotonin receptor desensitization, internalization and degradation in addition to G protein activation. We have previously found that the atypical antipsychotics clozapine and olanzapine inhibited G protein activation and, surprisingly, induced both internalization and lysosomal degradation of 5-HT7 receptors. Here, we aimed to determine the mechanism of clozapine- and olanzapine-mediated degradation of 5-HT7 receptors. In the C-terminus of the 5-HT7 receptor, we identified two YXXΦ motifs, LR residues, and a palmitoylated cysteine anchor as potential sites involved in receptor trafficking to lysosomes followed by receptor degradation. Mutating either of these sites inhibited clozapine- and olanzapine-mediated degradation of 5-HT7 receptors and also interfered with G protein activation. In addition, we tested whether receptor degradation was mediated by the GPCR-associated sorting protein-1 (GASP-1). We show that GASP-1 binds the 5-HT7 receptor and regulates the clozapine-mediated degradation. Mutations of the identified motifs and residues, located in or close to Helix-VIII of the 5-HT7 receptor, modified antipsychotic-stimulated binding of proteins (such as GASP-1), possibly by altering the flexibility of Helix-VIII, and also interfered with G protein activation. Taken together, our data demonstrate that binding of clozapine or olanzapine to the 5-HT7 receptor leads to antagonist-mediated lysosomal degradation by exposing key residues in the C-terminal tail that interact with GASP-1. PMID:25706089

  8. Herschel far-infrared observations of the Carina Nebula complex. III. Detailed cloud structure and feedback effects

    NASA Astrophysics Data System (ADS)

    Roccatagliata, V.; Preibisch, T.; Ratzka, T.; Gaczkowski, B.

    2013-06-01

    Context. The star formation process in large clusters/associations can be strongly influenced by the feedback from high-mass stars. Whether the resulting net effect of the feedback is predominantly negative (cloud dispersal) or positive (triggering of star formation due to cloud compression) is still an open question. Aims: The Carina Nebula complex (CNC) represents one of the most massive star-forming regions in our Galaxy. We use our Herschel far-infrared observations to study the properties of the clouds over the entire area of the CNC (with a diameter of ≈3.2°, which corresponds to ≈125 pc at a distance of 2.3 kpc). The good angular resolution (10''-36'') of the Herschel maps corresponds to physical scales of 0.1-0.4 pc, and allows us to analyze the small-scale (i.e., clump-size) structures of the clouds. Methods: The full extent of the CNC was mapped with PACS and SPIRE in the 70, 160, 250, 350, and 500 μm bands. We determined temperatures and column densities at each point in these maps by modeling the observed far-infrared spectral energy distributions. We also derived a map showing the strength of the UV radiation field. We investigated the relation between the cloud properties and the spatial distribution of the high-mass stars and computed total cloud masses for different density thresholds. Results: Our Herschel maps resolve for the first time the small-scale structure of the dense clouds over the entire spatial extent of the CNC. Several particularly interesting regions, including the prominent pillars south of η Car, are analyzed in detail. We compare the cloud masses derived from the Herschel data with previous mass estimates based on sub-mm and molecular line data. Our maps also reveal a peculiar wave-like pattern in the northern part of the Carina Nebula. Finally, we characterize two prominent cloud complexes at the periphery of our Herschel maps, which are probably molecular clouds in the Galactic background. Conclusions: We find that the

  9. The Herschel/PACS view of the Cep OB2 region: Global protoplanetary disk evolution and clumpy star formation

    NASA Astrophysics Data System (ADS)

    Sicilia-Aguilar, Aurora; Roccatagliata, Veronica; Getman, Konstantin; Rivière-Marichalar, Pablo; Birnstiel, Tilman; Merín, Bruno; Fang, Min; Henning, Thomas; Eiroa, Carlos; Currie, Thayne

    2015-01-01

    Context. The Cep OB2 region, with its two intermediate-aged clusters Tr 37 and NGC 7160, is a paradigm of sequential star formation and an ideal site for studies of protoplanetary disk evolution. Aims: We use Herschel data to study the protoplanetary disks and the star formation history of the region. Methods: Herschel/PACS observations at 70 and 160 μm probe the disk properties (mass, dust sizes, structure) and the evolutionary state of a large number of young stars. Far-IR data also trace the remnant cloud material and small-scale cloud structure. Results: We detect 95 protoplanetary disks at 70 μm, 41 at 160 μm, and obtain upper limits for more than 130 objects. The detection fraction at 70 μm depends on the spectral type (88% for K4 or earlier stars, 17% for M3 or later stars) and on the disk type (~50% for full and pre-transitional disks, ~35% for transitional disks, no low-excess/depleted disks detected). Non-accreting disks are not detected, suggesting significantly lower masses. Accreting transition and pre-transition disks have systematically higher 70 μm excesses than full disks, suggestive of more massive, flared and/or thicker disks. Herschel data also reveal several mini-clusters in Tr 37, which are small, compact structures containing a few young stars surrounded by nebulosity. Conclusions: Far-IR data are an excellent probe of the evolution of disks that are too faint for sub-millimetre observations. We find a strong link between far-IR emission and accretion, and between the inner and outer disk structure. Herschel confirms the dichotomy between accreting and non-accreting transition disks. Accretion is a powerful measure of global disk evolution: substantial mass depletion and global evolution need to occur to shut down accretion in a protoplanetary disk, even if the disk has inner holes. Disks likely follow different evolutionary paths: low disk masses do not imply opening inner holes, and having inner holes does not require low disk masses

  10. Openings

    PubMed Central

    Selwyn, Peter A.

    2015-01-01

    Reviewing his clinic patient schedule for the day, a physician reflects on the history of a young woman he has been caring for over the past 9 years. What starts out as a routine visit then turns into a unique opening for communication and connection. A chance glimpse out the window of the exam room leads to a deeper meditation on parenthood, survival, and healing, not only for the patient but also for the physician. How many missed opportunities have we all had, without even realizing it, to allow this kind of fleeting but profound opening? PMID:26195687

  11. Openings.

    PubMed

    Selwyn, Peter A

    2015-01-01

    Reviewing his clinic patient schedule for the day, a physician reflects on the history of a young woman he has been caring for over the past 9 years. What starts out as a routine visit then turns into a unique opening for communication and connection. A chance glimpse out the window of the exam room leads to a deeper meditation on parenthood, survival, and healing, not only for the patient but also for the physician. How many missed opportunities have we all had, without even realizing it, to allow this kind of fleeting but profound opening? PMID:26195687

  12. The CDF Archive: Herschel PACS and SPIRE Spectroscopic Data Pipeline and Products for Protostars and Young Stellar Objects

    NASA Astrophysics Data System (ADS)

    Green, Joel D.; Yang, Yao-Lun; Evans, Neal J., II; Karska, Agata; Herczeg, Gregory; van Dishoeck, Ewine F.; Lee, Jeong-Eun; Larson, Rebecca L.; Bouwman, Jeroen

    2016-03-01

    We present the COPS-DIGIT-FOOSH (CDF) Herschel spectroscopy data product archive, and related ancillary data products, along with data fidelity assessments, and a user-created archive in collaboration with the Herschel-PACS and SPIRE ICC groups. Our products include datacubes, contour maps, automated line fitting results, and best 1D spectra products for all protostellar and disk sources observed with PACS in RangeScan mode for two observing programs: the DIGIT Open Time Key Program (KPOT_nevans1 and SDP_nevans_1; PI: N. Evans), and the FOOSH Open Time Program (OT1_jgreen02_2; PI: J. Green). In addition, we provide our best SPIRE-FTS spectroscopic products for the COPS Open Time Program (OT2_jgreen02_6; PI: J. Green) and FOOSH sources. We include details of data processing, descriptions of output products, and tests of their reliability for user applications. We identify the parts of the data set to be used with caution. The resulting absolute flux calibration has improved in almost all cases. Compared to previous reductions, the resulting rotational temperatures and numbers of CO molecules have changed substantially in some sources. On average, however, the rotational temperatures have not changed substantially (<2%), but the number of warm (Trot ∼ 300 K) CO molecules has increased by about 18%.

  13. A Peculiar Class of Debris Disks from Herschel/DUNES: A Steep Fall Off in the Far Infrared

    NASA Technical Reports Server (NTRS)

    Ertel, S.; Wolf, S.; Marshall, J. P.; Eiroa, C.; Augereau, J. C.; Krivov, A. V.; Lohne, T.; Absil, O.; Ardila, D.; Arevalo, M.; Bayo, A.; Bryden, G.; del Burgo, C.; Greaves, J.; Kennedy, G.; Lebreton, J.; Liseau, R.; Maldonado, J.; Montesinos, B.; Mora, A.; Pilbratt, G. L.; Sanz-Forcada, J.; Stapelfeldt, K.; White, G. J.

    2012-01-01

    Context. The existence of debris disks around old main sequence stars is usually explained by continuous replenishment of small dust grains through collisions from a reservoir of larger objects. Aims. We present photometric data of debris disks around HIP 103389 (HD199260), HIP 100350 (HN Peg, HD206860), and HIP 114948 (HD 219482), obtained in the context of our Herschel Open TIme Key Program DUNES (DUst around NEarby Stars). Methods. We used Herschel/PACS to detect the thermal emission of the three debris disks with a 30 sigma sensitivity of a few mJy at l00 micron and 160 micron. In addition, we obtained Herschel/PACS photometric data at 70 micron for HIP 103389. These observations are complemented by a large variety of optical to far-infrared photometric data. Two different approaches are applied to reduce the Herschel data to investigate the impact of data reduction on the photometry. We fit analytical models to the available spectral energy distribution (SED) data using the fitting method of simulated therma1 annealing as well as a classical grid search method. Results. The SEDs of the three disks potentially exhibit an unusually steep decrease at wavelengths >= 70 micron. We investigate the significance of the peculiar shape of these SEDs and the impact on models of the disks provided it is real. Using grain compositions that have been applied successfully for modeling of many other debris disks, our modeling reveals that such a steep decrease of the SEDs in the long wavelength regime is inconsistent with a power-law exponent of the grain size distribution -3.5 expected from a standard equilibrium collisional cascade. In contrast, a steep grain size distribution or, alternatively an upper grain size in the range of few tens of micrometers are implied. This suggests that a very distinct range of grain sizes would dominate the thermal. emission of such disks. However, we demonstrate that the understanding of the data of faint sources obtained with Herschel is

  14. An incidence of skeletal fluorosis associated with groundwaters of the maritime carboniferous basin, Gaspé region, Quebec, Canada.

    PubMed

    Boyle, D R; Chagnon, M

    1995-03-01

    Consumption of unusually high concentrations of F(-) in groundwaters of the Maria area in the Gaspé peninsula of Quebec have resulted in symptoms of skeletal fluorosis in two members of the population. One of these individuals consumed approximately 50 mg of fluoride per day over a 6 year period before being hospitalized and later diagnosed with skeletal fluorosis. It is estimated that, until this case came to light, approximately 15-20% of the rural population (total approximately 1,600) in the area were consuming groundwaters with F(-) levels between 5 and 28 mg L(-1) for at least 6 years. The high concentrations of F(-) in well waters of the Maria area occur only in wells completed in Carboniferous sandstone-siltstone-conglomerate sediments that underlie a thick blanket of alluvial-colluvial-glacial overburden. These fluoriferous groundwaters exhibit high Na and HCO3 (-) contents and low Ca and Mg concentrations compared to those associated with the overburden sediments. The high F levels greatly increase the risk for fluorotic diseases such as skeletal fluorosis and skeletal radiculomyopathy. Wells completed in overburden, although having suboptimal F(-) levels are safer for the health of individuals in this region. Effective regulations for well drilling need to be formulated for regions underlain by Carboniferous formations in the Maritime provinces of Canada. In some regions, high F(-) levels (10-25 mg L(-1)) in groundwaters will seriously affect how, and to what extent, groundwater supplies can be developed for domestic use. PMID:24194033

  15. Sympathetic skin response following thermal, electrical, acoustic, and inspiratory gasp stimulation in familial dysautonomia patients and healthy persons.

    PubMed

    Hilz, M J; Azelrod, F B; Schweibold, G; Kolodny, E H

    1999-08-01

    To determine whether sympathetic skin response (SSR) testing evaluates afferent small or efferent sympathetic nerve fiber dysfunction, we studied SSR in patients with familial dysautonomia (FD) in whom both afferent small and efferent sympathetic fibers are largely reduced. We analyzed whether the response pattern to a combination of stimuli specific for large or small fiber activation allows differentiation between afferent and efferent small fiber dysfunction. In 52 volunteers and 13 FD patients, SSR was studied at palms and soles after warm, cold and heat as well as electrical, acoustic, and inspiratory gasp stimulation. In addition, thermal thresholds were assessed at four body sites using a Thermotest device (Somedic; Stockholm, Sweden). In volunteers, any stimulus induced reproducible SSRs. Only cold failed to evoke SSR in two volunteers. In all FD patients, electrical SSR was present, but amplitudes were reduced. Five patients had no acoustic SSR, four had no inspiratory SSR. Thermal SSR was absent in 10 patients with abnormal thermal perception and present in one patient with preserved thermal sensation. In two patients, thermal SSR was present only when skin areas with preserved temperature perception were stimulated. In patients with FD, preserved electrical SSR demonstrated the overall integrity of the SSR reflex but amplitude reduction suggested impaired sudomotor activation. SSR responses were dependent on the perception of the stimulus. In the presence of preserved electrical SSR, absent thermal SSR reflects afferent small fiber dysfunction. A combination of SSR stimulus types allows differentiation between afferent small or efferent sympathetic nerve fiber dysfunction. PMID:10574280

  16. A complete census of Herschel-detected infrared sources within the HST Frontier Fields

    NASA Astrophysics Data System (ADS)

    Rawle, T. D.; Altieri, B.; Egami, E.; Pérez-González, P. G.; Boone, F.; Clement, B.; Ivison, R. J.; Richard, J.; Rujopakarn, W.; Valtchanov, I.; Walth, G.; Weiner, B. J.; Blain, A. W.; Dessauges-Zavadsky, M.; Kneib, J.-P.; Lutz, D.; Rodighiero, G.; Schaerer, D.; Smail, I.

    2016-06-01

    We present a complete census of all Herschel-detected sources within the six massive lensing clusters of the HST Frontier Fields (HFF). We provide a robust legacy catalogue of 263 sources with Herschel fluxes, primarily based on imaging from the Herschel Lensing Survey and PEP/HerMES Key Programmes. We optimally combine Herschel, Spitzer and WISE infrared (IR) photometry with data from HST, VLA and ground-based observatories, identifying counterparts to gain source redshifts. For each Herschel-detected source we also present magnification factor (μ), intrinsic IR luminosity and characteristic dust temperature, providing a comprehensive view of dust-obscured star formation within the HFF. We demonstrate the utility of our catalogues through an exploratory overview of the magnified population, including more than 20 background sub-LIRGs unreachable by Herschel without the assistance gravitational lensing.

  17. A "large and graceful sinuosity". John Herschel's graphical method.

    PubMed

    Hankins, Thomas L

    2006-12-01

    In 1833 John Herschel published a graphical method for determining the orbits of double stars. He argued that his method, which depended on human judgment rather than mathematical analysis, gave better results than computation, given the uncertainty in the data. Herschel found that astronomy and terrestrial physics were especially suitable for graphical treatment, and he expected that graphs would soon become important in all areas of science. He argued with William Whewell and James D. Forbes over the process of induction, over the application of probability, and over the moral content of science. Graphs entered into all these debates; but because they constituted a method, not a metaphysics, they were acceptable to most practicing scientists and became increasingly popular throughout the nineteenth century. PMID:17367002

  18. HERSCHEL Sounding Rocket Mission Observations of the Helium Corona

    NASA Astrophysics Data System (ADS)

    Newmark, Jeffrey; Moses, J.; Antonucci, E.; Fineschi, S.; Abbo, L.; Telloni, D.; Auchere, F.; Barbey, N.; Romoli, M.

    2010-05-01

    The HERSCHEL (Helium Resonant Scattering in the Corona and Heliosphere) investigation successfully obtained unprecedented images of the helium and hydrogen components of the solar corona out to 3 solar radii during a suborbital flight on 14 September 2009. Preliminary analysis of these observations indicates the spatial distribution of the helium abundance and outflow velocity provides powerful diagnostics for the source and dynamics of the slow solar wind during the time of solar minimum activity. An analysis of co-temporal STEREO EUVI data to derive the temperature of low coronal structures associated with the regions of enhanced helium abundance observed by HERSCHEL provides evidence the relative first ionization potential (FIP) of helium and hydrogen may play an important role in the observed abundance distribution. NRL was supported by the Office of Naval Research and NASA under NDPRS6598G.

  19. Binaries in Nebulae: Recent Observations of John Herschel's List

    NASA Astrophysics Data System (ADS)

    Walker, R. L.

    1993-12-01

    During the 19th century John Herschel observed double stars from England and his Feldhausen Station in South Africa, using a 5-inch refractor and an 18-inch reflector, ``The 20-ft". A few of his discoveries were annotated ``nebulosity" in his 1874 catalog. Most of these ``nebulous binaries'' have been examined recently at the U.S. Naval Observatory's Flagstaff Station using the 1-m telescope equipped with a CCD. A few objects were added from lists by S. W. Burnham and W.H. van den Bos. This study began as an exploratory project to detect possible morphological connections between binaries and nebulosities, but it was soon apparent that Herschel's keen eyesight had originally detected more than double stars. The application of Aitken's criterion indicates few of the objects are physical binaries. Galaxy and gas-dust configurations are more descriptive of the nature of these objects.

  20. Herschel observation of C3 in star forming regions

    NASA Astrophysics Data System (ADS)

    Mookerjea, B.; Giesen, T.; Stutzki, J.; Cernicharo, J.; Goicoechea, J. R.; Black, J. H.

    2011-05-01

    We present spectrally resolved observations of triatomic carbon (C3) in several ro-vibrational transitions between the vibrational ground state and the low-energy ν2 bending mode at frequencies above 1.6 THz using HIFI onboard Herschel, towards several Galactic star forming regions including W31C, W49N, DR21(OH), W33A and W51. These observations have been performed as part of the Herschel key programme PRISMAS. C3 lines arising from the warm envelopes surrounding the hot cores associated with these star forming regions are detected in absorption. We shall present results of detailed radiative transfer models in which the C3 lines are excited by FIR pumping by the dust continuum.

  1. A "Large and Graceful Sinuosity": John Herschel's Graphical Method

    NASA Astrophysics Data System (ADS)

    Hankins, Thomas L.

    2006-12-01

    In 1833 John Herschel published a graphical method for determining the orbits of double stars. He argued that this method, which depended on human judgment rather than mathematical analysis, gave better results than computation, given the uncertainty in the data. Herschel found that astronomy and terrestrial physics were especially suitable for graphical treatment, and he expected that graphs would soon become important in all areas of science. He argued with William Whewell and James D. Forbes over the process of induction, over the application of probability, and over the moral content of science. Graphs entered into all these debates, but because they constituted a method, not a metaphysics, they were acceptable to most practicing scientists and became increasingly popular throughout the nineteenth century.

  2. Observations of Herbig Ae/Be Stars with Herschel/PACS: The Atomic and Molecular Contents of Their Protoplanetary Discs

    NASA Technical Reports Server (NTRS)

    Meeus, G.; Montesinos, B.; Mendigutia, I.; Kamp, I.; Thi, W. F.; Eiroa, C.; Grady, C. A.; Mathews, G.; Sandell, G.; Martin-Zaidi, C.; Brittain, S.; Dent, W. R. F.; Howard, C.; Menard, F.; Pinte, C.; Roberge, A.; Vandenbussche, B.; Williams, J. P.

    2012-01-01

    We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part of the GAS in Protoplanetary Systems (GASPS) project. The observations were done in spectroscopic mode, and cover the far-infrared lines of [OI], [CII], CO, CH+, H20, and OH. We have a [OI]63 micro/ detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. The [OI] 145 micron line is only detected in 25% and CO J = 18-17 in 45% (and fewer cases for higher J transitions) of the Herbig Ae/Be stars, while for [CII] 157 micron, we often find spatially variable background contamination. We show the first detection of water in a Herbig Ae disc, HD 163296, which has a settled disc. Hydroxyl is detected as well in this disc. First seen in HD 100546, CH+ emission is now detected for the second time in a Herbig Ae star, HD 97048. We report fluxes for each line and use the observations as line diagnostics of the gas properties. Furthermore, we look for correlations between the strength of the emission lines and either the stellar or disc parameters, such as stellar luminosity, ultraviolet and X-ray flux. accretion rate, polycyclic aromatic hydrocarbon (PAH) band strength, and flaring. We find that the stellar ultraviolet flux is the dominant excitation mechanism of [OI] 63 micron, with the highest line fluxes being found in objects with a large amount of flaring and among the largest PAH strengths. Neither the amount of accretion nor the X-ray luminosity has an influence on the line strength. We find correlations between the line flux of [OI]63 micron and [OI] 145 micron, CO J = IS-17 and [OI] 6300 A, and between the continuum flux at 63 micron and at 1.3 mm, while we find weak correlations between the line flux. of [OI] 63 micron and the PAH luminosity, the line flux of CO J = 3-2, the continuum flux at 63 pm, the stellar effective temperature, and the Br-gamma luminosity. Finally, we use a combination of the [OI] 63 micron and C(12)O J

  3. John Herschel and the Cape flora, 1834 - 1839.

    NASA Astrophysics Data System (ADS)

    Rourke, J. P.

    John Herschel's interest in botany was stimulated by his contact with the species-rich Cape flora while resident in Cape Town, 1834 - 1838. The comparative study of his extensive living collection of bulbous plants, mainly of the Iridaceae, Liliaceae, Amarayllidaceae and Orchidaceae led him to consider some basic aspects of the origin of species and of taxonomic theory, in letters to colleagues in Europe.

  4. Exploring science and technology through the Herschel space observatory

    NASA Astrophysics Data System (ADS)

    Minier, V.; Rouzé, M.

    2015-03-01

    Because modern astronomy associates the quest of our origins and high-tech instruments, communicating and teaching astronomy explore both science and technology. We report here on our work in communicating astronomy to the public through Web sites (www.herschel.fr), movies on Dailymotion (www.dailymotion.com/AstrophysiqueTV) and new ITC tools that describe interactively the technological dimension of a space mission for astrophysics.

  5. OT2_smalhotr_3: Herschel Extreme Lensing Line Observations (HELLO)

    NASA Astrophysics Data System (ADS)

    Malhotra, S.

    2011-09-01

    We request 59.8 hours of Herschel time to observe 20 normal star-forming galaxies in the [CII] 158 micron and [OI] 63 micron lines. These galaxies lie at high redshift (1Herschel offers the unique opportunity to study both lines with high sensitivity throughout this epoch (using HIFI for [CII] and PACS for [OI]). These two lines are the main cooling lines of the atomic medium. By measuring their fluxes, we will measure (1) the cooling efficiency of gas, (2) gas densities and temperatures near starforming regions, and (3) gas pressures, which are important to drive the winds that provide feedback to starformation processes. By combining the proposed observations with existing multiwavelength data on these objects, we will obtain as complete a picture of galaxy-scale star formation and ISM physical conditions at high redshifts as we have at z=0. Then perhaps we can understand why star formation and AGN activity peaked at this epoch. In Herschel cycle OT1, 49 high redshift IR luminous galaxies were approved for spectroscopy, but only two so-called normal galaxies were included. This is an imbalance that should be corrected, to balance Herschel's legacy.

  6. The poetry of light: Herschel, art and photography.

    NASA Astrophysics Data System (ADS)

    Schaaf, L. J.

    The public disclosure of photography was played out in a drama where personalities and nationalistic rivalries frequently overshadowed true scientific and artistic advances. Unwittingly plunged into centre of this confused drama was Sir John Herschel. His unusually diverse background equipped him to comprehend at once both the immedate practice and the future potential of photography. He supplied cruical elements to its technical foundation and established outlines for its systematic growth.

  7. Secondary ("Plain Mirror") Testing Methods of Sir William Herschel

    NASA Astrophysics Data System (ADS)

    Albin, E. F. M.

    2004-12-01

    Although many of Sir William Herschel's telescope designs did not require a secondary mirror, he did construct Newtonian style optical systems that used "plain mirrors." A look at Herschel's own writings on the matter gives some interesting insights into the techniques of this skilled 18th - 19th century telescope maker. The author provides glimpses acquired from unpublished Herschel documents that are now in the possession of the British RAS -- these include a four volume series entitled "Experiments on the Construction of Specula," a 129 page treaty called "On the Construction of Specula," and a 179 page manuscript entitled "Results of Experiments on the Construction of Mirrors." Herschel constructed secondary mirrors for his instruments by grinding and polishing his small mirrors in a sequence that involved two tools. He tested the optical quality of a small plain mirror by utilizing two slips of white card or pasteboard. One slip was made exactly twice the length of the second. The shorter card was placed against the mirror while the longer placed at some distance away so that its reflected image exactly matched the other. The larger card was carefully placed near the eye and oriented so that it was parallel to the shorter card strip. In order to test various sections of the secondary mirror, cards of different length were used. The mirror was judged flat if the reflected image was exactly identical to the card resting on the mirror. If the mirror were concave, the reflected image would be larger (i.e., magnified) than that of the smaller slip. However, should the reflected image be lesser in size, then the mirror was convex. Figuring was done with the mirror resting above the polishing tool. A convex mirror could be made plain by lengthening the stroke while a concave mirror could be made plain by shortening the stroke.

  8. A Herschel View on Galaxy/AGN Co-Evolution

    NASA Astrophysics Data System (ADS)

    Lutz, D.; Pep Consortium

    2011-10-01

    Deep far-infrared photometric surveys studying galaxy evolution and the nature of the cosmic infrared background are a key strength of the Herschel mission. The PACS Evolutionary Probe (PEP) guaranteed time key program obtains deep photometric surveys of some of the key extragalactic multiwavelength fields at wavelengths between 70 and 160μm. This contribution gives an overview of first science results, illustrating the potential of Herschel in providing calorimetric star formation rates for various high redshift galaxy populations, thus testing and superseding previous extrapolations from other wavelengths, and enabling a wide range of galaxy evolution studies. Herschel measured star formation rates of high redshift X-ray AGN suggest an interplay between two paths of AGN/host coevolution. A correlation of AGN luminosity and host star formation is traced locally over a wide range of luminosities and also extends to luminous high-z AGN. This correlation reflects an evolutionary connection, likely via merging. For lower AGN luminosities, star formation is similar to that in non-active massive galaxies and shows little dependence on AGN luminosity. The level of this secular, non-merger driven star formation increasingly dominates over the correlation at increasing redshift.

  9. THROES: A Catalogue of Herschel Observations of Evolved Stars

    NASA Astrophysics Data System (ADS)

    Ramos-Medina, J.; Sánchez-Contreras, C.; García-Lario, P.; Rodrigo, C.

    2015-12-01

    We are building a catalogue of fully-reprocessed observations of all evolved stars observed with Herschel (THROES). In a first stage, we focus on observations performed with the PACS instrument in its full range spectroscopy mode. Once finished, the catalogue will offer all reduced data for each observation, as well as, complementary information from other observatories. As a first step, we concentrate our efforts on two main activities: 1) the reprocessing and data-reduction of more than 200 individual sources, observed by Herschel/PACS in the 55-210 micron range, available in the Herschel Science Archive (HSA); 2) The creation of an initial catalogue, accesible via web and the Virtual Observatory (VO), with all the information relative to PACS observations and the classification of the sources. Our ultimate goal will be to carry out a comprehensive and systematic study of the far infrared properties of low-and intermediate-mass (1-8 FX1) evolved stars using these data. These objects cover the whole range of possible evolutionary stages in this short-lived phase of stellar evolution, from AGB phase to the PN stage, displaying a wide variety of chemical and physical properties.

  10. Herschel Observations of (21) Lutetia around the Rosetta Flyby

    NASA Astrophysics Data System (ADS)

    O'Rourke, L.; Müller, T.; Valtchanov, I.; Altieri, B.; González-Garcia, B. M.; Bhattacharya, B.; Jorda, L.; Carry, B.; Küppers, M.; Groussin, O.; Altwegg, K.; Barucci, M. A.; Bockelee-Morvan, D.; Crovisier, J.; Dotto, E.; Garcia-Lario, P.; Kidger, M.; Llorente, A.; Lorente, R.; Marston, A. P.; Sanchez Portal, M.; Schulz, R.; Sierra, M.; Teyssier, D.; Vavrek, R.

    2011-10-01

    Prior to and around ESA Rosetta's flyby of (21) Lutetia, a collaborative observation campaign using another ESA satellite, the ESA Herschel Space Observatory, was performed whereby Herschel's two photometers observed the asteroid in the far infrared, at wavelengths not covered by the Rosetta instruments. The Herschel observations, fed into a thermophysical model (TPM) using as input a flyby image based shape model (built upon Rosetta OSIRIS instrument observations) were further correlated with ~70 multi-wavelength (IRAS, ISOVISIR, IRTF, Akari, ESO-TIMMI2, Spitzer-IRAC) observations of Lutetia. We confirm the albedo measured by Rosetta and derive a "true" H-mag value based upon the cross-sections of the asteroid observed from all aspect angles. From our measurements we find that (21) Lutetia has an extremely low thermal inertia as well as a very low surface temperature. In addition, we have been able to identify a hill/crater surface feature located on the asteroids southern region not observed by Rosetta. We conclude that only through the merging of in-situ flyby based observations and remote sensing observations can a true global picture be obtained of this peculiar asteroid.

  11. Who Invented the Word Asteroid: William Herschel or Stephen Weston?

    NASA Astrophysics Data System (ADS)

    Cunningham, Clifford J.

    2011-01-01

    William Herschel made the first serious study of 1 Ceres and 2 Pallas in the year 1802. He was moved by their dissimilarities to the other planets to coin a new term to distinguish them. For this purpose he enlisted the aid of his good friends William Watson and Sir Joseph Banks. Watson gave him a long list of possible names, most of which sound quite ludicrous. With a lifetime of experience classifying and naming newly found objects in nature, Banks became the man both Erasmus Darwin (in 1781) and William Herschel (in 1802) turned to for sage advice in developing a new descriptive language. In the case of Ceres and Pallas, Banks turned the task over to his friend, the noted philologist Stephen Weston FRS. It has recently been stated by a noted British historian that it was Weston- not Herschel- who coined the term "asteroid" to collectively describe Ceres and Pallas. This claim is investigated, and parallels are drawn in the use of neologism in astronomy and botany.

  12. SHAPEMOL: the companion to SHAPE in the molecular era of ALMA and HERSCHEL

    NASA Astrophysics Data System (ADS)

    Santander-García, M.; Bujarrabal, V.; Alcolea, J.

    2013-05-01

    Modern instrumentation in radioastronomy constitutes a valuable tool for studying the Universe: ALMA will reach unprecedented sensitivities and spatial resolution, while Herschel/HIFI has opened a new window (most of the sub-mm and far infrared ranges are only accessible from space) for probing molecular warm gas (˜50-1000 K), complementing ground-based telescopes, which are better suited to study molecular molecular gas with temperatures under ˜100 K. On the other hand, the SHAPE software has emerged in the last few years as the standard tool for determinging the morphology and velocity field of different kinds of gaseous nebulae (mainly planetary nebulae, protoplanetary nebulae and nebulae around massive stars, although it can also be applied to H II regions and molecular clouds) via spatio-kinematical modelling. Standard SHAPE implements radiative transfer solving, but it is only available for atomic species and not for molecules. Being aware of the growing importance of the development of tools for easying the analyses of molecular data from new era observatories, we introduce the computer code shapemol, a plug-in for SHAPE with which we intend to fill the so far empty molecular niche. shapemol enables spatio-kinematic modeling with accurate non-LTE calculations of line excitation and radiative transfer in molecular species. This code has been succesfully tested in the study of the excitation conditions of the molecular envelope of the planetary nebula NGC 7027 using data from Herschel/HIFI and IRAM 30m. Currently, it allows radiative transfer solving in the ^{12}CO and ^{13}CO J=1-0 to J=17-16 lines. shapemol, used along SHAPE, allows to easily generate synthetic maps to test against interferometric observations, as well as synthetic line profiles to match single-dish observations.

  13. GT1_lorourke_9: Herschel In-situ Asteroid & Comet Observation programme

    NASA Astrophysics Data System (ADS)

    O'Rourke, L.

    2010-03-01

    In September 2010, 25 years will have passed since the first in-situ encounter of a space probe with a comet. This first visit occurred in September 1985 when the International Cometary Explorer (ICE), passed through the tail of P/Giacobini-Zinner. Up to that point, comet and asteroid scientific observations were always based upon remote sensing be they performed from ground or from space. The next opportunity for a comet encounter arose with the return of Halley's Comet in 1986, whereby many satellites (Giotto, Vega 1 & 2, Suisei & Sakigake) were launched to perform in-situ observations. The first asteroid flybys, Gaspra & Ida/Dactyl, occurred as part of Galileo's journey to Jupiter. Since this time, NEAR, DS1, Hayabusa, Rosetta, Deep Impact, Stardust-NExT and Dawn satellites have all been launched with the aim of performing flybys, orbiting & sample return. Remote sensing & in-situ measurements are considered highly complementary in nature: remote sensing shows the global picture, but conversion of measured fluxes in physical quantities frequently depends on poorly constrained model parameters (e.g. dust size distribution or fluorescence efficiencies). In-situ techniques measure physical quantities in a more direct way, but are limited in spatial coverage. The benefit of both combined is that we can compare surface composition, reflectance, albedos & temperatures of in-situ and remote sensing and as a result greatly improve the scientific understanding of the objects in question. This proposal focuses on using the Herschel Space Observatory to remotely observe a select set of in-situ comets/asteroids. The down-selection from 29 asteroids & comets to the final eight was made based upon many criteria, the main one being prioritisation of the most important open scientific issues existing for each of the targets for which the Herschel Space Observatory, its sensitivity & wavelength coverage, could indeed contribute in a highly significant and, in specific cases

  14. OT2_amoor_4: A census of debris disks in nearby young moving groups with Herschel.

    NASA Astrophysics Data System (ADS)

    Moór, A.

    2011-09-01

    Nearly all young stars harbour circumstellar disks, that serve as the reservoir for mass accretion onto the star, and later become the birthplace of planetary systems. After the disappearance of the gas component from the disk a dusty debris disk is formed that is believed to mark the location of the planetesimal belt as well. For outlining the evolution of such debris disks traditionally open clusters and field stars were studied, however we argue that the recently discovered young moving groups are more suitable objects for such analyses, due to their proximity and good coverage of the first 50 Myr period of the planetary system evolution. In this proposal we request 70/160 um Herschel/PACS photometric observations for so-far unobserved moving group members. These observations will provide a complete coverage of all known members within 80 pc of five nearby young moving groups (beta Pic Moving Group, Tucana-Horologium, Carina, Columba, and Argus), in the A to K spectral range. Based on the new observations we will identify new debris disks, characterize the disk population within individual moving groups, and study disk evolution by comparing the groups of different ages. The results will be used to verify predictions of the self-stirring model of the evolution of planetesimal disks. We will also compare the properties of debris disks in groups of the same age, looking for additional 'environmental' parameters that affect disk structure over a whole moving group. Our study will be a significant contribution to the census of debris disks in young moving groups, increasing the number of observed sources by a factor of 1.5. Since Spitzer could perform only a limited census and the so-far approved Herschel programs added very few additional moving group obervations, our programme is expected to have a high legacy value.

  15. Windblown Dunes on the Floor of Herschel Impact Basin

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Herschel Basin, one of many meteor impact craters on Mars, has some dark material on its floor that appeared from earlier spacecraft missions to have been blown and/or deposited by wind. Herschel Basin was imaged at low resolution by the Mariner 9 and Viking orbiters ((A) above) in the 1970s, and again by the Phobos 2 orbiter in 1989.

    On June 14, 1998, Mars Global Surveyor's Mars Orbiter Camera revealed that part of the dark surface on the floor of Herschel Basin consists of a field of sand dunes ((B) above). These dunes have a distinct crescent-like shape characteristic of dunes on Earth called barchan dunes. They result from winds that blow from a single dominant direction.

    In the case of Herschel Basin, the dunes indicate that the strongest winds blow approximately north-to-south. The crescent horns on the ends of some of the dunes in this image are elongated. This condition indicates that the dominant winds do not always blow in exactly the same direction-- sometimes the winds blow from the northeast, sometimes from the northwest, and sometimes from the north. The local topography probably influences the wind direction--and hence dune shape--because this dune field is located on a narrow, low plain between a high crater rim to the east, and a narrow mountain range-- the inner ring of the Herschel impact basin--to the west (see image (A)).

    MOC image 36507 was obtained on Mars Global Surveyor's 365th orbit around 10:51 a.m. PDT on June 14, 1998. This subframe is centered around 14.27oS, 231.68oW.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  16. Exceptional outburst of the blazar CTA 102 in 2012: the GASP-WEBT campaign and its extension

    NASA Astrophysics Data System (ADS)

    Larionov, V. M.; Villata, M.; Raiteri, C. M.; Jorstad, S. G.; Marscher, A. P.; Agudo, I.; Smith, P. S.; Acosta-Pulido, J. A.; ˙arévalo, M. J.; Arkharov, A. A.; Bachev, R.; Blinov, D. A.; Borisov, G.; Borman, G. A.; Bozhilov, V.; Bueno, A.; Carnerero, M. I.; Carosati, D.; Casadio, C.; Chen, W. P.; Clemens, D. P.; Di Paola, A.; Ehgamberdiev, Sh. A.; Gómez, J. L.; González-Morales, P. A.; Griñón-Marín, A.; Grishina, T. S.; Hagen-Thorn, V. A.; Ibryamov, S.; Itoh, R.; Joshi, M.; Kopatskaya, E. N.; Koptelova, E.; Lázaro, C.; Larionova, E. G.; Larionova, L. V.; Manilla-Robles, A.; Metodieva, Y.; Milanova, Yu. V.; Mirzaqulov, D. O.; Molina, S. N.; Morozova, D. A.; Nazarov, S. V.; Ovcharov, E.; Peneva, S.; Ros, J. A.; Sadun, A. C.; Savchenko, S. S.; Semkov, E.; Sergeev, S. G.; Strigachev, A.; Troitskaya, Yu. V.; Troitsky, I. S.

    2016-09-01

    After several years of quiescence, the blazar CTA 102 underwent an exceptional outburst in 2012 September-October. The flare was tracked from γ-ray to near-infrared (NIR) frequencies, including Fermi and Swift data as well as photometric and polarimetric data from several observatories. An intensive Glast-Agile support programme of the Whole Earth Blazar Telescope (GASP-WEBT) collaboration campaign in optical and NIR bands, with an addition of previously unpublished archival data and extension through fall 2015, allows comparison of this outburst with the previous activity period of this blazar in 2004-2005. We find remarkable similarity between the optical and γ-ray behaviour of CTA 102 during the outburst, with a time lag between the two light curves of ≈1 h, indicative of cospatiality of the optical and γ-ray emission regions. The relation between the γ-ray and optical fluxes is consistent with the synchrotron self-Compton (SSC) mechanism, with a quadratic dependence of the SSC γ-ray flux on the synchrotron optical flux evident in the post-outburst stage. However, the γ-ray/optical relationship is linear during the outburst; we attribute this to changes in the Doppler factor. A strong harder-when-brighter spectral dependence is seen both the in γ-ray and optical non-thermal emission. This hardening can be explained by convexity of the UV-NIR spectrum that moves to higher frequencies owing to an increased Doppler shift as the viewing angle decreases during the outburst stage. The overall pattern of Stokes parameter variations agrees with a model of a radiating blob or shock wave that moves along a helical path down the jet.

  17. 15N/14N Ratio Determination in the ISM with Herschel with High Resolution Spectroscopy of Nitrogen Radicals

    NASA Astrophysics Data System (ADS)

    Margulès, L.; Bailleux, S.; Wlodarczak, G.; Pirali, O.; Martin-Drumel, M.-A.; Roy, P.; Roueff, E.; Gerin, M.

    2011-06-01

    The very high resolution of the HIFI instrument (134 kHz-1MHz) on board of Herschel needs very accurate laboratory measurements to detect unambiguously the signature of stable and unstable molecular species. Concerning the pure rotation spectra of new species, and particularly of open shell molecules, the first prediction could be far away and up to few hundred MHz. The 15N/14N ratio is not well measured in the ISM. However, the 15N/14N in the isotopomers is a potential tracer of the formation processes and the possible link with cometary molecules. Recent measurements include the detection of 15NH_2D N15NH+ and 15NH_3. The NH and NH_2 species are the simplest nitrogen radicals and are intermediate products in the NH_3 synthesis. They have been easily detected by Herschel and it therefore is interesting to now search for 15NH and 15NH_2. No spectrocopic data have been reported for these two radicals up to now. We present here the studies with high resolution spectroscopy in the THz range. The high sensitivity and the wide range of Synchrotron (0.6-6 THz) was essential to improve the prediction of the spectra of these two species in order to measure them in Lille (0.6-1 THz) with both a higher accuracy and resolution. The combined studies now give the most accurate predictions. ISM searches on these radicals are in progress in the HERSCHEL spectra. This work is supported by the Programme National de Physico-Chimie du Milieu Interstellaire (PCMI-CNRS) M. Gerin, N. Marcellino, N. Biver, et al., Astron. & Astrophys. 498 (2009) 9. L. Bizzochi, P. Caselli, and L. Dore, Astron. & Astrophys. 510 (2010) L5. D. C. Lis, A. Wooten, M. Gerin and E. Roueff, Astrophys. J. 710 (2010) L49.

  18. A Herschel view of IC 1396 A: Unveiling the different sequences of star formation

    NASA Astrophysics Data System (ADS)

    Sicilia-Aguilar, Aurora; Roccatagliata, Veronica; Getman, Konstantin; Henning, Thomas; Merín, Bruno; Eiroa, Carlos; Rivière-Marichalar, Pablo; Currie, Thayne

    2014-02-01

    more evolved population of Class I/II/III objects in the cloud are uncertain. Heating of most of the remaining cloud by Class I/Class II objects and by HD 206267 itself may preclude further star formation in the region. Based on observations obtained with the Herschel Space Telescope within open time proposal "Disk dispersal in Cep OB2", OT1_asicilia_1. Herschel is an ESA space observatory with science instruments provided by European-led PI consortia and with important participation from NASA.

  19. Experimental study of neutron-rich nuclei near the N = 82 closed shell using the 4096Zr +50124Sn reaction with GASP and PRISMA-CLARA arrays

    NASA Astrophysics Data System (ADS)

    Rodríguez, W.; Torres, D. A.; Cristancho, F.; Medina, N. H.; Chapman, R.; Smith, J. F.; Mengoni, D.; Truesdale, V.; Grocutt, L.; Mulholland, K.; Kumar, V.; Hadinia, B.; Labiche, M.; Liang, X.; O'Donell, D.; Ollier, J.; Orlandi, R.; Smith, J. F.; Spohr, K. M.; Wady, P.; Wang, Z. M.; Gadea, A.; Ur, C. A.; Lenzi, S. M.; Capponi, L.; Michelangnoli, C.; Bazzacco, D.; Beghini, S.; Mǎrginean, R.; Mengoni, D.; Montagnoli, G.; Recchia, F.; Scarlassara, F.; Lunardi, S.; Kröll, T.; Napoli, D. R.; Corradi, L.; Fioretto, E.; de Angelis, G.; Mǎrginean, N.; Sahin, E.; Stefanini, A. M.; Valiente-Dobon, J. J.; Vedova, F. D.; Axiotis, M.; Martinez, T.; Szilner, S.; Freeman, S. J.; Smith, A. G.; Jones, G.; Thompson, N.; Pollarolo, G.

    2014-11-01

    In this contribution an experimental study of the deep-inelastic reaction 4096Zr +50124Sn at 530 MeV, using the GASP and PRISMA-CLARA arrays, is presented. The experiments populate a wealth of projectile-like and target-like binary fragments, in a large neutron-rich region around N ≥ 50 and Z ≈ 40. Preliminary results on the study of the yrast and near-yrast states for 95Nb will be shown, along with a comparison of the experimental yields obtained in the experiments.

  20. Patterns of respiration in diving penguins: is the last gasp an inspired tactic?

    PubMed

    Wilson, Rory P; Simeone, Alejandro; Luna-Jorquera, Guillermo; Steinfurth, Antje; Jackson, Sue; Fahlman, Andreas

    2003-05-01

    Humboldt penguins Spheniscus humboldti in captivity and free-living Magellanic penguins S. magellanicus were fitted with loggers to determine beak angles during breathing. The Humboldt penguins were also fitted with masks for determining rates of air flow during breathing. During periods of higher gas exchange requirement, Humboldt penguins opened their beaks during inspiration, where tidal volume was linearly correlated with both change in beak angle and maximum beak angle, closed them slightly during the final stages of inspiration and finally closed them during expiration. Substantial differences were apparent between individuals. Contrary to the condition proposed for most birds, our data suggest that expiration is passive during periods of high respiratory tidal volumes, and that the increased resistance of the respiratory pathway serves to slow air flow so as to maximize gas exchange in the lungs. During foraging, Magellanic penguins at the surface between dives showed similar breathing patterns but maximum beak angles were much higher and breath cycle time shorter, as would be expected for animals attempting to maximize gas exchange. Both maximum beak angle per breath and breath frequency changed systematically over the surface pause; both were initially high, then decreased to a low before rising again to a maximum just before diving. Based on known changes in tidal volume with beak angle derived from Humboldt penguins, a simple model is proposed to examine rates of gas exchange over the surface pause. This indicates that the observed patterns do not maximize the rate of transfer of oxygen over the whole of the surface pause but are rather concerned with an initial rapid accumulation of oxygen in the tissues followed by effective carbon dioxide release. PMID:12682106

  1. Herschel detects oxygen in the β Pictoris debris disk

    NASA Astrophysics Data System (ADS)

    Brandeker, A.; Cataldi, G.; Olofsson, G.; Vandenbussche, B.; Acke, B.; Barlow, M. J.; Blommaert, J. A. D. L.; Cohen, M.; Dent, W. R. F.; Dominik, C.; Di Francesco, J.; Fridlund, M.; Gear, W. K.; Glauser, A. M.; Greaves, J. S.; Harvey, P. M.; Heras, A. M.; Hogerheijde, M. R.; Holland, W. S.; Huygen, R.; Ivison, R. J.; Leeks, S. J.; Lim, T. L.; Liseau, R.; Matthews, B. C.; Pantin, E.; Pilbratt, G. L.; Royer, P.; Sibthorpe, B.; Waelkens, C.; Walker, H. J.

    2016-06-01

    The young star β Pictoris is well known for its dusty debris disk produced through collisional grinding of planetesimals, kilometre-sized bodies in orbit around the star. In addition to dust, small amounts of gas are also known to orbit the star; this gas is likely the result of vaporisation of violently colliding dust grains. The disk is seen edge on and from previous absorption spectroscopy we know that the gas is very rich in carbon relative to other elements. The oxygen content has been more difficult to assess, however, with early estimates finding very little oxygen in the gas at a C/O ratio that is 20 × higher than the cosmic value. A C/O ratio that high is difficult to explain and would have far-reaching consequences for planet formation. Here we report on observations by the far-infrared space telescope Herschel, using PACS, of emission lines from ionised carbon and neutral oxygen. The detected emission from C+ is consistent withthat previously reported observed by the HIFI instrument on Herschel, while the emission from O is hard to explain without assuming a higher density region in the disk, perhaps in the shape of a clump or a dense torus required to sufficiently excite the O atoms. A possible scenario is that the C/O gas is produced by the same process responsible for the CO clump recently observed by the Atacama Large Millimeter/submillimeter Array in the disk and that the redistribution of the gas takes longer than previously assumed. A more detailed estimate of the C/O ratio and the mass of O will have to await better constraints on the C/O gas spatial distribution. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. The Herschel Multi-tiered Extragalactic Survey: HerMES

    NASA Technical Reports Server (NTRS)

    Oliver, S.J.; Bock, J.; Altieri, B.; Amblard, A.; Arumugam, V.; Aussel, H.; Babbedge, T.; Beelen, A.; Bethermin, M.; Blain, A.; Boselli, A.; Bridge, C.; Brisbin, D; Buat, V.; Burgarella, D.; Castro-Rodriguez, N.; Cava, A.; Chanial, P.; Cirasuolo, M.; Clements, D. L.; Conley, A.; Conversi, L.; Dwek, E.; Levenson, L.; Nguyen, H. T.

    2012-01-01

    The Herschel Multi-tiered Extragalactic Survey, HerMES, is a legacy program designed to map a set of nested fields totalling approx. 380 deg(exp 2). Fields range in size from 0.01 to approx. 20 deg (exp 2), using Herschel-SPIRE (at 250, 350 and 500 micron), and Herschel-PACS (at 100 and 160 micron), with an additional wider component of 270 deg. (exp. 2) with SPIRE alone. These bands cover the peak of the redshifted thermal spectral energy distribution from interstellar dust and thus capture the re-processed optical and ultra-violet radiation from star formation that has been absorbed by dust, and are critical for forming a complete multi-wavelength understanding of galaxy formation and evolution. The survey will detect of order 100,000 galaxies at 5-sigma in some of the best studied fields in the sky. Additionally, HerMES is closely coordinated with the PACS Evolutionary Probe survey. Making maximum use of the full spectrum of ancillary data, from radio to X-ray wavelengths, it is designed to: facilitate redshift determination; rapidly identify unusual objects; and understand the relationships between thermal emission from dust and other processes. Scientific questions HerMES will be used to answer include: the total infrared emission of galaxies; the evolution of the luminosity function; the clustering properties of dusty galaxies; and the properties of populations of galaxies which lie below the confusion limit through lensing and statistical techniques. This paper defines the survey observations and data products, outlines the primary scientific goals of the HerMES team, and reviews some of the early results.

  3. The Herschel Data Processing System - Hipe And Pipelines - During The Early Mission Phase

    NASA Astrophysics Data System (ADS)

    Ardila, David R.; Herschel Science Ground Segment Consortium

    2010-01-01

    The Herschel Space Observatory, the fourth cornerstone mission in the ESA science program, was launched 14th of May 2009. With a 3.5 m telescope, it is the largest space telescope ever launched. Herschel's three instruments (HIFI, PACS, and SPIRE) perform photometry and spectroscopy in the 55 - 672 micron range and will deliver exciting science for the astronomical community during at least three years of routine observations. Here we summarize the state of the Herschel Data Processing System and give an overview about future development milestones and plans. The development of the Herschel Data Processing System started seven years ago to support the data analysis for Instrument Level Tests. Resources were made available to implement a freely distributable Data Processing System capable of interactively and automatically reduce Herschel data at different processing levels. The system combines data retrieval, pipeline execution and scientific analysis in one single environment. The software is coded in Java and Jython to be platform independent and to avoid the need for commercial licenses. The Herschel Interactive Processing Environment (HIPE) is the user-friendly face of Herschel Data Processing. The first PACS preview observation of M51 was processed with HIPE, using basic pipeline scripts to a fantastic image within 30 minutes of data reception. Also the first HIFI observations on DR-21 were successfully reduced to high quality spectra, followed by SPIRE observations on M66 and M74. The Herschel Data Processing System is a joint development by the Herschel Science Ground Segment Consortium, consisting of ESA, the NASA Herschel Science Center, and the HIFI, PACS and SPIRE consortium members.

  4. Herschel observations of the debris disc around HIP 92043

    NASA Astrophysics Data System (ADS)

    Marshall, J. P.; Krivov, A. V.; del Burgo, C.; Eiroa, C.; Mora, A.; Montesinos, B.; Ertel, S.; Bryden, G.; Liseau, R.; Augereau, J.-C.; Bayo, A.; Danchi, W.; Löhne, T.; Maldonado, J.; Pilbratt, G. L.; Stapelfeldt, K.; Thebault, P.; White, G. J.; Wolf, S.

    2013-09-01

    Context. Typical debris discs are composed of particles ranging from several micron sized dust grains to km sized asteroidal bodies, and their infrared emission peaks at wavelengths 60-100 μm. Recent Herschel DUNES observations have identified several debris discs around nearby Sun-like stars (F, G and K spectral type) with significant excess emission only at 160 μm. Aims: We observed HIP 92043 (110 Her, HD 173667) at far-infrared and sub-millimetre wavelengths with Herschel PACS and SPIRE. Identification of the presence of excess emission from HIP 92043 and the origin and physical properties of any excess was undertaken through analysis of its spectral energy distribution (SED) and the PACS images. Methods: The PACS and SPIRE images were produced using the HIPE photProject map maker routine. Fluxes were measured using aperture photometry. A stellar photosphere model was scaled to optical and near infrared photometry and subtracted from the far-infared and sub-mm fluxes to determine the presence of excess emission. Source radial profiles were fitted using a 2D Gaussian and compared to a PSF model based on Herschel observations of α Boo to check for extended emission. Results: Clear excess emission from HIP 92043 was observed at 70 and 100 μm. Marginal excess was observed at 160 and 250 μm. Analysis of the images reveals that the source is extended at 160 μm. A fit to the source SED is inconsistent with a photosphere and single temperature black body. Conclusions: The excess emission from HIP 92043 is consistent with the presence of an unresolved circumstellar debris disc at 70 and 100 μm, with low probability of background contamination. The extended 160 μm emission may be interpreted as an additional cold component to the debris disc or as the result of background contamination along the line of sight. The nature of the 160 μm excess cannot be determined absolutely from the available data, but we favour a debris disc interpretation, drawing parallels with

  5. Herschel survey of brown dwarf disks in ρ Ophiuchi

    NASA Astrophysics Data System (ADS)

    Alves de Oliveira, C.; Ábrahám, P.; Marton, G.; Pinte, C.; Kiss, Cs.; Kun, M.; Kóspál, Á.; André, P.; Könyves, V.

    2013-11-01

    Context. Young brown dwarfs are known to possess circumstellar disks, a characteristic that is fundamental to the understanding of their formation process, and raises the possibility that these objects harbour planets. Aims: We want to characterise the far-IR emission of disks around the young brown dwarf population of the ρ Ophiuchi cluster in LDN 1688. Methods: Recent observations of the ρ Ophiuchi cluster with the Herschel Space Observatory allow us to probe the spectral energy distribution (SED) of the brown dwarf population in the far-IR, where the disk emission peaks. We performed aperture photometry at 70, 100, and 160 μm, and constructed SEDs for all previously known brown dwarfs detected. These were complemented with ancillary photometry at shorter wavelengths. We compared the observed SEDs to a grid of synthetic disks produced with the radiative transfer code MCFOST, and used the relative figure of merit estimated from the Bayesian inference of each disk parameter to analyse the structural properties. Results: We detected 12 Class II brown dwarfs with Herschel, which corresponds to one-third of all currently known brown dwarf members of ρ Ophiuchi. We did not detect any of the known Class III brown dwarfs. Comparison to models reveals that the disks are best described by an inner radius between 0.01 and 0.07 AU, and a flared disk geometry with a flaring index between 1.05 and 1.2. Furthermore, we can exclude values of the disk scale-height lower than 10 AU (measured at a fiducial radius of 100 AU). We combined the Herschel data with recent ALMA observations of the brown dwarf GY92 204 (ISO-Oph 102), and by comparing its SED to the same grid of disk models, we derived an inner disk radius of 0.035 AU, a scale height of 15 AU with a flaring index of β ~ 1.15, an exponent for dust settling of -1.5, and a disk mass of 0.001 M⊙. This corresponds to a disk-to-central object mass ratio of ~1%. Conclusions: The structural parameters constrained by the

  6. The Photoconductor Array Camera & Spectrometer (PACS) instrument for Herschel.

    NASA Astrophysics Data System (ADS)

    Ali, Babar; Frayer, D. T.; Fadda, D.; Appleton, P.; Latter, B.

    2007-05-01

    PACS is one of three science instruments for ESA ’ s Herschel Space Observatory (HSO, formerly known as FIRST). It operates either as an imaging photometer or an integral field spectrometer over the spectral band from 57 to 210 µm. PACS is being designed and built by a consortium of institutes and university departments from across Europe under the leadership of Principal Investigator Albrecht Poglitsch located at Max-Planck-Institute for Extraterrestrial Physics (MPE), Garching, Germany. Consortium members are: Austria: UVIE; Belgium: IMEC, KUL, CSL; France: CEA, OAMP; Germany: MPE, MPIA; Italy: IFSI, OAP/OAT, OAA/CAISMI, LENS, SISSA; Spain: IAC.

  7. Beam profile for the Herschel-SPIRE Fourier transform spectrometer.

    PubMed

    Makiwa, Gibion; Naylor, David A; Ferlet, Marc; Salji, Carl; Swinyard, Bruce; Polehampton, Edward; van der Wiel, Matthijs H D

    2013-06-01

    One of the instruments on board the Herschel Space Observatory is the Spectral and Photometric Imaging Receiver (SPIRE). SPIRE employs a Fourier transform spectrometer with feed-horn-coupled bolometers to provide imaging spectroscopy. To interpret the resultant spectral images requires knowledge of the wavelength-dependent beam, which in the case of SPIRE is complicated by the use of multimoded feed horns. In this paper we describe a series of observations and the analysis conducted to determine the wavelength dependence of the SPIRE spectrometer beam profile. PMID:23736346

  8. Herschel and Planck: surprises in the sub-mm band

    NASA Astrophysics Data System (ADS)

    González-Nuevo González, J.

    2015-05-01

    This paper focused on three of the most spectacular and almost unexpected results obtained from the observations in the sub-mm band coming from the ESA's Herschel and Planck missions: the detection of hundred of strongly lensed galaxies, the identification of high-z proto-clusters, and the study of the weak lensing signal through the cross-correlation analysis. Although, there were theoretical works that anticipate them, none of these interesting results appeared in the original scientific programs of both mission. For this reason we have called them ``surprises''.

  9. Candidate High Redshift Clusters of Dusty Galaxies from Herschel & Planck

    NASA Astrophysics Data System (ADS)

    Clements, David L.

    2015-08-01

    The cross identification of Planck compact sources with objects in karger area Herschel surveys, such as HerMES and H-ATLAS, has led to the discovery of candidate high redshift (out to z~3) clusters of far-IR luminous star forming galaxies. These objects are not easily reproduced in the current generations of galaxy and large scale formation simulations and are thus a potentially powerful new tool for comnstraining galaxy and cluster formation models. We will review the current results on these sources and examine future prospects for progress in this novel and potentially important new field.

  10. OT2_sserje01_2: THE HERSCHEL-AKARI NEP DEEP SURVEY: the cosmological history of stellar mass assembly and black hole accretion

    NASA Astrophysics Data System (ADS)

    Serjeant, S.

    2011-09-01

    We propose a far-IR and submm mapping survey of the premier AKARI deep field in the North Ecliptic Pole, in PACS/SPIRE parallel mode. This is the only major deep infrared field not yet covered by Herschel guaranteed or open time key projects. The outstanding and unparalleled continuous mid-IR photometric coverage from AKARI, far better than equivalent Spitzer surveys, enables a wide range of galaxy evolution diagnostics unachievable in any other survey field (including Herschel HerMES/PEP fields), by spanning the wavelengths of redshifted PAH and silicate features and the peak energy output of AGN dust tori. The investment by AKARI in the NEP represents ~10 percent of the entire pointed observations available throughout the lifetime of AKARI. Our proposal remedies the remarkable omission from Herschel's legacy surveys of the premier extragalactic deep field from another IR space telescope. We will simultaneously identify and find photometric redshifts for the Herschel point source population, make stacking analysis detections of the galaxies which dominate the submm extragalactic background light as a function of redshift, determine the bolometric power outputs of the galaxies that dominate the submm background, compare the UV/optical/mid-IR continuum/PAH/far-IR/submm/radio star formation rate estimator in the most comprehensive IR survey data set to date, and track the coupled stellar mass assembly and black hole accretion throughout most of the history of the Universe. In OT1 the HOTAC concluded "The science output from the proposed survey will be outstanding [...] The panel was convinced that these observations should be done" but it since became clear that priority 2 time is very unlikely to be executed, so we request reclassification to priority 1.

  11. Cryogenic Testing of the Herschel Flight Model Spacecraft

    NASA Astrophysics Data System (ADS)

    Jahn, G.; Langfermann, M.; Wagner, K.; Hohn, R.; Demolder, B.; Jewell, C.; Linder, M.

    2010-04-01

    The `Herschel Space Observatory' is the fourth cornerstone mission in the `Horizons 2000' program of the European Space Agency (ESA), with the objectives to study the formation of galaxies in the early universe and the creation of stars. It will observe the chemical composition of surfaces and atmospheres of comets, planets and natural satellites, and examine the molecular chemistry of the universe. Herschel was launched into an operational Lissajous orbit around the Earth-Sun L2 point by an Ariane 5 on May 14th 2009 to perform photometer and spectrometer measurements, covering the full far infrared to sub-millimeter wavelength range from 60 to 670 micrometers during its operational lifetime of more than four years. This paper gives a short overview of the cryogenic system and summarises the cryogenic aspects of the different phases of the acceptance test campaign, including the launch preparation phase as well as the post-launch transient cool-down of the system, the verification of the Passive Phase Separator performance and the evaluation of pressure drop measurements performed on the helium venting system. The impact of thermo-acoustic oscillations within the helium subsystem is described, which were present during the initial cool-down test phase. A comparison of measurements to numerical analysis results is shown.

  12. Water in star-forming regions with Herschel (WISH)

    NASA Astrophysics Data System (ADS)

    van Dishoeck, Ewine

    2015-08-01

    Water is a key molecule in the physics and chemistry of regions in which new stars and planets are born. This poster summarizes recent results on the chemistry of water in protostellar envelopes and protoplanetary disks obtained with the Herschel-HIFI and PACS instruments in the context of the 'Water in Star-forming Regions with Herschel' (WISH) Key Program. About 80 sources have been observed, covering a wide range of masses as well as evolutionary stages -from the earliest stages represented by pre-stellar cores to the late stages represented by the pre-main sequence stars surrounded only by disks. The data elucidate the physical and dynamical processes associated with forming stars and planets (outflow, infall, expansion), test basic gas-phase and gas-grain chemical processes, and reveal the chemical evolution of water and the oxygen-reservoir into planet-forming disks.This poster is presented on behalf of the WISH team. See http://www.strw.leidenuniv.nl/WISH for list of papers and results.

  13. Star formation in Herschel's Monsters versus semi-analytic models

    NASA Astrophysics Data System (ADS)

    Gruppioni, C.; Calura, F.; Pozzi, F.; Delvecchio, I.; Berta, S.; De Lucia, G.; Fontanot, F.; Franceschini, A.; Marchetti, L.; Menci, N.; Monaco, P.; Vaccari, M.

    2015-08-01

    We present a direct comparison between the observed star formation rate functions (SFRFs) and the state-of-the-art predictions of semi-analytic models (SAMs) of galaxy formation and evolution. We use the PACS Evolutionary Probe Survey and Herschel Multi-tiered Extragalactic Survey data sets in the COSMOS and GOODS-South fields, combined with broad-band photometry from UV to sub-mm, to obtain total (IR+UV) instantaneous star formation rates (SFRs) for individual Herschel galaxies up to z ˜ 4, subtracted of possible active galactic nucleus (AGN) contamination. The comparison with model predictions shows that SAMs broadly reproduce the observed SFRFs up to z ˜ 2, when the observational errors on the SFR are taken into account. However, all the models seem to underpredict the bright end of the SFRF at z ≳ 2. The cause of this underprediction could lie in an improper modelling of several model ingredients, like too strong (AGN or stellar) feedback in the brighter objects or too low fallback of gas, caused by weak feedback and outflows at earlier epochs.

  14. A snapshot beyond the Local Universe with Herschel/SPIRE

    NASA Astrophysics Data System (ADS)

    Pinter, Sandor; Marton, Gabor; Toth, L. Viktor; Pearson, Chris; Bagoly, Zsolt; Balazs, Lajos G.; Horvath, Istvan; Racz, Istvan I.

    The European Large-Area ISO Survey (ELAIS) N1 field is one of the extragalactic windows where the lack of the Galactic ISM allows us to analyze the unbiased FIR properties of extragalactic objects. The field was investigated recently based on Herschel observations by the HerMES key project. We present a survey of the field covering a larger area than HerMES (12.54 deg2 vs 3.47 deg2). We provide accurate 250, 350, and 500 micrometer flux densities for about 8000 point sources using the latest Herschel analysis and calibration procedures. Based on SDSS spectroscopic and SWIRE photometric data our sample has approximately 4000 and 4500 galaxies with 0.2 < z < 0.5 and z > 0.5 redshifts, respectively. The new flux densities are crucial limiting the star-forming activity of galaxies outside the Local Universe, as it is demonstrated in the star-forming galaxy 2MASS J16072472+5412119.

  15. A snapshot beyond the Local Universe with Herschel/SPIRE

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Pinter, Sandor; Toth, L. Viktor

    2015-08-01

    The European Large-Area ISO Survey (ELAIS) N1 field is one of the extragalactic windows where the lack of the Galactic ISM allows us to analyze the unbiased FIR properties of extragalactic objects. The field was observed by the ISO and Spitzer infrared space telescopes, and followed-up with a number of ground base measurements in various wavelength bands. Its content was investigated in more details recently based on deep Herschel observations by the HerMES key project. We present a list of objects from observations covering a larger area than that of the HerMES ones and correlate our results with theirs to achieve a sufficient photometric accuracy. We provide accurate 250 micrometer flux densities for about 8000 point sources using the latest Herschel analysis and calibration procedures. Our sample has approximately 500 and 6000 galaxies with 0.21 redshifts respectively based on SDSS spectroscopic data. The new flux densities are crucial limiting the star forming activity of galaxies outside the Local Universe, and especially for the ones at z>1.

  16. Herschel Observations of Circinus X-1 during Outburst and Quiescence

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.; Gelino, Dawn M.; Buxton, Michelle; Fost, Tyler

    2014-07-01

    We have used the Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging REceiver instruments on the Herschel Space Observatory to observe Cir X-1 both in and out of outburst. We detected Cir X-1 during outburst at 70 μm. Unfortunately, a cold background source dominates Cir X-1 at longer wavelengths. We have assembled optical and infrared (IR) data for Cir X-1 to model its spectral energy distribution (SED) in both quiescence and outburst and find that in both states it is consistent with a heavily reddened, 10,000 K blackbody. We believe this behavior is completely consistent with previous suggestions that these outbursts are due to accretion disk events, not unlike those of dwarf novae. To explore the behavior of other low-mass X-ray binaries with reported synchrotron jets, we have extracted and/or compiled optical and near- and mid-IR data sets for five such systems to construct their SEDs. The Z-source GX 349+2 and the black hole system GRS 1915+105 have strong and variable mid-IR excesses that suggest synchrotron emission. The other Z-sources have rather weak (or no) IR excesses that can be explained as reddened blackbody spectra with the addition of either synchrotron or bremsstrahlung components. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  17. The Herschel-ATLAS survey: main results and data release

    NASA Astrophysics Data System (ADS)

    Valiante, Elisabetta

    2015-08-01

    I describe the first major data release of the largest single key-project carried out in opentime with the Herschel Space Observatory. The Herschel Astrophysical Terahertz Large Area Survey(H-ATLAS) was a survey of 550 deg^2 in five photometric bands: 100, 160, 250, 350 and 500 micron.In this talk I will show some of the results of the survey: 1) the development of a technique to select lensed objects with 100% efficiency, 2) how to select up to 1000 lensed sources, 3) the development of a technique to select very high redshift galaxies, 4) the discover of a high-redshift proto-cluster, 5) the definition of the local far-ir luminosity function, 6) dust properties of nearby galaxies.Moreover, I will describe images and catalogues of the three fields on the celestial equator previouslyobserved in the Galaxy and Mass Assembly (GAMA) redshift survey, which cover a total area of 161.6 deg^2. These data will be released and made available to the public during 2015.Our catalogues include ~3x10^5 sources detected at 5 sigma at 250, 350 and 500 micron, respectively. I will describe a detailed analysis of the effects of instrumental noise and source confusion on the images and the catalogues, as well as other simulations which will aid the interpretation of the H-ATLAS data by the astronomical community.

  18. The Herschel-ATLAS survey: main results and data release

    NASA Astrophysics Data System (ADS)

    Valiante, Elisabetta

    2015-08-01

    I describe the first major data release of the largest single key-project carried out in opentime with the Herschel Space Observatory. The Herschel Astrophysical Terahertz Large Area Survey(H-ATLAS) was a survey of 550 deg^2 in five photometric bands: 100, 160, 250, 350 and 500 micron.In this talk I will show some of the results of the survey: 1) the development of a technique to select lensed objects with 100% efficiency, 2) how to select up to 1000 lensed sources, 3) the development of a technique to select very high redshift galaxies, 4) the discover of a high-redshift proto-cluster, 5) the definition of the local far-ir luminosity function, 6) dust properties of nearby galaxies.Moreover, I will describe images and catalogues of the three fields on the celestial equator previously observed in the Galaxy and Mass Assembly (GAMA) redshift survey, which cover a total area of 161.6 deg^2. These data will be released and made available to the public during 2015.Our catalogues include ~3x10^5 sources detected at 5 sigma at 250, 350 and 500 micron, respectively. I will describe a detailed analysis of the effects of instrumental noise and source confusion on the images and the catalogues, as well as other simulations which will aid the interpretation of the H-ATLAS data by the astronomical community.

  19. The JCMT and Herschel Gould Belt Surveys: A comparison of SCUBA-2 and Herschel data of dense cores in the Taurus dark cloud L1495

    NASA Astrophysics Data System (ADS)

    Ward-Thompson, D.; Pattle, K.; Kirk, J. M.; Marsh, K.; Buckle, J.; Hatchell, J.; Nutter, D. J.; Griffin, M. J.; Di Francesco, J.; André, P.; Beaulieu, S.; Berry, D.; Broekhoven-Fiene, H.; Currie, M.; Fich, M.; Jenness, T.; Johnstone, D.; Kirk, H.; Mottram, J.; Pineda, J.; Quinn, C.; Sadavoy, S.; Salji, C.; Tisi, S.; Walker-Smith, S.; White, G.; Hill, T.; Könyves, V.; Palmeirim, P.; Pezzuto, S.

    2016-08-01

    We present a comparison of SCUBA-2 850-μm and Herschel 70-500-μm observations of the L1495 filament in the Taurus Molecular Cloud with the goal of characterising the SCUBA-2 Gould Belt Survey (GBS) data set. We identify and characterise starless cores in three data sets: SCUBA-2 850-μm, Herschel 250-μm, and Herschel 250-μm spatially filtered to mimic the SCUBA-2 data. SCUBA-2 detects only the highest-surface-brightness sources, principally detecting protostellar sources and starless cores embedded in filaments, while Herschel is sensitive to most of the cloud structure, including extended low-surface-brightness emission. Herschel detects considerably more sources than SCUBA-2 even after spatial filtering. We investigate which properties of a starless core detected by Herschel determine its detectability by SCUBA-2, and find that they are the core's temperature and column density (for given dust properties). For similar-temperature cores, such as those seen in L1495, the surface brightnesses of the cores are determined by their column densities, with the highest-column-density cores being detected by SCUBA-2. For roughly spherical geometries, column density corresponds to volume density, and so SCUBA-2 selects the densest cores from a population at a given temperature. This selection effect, which we quantify as a function of distance, makes SCUBA-2 ideal for identifying those cores in Herschel catalogues that are closest to forming stars. Our results can now be used by anyone wishing to use the SCUBA-2 GBS data set.

  20. Philomaths, Herschel, and the myth of the self-taught man.

    PubMed

    Winterburn, Emily

    2014-09-20

    The role of technicians and background characters in the historical practice of science is slowly gaining recognition. This paper looks at the collective effort involved in learning science, using as my case study the eighteenth-century musician turned astronomer, William Herschel. Lacking a university education, Herschel, like many contemporaries, presented himself as self-taught, thereby hiding his engagement with a rich network of didactic resources. Placing Herschel's story within the history of pedagogy, I argue that this network, previously discussed only in the context of popular or marketplace science, was an important resource for science education at its highest level. PMID:25254276

  1. Philomaths, Herschel, and the myth of the self-taught man

    PubMed Central

    Winterburn, Emily

    2014-01-01

    The role of technicians and background characters in the historical practice of science is slowly gaining recognition. This paper looks at the collective effort involved in learning science, using as my case study the eighteenth-century musician turned astronomer, William Herschel. Lacking a university education, Herschel, like many contemporaries, presented himself as self-taught, thereby hiding his engagement with a rich network of didactic resources. Placing Herschel's story within the history of pedagogy, I argue that this network, previously discussed only in the context of popular or marketplace science, was an important resource for science education at its highest level. PMID:25254276

  2. Herschel Search for O2 toward the Orion Bar

    NASA Astrophysics Data System (ADS)

    Melnick, Gary J.; Tolls, Volker; Goldsmith, Paul F.; Kaufman, Michael J.; Hollenbach, David J.; Black, John H.; Encrenaz, Pierre; Falgarone, Edith; Gerin, Maryvonne; Hjalmarson, Åke; Li, Di; Lis, Dariusz C.; Liseau, René; Neufeld, David A.; Pagani, Laurent; Snell, Ronald L.; van der Tak, Floris; van Dishoeck, Ewine F.

    2012-06-01

    We report the results of a search for molecular oxygen (O2) toward the Orion Bar, a prominent photodissociation region at the southern edge of the H II region created by the luminous Trapezium stars. We observed the spectral region around the frequency of the O2 NJ = 33-12 transition at 487 GHz and the 54-34 transition at 774 GHz using the Heterodyne Instrument for the Far-Infrared on the Herschel Space Observatory. Neither line was detected, but the 3σ upper limits established here translate to a total line-of-sight O2 column density <1.5 × 1016 cm-2 for an emitting region whose temperature is between 30 K and 250 K, or <1 × 1016 cm-2 if the O2 emitting region is primarily at a temperature of lsim100 K. Because the Orion Bar is oriented nearly edge-on relative to our line of sight, the observed column density is enhanced by a factor estimated to be between 4 and 20 relative to the face-on value. Our upper limits imply that the face-on O2 column density is less than 4 × 1015 cm-2, a value that is below, and possibly well below, model predictions for gas with a density of 104-105 cm-3 exposed to a far-ultraviolet flux 104 times the local value, conditions inferred from previous observations of the Orion Bar. The discrepancy might be resolved if (1) the adsorption energy of O atoms to ice is greater than 800 K (2) the total face-on A V of the Bar is less than required for O2 to reach peak abundance; (3) the O2 emission arises within dense clumps with a small beam filling factor; or (4) the face-on depth into the Bar where O2 reaches its peak abundance, which is density dependent, corresponds to a sky position different from that sampled by our Herschel beams. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. Herschel/HIFI deepens the circumstellar NH3 enigma

    NASA Astrophysics Data System (ADS)

    Menten, K. M.; Wyrowski, F.; Alcolea, J.; De Beck, E.; Decin, L.; Marston, A. P.; Bujarrabal, V.; Cernicharo, J.; Dominik, C.; Justtanont, K.; de Koter, A.; Melnick, G.; Neufeld, D. A.; Olofsson, H.; Planesas, P.; Schmidt, M.; Schöier, F. L.; Szczerba, R.; Teyssier, D.; Waters, L. B. F. M.; Edwards, K.; Olberg, M.; Phillips, T. G.; Morris, P.; Salez, M.; Caux, E.

    2010-10-01

    Context. Circumstellar envelopes (CSEs) of a variety of evolved stars have been found to contain ammonia (NH3) in amounts that exceed predictions from conventional chemical models by many orders of magnitude. Aims: The observations reported here were performed in order to better constrain the NH3 abundance in the CSEs of four, quite diverse, oxygen-rich stars using the NH3 ortho JK = 10-00 ground-state line. Methods: We used the Heterodyne Instrument for the Far Infrared aboard Herschel to observe the NH3 JK = 10-00 transition near 572.5 GHz, simultaneously with the ortho-H2O JKa , Kc = 11,0 - 10,1 transition, toward VY CMa, OH 26.5+0.6, IRC+10420, and IK Tau. We conducted non-LTE radiative transfer modeling with the goal to derive the NH3 abundance in these objects' CSEs. For the last two stars, Very Large Array imaging of NH3 radio-wavelength inversion lines were used to provide further constraints, particularly on the spatial extent of the NH3-emitting regions. Results: We find remarkably strong NH3 emission in all of our objects with the NH3 line intensities rivaling those of the ground state H2O line. The NH3 abundances relative to H2 are very high and range from 2×10-7 to 3×10-6 for the objects we have studied. Conclusions: Our observations confirm and even deepen the circumstellar NH3 enigma. While our radiative transfer modeling does not yield satisfactory fits to the observed line profiles, it does lead to abundance estimates that confirm the very high values found in earlier studies. New ways to tackle this mystery will include further Herschel observations of more NH3 lines and imaging with the Expanded Very Large Array. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix A (page 5) is only available in electronic form at http://www.aanda.org

  4. High-resolution incremental tape encoder on the William Herschel Telescope

    NASA Astrophysics Data System (ADS)

    Fisher, Martin

    1994-06-01

    Large, modern optical telescopes demand high performance pointing and tracking of the mount unless alternative methods of correcting the telescope `beam' are to be completely relied upon. This is rarely the case and `open-loop' specifications are still very demanding. The move from precision-geared to friction driven axes has excluded the use of gear-driven encoders while friction-driven encoders have not proved successful. Fiber and laser gyros are not sufficiently developed for use as a primary encoding system although they have useful inertial properties for inclusion in some systems. Tape encoders, which have been around for a very long time, are the major contender for today's applications. A commercially available inductive tape encoder system has been fitted to the 4.2 m William Herschel Telescope in order to properly evaluate its performance and hence its suitability for use with the 8 m Gemini telescopes. The encoder system and the method adopted for fitting it to an operational telescope is briefly described and the results from performance tests are presented. Subsequent investigations into sources of error and the desirability and methods of correcting them are discussed and future work is considered.

  5. Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?

    NASA Technical Reports Server (NTRS)

    Krivov, A. V.; Eiroa, C.; Loehne, T.; Marshall, J. P.; Montesinos, B.; DelBurgo, C.; Absil, O.; Ardila, D.; Augereau, J.-C.; Bayo, A.; Bryden, G.; Danchi, W.; Ertel, S.; Lebreton, J.; Liseau, R.; Mora, A.; Mustill, A. J.; Mutschke, H.; Neuhaeuser, R.; Pilbratt, G. L.; Roberge, A.; Schmidt, T. O. B.; Stapelfeldt, K. R.; Thebault, Ph.; Vitense, Ch.; White, G. J.; Wolf, S.

    2013-01-01

    Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around approx, 100 micron or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant-and in some cases extended-excess emission at 160 micron, which is larger than the 100 micron excess. This excess emission has been attributed to circumstellar dust and has been suggested to stem from debris disks colder than those known previously. Since the excess emission of the cold disk candidates is extremely weak, challenging even the unrivaled sensitivity of Herschel, it is prudent to carefully consider whether some or even all of them may represent unrelated galactic or extragalactic emission, or even instrumental noise. We re-address these issues using several distinct methods and conclude that it is highly unlikely that none of the candidates represents a true circumstellar disk. For true disks, both the dust temperatures inferred from the spectral energy distributions and the disk radii estimated from the images suggest that the dust is nearly as cold as a blackbody. This requires the grains to be larger than approx. 100 micron, even if they are rich in ices or are composed of any other material with a low absorption in the visible. The dearth of small grains is puzzling, since collisional models of debris disks predict that grains of all sizes down to several times the radiation pressure blowout limit should be present. We explore several conceivable scenarios: transport-dominated disks, disks of low dynamical excitation, and disks of unstirred primordial macroscopic grains. Our qualitative analysis and collisional simulations rule out the first two of these scenarios, but show the feasibility of the third one. We show that such disks can indeed survive for gigayears, largely preserving the primordial size distribution. They should be composed of macroscopic solids larger than millimeters, but

  6. HERSCHEL's ''COLD DEBRIS DISKS'': BACKGROUND GALAXIES OR QUIESCENT RIMS OF PLANETARY SYSTEMS?

    SciTech Connect

    Krivov, A. V.; Loehne, T.; Mutschke, H.; Neuhaeuser, R.; Eiroa, C.; Marshall, J. P.; Mustill, A. J.; Montesinos, B.; Del Burgo, C.; Absil, O.; Ardila, D.; Augereau, J.-C.; Ertel, S.; Lebreton, J.; Bryden, G.; Danchi, W.; Liseau, R.; Mora, A.; Pilbratt, G. L. [ESA Astrophysics and Fundamental Physics Missions Division, ESTEC and others

    2013-07-20

    Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around {approx}100 {mu}m or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant-and in some cases extended-excess emission at 160 {mu}m, which is larger than the 100 {mu}m excess. This excess emission has been attributed to circumstellar dust and has been suggested to stem from debris disks colder than those known previously. Since the excess emission of the cold disk candidates is extremely weak, challenging even the unrivaled sensitivity of Herschel, it is prudent to carefully consider whether some or even all of them may represent unrelated galactic or extragalactic emission, or even instrumental noise. We re-address these issues using several distinct methods and conclude that it is highly unlikely that none of the candidates represents a true circumstellar disk. For true disks, both the dust temperatures inferred from the spectral energy distributions and the disk radii estimated from the images suggest that the dust is nearly as cold as a blackbody. This requires the grains to be larger than {approx}100 {mu}m, even if they are rich in ices or are composed of any other material with a low absorption in the visible. The dearth of small grains is puzzling, since collisional models of debris disks predict that grains of all sizes down to several times the radiation pressure blowout limit should be present. We explore several conceivable scenarios: transport-dominated disks, disks of low dynamical excitation, and disks of unstirred primordial macroscopic grains. Our qualitative analysis and collisional simulations rule out the first two of these scenarios, but show the feasibility of the third one. We show that such disks can indeed survive for gigayears, largely preserving the primordial size distribution. They should be composed of macroscopic solids larger than millimeters, but smaller

  7. The Spectral And Photometric Imaging Receiver For Herschel (spire

    NASA Astrophysics Data System (ADS)

    Schulz, Bernhard; Lu, N.; Schwartz, A.; Shupe, D.; Xu, K.; Zhang, L.

    2007-05-01

    SPIRE is one of three instruments to be carried on the European Space Agency's Herschel Space Observatory (formerly called FIRST). We are describing the instrument which is designed for observations at far infrared and submillimetre wavelengths and its scientific potential. SPIRE features an imaging photometer with passbands around 250, 350 and 500 microns, and an imaging Fourier transform spectrometer covering the wavelength range between 194 and 672 microns. The instrument is being developed by a consortium of European and American scientists, led by PI Professor Matt Griffin at the Physics and Astronomy Department of Cardiff University (UK). The US is playing a crucial role in SPIRE by delivering its detector arrays, consisting of so-called "Spider Web Bolometers" developed by SPIRE Co-I Jamie Bock at JPL.

  8. Herschel Observations of the Hayabusa-2 Asteroid 162173 (1999 JU3)

    NASA Astrophysics Data System (ADS)

    O'Rourke, L.; Müller, T.; Altieri, B.; Gónzalez-García, B.; Kiss, C.; Pal, A.; Barucci, A.; Yoshikawa, M.; Dotto, E.; Küppers, M.; Sanchez Portal, M.

    2012-05-01

    Herschel observed the Hayabusa-2 target in early April 2012. Our measurements through the use of a thermophysical model (TPM) will aid to derive its rotation direction, thermal inertia & address its surface properties; all important for the mission.

  9. VizieR Online Data Catalog: Spectroscopy of Herschel Dwarf Galaxy Survey (Cormier+, 2015)

    NASA Astrophysics Data System (ADS)

    Cormier, D.; Madden, S. C.; Lebouteiller, V.; Abel, N.; Hony, S.; Galliano, F.; Remy-Ruyer, A.; Bigiel, F.; Baes, M.; Boselli, A.; Chevance, M.; Cooray, A.; de Looze, I.; Doublier, V.; Galametz, M.; Hugues, T.; Karczewski, O. L.; Lee, M.-Y.; Lu, N.; Spinoglio, L.

    2015-02-01

    Far-infrared line fluxes from the Herschel PACS instrument are provided for the 48 galaxies of the Dwarf Galaxy Survey. An atlas of images also shows spectral maps and line profiles for all sources. (9 data files).

  10. JCMT in the Post-Herschel ERA of Alma

    NASA Astrophysics Data System (ADS)

    Johnstone, Doug

    2013-07-01

    The James Clerk Maxwell Telescope (JCMT), with a 15m dish, is the largest single-dish astronomical telescope in the world designed specifically to operate in the sub-mm wavelength regime. The JCMT is located close to the summit of Mauna Kea, Hawaii, at an altitude of 4092m. The most recent addition to the JCMT's suite of instruments is the 10,000 bolometer sub-mm continuum instrument: SCUBA-2. SCUBA-2 operates simultaneously with 7' x7' foot print sub-arrays at both 450 and 850-microns. SCUBA-2's wide field surveying potential, combined with a 65% shared view of the sky from both sites, makes it the ideal instrument to provide complementary data for the ALMA Project. Furthermore, the SCUBA-2 sub-millimetre wavelength coverage and angular resolution complement existing Herschel observations. A set of comprehensive surveys of the submillimetre sky is underway at the James Clerk Maxwell Telescope (JCMT) using SCUBA-2 and HARP, a heterodyne array receiver operating between 325 and 375 GHz. The JCMT Legacy Survey (JLS) is comprised of seven survey projects, and ranges in scope from the study of nearby debris disk systems, the study of star formation in nearby molecular cloud systems and more distant structures in our Galactic Plane, to the structure and composition of galaxies in our local neighbourhood and the number and evolution of submillimetre galaxies at high redshifts in the early Universe. In addition to the JLS, the COHR survey is imaging the Galactic plane in CO (3-2) and a JAC Staff-led project is using SCUBA-2 to survey the Galactic Centre. This poster highlights the significant survey capabilities of SCUBA-2 and HARP and reveals the continuing importance of the JCMT in a post-Herschel, ALMA world.

  11. Physical Properties of the Haumea Family from Herschel

    NASA Astrophysics Data System (ADS)

    Stansberry, J. A.; Mueller, T. G.; Ortiz, J.-L.; Santos-Sanz, P.; Vilenius, E.; Lellouch, E.; Kiss, C.

    2011-10-01

    We present thermal observations and results for 10 objects that are dynamically associated with the large TNO, Haumea. The data were acquired under the "TNOs are Cool" Herschel Key Programme (T. Mueller, PI). The targets are about evenly divided between those with IR spectra and/or colors consistent with the presence of water ice (postulated to be part of the Haumea collisional family [1]), and those lacking evidence of water ice [2]. Final reduction of the Herschel data is incomplete at this time, and only 2 objects have good Spitzer data, precluding us from giving results here. Our goal is to test the hypothesis that the targets with water ice on their surfaces have albedos (and possibly diameters) that are distinct from those lacking surficial water ice. A positive outcome would strengthen the idea that the true Haumea family members can be identified based on their reflectance properties (in addition to their dynamical association with Haumea), and that dynamically associated TNOs lacking water ice are not family members. A negative outcome would suggest that the Haumea family might be significantly larger than currently thought, since it could well include dynamically associated objects that lack clear evidence of surficial water ice. If the latter is true, it could have significant implications for size of the parent body and formation scenarios. If most of the targets are detected at adequate signalto- noise ratio (SNR), we will use the data to perform the test just outlined. If not, we will present albedo and diameter results for those targets with clean detections, and explore why the detections lacked sufficient SNR, and draw whatever more limited conclusions are possible.

  12. Herschel SPIRE-FTS observations of RCW 120

    NASA Astrophysics Data System (ADS)

    Rodón, J. A.; Zavagno, A.; Baluteau, J.-P.; Habart, E.; Köhler, M.; Le Bourlot, J.; Le Petit, F.; Abergel, A.

    2015-07-01

    Context. The expansion of Galactic H ii regions can trigger the formation of a new generation of stars. However, little is know about the physical conditions that prevail in these regions. Aims: We study the physical conditions that prevail in specific zones towards expanding H ii regions that trace representative media such as the photodissociation region, the ionized region, and condensations with and without ongoing star formation. Methods: We use the SPIRE Fourier Transform Spectrometer (FTS) on board Herschel to observe the H ii region RCW 120. Continuum and lines are observed in the 190-670μm range. Line intensities and line ratios are obtained and used as physical diagnostics of the gas. We used the Meudon PDR code and the RADEX code to derive the gas density and the radiation field at nine distinct positions including the PDR surface and regions with and without star-formation activity. Results: For the different regions we detect the atomic lines [NII] at 205μm and [CI] at 370 and 609μm, the 12CO ladder between the J = 4 and J = 13 levels and the 13CO ladder between the J = 5 and J = 14 levels, as well as CH+ in absorption. We find gas temperatures in the range 45-250 K for densities of 104-106 cm-3, and a high column density on the order of NH ~ 1022 cm-2 that is in agreement with dust analysis. The ubiquitousness of the atomic and CH+ emission suggests the presence of a low-density PDR throughout RCW 120. High-excitation lines of CO indicate the presence of irradiated dense structures or small dense clumps containing young stellar objects, while we also find a less dense medium (NH ~ 1020 cm-2) with high temperatures (80-200 K). Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  13. Water Vapor in nearby Infrared Galaxies as Probed by Herschel

    NASA Astrophysics Data System (ADS)

    Yang, Chentao; Gao, Yu; Omont, A.; Liu, Daizhong; Isaak, K. G.; Downes, D.; van der Werf, P. P.; Lu, Nanyao

    2013-07-01

    We report the first systematic study of the submillimeter water vapor rotational emission lines in infrared (IR) galaxies based on the Fourier Transform Spectrometer (FTS) data of Herschel SPIRE. Among the 176 galaxies with publicly available FTS data, 45 have at least one H2O emission line detected. The H2O line luminosities range from ~1 × 105 L ⊙ to ~5 × 107 L ⊙ while the total IR luminosities (L IR) have a similar spread (~1-300 × 1010 L ⊙). In addition, emission lines of H2O+ and H_2^{18}O are also detected. H2O is found, for most galaxies, to be the strongest molecular emitter after CO in FTS spectra. The luminosity of the five most important H2O lines is near-linearly correlated with L IR, regardless of whether or not strong active galactic nucleus signature is present. However, the luminosity of H2O(211-202) and H2O(220-211) appears to increase slightly faster than linear with L IR. Although the slope turns out to be slightly steeper when z ~ 2-4 ULIRGs are included, the correlation is still closely linear. We find that L_{H_2O}/L IR decreases with increasing f 25/f 60, but see no dependence on f 60/f 100, possibly indicating that very warm dust contributes little to the excitation of the submillimeter H2O lines. The average spectral line energy distribution (SLED) of the entire sample is consistent with individual SLEDs and the IR pumping plus collisional excitation model, showing that the strongest lines are H2O(202-111) and H2O(321-312). Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  14. VizieR Online Data Catalog: Herschel counterparts of SDC (Peretto+, 2016)

    NASA Astrophysics Data System (ADS)

    Peretto, N.; Lenfestey, C.; Fuller, G. A.; Traficante, A.; Molinari, S.; Thompson, M. A.; Ward-Thompson, D.

    2016-03-01

    The goal of this paper is to identify which of the clouds from the Spitzer Dark Cloud catalogue (Peretto & Fuller, 2009, Cat. J/A+A/505/405) are real, which are artefacts. For this we used Herschel Hi-GAL (Molinari et al., 2010PASP..122..314M) column density maps and search for spatial associations between Spitzer Dark Cloud and Herschel column density peaks. Description: This table provides some of the key properties of the Spitzer Dark Clouds that we estimated using the Herschel data and used to disentangle between real and spurious clouds. For each cloud of the Peretto & Fuller (2009, Cat. J/A+A/505/405) catalogue we give the cloud name, the cloud equivalent radius, the average Herschel column density within the boundaries of the SDCs, the average Herschel column density immediately outside the boundary of the SDCs, the Herschel column density noise at the position of the SDC, the Herschel column density peak within the boundaries of the SDCs, the value for criterion c1, the value for criterion c2, the value for criterion c3, and a tag that indicates if the cloud has been identified as real by our automated detection scheme based on the values of c1 and c2. This tag can take a number of values. These are: 'y' for yes; n for no; 'sat' for a SDC entirely located in a saturated portion of the Herschel images; 'ysat' for a cloud that is considered real despite being partially saturated; 'out' for a SDC that is not covered by Herschel images; 'yout' for a cloud that is considered real despite being partially covered by Herschel images; 'nout' for a cloud considered spurious despite being partially covered by Herschel images. Also, note that the column referring to the equivalent radius Req is the same quantity as the one quoted in Table 1 column 11 of Peretto & Fuller (2009, Cat. J/A+A/505/405). However, these latter values should be discarded since a mistake has been found in the calculation of the equivalent radius. Only the new values, the ones provided in Table 1

  15. A 'private adventure'? John Herschel's Cape voyage and the production of the 'Cape Results'

    NASA Astrophysics Data System (ADS)

    Ruskin, Steven William

    2002-07-01

    This dissertation considers the life of John Herschel (1792 1871) from the years 1833 to 1847. In 1833 Herschel sailed from London to Cape Town, southern Africa, to undertake (at his own expense) an astronomical exploration of the southern heavens, as well as a terrestrial exploration of the area around Cape Town. After his return to England in 1838, he was highly esteemed and became Britain's most recognized scientist. In 1847 his southern hemisphere astronomical observations were published as the Cape Results. The main argument of this dissertation is that Herschel's voyage, and the publication of the Cape Results, in addition to their contemporary scientific importance, were also significant for nineteenth-century politics and culture. This dissertation is a two-part dissertation. The first part is entitled “John Herschel's Cape Voyage: Private Science, Public Imagination, and the Ambitions of Empire”; and the second part, “The Production of the Cape Results.” In the first part it is demonstrated that the reason for Herschel's cultural renown was the popular notion that his voyage to the Cape was a project aligned with the imperial ambitions of the British government. By leaving England for one of its colonies, and pursuing there a significant scientific project, Herschel was seen in the same light as other British men of science who had also undertaken voyages of exploration and discovery. It is then demonstrated, in the second part of this work, that the production of the Cape Results, in part because of Herschel's status as Britain's scientific figurehead, was a significant political and cultural event. In addition to the narrow area of Herschel scholarship, this dissertation touches on other areas of research in the history of science as well: science and culture, science and empire, science and politics, and what has been called the “new” history of scientific books.

  16. Are low altitude alpine tundra ecosystems under threat? A case study from the Parc National de la Gaspésie, Québec

    NASA Astrophysics Data System (ADS)

    Dumais, Catherine; Ropars, Pascale; Denis, Marie-Pier; Dufour-Tremblay, Geneviève; Boudreau, Stéphane

    2014-09-01

    According to the 2007 IPCC report, the alpine tundra ecosystems found on low mountains of the northern hemisphere are amongst the most threatened by climate change. A treeline advance or a significant erect shrub expansion could result in increased competition for the arctic-alpine species usually found on mountaintops and eventually lead to their local extinction. The objectives of our study were to identify recent changes in the cover and growth of erect woody vegetation in the alpine tundra of Mont de la Passe, in the Parc National de la Gaspésie (Québec, Canada). The comparison of two orthorectified aerial photos revealed no significant shift of the treeline between 1975 and 2004. During the same period however, shrub species cover increased from 20.2% to 30.4% in the lower alpine zone. Dendrochronological analyses conducted on Betula glandulosa Michx. sampled at three different positions along an altitudinal gradient (low, intermediate and high alpine zone) revealed that the climatic determinants of B. glandulosa radial growth become more complex with increasing altitude. In the lower alpine zone, B. glandulosa radial growth is only significantly associated positively to July temperature. In the intermediate alpine zone, radial growth is associated positively to July temperature but negatively to March temperature. In the high alpine zone, radial growth is positively associated to January, July and August temperature but negatively to March temperature. The positive association between summer temperatures and radial growth suggests that B. glandulosa could potentially benefit from warmer temperatures, a phenomenon that could lead to an increase in its cover over the next few decades. Although alpine tundra vegetation is not threatened in the short-term in the Parc National de la Gaspésie, erect shrub cover, especially B. glandulosa, could likely increase in the near future, threatening the local arctic-alpine flora.

  17. Herschel Observations of the Pre-Collapse Phase of Star Formation

    NASA Astrophysics Data System (ADS)

    Di Francesco, J.

    2012-03-01

    Stars form after compact gas cores condense out of larger molecular clouds and collapse. How these cores themselves form has been difficult to observe, given the limitations of detecting from the ground faint, diffuse sub-structure in clouds (e.g., clumps and filaments). With its sensitive, spaceborne instrumentation, however, Herschel has now detected these structures in numerous clouds out to several kiloparsecs from their continuum emission. Indeed, the continuum data from PACS and SPIRE are revolutionizing our understanding of the environments from which cores themselves arise. In this review, we will summarize the recent results of several Herschel Key Programmes whose goals include better physical understanding of these environments. The specific programmes with prestellar core targets include the Herschel Gould Belt Survey (GBS; PI: Ph. André), the Herschel OB Young Star survey (HOBYS; PI: F. Motte), Galactic Cold Cores (GCC; PI: M. Juvela), the Earliest Phases of Star Formation (EPoS; PI: O. Krause), and the Herschel Galactic Plane Survey (HiGAL; PI: S. Molinari). We show in general that filaments are found on many scales throughout the Galaxy, and are a key aspect to the pre-collapse phase of star formation not previously appreciated before Herschel. In addition, the continuum data are providing new direct probes of the thermal and density structures of pre-collapse star-forming objects.

  18. The Herschel Planetary Nebula Survey (HerPlaNS). I. Data overview and analysis demonstration with NGC 6781

    NASA Astrophysics Data System (ADS)

    Ueta, T.; Ladjal, D.; Exter, K. M.; Otsuka, M.; Szczerba, R.; Siódmiak, N.; Aleman, I.; van Hoof, P. A. M.; Kastner, J. H.; Montez, R.; McDonald, I.; Wittkowski, M.; Sandin, C.; Ramstedt, S.; De Marco, O.; Villaver, E.; Chu, Y.-H.; Vlemmings, W.; Izumiura, H.; Sahai, R.; Lopez, J. A.; Balick, B.; Zijlstra, A.; Tielens, A. G. G. M.; Rattray, R. E.; Behar, E.; Blackman, E. G.; Hebden, K.; Hora, J. L.; Murakawa, K.; Nordhaus, J.; Nordon, R.; Yamamura, I.

    2014-05-01

    Context. This is the first of a series of investigations into far-IR characteristics of 11 planetary nebulae (PNe) under the Herschel Space Observatory open time 1 program, Herschel Planetary Nebula Survey (HerPlaNS). Aims: Using the HerPlaNS data set, we look into the PN energetics and variations of the physical conditions within the target nebulae. In the present work, we provide an overview of the survey, data acquisition and processing, and resulting data products. Methods: We performed (1) PACS/SPIRE broadband imaging to determine the spatial distribution of the cold dust component in the target PNe and (2) PACS/SPIRE spectral-energy-distribution and line spectroscopy to determine the spatial distribution of the gas component in the target PNe. Results: For the case of NGC 6781, the broadband maps confirm the nearly pole-on barrel structure of the amorphous carbon-rich dust shell and the surrounding halo having temperatures of 26-40 K. The PACS/SPIRE multiposition spectra show spatial variations of far-IR lines that reflect the physical stratification of the nebula. We demonstrate that spatially resolved far-IR line diagnostics yield the (Te, ne) profiles, from which distributions of ionized, atomic, and molecular gases can be determined. Direct comparison of the dust and gas column mass maps constrained by the HerPlaNS data allows to construct an empirical gas-to-dust mass ratio map, which shows a range of ratios with the median of 195 ± 110. The present analysis yields estimates of the total mass of the shell to be 0.86 M⊙, consisting of 0.54 M⊙ of ionized gas, 0.12 M⊙ of atomic gas, 0.2 M⊙ of molecular gas, and 4 × 10-3 M⊙ of dust grains. These estimates also suggest that the central star of about 1.5 M⊙ initial mass is terminating its PN evolution onto the white dwarf cooling track. Conclusions: The HerPlaNS data provide various diagnostics for both the dust and gas components in a spatially resolved manner. In the forthcoming papers of the

  19. William Herschel's fifty-two fields of extensive diffused nebulosity - a revision

    NASA Astrophysics Data System (ADS)

    Latusseck, Arndt

    2008-11-01

    Since its publication in 1811, William Herschel's list of fifty-two fields of extensive nebulosity has been largely disregarded, or even discredited, by the astronomical community. Neither he nor his successors decided to include the observations of large structureless fields of background nebulosity in their major catalogues. lt was only during a short period in the early twentieth century that astronomers like I. Roberts, E.E. Barnard, and M. Wolf started more serious investigations into the nature and reality of Herschel's nebulosities, but without deriving conclusive results. Those few who tried to understand Herschel's elusive observations were often puzzled by his ambiguous descriptions and frequently tended to reject the nebulosities as being optical illusions, because only a small number of them could be proven by celestial photography. The only unconditional supporter of the reality of the nebulosities was Johann Georg Hagen, who in the 1920s used them as evidence for his hypothesis that nebulous matter covered almost the entire celestial sphere. He claimed to have succeeded in visually observing nebulous matter in every single one of Herschel's fields, which raised sharp opposition from his numerous critics. The questionable quality of Herschel's original descriptions, the weak supporting arguments, and the lack of photographic evidence, finally led historians to conclude that Herschel's fifty-two fields of extensive nebulosity were illusions. But it would seem astonishing that this gifted observer could have been fooled to such an extent. As a first approach to investigate this apparent anomaly, a complete analysis of Herschel's observing books was carried out, and the raw observations of the various catalogued nebulous fields were extracted. Some important stylistic uncertainties in the descriptions of the visual appearance of the nebulosities were cleared up, leading to a better understanding of what Herschel actually saw. Possible sources of error

  20. Long-term changes in UT/LS ozone between the late 1970s and the 1990s deduced from the GASP and MOZAIC aircraft programs and from ozonesondes

    NASA Astrophysics Data System (ADS)

    Schnadt Poberaj, C.; Staehelin, J.; Brunner, D.; Thouret, V.; de Backer, H.; Stübi, R.

    2009-01-01

    We present ozone measurements of the Global Atmospheric Sampling Program (GASP) performed from four commercial and one research aircraft in the late 1970s to compare them with respective measurements of the ongoing MOZAIC project. Climatologies of UT/LS ozone were built using the aircraft data sets (1975-1979 and 1994-2001), and long-term changes between the 1970s and 1990s were derived by comparison. The data were binned relative to the dynamical tropopause to separate between UT and LS air masses. LS data were analysed using equivalent latitudes. In the UT, pronounced increases are found over the Middle East and South Asia in the spring and summer seasons. Increases are also found over Japan, Europe, and the eastern parts of the Unites States depending on season. LS ozone over northern mid- and high latitudes was found to be lower in the 1990s compared to the 1970s in all seasons of the year. In addition, a comparison with long-term changes deduced from ozonesondes is presented. An altitude offset was applied to the sonde data to account for the slow response time of the ozone sensors. The early 1970s European Brewer-Mast (BM) sonde data agree with GASP within the range of uncertainty (UT) or measured slightly less ozone (LS). In contrast, the 1990s BM sensors show consistently and significantly higher UT/LS ozone values than MOZAIC. This unequal behaviour of aircraft/sonde comparisons in the 1970s and 1990s leads to differences in the estimated long-term changes over Europe: while the comparison between GASP and MOZAIC indicates ozone changes of -5% to 10% over Europe, the sondes suggest a much larger increase of 10%-35% depending on station and season, although statistical significance is not conclusive due to data sample limitations. In contrast to the BM sondes, the Electrochemical Cell (ECC) sonde at Wallops Island, USA, measured higher UT ozone than both GASP and MOZAIC. Hence, long-term changes from GASP/MOZAIC agree within the range of uncertainty with

  1. Herschel Survey of the Trans-Neptunian Population

    NASA Astrophysics Data System (ADS)

    Mueller, Thomas G.

    2015-08-01

    Transneptunian Objects (TNOs) are believed to retain the most pristine and least altered material of the Solar System. We studied a sample of more than 130 objects with Herschel as part of a key program "TNOs are Cool" and smaller projects related to prominent targets.Our sample includes TNOs in each of the dynamical classes, including Centaurs, and 2 satellites. The PACS data were used to determine diameters and albedos for over 100 of those targets. We were also able to constrain the temperature distribution on the surfaces of over 80 objects, in some cases by combining the Herschel data with shorter-wavelength Spitzer or WISE measurements. The temperature distribution is controlled by the thermal inertia and roughness of the surface, and so gives deeper insight into surface processes in the outer Solar System. We obtained thermal lightcurve observations for a few interesting targets like Haumea, Eris, Varuna, to discriminate between shape and surface variegation effects. For the characterization of dwarf planets (e.g. Makemake, Orcus, Quaoar) and other bright object we extented the wavelength coverage into the submm by using the SPIRE photometer. Also the two Centaurs with ring systems -Chariklo and Chiron- have been observed at far-IR wavelengths with very high photometric accuracy. We were also able to study a few Centaurs with extreme orbits, including the super-comet candidate 2013 AZ60 showing very perculiar properties.The diameters measured in this program have been combined with mass-determinations for binary systems to give an intriguing first-look at the density of TNOs as a function of size. The analysis of albedo data revealed the existence of two distinct types of surface among mid-sized TNOs: The colour-albedo diagram shows that the objects located in dynamically stable orbits within the classical Kuiper Belt region and beyond have high albedo and red colours, implying a formation further from the Sun than the dark, neutral-colour bodies.The results

  2. The Footprint Database and Web Services of the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Dobos, László; Varga-Verebélyi, Erika; Verdugo, Eva; Teyssier, David; Exter, Katrina; Valtchanov, Ivan; Budavári, Tamás; Kiss, Csaba

    2016-07-01

    Data from the Herschel Space Observatory is freely available to the public but no uniformly processed catalogue of the observations has been published so far. To date, the Herschel Science Archive does not contain the exact sky coverage (footprint) of individual observations and supports search for measurements based on bounding circles only. Drawing on previous experience in implementing footprint databases, we built the Herschel Footprint Database and Web Services for the Herschel Space Observatory to provide efficient search capabilities for typical astronomical queries. The database was designed with the following main goals in mind: (a) provide a unified data model for meta-data of all instruments and observational modes, (b) quickly find observations covering a selected object and its neighbourhood, (c) quickly find every observation in a larger area of the sky, (d) allow for finding solar system objects crossing observation fields. As a first step, we developed a unified data model of observations of all three Herschel instruments for all pointing and instrument modes. Then, using telescope pointing information and observational meta-data, we compiled a database of footprints. As opposed to methods using pixellation of the sphere, we represent sky coverage in an exact geometric form allowing for precise area calculations. For easier handling of Herschel observation footprints with rather complex shapes, two algorithms were implemented to reduce the outline. Furthermore, a new visualisation tool to plot footprints with various spherical projections was developed. Indexing of the footprints using Hierarchical Triangular Mesh makes it possible to quickly find observations based on sky coverage, time and meta-data. The database is accessible via a web site http://herschel.vo.elte.hu and also as a set of REST web service functions, which makes it readily usable from programming environments such as Python or IDL. The web service allows downloading footprint data

  3. Herschel's View of LITTLE THINGS Metal-Poor Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Cigan, Phil; Young, Lisa; Cormier, Diane; Lebouteiller, Vianney; Hunter, Deidre Ann; Madden, Suzanne; Little Things

    2015-01-01

    Dwarf galaxies present interesting challenges for the studies of various galaxy properties, due in part to their faintness and their typically low metal content. Low metallicity can lead to quite different physical conditions in the ISM of these systems, which can affect star formation and other processes. To determine the structure of star-forming molecular clouds at low metallicity and moderate star formation rates, far infrared (FIR) fine-structure lines were mapped with Herschel in selected regions of five dwarf irregular galaxies with metal abundances ranging from 13% down to 5% of solar. Abundances of [C II] 158, [O I] 63, [N II] 122, and [O III] 88 microns - the major FIR cooling lines - help to probe the conditions in the gas, and allow us to put these dwarfs in context with spirals and other galaxy types. We report our integrated fluxes and line ratios, and discuss the results: [C II] is the dominant FIR coolant in these systems, and it mostly originates in PDRs instead of the more diffuse phase. Funding for this project was provided by NASA JPL RSA grant 1433776.

  4. Fan Noise Control Using Herschel-quincke Resonators

    NASA Technical Reports Server (NTRS)

    Burdisso, Ricardo A.; Ng, Wing F.; Provenza, Andrew (Technical Monitor)

    2003-01-01

    The research effort proposed for this NASA NRA is mainly experimental. In addition, Virginia Tech is working in partnership with Goodrich Aerospace, Aerostructures Group for the analytical development needed to support the experimental endeavor, i.e. model development, design, and system studies. In this project, Herschel-Quincke (HQ)liner technology experiments will be performed at the NASA Glenn Active Noise Control Fan (ANCF) facility. A schematic of both inlet and aft HQ-liner systems installed in the ANCF rig as well as a picture of the Glenn facility is shown. The main goal is to simultaneously test in both the inlet and bypass duct sections. The by-pass duct will have HQ-systems in both the inner and outer duct walls. The main advantages of performing tests at the ANCF facility are that the effect of the inlet HQ-system on the by-pass HQ-system and vice versa, can be accurately determined from the in-duct modal data. Another significant advantage is that it offers the opportunity to assess (on a common basis) the proposed noise reduction concept on the ANCF rig which in the past has been used for assessing other active and passive noise reduction strategies.

  5. Fan Noise Control Using Herschel-Quincke Resonators

    NASA Astrophysics Data System (ADS)

    Burdisso, Ricardo A.; Ng, Wing F.

    2003-01-01

    The research effort proposed for this NASA NRA is mainly experimental. In addition, Virginia Tech is working in partnership with Goodrich Aerospace, Aerostructures Group for the analytical development needed to support the experimental endeavor, i.e. model development, design, and system studies. In this project, Herschel-Quincke (HQ)liner technology experiments will be performed at the NASA Glenn Active Noise Control Fan (ANCF) facility. A schematic of both inlet and aft HQ-liner systems installed in the ANCF rig as well as a picture of the Glenn facility is shown. The main goal is to simultaneously test in both the inlet and bypass duct sections. The by-pass duct will have HQ-systems in both the inner and outer duct walls. The main advantages of performing tests at the ANCF facility are that the effect of the inlet HQ-system on the by-pass HQ-system and vice versa, can be accurately determined from the in-duct modal data. Another significant advantage is that it offers the opportunity to assess (on a common basis) the proposed noise reduction concept on the ANCF rig which in the past has been used for assessing other active and passive noise reduction strategies.

  6. The Herschel/planck Programme Planck Pfm Testing Campaign

    NASA Astrophysics Data System (ADS)

    Reix, Jean-Michel; Rideau, Pascal; Gavila, Emmanuel; Chambelland, Jean-Philippe; Collaudin, Bernard; Passvogel, Thomas; Guillaume, Bernard

    2010-04-01

    The two science missions Herschel, an observatory-type mission, and Planck, a survey mission, are combined in one programme within ESAs long-term science programme. The objective for Planck is to image systematically the whole sky simultaneously with two scientific instruments in nine frequency channels between 30 and 900 GHz to unravel the temperature fluctuations, the anisotropy, of the cosmic background radiation. For both satellites, which have now been launched from the European Space Port in Kourou, French Guiana, on a single Ariane 5 launcher, the orbits will be Lissajous orbits around the 2nd Lagrange Point L2 of the Earth-Sun system. Having surpassed the technological problems and more generally the development phase, this paper focuses on the extensive assembly, integration and tests undertaken for the Proto-Flight Model (PFM) of the Planck Satellite. The paper details the early stages of the integration of the PFM until completeness of the assembly. It then describes the logic and the various tests implemented for the acceptance verification of the Planck PFM. It finally depicts the Launch campaign activities up to the launch from Kourou in the first half of May 2009.

  7. THE DEBRIS DISK AROUND {gamma} DORADUS RESOLVED WITH HERSCHEL

    SciTech Connect

    Broekhoven-Fiene, Hannah; Matthews, Brenda C.; Booth, Mark; Kavelaars, J. J.; Koning, Alice; Kennedy, Grant M.; Wyatt, Mark C.; Sibthorpe, Bruce; Lawler, Samantha M.; Qi, Chenruo; Su, Kate Y. L.; Rieke, George H.; Wilner, David J.; Greaves, Jane S.

    2013-01-01

    We present observations of the debris disk around {gamma} Doradus, an F1V star, from the Herschel Key Programme DEBRIS (Disc Emission via Bias-free Reconnaissance in the Infrared/Submillimetre). The disk is well resolved at 70, 100, and 160 {mu}m, resolved along its major axis at 250 {mu}m, detected but not resolved at 350 {mu}m, and confused with a background source at 500 {mu}m. It is one of our best resolved targets and we find it to have a radially broad dust distribution. The modeling of the resolved images cannot distinguish between two configurations: an arrangement of a warm inner ring at several AU (best fit 4 AU) and a cool outer belt extending from {approx}55 to 400 AU or an arrangement of two cool, narrow rings at {approx}70 AU and {approx}190 AU. This suggests that any configuration between these two is also possible. Both models have a total fractional luminosity of {approx}10{sup -5} and are consistent with the disk being aligned with the stellar equator. The inner edge of either possible configuration suggests that the most likely region to find planets in this system would be within {approx}55 AU of the star. A transient event is not needed to explain the warm dust's fractional luminosity.

  8. Winds of Binary AGB Stars as Observed by Herschel

    NASA Astrophysics Data System (ADS)

    Mayer, A.; Jorissen, A.; Kerschbaum, F.; Ottensamer, R.; Mečina, M.; Paladini, C.; Cox, N. L. J.; Nowotny, W.; Aringer, B.; Pourbaix, D.; Mohamed, S.; Siopis, C.; Groenewegen, M. A. T.

    2015-08-01

    We present Herschel/PACS observations of the large-scale environments of binary AGB stars as part of the Mass-loss of Evolved StarS (MESS) sample. From the literature we found 18 of the objects to be members of physically bound multiple systems. Several show a large-scale far-IR emission which differs significantly from spherical symmetry. A probable cause is the gravitational force of the companion on the stellar AGB wind and the mass-losing star itself. A spiral pattern is thereby imprinted in the dusty stellar wind. The most remarkable structures are found around o Ceti, W Aquilæ, R Aquarii, and π1 Gruis. The environments of o Cet and W Aql show a spiral pattern while the symbiotic nature of R Aqr is revealed as two opposing arms which reflect a nova outburst. The emission around π1 Gru is dominated by two structures, a disk and an arc, which are presumably not caused by the same companion. We found evidence that π1 Gru is a hierarchical triple system in which a close companion attracts the AGB wind onto the orbital plane and the outer companion forms a spiral arm. These far-IR observations underline the role of a companion as a major external influence in creating asymmetric winds in the AGB phase, even before the star becomes a planetary nebula (PN).

  9. Present-day aeolian activity in Herschel Crater, Mars

    NASA Astrophysics Data System (ADS)

    Cardinale, Marco; Silvestro, Simone; Vaz, David A.; Michaels, Timothy; Bourke, Mary C.; Komatsu, Goro; Marinangeli, Lucia

    2016-02-01

    In this report, we show evidence for ripple and dune migration in Herschel Crater on Mars. We estimate an average dune migration of 0.8 m and a minimum ripple migration of 1.1 m in a time span of 3.7 Earth-years. These dunes and ripples are mainly shaped by prevailing winds coming from the north, however we also report the presence of secondary winds which elongate the barchans' horns. Such a complex wind scenario is likely caused by the influence of winds blowing off the western crater rim as suggested by the Mars Regional Atmospheric Modeling System (MRAMS), an atmospheric mesoscale model. A multi-directional wind regime at the local scale is also supported by the observed bimodal distribution of the ripple trends. For the first time, a survey integrating the assessment of dune and ripple migration is presented, showing how dune topography can influence the migration patterns of ripples and how underlying topography appears to control the rates of dune migration.

  10. Herschel-SPIRE spectroscopy of nearby Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Sacchi, N.; Spinoglio, L.; Wilson, C. D.; Kamenetzky, J.; Rangwala, N.; Rykala, A.; Isaak, K. G.; Bendo, G. J.; Bradford, M.; Glenn, J.; Maloney, P. R.; Schirm, M. R. P.; Auld, R.; Baes, M.; Barlow, M. J.; Bock, J. J.; Boselli, A.; Buat, V.; Castro-Rodriguez, N.; Chanial, P.; Charlot, S.; Ciesla, L.; Clements, D. L.; Cooray, A.; Cormier, D.; Cortese, L.; Davies, J. I.; Dwek, E.; Eales, S. A.; Elbaz, D.; Galametz, M.; Galliano, F.; Gear, W. K.; Gomez, H. L.; Griffin, M.; Hony, S.; Levenson, L. R.; Lu, N.; Madden, S.; O'Halloran, B.; Okumura, K.; Oliver, S.; Page, M. J.; Panuzzo, P.; Papageorgiou, A.; Parkin, T. J.; Perez-Fournon, I.; Pohlen, M.; Rigby, E. E.; Roussel, H.; Sauvage, M.; Schulz, B.; Smith, M. W. L.; Stevens, J. A.; Sundar, S.; Symeonidis, M.; Trichas, M.; Vaccari, M.; Vigroux, L.; Wozniak, H.; Wright, G. S.; Zeilinger, W. W.

    2011-05-01

    We present the 450-1550 GHz spectra of three nearby Seyfert galaxies (NGC1068, NGC7130 and NGC7582) taken with the Herschel SPIRE FTS. For the case of NGC1068 we reconstruct the nuclear spectral line energy distribution (SLED) of the CO lines, applying nonLTE radiative transfer and a Bayesian likelihood analysis to estimate the physical properties of the molecular gas in the circumnuclear region. Groundbased observations of the low-J transitions with high (few arcsec) angular resolution are required to reconstruct the nuclear SLED avoiding contamination from colder molecular gas on larger galactic scales. We find evidence for a very warm molecular gas component with a density ~10^3.9 cm-3, similar to that found in previous works (Papadopoulos & Seaquist 1999, Usero et al. 2004, Kamenetzky et al. 2011), but with a much higher temperature (~ 550 K instead of 20-160 K). The higher-J transitions of CO are compatible with being excited in X-ray dissociation regions (XDR). However, in order to explain the entire CO SLED a comparable contribution from photodissociation regions (PDR) is required.

  11. Herschel FIR Spectroscopic Observations of L1448-MM

    NASA Astrophysics Data System (ADS)

    Lee, Jinhee; Lee, J.; DIGIT Team

    2012-01-01

    We present the FIR (continuum and line) maps and spectra of L1448-MM at 55 to 210 micron observed with the range scan mode of PACS on the Herschel Space Observatory, as part of the DIGIT key program. L1448-MM was previously known as an embedded Class 0 and prominent outflow source, and a secondary YSO was claimed by the Spitzer images and confirmed by submm interferometric observations. The PACS detected various CO, OH, H2O, and OI lines. The PACS line and continuum maps show that the emission at shorter wavelengths peaks at the central spatial pixel (the primary YSO position) although the line emission of low energy levels distributes along the outflow direction. According to our excitation analysis, the CO gas has two temperature components (warm and hot) that are tentatively attributed to PDR and shock, respectively. However, the H2O gas with the rotational temperature of 200 K seems to trace the shock. Interestingly, the relative strength of OH transitions suggests the IR pumping process dominates in L1448-MM. The gas along the outflow cavities in L1448-MM seems to be heated mainly by shock and UV photons, and relative line luminosities indicate that H2O and CO are the main coolants of this gas, although cooling by OI and OH cannot be ignored.

  12. Herschel observations of Circinus X-1 during outburst and quiescence

    SciTech Connect

    Harrison, Thomas E.; Gelino, Dawn M.; Buxton, Michelle; Fost, Tyler E-mail: dawn@ipac.caltech.edu E-mail: tyler.fost@gmail.com

    2014-07-01

    We have used the Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging REceiver instruments on the Herschel Space Observatory to observe Cir X-1 both in and out of outburst. We detected Cir X-1 during outburst at 70 μm. Unfortunately, a cold background source dominates Cir X-1 at longer wavelengths. We have assembled optical and infrared (IR) data for Cir X-1 to model its spectral energy distribution (SED) in both quiescence and outburst and find that in both states it is consistent with a heavily reddened, 10,000 K blackbody. We believe this behavior is completely consistent with previous suggestions that these outbursts are due to accretion disk events, not unlike those of dwarf novae. To explore the behavior of other low-mass X-ray binaries with reported synchrotron jets, we have extracted and/or compiled optical and near- and mid-IR data sets for five such systems to construct their SEDs. The Z-source GX 349+2 and the black hole system GRS 1915+105 have strong and variable mid-IR excesses that suggest synchrotron emission. The other Z-sources have rather weak (or no) IR excesses that can be explained as reddened blackbody spectra with the addition of either synchrotron or bremsstrahlung components.

  13. The Herschel/HIFI spectral survey of OMC-2 FIR 4 (CHESS). An overview of the 480 to 1902 GHz range

    NASA Astrophysics Data System (ADS)

    Kama, M.; López-Sepulcre, A.; Dominik, C.; Ceccarelli, C.; Fuente, A.; Caux, E.; Higgins, R.; Tielens, A. G. G. M.; Alonso-Albi, T.

    2013-08-01

    Context. Broadband spectral surveys of protostars offer a rich view of the physical, chemical and dynamical structure and evolution of star-forming regions. The Herschel Space Observatory opened up the terahertz regime to such surveys, giving access to the fundamental transitions of many hydrides and to the high-energy transitions of many other species. Aims: A comparative analysis of the chemical inventories and physical processes and properties of protostars of various masses and evolutionary states is the goal of the Herschel CHEmical Surveys of Star forming regions (CHESS) key program. This paper focusses on the intermediate-mass protostar, OMC-2 FIR 4. Methods: We obtained a spectrum of OMC-2 FIR 4 in the 480 to 1902 GHz range with the HIFI spectrometer onboard Herschel and carried out the reduction, line identification, and a broad analysis of the line profile components, excitation, and cooling. Results: We detect 719 spectral lines from 40 species and isotopologs. The line flux is dominated by CO, H2O, and CH3OH. The line profiles are complex and vary with species and upper level energy, but clearly contain signatures from quiescent gas, a broad component likely due to an outflow, and a foreground cloud. Conclusions: We find abundant evidence for warm, dense gas, as well as for an outflow in the field of view. Line flux represents 2% of the 7 L⊙ luminosity detected with HIFI in the 480 to 1250 GHz range. Of the total line flux, 60% is from CO, 13% from H2O and 9% from CH3OH. A comparison with similar HIFI spectra of other sources is set to provide much new insight into star formation regions, a case in point being a difference of two orders of magnitude in the relative contribution of sulphur oxides to the line cooling of Orion KL and OMC-2 FIR 4. Appendix A is available in electronic form at http://www.aanda.org

  14. First Year In-Flight and Early Science with the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    García-Lario, P.

    2011-07-01

    Herschel, an ESA space observatory equipped with science instruments provided by European-led Principal Investigator consortia with important participation from NASA, was launched on 14 May 2009. With its 3.5m diameter primary mirror, Herschel is the largest telescope ever launched into space. Herschel carries three science instruments whose focal plane units are cryogenically cooled inside a superfluid helium cryostat. The PACS and SPIRE instruments provide broadband imaging photometry in six bands centered on 75, 100, 160, 250, 350, and 500 μm and imaging spectroscopy over the range 55-672 μm. The HIFI instrument provides very high-resolution heterodyne spectroscopy over the ranges 157-212 and 240-625 μm. The prime science objectives of Herschel are intimately connected to the physics of, and processes in, the interstellar medium (ISM) in the widest sense. Near and far in both space and time, they stretch from solar system objects and the relics of the formation of the sun and our solar system, through star formation in the ISM and the feedback material returned by evolved stars to the ISM, to the star formation history of the universe, galaxy evolution, and cosmology. The very first observational results from Herschel already show that it will have strong impact on research in all of these fields, as exemplified by the few observational results presented here, These are just the tip of the iceberg of what is yet to come in the remaining 2 years of operations.

  15. Herschel spectral surveys of star-forming regions. Overview of the 555-636 GHz range

    NASA Astrophysics Data System (ADS)

    Ceccarelli, C.; Bacmann, A.; Boogert, A.; Caux, E.; Dominik, C.; Lefloch, B.; Lis, D.; Schilke, P.; van der Tak, F.; Caselli, P.; Cernicharo, J.; Codella, C.; Comito, C.; Fuente, A.; Baudry, A.; Bell, T.; Benedettini, M.; Bergin, E. A.; Blake, G. A.; Bottinelli, S.; Cabrit, S.; Castets, A.; Coutens, A.; Crimier, N.; Demyk, K.; Encrenaz, P.; Falgarone, E.; Gerin, M.; Goldsmith, P. F.; Helmich, F.; Hennebelle, P.; Henning, T.; Herbst, E.; Hily-Blant, P.; Jacq, T.; Kahane, C.; Kama, M.; Klotz, A.; Langer, W.; Lord, S.; Lorenzani, A.; Maret, S.; Melnick, G.; Neufeld, D.; Nisini, B.; Pacheco, S.; Pagani, L.; Parise, B.; Pearson, J.; Phillips, T.; Salez, M.; Saraceno, P.; Schuster, K.; Tielens, X.; van der Wiel, M. H. D.; Vastel, C.; Viti, S.; Wakelam, V.; Walters, A.; Wyrowski, F.; Yorke, H.; Liseau, R.; Olberg, M.; Szczerba, R.; Benz, A. O.; Melchior, M.

    2010-10-01

    High resolution line spectra of star-forming regions are mines of information: they provide unique clues to reconstruct the chemical, dynamical, and physical structure of the observed source. We present the first results from the Herschel key project “Chemical HErschel Surveys of Star forming regions”, CHESS. We report and discuss observations towards five CHESS targets, one outflow shock spot and four protostars with luminosities bewteen 20 and 2 × 105 L_⊙: L1157-B1, IRAS 16293-2422, OMC2-FIR4, AFGL 2591, and NGC 6334I. The observations were obtained with the heterodyne spectrometer HIFI on board Herschel, with a spectral resolution of 1 MHz. They cover the frequency range 555-636 GHz, a range largely unexplored before the launch of the Herschel satellite. A comparison of the five spectra highlights spectacular differences in the five sources, for example in the density of methanol lines, or the presence/absence of lines from S-bearing molecules or deuterated species. We discuss how these differences can be attributed to the different star-forming mass or evolutionary status. Herschel is an ESA space observatory with science instruments provided by European-led principal Investigator consortia and with important participation from NASA.Figures [see full textsee full text]-[see full textsee full text] and Tables 3, 4 (pages 6 to 8) are only available in electronic form at http://www.aanda.org

  16. 'Land-marks of the universe': John Herschel against the background of positional astronomy.

    PubMed

    Case, Stephen

    2015-01-01

    John Herschel (1792-1871) was the leading British natural philosopher of the nineteenth century, widely known and regarded for his work in philosophy, optics and chemistry as well as his important research and popular publications on astronomy. To date, however, there exists no extended treatment of his astronomical career. This paper, part of a larger study exploring Herschel's contributions to astronomy, examines his work in the context of positional astronomy, the dominant form of astronomical practice throughout his lifetime. Herschel, who did not himself practice positional astronomy and who was known for his non-meridional observations of specific stellar objects, was nonetheless a strong advocate for positional astronomy-but for very different reasons than the terrestrial applications to which it was most often put. For Herschel, the star catalogues of positional astronomy were the necessary observational foundation upon which information about the stars as physical objects could be constructed. Positional astronomy practiced in the great national observatories was not about navigation or timekeeping; it was a way to standardize stellar observations and make them useful data for constructing theories of the stars themselves. For Herschel, the seeds of the new astronomy emerged from the practices of the old. PMID:26221834

  17. 'Land-marks of the universe': John Herschel against the background of positional astronomy

    NASA Astrophysics Data System (ADS)

    Case, Stephen

    2015-04-01

    John Herschel (1792-1871) was the leading British natural philosopher of the nineteenth century, widely known and regarded for his work in philosophy, optics and chemistry as well as his important research and popular publications on astronomy. To date, however, there exists no extended treatment of his astronomical career. This paper, part of a larger study exploring Herschel's contributions to astronomy, examines his work in the context of positional astronomy, the dominant form of astronomical practice throughout his lifetime. Herschel, who did not himself practice positional astronomy and who was known for his non-meridional observations of specific stellar objects, was nonetheless a strong advocate for positional astronomy - but for very different reasons than the terrestrial applications to which it was most often put. For Herschel, the star catalogues of positional astronomy were the necessary observational foundation upon which information about the stars as physical objects could be constructed. Positional astronomy practiced in the great national observatories was not about navigation or timekeeping; it was a way to standardize stellar observations and make them useful data for constructing theories of the stars themselves. For Herschel, the seeds of the new astronomy emerged from the practices of the old.

  18. UNIMAP: a generalized least-squares map maker for Herschel data

    NASA Astrophysics Data System (ADS)

    Piazzo, Lorenzo; Calzoletti, Luca; Faustini, Fabiana; Pestalozzi, Michele; Pezzuto, Stefano; Elia, Davide; di Giorgio, Anna; Molinari, Sergio

    2015-02-01

    The Herschel space telescope hosts two infrared photometers having an unprecedented resolution, sensitivity and dynamic range. The map making, i.e. the formation of sky images from the instruments' data, is critical for the full exploitation of the satellite and is a difficult task, since the readouts are affected by several disturbances, most notably by correlated noise. An effective map making approach is based on generalized least squares (GLS). However, when applied to Herschel data this approach poses several challenges and requires a specific pre- and post-processing. In the paper, we describe these challenges and introduce a set of algorithms and procedures which successfully address the issues. We also describe the implementation of the procedures and how these are integrated into an image formation software called UNIMAP, which is the first GLS map maker capable of automatically producing quality Herschel images with manageable memory and complexity requirements.

  19. VizieR Online Data Catalog: The Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)

    NASA Astrophysics Data System (ADS)

    Furlan, E.; Fischer, W. J.; Ali, B.; Stutz, A. M.; Stanke, T.; Tobin, J. J.; Megeath, S. T.; Osorio, M.; Hartmann, L.; Calvet, N.; Poteet, C. A.; Booker, J.; Manoj, P.; Watson, D. M.; Allen, L.

    2016-06-01

    To summarize, starting from a sample of 410 Herschel Orion Protostar Survey (HOPS) targets (see section 2), but excluding likely contaminants and objects not observed or detected by PACS, there are 330 remaining objects that have Spitzer and Herschel data and are considered protostars (based on their Spitzer classification from Megeath et al. 2012, J/AJ/144/192). They form the sample studied in this work. In order to construct SEDs for our sample of 330 YSOs, we combined our own Herschel/PACS observations (see Proposal KPOTtmegeath2) with data from the literature and existing catalogs (see section 3.1). To extend the SEDs into the submillimeter, most of the YSOs were also observed in the continuum at 350 and 870um with the Atacama Pathfinder Experiment (APEX) telescope (Stutz et al. 2013, J/ApJ/767/36). (5 data files).

  20. A Herschel and CARMA view of CO and [C ii] in Hickson Compact groups

    NASA Astrophysics Data System (ADS)

    Alatalo, Katherine; Appleton, Philip N.; Lisenfeld, Ute

    2015-02-01

    Understanding the evolution of galaxies from the starforming blue cloud to the quiescent red sequence has been revolutionized by observations taken with Herschel Space Observatory, and the onset of the era of sensitive millimeter interferometers, allowing astronomers to probe both cold dust as well as the cool interstellar medium in a large set of galaxies with unprecedented sensitivity. Recent Herschel observations of of H2-bright Hickson Compact Groups of galaxies (HCGs) has shown that [C ii] may be boosted in diffuse shocked gas. CARMA CO(1-0) observations of these [C ii]-bright HCGs has shown that these turbulent systems also can show suppression of SF. Here we present preliminary results from observations of HCGs with Herschel and CARMA, and their [C ii] and CO(1-0) properties to discuss how shocks influence galaxy transitions and star formation.

  1. Determining the Importance of Shocks on Galaxy Evolution in Compact Groups: a Herschel and CARMA View

    NASA Astrophysics Data System (ADS)

    Alatalo, Katherine A.; Appleton, P. N.; Lisenfeld, U.; Cluver, M. E.; Bitsakis, T.; Guillard, P.; Charmandaris, V.

    2014-01-01

    Understanding the evolution of galaxies from starforming blue cloud objects into quiescent red sequence galaxies has been revolutionized by observations taken with the Herschel Space Observatory, allowing astronomers to probe both the cold dust as well as the cool ISM in a large set of galaxies, with unprecedented sensitivity. Recent Herschel observations of [C II], a known tracer of star formation, in Hickson Compact Groups of galaxies (HCGs) has shown that [C II] can also be highly excited in shocks. CARMA CO observations of these [C II]-bright HCGs therefore shed light on the impact of shocks on the excitation of the ISM, as well as the starforming (molecular) material. I will present preliminary results from our Herschel-CARMA combined observations of HCGs, which are able to tell us about the synergistic relationships between shocks, star formation and the cool ISM in the context of galaxy evolution.

  2. The multiplicity of 250-μm Herschel sources in the COSMOS field

    NASA Astrophysics Data System (ADS)

    Scudder, Jillian M.; Oliver, Seb; Hurley, Peter D.; Griffin, Matt; Sargent, Mark T.; Scott, Douglas; Wang, Lingyu; Wardlow, Julie L.

    2016-07-01

    We investigate the multiplicity of extragalactic sources detected by the Herschel Space Observatory in the COSMOS field. Using 3.6- and 24-μm catalogues, in conjunction with 250-μm data from Herschel, we seek to determine if a significant fraction of Herschel sources are composed of multiple components emitting at 250 μm. We use the XID+ code, using Bayesian inference methods to produce probability distributions of the possible contributions to the observed 250-μm flux for each potential component. The fraction of Herschel flux assigned to the brightest component is highest for sources with total 250-μm fluxes <45 mJy; however, the flux in the brightest component is still highest in the brightest Herschel sources. The faintest 250-μm sources (30-45 mJy) have the majority of their flux assigned to a single bright component; the second brightest component is typically significantly weaker, and contains the remainder of the 250-μm source flux. At the highest 250-μm fluxes (45-110 mJy), the brightest and second brightest components are assigned roughly equal fluxes, and together are insufficient to reach 100 per cent of the 250-μm source flux. This indicates that additional components are required, beyond the brightest two components, to reproduce the observed flux. 95 per cent of the sources in our sample have a second component that contains more than 10 per cent of the total source flux. Particularly for the brightest Herschel sources, assigning the total flux to a single source may overestimate the flux contributed by around 150 per cent.

  3. Spitzer Imaging of Strongly lensed Herschel-selected Dusty Star-forming Galaxies

    NASA Astrophysics Data System (ADS)

    Ma, Brian; Cooray, Asantha; Calanog, J. A.; Nayyeri, H.; Timmons, N.; Casey, C.; Baes, M.; Chapman, S.; Dannerbauer, H.; da Cunha, E.; De Zotti, G.; Dunne, L.; Farrah, D.; Fu, Hai; Gonzalez-Nuevo, J.; Magdis, G.; Michałowski, M. J.; Oteo, I.; Riechers, D. A.; Scott, D.; Smith, M. W. L.; Wang, L.; Wardlow, J.; Vaccari, M.; Viaene, S.; Vieira, J. D.

    2015-11-01

    We present the rest-frame optical spectral energy distribution (SED) and stellar masses of six Herschel-selected gravitationally lensed dusty, star-forming galaxies (DSFGs) at 1 < z < 3. These galaxies were first identified with Herschel/SPIRE imaging data from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). The targets were observed with Spitzer/IRAC at 3.6 and 4.5 μm. Due to the spatial resolution of the IRAC observations at the level of 2″, the lensing features of a background DSFG in the near-infrared are blended with the flux from the foreground lensing galaxy in the IRAC imaging data. We make use of higher resolution Hubble/WFC3 or Keck/NIRC2 Adaptive Optics imaging data to fit light profiles of the foreground lensing galaxy (or galaxies) as a way to model the foreground components, in order to successfully disentangle the foreground lens and background source flux densities in the IRAC images. The flux density measurements at 3.6 and 4.5 μm, once combined with Hubble/WFC3 and Keck/NIRC2 data, provide important constraints on the rest-frame optical SED of the Herschel-selected lensed DSFGs. We model the combined UV- to millimeter-wavelength SEDs to establish the stellar mass, dust mass, star formation rate, visual extinction, and other parameters for each of these Herschel-selected DSFGs. These systems have inferred stellar masses in the range 8 × 1010-4 × 1011 M⊙ and star formation rates of around 100 M⊙ yr-1. This puts these lensed submillimeter systems well above the SFR-M* relation observed for normal star-forming galaxies at similar redshifts. The high values of SFR inferred for these systems are consistent with a major merger-driven scenario for star formation.

  4. The multiplicity of 250-μm Herschel sources in the COSMOS field

    NASA Astrophysics Data System (ADS)

    Scudder, Jillian M.; Oliver, Seb; Hurley, Peter D.; Griffin, Matt; Sargent, Mark T.; Scott, Douglas; Wang, Lingyu; Wardlow, Julie L.

    2016-05-01

    We investigate the multiplicity of extragalactic sources detected by the Herschel Space Observatory in the COSMOS field. Using 3.6- and 24-μm catalogues, in conjunction with 250-μm data from Herschel, we seek to determine if a significant fraction of Herschel sources are composed of multiple components emitting at 250 μm. We use the XID+ code, using Bayesian inference methods to produce probability distributions of the possible contributions to the observed 250-μm flux for each potential component. The fraction of Herschel flux assigned to the brightest component is highest for sources with total 250-μm fluxes <45 mJy; however, the flux in the brightest component is still highest in the brightest Herschel sources. The faintest 250-μm sources (30-45 mJy) have the majority of their flux assigned to a single bright component; the second brightest component is typically significantly weaker, and contains the remainder of the 250-μm source flux. At the highest 250-μm fluxes (45-110 mJy), the brightest and second brightest components are assigned roughly equal fluxes, and together are insufficient to reach 100 per cent of the 250-μm source flux. This indicates that additional components are required, beyond the brightest two components, to reproduce the observed flux. 95 per cent of the sources in our sample have a second component that contains more than 10 per cent of the total source flux. Particularly for the brightest Herschel sources, assigning the total flux to a single source may overestimate the flux contributed by around 150 per cent.

  5. HerMES: point source catalogues from Herschel-SPIRE observations II

    NASA Astrophysics Data System (ADS)

    Wang, L.; Viero, M.; Clarke, C.; Bock, J.; Buat, V.; Conley, A.; Farrah, D.; Guo, K.; Heinis, S.; Magdis, G.; Marchetti, L.; Marsden, G.; Norberg, P.; Oliver, S. J.; Page, M. J.; Roehlly, Y.; Roseboom, I. G.; Schulz, B.; Smith, A. J.; Vaccari, M.; Zemcov, M.

    2014-11-01

    The Herschel Multi-tiered Extragalactic Survey (HerMES) is the largest Guaranteed Time Key Programme on the Herschel Space Observatory. With a wedding cake survey strategy, it consists of nested fields with varying depth and area totalling ˜380 deg2. In this paper, we present deep point source catalogues extracted from Herschel-Spectral and Photometric Imaging Receiver (SPIRE) observations of all HerMES fields, except for the later addition of the 270 deg2 HerMES Large-Mode Survey (HeLMS) field. These catalogues constitute the second Data Release (DR2) made in 2013 October. A sub-set of these catalogues, which consists of bright sources extracted from Herschel-SPIRE observations completed by 2010 May 1 (covering ˜74 deg2) were released earlier in the first extensive data release in 2012 March. Two different methods are used to generate the point source catalogues, the SUSSEXTRACTOR point source extractor used in two earlier data releases (EDR and EDR2) and a new source detection and photometry method. The latter combines an iterative source detection algorithm, STARFINDER, and a De-blended SPIRE Photometry algorithm. We use end-to-end Herschel-SPIRE simulations with realistic number counts and clustering properties to characterize basic properties of the point source catalogues, such as the completeness, reliability, photometric and positional accuracy. Over 500 000 catalogue entries in HerMES fields (except HeLMS) are released to the public through the HeDAM (Herschel Database in Marseille) website (http://hedam.lam.fr/HerMES).

  6. Resolved imaging of the HR 8799 Debris disk with Herschel

    SciTech Connect

    Matthews, Brenda; Booth, Mark; Broekhoven-Fiene, Hannah; Marois, Christian; Kennedy, Grant; Wyatt, Mark; Sibthorpe, Bruce; Macintosh, Bruce

    2014-01-01

    We present Herschel far-infrared and submillimeter maps of the debris disk associated with the HR 8799 planetary system. We resolve the outer disk emission at 70, 100, 160, and 250 μm and detect the disk at 350 and 500 μm. A smooth model explains the observed disk emission well. We observe no obvious clumps or asymmetries associated with the trapping of planetesimals that is a potential consequence of planetary migration in the system. We estimate that the disk eccentricity must be <0.1. As in previous work by Su et al., we find a disk with three components: a warm inner component and two outer components, a planetesimal belt extending from 100 to 310 AU, with some flexibility (±10 AU) on the inner edge, and the external halo that extends to ∼2000 AU. We measure the disk inclination to be 26° ± 3° from face-on at a position angle of 64° E of N, establishing that the disk is coplanar with the star and planets. The spectral energy distribution of the disk is well fit by blackbody grains whose semi-major axes lie within the planetesimal belt, suggesting an absence of small grains. The wavelength at which the spectrum steepens from blackbody, 47 ± 30 μm, however, is short compared with other A star debris disks, suggesting that there are atypically small grains likely populating the halo. The PACS longer wavelength data yield a lower disk color temperature than do MIPS data (24 and 70 μm), implying two distinct halo dust-grain populations.

  7. HERSCHEL/SPIRE SUBMILLIMETER SPECTRA OF LOCAL ACTIVE GALAXIES {sup ,}

    SciTech Connect

    Pereira-Santaella, Miguel; Spinoglio, Luigi; Busquet, Gemma; Wilson, Christine D.; Schirm, Maximilien R. P.; Glenn, Jason; Kamenetzky, Julia; Rangwala, Naseem; Isaak, Kate G.; Baes, Maarten; Barlow, Michael J.; Boselli, Alessandro; Cooray, Asantha; Cormier, Diane

    2013-05-01

    We present the submillimeter spectra from 450 to 1550 GHz of 11 nearby active galaxies observed with the SPIRE Fourier Transform Spectrometer (SPIRE/FTS) on board Herschel. We detect CO transitions from J{sub up} = 4 to 12, as well as the two [C I] fine structure lines at 492 and 809 GHz and the [N II]1461 GHz line. We used radiative transfer models to analyze the observed CO spectral line energy distributions. The FTS CO data were complemented with ground-based observations of the low-J CO lines. We found that the warm molecular gas traced by the mid-J CO transitions has similar physical conditions (n{sub H{sub 2}}{approx} 10{sup 3.2}-10{sup 3.9} cm{sup -3} and T{sub kin} {approx} 300-800 K) in most of our galaxies. Furthermore, we found that this warm gas is likely producing the mid-IR rotational H{sub 2} emission. We could not determine the specific heating mechanism of the warm gas, however, it is possibly related to the star formation activity in these galaxies. Our modeling of the [C I] emission suggests that it is produced in cold (T{sub kin} < 30 K) and dense (n{sub H{sub 2}}>10{sup 3} cm{sup -3}) molecular gas. Transitions of other molecules are often detected in our SPIRE/FTS spectra. The HF J = 1-0 transition at 1232 GHz is detected in absorption in UGC 05101 and in emission in NGC 7130. In the latter, near-infrared pumping, chemical pumping, or collisional excitation with electrons are plausible excitation mechanisms likely related to the active galactic nucleus of this galaxy. In some galaxies, few H{sub 2}O emission lines are present. Additionally, three OH{sup +} lines at 909, 971, and 1033 GHz are identified in NGC 7130.

  8. Systematic characterization of the Herschel SPIRE Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Hopwood, R.; Polehampton, E. T.; Valtchanov, I.; Swinyard, B. M.; Fulton, T.; Lu, N.; Marchili, N.; van der Wiel, M. H. D.; Benielli, D.; Imhof, P.; Baluteau, J.-P.; Pearson, C.; Clements, D. L.; Griffin, M. J.; Lim, T. L.; Makiwa, G.; Naylor, D. A.; Noble, G.; Puga, E.; Spencer, L. D.

    2015-05-01

    A systematic programme of calibration observations was carried out to monitor the performance of the Spectral and Photometric Imaging REceiver (SPIRE) Fourier Transform Spectrometer (FTS) instrument on board the Herschel Space Observatory. Observations of planets (including the prime point-source calibrator, Uranus), asteroids, line sources, dark sky and cross-calibration sources were made in order to monitor repeatability and sensitivity, and to improve FTS calibration. We present a complete analysis of the full set of calibration observations and use them to assess the performance of the FTS. Particular care is taken to understand and separate out the effect of pointing uncertainties, including the position of the internal beam steering mirror for sparse observations in the early part of the mission. The repeatability of spectral-line centre positions is <5 km s-1, for lines with signal-to-noise ratios >40, corresponding to <0.5-2.0 per cent of a resolution element. For spectral-line flux, the repeatability is better than 6 per cent, which improves to 1-2 per cent for spectra corrected for pointing offsets. The continuum repeatability is 4.4 per cent for the SPIRE Long Wavelength spectrometer (SLW) band and 13.6 per cent for the SPIRE Short Wavelength spectrometer (SSW) band, which reduces to ˜1 per cent once the data have been corrected for pointing offsets. Observations of dark sky were used to assess the sensitivity and the systematic offset in the continuum, both of which were found to be consistent across the FTS-detector arrays. The average point-source calibrated sensitivity for the centre detectors is 0.20 and 0.21 Jy [1σ; 1 h], for SLW and SSW. The average continuum offset is 0.40 Jy for the SLW band and 0.28 Jy for the SSW band.

  9. HERSCHEL OBSERVATIONS REVEAL ANOMALOUS MOLECULAR ABUNDANCES TOWARD THE GALACTIC CENTER

    SciTech Connect

    Sonnentrucker, P.; Neufeld, D. A.; Indriolo, N.; Gerin, M.; De Luca, M.; Lis, D. C.; Goicoechea, J. R.

    2013-01-20

    We report the Herschel detections of hydrogen fluoride (HF) and para-water (p-H{sub 2}O) in gas intercepting the sight lines to two well-studied molecular clouds in the vicinity of the Sgr A complex: G-0.02-0.07 (the {sup +}50 km s{sup -1} cloud{sup )} and G-0.13-0.08 (the {sup +}20 km s{sup -1} cloud{sup )}. Toward both sight lines, HF and water absorption components are detected over a wide range of velocities covering {approx}250 km s{sup -1}. For all velocity components with V{sub LSR} > -85 km s{sup -1}, we find that the HF and water abundances are consistent with those measured toward other sight lines probing the Galactic disk gas. The velocity components with V{sub LSR} {<=} -85 km s{sup -1}, which are known to trace gas residing within {approx}200 pc of the Galactic center, however, exhibit water vapor abundances with respect to HF at least a factor three higher than those found in the Galactic disk gas. Comparison with CH data indicates that our observations are consistent with a picture where HF and a fraction of the H{sub 2}O absorption arise in diffuse molecular clouds showing Galactic disk-like abundances while the bulk of the water absorption arises in warmer (T {>=} 400 K) diffuse molecular gas for V{sub LSR} {<=} -85 km s{sup -1}. This diffuse Interstellar Medium (ISM) phase has also been recently revealed through observations of CO, HF, H{sup +}{sub 3}, and H{sub 3}O{sup +} absorption toward other sight lines probing the Galactic center inner region.

  10. Herschel Spectroscopic Observations of Little Things Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Cigan, Phil; Young, Lisa; Cormier, Diane; Lebouteiller, Vianney; Madden, Suzanne; Hunter, Deidre; Brinks, Elias; Elmegreen, Bruce; Schruba, Andreas; Heesen, Volker; the Little Things Team

    2016-01-01

    We present far-infrared (FIR) spectral line observations of five galaxies from the Little Things sample: DDO 69, DDO 70, DDO 75, DDO 155, and WLM. While most studies of dwarfs focus on bright systems or starbursts due to observational constraints, our data extend the observed parameter space into the regime of low surface brightness dwarf galaxies with low metallicities and moderate star formation rates. Our targets were observed with Herschel at the [C ii] 158 μm, [O i] 63 μm, [O iii] 88 μm, and [N ii] 122 μm emission lines using the PACS Spectrometer. These high-resolution maps allow us for the first time to study the FIR properties of these systems on the scales of larger star-forming complexes. The spatial resolution in our maps, in combination with star formation tracers, allows us to identify separate photodissociation regions (PDRs) in some of the regions we observed. Our systems have widespread [C ii] emission that is bright relative to continuum, averaging near 0.5% of the total infrared (TIR) budget—higher than in solar-metallicity galaxies of other types. [N ii] is weak, suggesting that the [C ii] emission in our galaxies comes mostly from PDRs instead of the diffuse ionized interstellar medium (ISM). These systems exhibit efficient cooling at low dust temperatures, as shown by ([O i]+[C ii])/TIR in relation to 60 μm/100 μm, and low [O i]/[C ii] ratios which indicate that [C ii] is the dominant coolant of the ISM. We observe [O iii]/[C ii] ratios in our galaxies that are lower than those published for other dwarfs, but similar to levels noted in spirals.

  11. Chemical Herschel Surveys of Star Forming Regions (chess)

    NASA Astrophysics Data System (ADS)

    Emprechtinger, Martin

    2011-06-01

    CHESS is an unbiased line survey of low-, intermediate-, and high-mass star forming regions at different stages of their evolution. The eight sources in the CHESS program are observed with the HIFI instrument on board of the Herschel Space Telescope, which provides a high spectral resolution (R˜ 10^6) and covers a frequency range from 480 to 1910 GHz. The objective of CHESS is to study the chemical composition and physical conditions in star forming regions and their variation with mass and evolutionary stage. To date about 50% of the program have been completed. One of the eight objects in the CHESS program is the hot core NGC 6334 I. With an envelope mass of 200 M_⊙ and temperatures 100 K, NGC 6334 I is very line rich. In this object emission lines of more than 40 species have been identified, including first detections of H_2Cl^+ (Lis et al. 2010) and H_2O^+ (Ossenkopf et al. 2010). Furthermore, several lines of ortho and para water and ammonia have been detected, allowing to determine the ortho/para ratio of these crucial species. In addition many hydrides (HF, CH) and hydride ions (SH^+, OH^+, CH^+) have been found. In the low mass protostar IRAS 16293-2422, another source of our sample, several deuterated species, including the first detection of ND (Bacmann et al. 2010), were found. The data allowed also the first determination of the ortho/para ratio of D_2H^+ (>2.6) (Vastel et al. 2010). In this talk I will give a summary of the conducted observation and highlight the most important results.

  12. [CII] emission across M31 seen by Herschel and ISO

    NASA Astrophysics Data System (ADS)

    Kapala, Maria Julia; Groves, Brent; Sandstrom, Karin; Survey of Lines in M31 (SLIM)

    2015-01-01

    The [CII] 158 micron line is typically the brightest far-IR emission line from star-forming (SF) galaxies. As such, this line is a potentially useful tracer of star formation. To calibrate such applications, we must understand the relative contributions of different ISM phases to the [CII] emission. Using high physical resolution observations of the [CII] 158 micron line from Herschel PACS in five 3'x3' field in M31 and optical IFU spectra from PPaK and ancillary IR data, we are able to spatially separate out the ISM phases. Additionally, to study the full radial profile of heating and cooling of the ISM in Andromeda, we include [CII] observations from ISO in the bulge. We find that SF regions in M31 do not exhibit a "[CII] line deficit" on 50 pc scales, even in regions where the dust is very warm. Using the optical line emission, we determine the fraction of [CII] emission spatially associated with SF regions. Our method implies a high fraction ~20-90% of [CII] emission is coming from diffuse regions. These diffuse regions appear to dominated by the UV interstellar radiation field which arises from B stars and possible photon leakage from the SF regions. Due to the presence of this large diffuse fraction, we find on ~50pc scales that the relation between [CII] and SFR is sub-linear in most of the fields. However, when averaged over ~700pc scales it becomes steeper and is in agreement with other extragalactic studies on similar scales. Interestingly, even with this correlation of SFR & [CII], we find that [CII]/TIR decreases with radius by a factor of ~3 from 16 to 7 kpc, with a slight increase in the bulge. We discuss metallicity, stellar radiation fields and emission from diffuse ionized phase as possible explanations for these trends.

  13. Long-term changes in UT/LS ozone between the late 1970s and the 1990s deduced from the GASP and MOZAIC aircraft programs and from ozonesondes

    NASA Astrophysics Data System (ADS)

    Schnadt Poberaj, C.; Staehelin, J.; Brunner, D.; Thouret, V.; de Backer, H.; Stübi, R.

    2009-07-01

    We present ozone measurements of the Global Atmospheric Sampling Program (GASP) performed from four commercial and one research aircraft in the late 1970s to compare them with respective measurements of the ongoing MOZAIC project. Multi-annual averages of UT/LS ozone were built using the aircraft data sets (1975-1979 and 1994-2001), and long-term changes between the 1970s and 1990s were derived by comparison. The data were binned relative to the dynamical tropopause to separate between UT and LS air masses. LS data were analysed using equivalent latitudes. In the UT, pronounced increases of 20-40% are found over the Middle East and South Asia in the spring and summer seasons. Increases are also found over Japan, Europe, and the eastern parts of the United States depending on season. LS ozone over northern mid- and high latitudes was found to be lower in the 1990s compared to the 1970s in all seasons of the year. In addition, a comparison with long-term changes deduced from ozonesondes is presented. The early 1970s European Brewer-Mast (BM) sonde data agree with GASP within the range of uncertainty (UT) or measured slightly less ozone (LS). In contrast, the 1990s BM sensors show consistently and significantly higher UT/LS ozone values than MOZAIC. This unequal behaviour of aircraft/sonde comparisons in the 1970s and 1990s leads to differences in the estimated long-term changes over Europe: while the comparison between GASP and MOZAIC indicates ozone changes of -5% to 10% over Europe, the sondes suggest a much larger increase of 10%-35% depending on station and season, although statistical significance is not conclusive due to data sample limitations. In contrast to the BM sondes, the Electrochemical Cell (ECC) sonde at Wallops Island, USA, measured higher UT ozone than both GASP and MOZAIC. Hence, long-term changes from GASP/MOZAIC agree within the range of uncertainty with the changes deduced from Wallops Island.

  14. Sir John F. W. Herschel, meteoroid streams and the solar cycle

    NASA Astrophysics Data System (ADS)

    Hughes, David W.

    Some theories flourish and some die quickly. In 1864 Sir John Herschel tried to link two fashionable astronomical topics, these being the meteor showers, seen periodically in the Earth's atmosphere, and solar spot activity. Lurking in the wings at that time was the impression that the solar luminosity was obtained from the kinetic energy of impacting meteorites. Herschel suggested that the Sun's steady rain of meteoritic material was enhanced by periodic swarms of meteoroids, these causing the 11.1 year and 56 year sunspot cycles. Just over four decades later it was realised that sunspots and meteor showers have absolutely nothing to do with each other.

  15. Modelling the evolution of Comet Siding Spring's activity using Herschel Space Observatory measurements

    NASA Astrophysics Data System (ADS)

    Kiss, Csaba; Müller, Thomas; Kidger, Mark Richard; Mattisson, Peter; Marton, Gabor

    2015-08-01

    Comet Siding Spring was observed with the Herschel Space Observatory in March 2013 at a heliocentric distance of 6.5 au, already showing siginficant activity. Using the far-infrared radial intensity profiles of the coma at 70, 100 and 160um we were able to construct a detailed model of the dust emission and costrain the dust properties. Our results show a significant overaboundance of large grains in the coma with a size frequency index of ~2. We were also able to estimate the activity onset time: this likely happened at a helicentric distance of ~8 au, six months before the Herschel observations.

  16. Herschel Observations of Extraordinary Sources: Analysis of the Full Herschel/HIFI Molecular Line Survey of Sagittarius B2(N)

    NASA Astrophysics Data System (ADS)

    Neill, Justin L.; Bergin, Edwin A.; Lis, Dariusz C.; Schilke, Peter; Crockett, Nathan R.; Favre, Cécile; Emprechtinger, Martin; Comito, Claudia; Qin, Sheng-Li; Anderson, Dana E.; Burkhardt, Andrew M.; Chen, Jo-Hsin; Harris, Brent J.; Lord, Steven D.; McGuire, Brett A.; McNeill, Trevor D.; Monje, Raquel R.; Phillips, Thomas G.; Steber, Amanda L.; Vasyunina, Tatiana; Yu, Shanshan

    2014-07-01

    A sensitive broadband molecular line survey of the Sagittarius B2(N) star-forming region has been obtained with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on the Herschel Space Observatory, offering the first high spectral resolution look at this well-studied source in a wavelength region largely inaccessible from the ground (625-157 μm). From the roughly 8000 spectral features in the survey, a total of 72 isotopologues arising from 44 different molecules have been identified, ranging from light hydrides to complex organics, and arising from a variety of environments from cold and diffuse to hot and dense gas. We present a local thermodynamic equilibrium (LTE) model to the spectral signatures of each molecule, constraining the source sizes for hot core species with complementary Submillimeter Array interferometric observations and assuming that molecules with related functional group composition are cospatial. For each molecule, a single model is given to fit all of the emission and absorption features of that species across the entire 480-1910 GHz spectral range, accounting for multiple temperature and velocity components when needed to describe the spectrum. As with other HIFI surveys toward massive star-forming regions, methanol is found to contribute more integrated line intensity to the spectrum than any other species. We discuss the molecular abundances derived for the hot core where the LTE approximation is generally found to describe the spectrum well, in comparison to abundances derived for the same molecules in the Orion KL region from a similar HIFI survey. Notably, we find significantly higher abundances of amine- and amide-bearing molecules (CH3NH2, CH2NH, and NH2CHO) toward Sgr B2(N) than Orion KL and lower abundances of some complex oxygen-bearing molecules (CH3OCHO in particular). In addition to information on the chemical composition of the hot core, the strong far-infrared dust continuum allows a number of molecules to be

  17. WATER VAPOR IN NEARBY INFRARED GALAXIES AS PROBED BY HERSCHEL

    SciTech Connect

    Yang Chentao; Gao Yu; Liu Daizhong; Isaak, K. G.; Downes, D.; Van der Werf, P. P.; Lu Nanyao

    2013-07-10

    We report the first systematic study of the submillimeter water vapor rotational emission lines in infrared (IR) galaxies based on the Fourier Transform Spectrometer (FTS) data of Herschel SPIRE. Among the 176 galaxies with publicly available FTS data, 45 have at least one H{sub 2}O emission line detected. The H{sub 2}O line luminosities range from {approx}1 Multiplication-Sign 10{sup 5} L{sub Sun} to {approx}5 Multiplication-Sign 10{sup 7} L{sub Sun} while the total IR luminosities (L{sub IR}) have a similar spread ({approx}1-300 Multiplication-Sign 10{sup 10} L{sub Sun }). In addition, emission lines of H{sub 2}O{sup +} and H{sub 2}{sup 18}O are also detected. H{sub 2}O is found, for most galaxies, to be the strongest molecular emitter after CO in FTS spectra. The luminosity of the five most important H{sub 2}O lines is near-linearly correlated with L{sub IR}, regardless of whether or not strong active galactic nucleus signature is present. However, the luminosity of H{sub 2}O(2{sub 11}-2{sub 02}) and H{sub 2}O(2{sub 20}-2{sub 11}) appears to increase slightly faster than linear with L{sub IR}. Although the slope turns out to be slightly steeper when z {approx} 2-4 ULIRGs are included, the correlation is still closely linear. We find that L{sub H{sub 2O}}/L{sub IR} decreases with increasing f{sub 25}/f{sub 60}, but see no dependence on f{sub 60}/f{sub 100}, possibly indicating that very warm dust contributes little to the excitation of the submillimeter H{sub 2}O lines. The average spectral line energy distribution (SLED) of the entire sample is consistent with individual SLEDs and the IR pumping plus collisional excitation model, showing that the strongest lines are H{sub 2}O(2{sub 02}-1{sub 11}) and H{sub 2}O(3{sub 21}-3{sub 12}).

  18. The Herschel census of infrared SEDs through cosmic time

    NASA Astrophysics Data System (ADS)

    Symeonidis, M.; Vaccari, M.; Berta, S.; Page, M. J.; Lutz, D.; Arumugam, V.; Aussel, H.; Bock, J.; Boselli, A.; Buat, V.; Capak, P. L.; Clements, D. L.; Conley, A.; Conversi, L.; Cooray, A.; Dowell, C. D.; Farrah, D.; Franceschini, A.; Giovannoli, E.; Glenn, J.; Griffin, M.; Hatziminaoglou, E.; Hwang, H.-S.; Ibar, E.; Ilbert, O.; Ivison, R. J.; Floc'h, E. Le; Lilly, S.; Kartaltepe, J. S.; Magnelli, B.; Magdis, G.; Marchetti, L.; Nguyen, H. T.; Nordon, R.; O'Halloran, B.; Oliver, S. J.; Omont, A.; Papageorgiou, A.; Patel, H.; Pearson, C. P.; Pérez-Fournon, I.; Pohlen, M.; Popesso, P.; Pozzi, F.; Rigopoulou, D.; Riguccini, L.; Rosario, D.; Roseboom, I. G.; Rowan-Robinson, M.; Salvato, M.; Schulz, B.; Scott, Douglas; Seymour, N.; Shupe, D. L.; Smith, A. J.; Valtchanov, I.; Wang, L.; Xu, C. K.; Zemcov, M.; Wuyts, S.

    2013-05-01

    Using Herschel data from the deepest SPIRE and PACS surveys (HerMES and PEP) in COSMOS, GOODS-S and GOODS-N, we examine the dust properties of infrared (IR)-luminous (LIR > 1010 L⊙) galaxies at 0.1 < z < 2 and determine how these evolve with cosmic time. The unique angle of this work is the rigorous analysis of survey selection effects, making this the first study of the star-formation-dominated, IR-luminous population within a framework almost entirely free of selection biases. We find that IR-luminous galaxies have spectral energy distributions (SEDs) with broad far-IR peaks characterized by cool/extended dust emission and average dust temperatures in the 25-45 K range. Hot (T > 45 K) SEDs and cold (T < 25 K), cirrus-dominated SEDs are rare, with most sources being within the range occupied by warm starbursts such as M82 and cool spirals such as M51. We observe a luminosity-temperature (L-T) relation, where the average dust temperature of log [LIR/L⊙] ˜ 12.5 galaxies is about 10 K higher than that of their log [LIR/L⊙] ˜ 10.5 counterparts. However, although the increased dust heating in more luminous systems is the driving factor behind the L-T relation, the increase in dust mass and/or starburst size with luminosity plays a dominant role in shaping it. Our results show that the dust conditions in IR-luminous sources evolve with cosmic time: at high redshift, dust temperatures are on average up to 10 K lower than what is measured locally (z ≲ 0.1). This is manifested as a flattening of the L-T relation, suggesting that (ultra)luminous infrared galaxies [(U)LIRGs] in the early Universe are typically characterized by a more extended dust distribution and/or higher dust masses than local equivalent sources. Interestingly, the evolution in dust temperature is luminosity dependent, with the fraction of LIRGs with T < 35 K showing a two-fold increase from z ˜ 0 to z ˜ 2, whereas that of ULIRGs with T < 35 K shows a six-fold increase. Our results suggest a

  19. Biorheological Model on Flow of Herschel-Bulkley Fluid through a Tapered Arterial Stenosis with Dilatation

    PubMed Central

    Priyadharshini, S.; Ponalagusamy, R.

    2015-01-01

    An analysis of blood flow through a tapered artery with stenosis and dilatation has been carried out where the blood is treated as incompressible Herschel-Bulkley fluid. A comparison between numerical values and analytical values of pressure gradient at the midpoint of stenotic region shows that the analytical expression for pressure gradient works well for the values of yield stress till 2.4. The wall shear stress and flow resistance increase significantly with axial distance and the increase is more in the case of converging tapered artery. A comparison study of velocity profiles, wall shear stress, and flow resistance for Newtonian, power law, Bingham-plastic, and Herschel-Bulkley fluids shows that the variation is greater for Herschel-Bulkley fluid than the other fluids. The obtained velocity profiles have been compared with the experimental data and it is observed that blood behaves like a Herschel-Bulkley fluid rather than power law, Bingham, and Newtonian fluids. It is observed that, in the case of a tapered stenosed tube, the streamline pattern follows a convex pattern when we move from r/R = 0 to r/R = 1 and it follows a concave pattern when we move from r/R = 0 to r/R = −1. Further, it is of opposite behaviour in the case of a tapered dilatation tube which forms new information that is, for the first time, added to the literature. PMID:27041979

  20. Herschel observations of the Rosetta target 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    O'Rourke, L.; Bockelee-Morvan, D.; Groussin, O.; Küppers, M.; Müller, T.; Kiss, C.; Crovisier, J.; Altieri, B.; Gònzalez-Garcìa, B.; Altwegg, K.; Schulz, R.

    2012-09-01

    In June 2010, the Herschel Space Observatory observed comet 67P/Churyumov- Gerasimenko with the PACS Instrument when the comet was at a heliocentric distance of 4.1 AU. This comet is the prime target for the Rosetta spacecraft due to arrive to orbit it in mid-2014 [1].

  1. The first release of data from the Herschel ATLAS: the SPIRE images

    NASA Astrophysics Data System (ADS)

    Pascale, E.; Auld, R.; Dariush, A.; Dunne, L.; Eales, S.; Maddox, S.; Panuzzo, P.; Pohlen, M.; Smith, D. J. B.; Buttiglione, S.; Cava, A.; Clements, D. L.; Cooray, A.; Dye, S.; de Zotti, G.; Fritz, J.; Hopwood, R.; Ibar, E.; Ivison, R. J.; Jarvis, M. J.; Leeuw, L.; López-Caniego, M.; Rigby, E.; Rodighiero, G.; Scott, D.; Smith, M. W. L.; Temi, P.; Vaccari, M.; Valtchanov, I.

    2011-07-01

    We have reduced the data taken with the Spectral and Photometric Imaging Receiver (SPIRE) photometer on board the Herschel Space Observatory in the Science Demonstration Phase (SDP) of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). We describe the data reduction, which poses specific challenges, both because of the large number of detectors which can have noise correlated in each array, and because only two scans are made for each region. We implement effective solutions to process the bolometric timelines into maps, and show that correlations among detectors are negligible, and that the photometer is stable on time scales up to 250 s. This is longer than the time the telescope takes to cross the observed sky region, and it allows us to use naive binning methods for an optimal reconstruction of the sky emission. The maps have equal contribution of confusion and white instrumental noise, and the former is estimated to 5.3, 6.4 and 6.7 mJy beam-1 (1σ), at 250, 350 and 500 μm, respectively. This pipeline is used to reduce other H-ATLAS observations, as they became available, and we discuss how it can be used with the optimal map maker implemented in the Herschel Interactive Processing Environment (HIPE), to improve computational efficiency and stability. The SDP data set is available from . Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. Java-Based Astronomical Software - The HERSCHEL/ PACS Common Software System as Example

    NASA Astrophysics Data System (ADS)

    Wieprecht, E.; Huygen, R.; Vandenbussche, B.; De Meester, W.; Guest, S.; de Jonge, A.; Zaal, P.; Osterhage, S.; Wetzstein, M.

    2005-12-01

    ESA's Herschel Space Observatory, planned to be launched in 2007, is the first space observatory covering the full far-infrared and submillimetre wavelength range (60 - 670 microns). The Photodetector Array Camera and Spectrometer (PACS) is one of its three science instruments. It employs two Ge:Ga photoconductor arrays and two bolometer arrays to perform imaging line spectroscopy and imaging photometry in the 60 - 210 micron wavelength band. The HERSCHEL Common Software System (HCSS) forms the base of the HERSCHEL ground segment. HCSS is implemented using JAVA/Jython technology and interacts with an object oriented database. It is written in a common effort by the HERSCHEL Science Centre and the three instrument teams. The PACS Common Software System (PCSS) is based on the HCSS. Both systems were designed for a smooth transition between the different phases of the project. Instrument engineers use PCSS during instrument tests, calibration specialists for instrument characterization on ground and in orbit, and finally the observer will use it for data reduction. The design allows use of the same components for automatic processing, quick look analysis, and interactive processing. We outline some design aspects of such a highly complex system and present user experiences with PCSS, gathered during first instrument tests of PACS.

  3. How bright planets became dim stars: planetary speculations in John Herschel's double star astronomy.

    PubMed

    Case, Stephen

    2014-03-01

    Previous research on the origins of double star astronomy in the early nineteenth century emphasized the role mathematical methods and instrumentation played in motivating early observations of these objects. The work of the British astronomer John Herschel, however, shows that questions regarding the physical nature of double stars were also important. In particular, an analysis of John Herschel's early work on double stars illustrates the way in which speculations regarding these objects were shaped by assumptions of the properties of stars themselves. For Herschel, a major consideration in double star astronomy was distinguishing between types of double stars. Optical doubles were useful in determining parallax while binary doubles were not. In practice, classification of a specific double star pair into one of these categories was based on the assumption that stars were of approximately the same luminosity and thus differences in relative brightness between stars were caused by difference in distances. Such assumptions, though ultimately abandoned, would lead Herschel in the 1830s to advance the possibility that the dim companion stars in certain double star pairs were not stars at all but in fact planets. PMID:24508199

  4. The New Era of Sub-millimeter Cosmoloty: First Results from Herschel Space Observatory

    SciTech Connect

    Cooray, Asantha

    2010-12-01

    This talk will summarize some of the first science results from the Herschel Space Observatory, now imaging the universe at 100 to 500 microns. The results come from the SPIRE Instrument Team's science program (HerMES) and a separate large area survey, Herschel-ATLAS. At the sub-mm wavelengths, we are sensitive to the thermal re-radiation by dust in star-forming galaxies and previous studies had already shown the presence of a large number of galaxies in the distant universe that remain hidden to the visible light. With Herschel, we are now finally able to obtain adequate statistics on this galaxy population, their nature and evolution, and connections to galaxies we see in the local universe. I will also show several cosmological results, including studies that can be done with a large population of gravitationally lensed sub-mm galaxies by foreground massive galaxies and the dark matter properties of bright and faint sub-mm galaxies as revealed by clustering and fluctuation studies. I will also summarize the scientific goals of the Herschel-SPIRE Legacy Survey, a program proposed to ESA to cover 4000 sq. degrees with SPIRE in a fast-scan mode with the ultimate goal of recovering a catalog of 2.5 to 3 million bright sub-mm sources for future studies with ALMA, CCAT, and SPICA.

  5. Tracing the gas composition of Titan's atmosphere with Herschel : Advances and Discoveries

    NASA Astrophysics Data System (ADS)

    Rengel, Miriam; Moreno, Raphael; Courtin, Régis; Lellouch, Emmanuel; Sagawa, Hideo; Hartogh, Paul; Swinyard, Bruce; Lara, Luisa; Feuchtgruber, Helmut; Jarchow, Christopher; Fulton, Trevor; Cernicharo, José; Bockelée-Morvan, Dominique; Biver, Nicolás; Banaszkiewicz, Marek; González, Armando

    2014-11-01

    The nitrogen-dominated atmosphere of Titan exhibits a great diversity and complexity of molecules and high organic material abundances. The origin of Titan atmosphere is poorly understood and its chemistry is rather complicated. In the framework of the Herschel guaranteed time key programme "Water and Related Chemistry in the Solar System" (Hartogh et al 2009), we carried out observations of the atmosphere of Titan with HIFI, PACS and SPIRE onboard Herschel (Rengel et al. 2014; Courtin et al. 2011, Moreno et al. 2011, 2012). Here we will review key results and discoveries on the atmosphere of Titan obtained with Herschel:-an inventory of species detected including some isotopes from a new survey between 51 and 671 microns.-the determination of the abundance of trace constituents and comparisons with previous efforts.-the unexpected detection of hydrogen isocyanide (HNC), a specie not previously identified in Titan's atmosphere, and the measurement of 16O/18O ratio in CO in Titan for the first time published.-the determination of the vertical profile of water vapor over the 100-450 km altitude range, distribution which does not follow previous predictions and allows to strength an Enceladus' activity as the source for the current water on Titan.With the advent of Herschel, these advances and discoveries allow a further characterization of the complex atmosphere of Titan and help to advance the study of the abundance distribution and the investigation of a variety of processes in Titan atmosphere.

  6. VizieR Online Data Catalog: Cold gas properties of Herschel Reference Survey (Boselli+, 2014)

    NASA Astrophysics Data System (ADS)

    Boselli, A.; Cortese, L.; Boquien, M.

    2013-11-01

    12CO(1-0) and HI data for galaxies of the Herschel Reference (Boselli et al., 2010, Cat. J/PASP/122/261). The data are either collected in the literature, or taken from our own observations done with the 12m Keat Peak radio telescope. (7 data files).

  7. Biorheological Model on Flow of Herschel-Bulkley Fluid through a Tapered Arterial Stenosis with Dilatation.

    PubMed

    Priyadharshini, S; Ponalagusamy, R

    2015-01-01

    An analysis of blood flow through a tapered artery with stenosis and dilatation has been carried out where the blood is treated as incompressible Herschel-Bulkley fluid. A comparison between numerical values and analytical values of pressure gradient at the midpoint of stenotic region shows that the analytical expression for pressure gradient works well for the values of yield stress till 2.4. The wall shear stress and flow resistance increase significantly with axial distance and the increase is more in the case of converging tapered artery. A comparison study of velocity profiles, wall shear stress, and flow resistance for Newtonian, power law, Bingham-plastic, and Herschel-Bulkley fluids shows that the variation is greater for Herschel-Bulkley fluid than the other fluids. The obtained velocity profiles have been compared with the experimental data and it is observed that blood behaves like a Herschel-Bulkley fluid rather than power law, Bingham, and Newtonian fluids. It is observed that, in the case of a tapered stenosed tube, the streamline pattern follows a convex pattern when we move from r/R = 0 to r/R = 1 and it follows a concave pattern when we move from r/R = 0 to r/R = -1. Further, it is of opposite behaviour in the case of a tapered dilatation tube which forms new information that is, for the first time, added to the literature. PMID:27041979

  8. HerMES: ALMA Imaging of Herschel-selected Dusty Star-forming Galaxies

    NASA Astrophysics Data System (ADS)

    Bussmann, R. S.; Riechers, D.; Fialkov, A.; Scudder, J.; Hayward, C. C.; Cowley, W. I.; Bock, J.; Calanog, J.; Chapman, S. C.; Cooray, A.; De Bernardis, F.; Farrah, D.; Fu, Hai; Gavazzi, R.; Hopwood, R.; Ivison, R. J.; Jarvis, M.; Lacey, C.; Loeb, A.; Oliver, S. J.; Pérez-Fournon, I.; Rigopoulou, D.; Roseboom, I. G.; Scott, Douglas; Smith, A. J.; Vieira, J. D.; Wang, L.; Wardlow, J.

    2015-10-01

    The Herschel Multi-tiered Extragalactic Survey (HerMES) has identified large numbers of dusty star-forming galaxies (DSFGs) over a wide range in redshift. A detailed understanding of these DSFGs is hampered by the limited spatial resolution of Herschel. We present 870 μm 0.″45 resolution imaging obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) of a sample of 29 HerMES DSFGs that have far-infrared (FIR) flux densities that lie between the brightest of sources found by Herschel and fainter DSFGs found via ground-based surveys in the submillimeter region. The ALMA imaging reveals that these DSFGs comprise a total of 62 sources (down to the 5σ point-source sensitivity limit in our ALMA sample; σ ≈ 0.2 {mJy}). Optical or near-infrared imaging indicates that 36 of the ALMA sources experience a significant flux boost from gravitational lensing (μ \\gt 1.1), but only six are strongly lensed and show multiple images. We introduce and make use of uvmcmcfit, a general-purpose and publicly available Markov chain Monte Carlo visibility-plane analysis tool to analyze the source properties. Combined with our previous work on brighter Herschel sources, the lens models presented here tentatively favor intrinsic number counts for DSFGs with a break near 8 {mJy} at 880 μ {{m}} and a steep fall-off at higher flux densities. Nearly 70% of the Herschel sources break down into multiple ALMA counterparts, consistent with previous research indicating that the multiplicity rate is high in bright sources discovered in single-dish submillimeter or FIR surveys. The ALMA counterparts to our Herschel targets are located significantly closer to each other than ALMA counterparts to sources found in the LABOCA ECDFS Submillimeter Survey. Theoretical models underpredict the excess number of sources with small separations seen in our ALMA sample. The high multiplicity rate and small projected separations between sources seen in our sample argue in favor of interactions

  9. The long-lasting activity of 3C 454.3. GASP-WEBT and satellite observations in 2008-2010

    NASA Astrophysics Data System (ADS)

    Raiteri, C. M.; Villata, M.; Aller, M. F.; Gurwell, M. A.; Kurtanidze, O. M.; Lähteenmäki, A.; Larionov, V. M.; Romano, P.; Vercellone, S.; Agudo, I.; Aller, H. D.; Arkharov, A. A.; Bach, U.; Benítez, E.; Berdyugin, A.; Blinov, D. A.; Borisova, E. V.; Böttcher, M.; Bravo Calle, O. J. A.; Buemi, C. S.; Calcidese, P.; Carosati, D.; Casas, R.; Chen, W.-P.; Efimova, N. V.; Gómez, J. L.; Gusbar, C.; Hawkins, K.; Heidt, J.; Hiriart, D.; Hsiao, H. Y.; Jordan, B.; Jorstad, S. G.; Joshi, M.; Kimeridze, G. N.; Koptelova, E.; Konstantinova, T. S.; Kopatskaya, E. N.; Kurtanidze, S. O.; Larionova, E. G.; Larionova, L. V.; Leto, P.; Li, Y.; Ligustri, R.; Lindfors, E.; Lister, M.; Marscher, A. P.; Molina, S. N.; Morozova, D. A.; Nieppola, E.; Nikolashvili, M. G.; Nilsson, K.; Palma, N.; Pasanen, M.; Reinthal, R.; Roberts, V.; Ros, J. A.; Roustazadeh, P.; Sadun, A. C.; Sakamoto, T.; Schwartz, R. D.; Sigua, L. A.; Sillanpää, A.; Takalo, L. O.; Tammi, J.; Taylor, B.; Tornikoski, M.; Trigilio, C.; Troitsky, I. S.; Umana, G.; Volvach, A.; Yuldasheva, T. A.

    2011-10-01

    Context. The blazar 3C 454.3 is one of the most active sources from the radio to the γ-ray frequencies observed in the past few years. Aims: We present multiwavelength observations of this source from April 2008 to March 2010. The radio to optical data are mostly from the GASP-WEBT, UV and X-ray data from Swift, and γ-ray data from the AGILE and Fermi satellites. The aim is to understand the connection among emissions at different frequencies and to derive information on the emitting jet. Methods: Light curves in 18 bands were carefully assembled to study flux variability correlations. We improved the calibration of optical-UV data from the UVOT and OM instruments and estimated the Lyα flux to disentangle the contributions from different components in this spectral region. Results: The observations reveal prominent variability above 8 GHz. In the optical-UV band, the variability amplitude decreases with increasing frequency due to a steadier radiation from both a broad line region and an accretion disc. The optical flux reaches nearly the same levels in the 2008-2009 and 2009-2010 observing seasons; the mm one shows similar behaviour, whereas the γ and X-ray flux levels rise in the second period. Two prominent γ-ray flares in mid 2008 and late 2009 show a double-peaked structure, with a variable γ/optical flux ratio. The X-ray flux variations seem to follow the γ-ray and optical ones by about 0.5 and 1 d, respectively. Conclusions: We interpret the multifrequency behaviour in terms of an inhomogeneous curved jet, where synchrotron radiation of increasing wavelength is produced in progressively outer and wider jet regions, which can change their orientation in time. In particular, we assume that the long-term variability is due to this geometrical effect. By combining the optical and mm light curves to fit the γ and X-ray ones, we find that the γ (X-ray) emission may be explained by inverse-Comptonisation of synchrotron optical (IR) photons by their parent

  10. Herschel-ATLAS: Dusty early-type galaxies

    NASA Astrophysics Data System (ADS)

    Rowlands, K.; Dunne, L.; Maddox, S.

    2015-03-01

    Early-type galaxies (ETGs) are thought to be devoid of dust and star-formation, having formed most of their stars at early epochs. We present the detection of the dustiest ETGs in a large-area blind submillimetre survey with Herschel (H-ATLAS, Eales et al. 2010), where the lack of pre-selection in other bands makes it the first unbiased survey for cold dust in ETGs. The parent sample of 1087 H-ATLAS galaxies in this study have a >= 5σ detection at 250μm, a reliable optical counterpart to the submillimetre source (Smith et al. 2011) and a spectroscopic redshift from the GAMA survey (Driver et al. 2011). Additionally, we construct a control sample of 1052 optically selected galaxies undetected at 250μm and matched in stellar mass to the H-ATLAS parent sample to eliminate selection effects. ETGs were selected from both samples via visual classifications using SDSS images. Further details can be found in Rowlands et al. (2012). Physical parameters are derived for each galaxy using the multiwavelength spectral energy distribution (SED) fitting code of da Cunha, Charlot and Elbaz (2008), Smith et al. 2012, using an energy balance argument. We investigate the differences between the dusty ETGs and the general ETG population, and find that the H-ATLAS ETGs are more than an order of magnitude dustier than the control ETGs. The mean dust mass of the 42 H-ATLAS ETGs is 5.5 × 107M⊙ (comparable to the dust mass of spirals in our sample), whereas the dust mass of the 233 control ETGs inferred from stacking at optical positions on the 250μm map is (0.8 - 4.0) × 106M⊙ for 25-15 K dust. The average star-formation rate of the H-ATLAS ETGs is 1.0 dex higher than that of control ETGs, and the mean r-band light-weighted age of the H-ATLAS ETGs is 1.8 Gyr younger than the control ETGs. The rest-frame NUV - r colours of the H-ATLAS ETGs are 1.0 magnitudes bluer than the control ETGs, and some ETGs may be transitioning from the blue cloud to the red sequence. Some H-ATLAS ETGs

  11. Experimental study of neutron-rich nuclei near the N = 82 closed shell using the {sub 40}{sup 96}Zr+{sub 50}{sup 124}Sn reaction with GASP and PRISMA-CLARA arrays

    SciTech Connect

    Rodríguez, W.; Torres, D. A.; Cristancho, F.; Medina, N. H.; Chapman, R.; Smith, J. F.; Mengoni, D.; Truesdale, V.; Grocutt, L.; Mulholland, K.; Kumar, V.; Hadinia, B.; Labiche, M.; Liang, X.; O'Donell, D.; Ollier, J.; Orlandi, R.; Smith, J. F.; Spohr, K. M.; Wady, P.; and others

    2014-11-11

    In this contribution an experimental study of the deep-inelastic reaction {sub 40}{sup 96}Zr+{sub 50}{sup 124}Sn at 530 MeV, using the GASP and PRISMA-CLARA arrays, is presented. The experiments populate a wealth of projectile-like and target-like binary fragments, in a large neutron-rich region around N ≥ 50 and Z ≈ 40. Preliminary results on the study of the yrast and near-yrast states for {sup 95}Nb will be shown, along with a comparison of the experimental yields obtained in the experiments.

  12. The Last Gasp of Gas Giant Planet Formation: A Spitzer Study of the 5 Myr Old Cluster NGC 2362

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Lada, Charles J.; Plavchan, Peter; Robitaille, Thomas P.; Irwin, Jonathan; Kenyon, Scott J.

    2009-06-01

    Expanding upon the Infrared Array Camera (IRAC) survey from Dahm & Hillenbrand, we describe Spitzer IRAC and Multiband Imaging Photometer for Spitzer observations of the populous, 5 Myr old open cluster NGC 2362. We analyze the mid-IR colors of cluster members and compared their spectral energy distributions (SEDs) to star+circumstellar disk models to constrain the disk morphologies and evolutionary states. Early/intermediate-type confirmed/candidate cluster members either have photospheric mid-IR emission or weak, optically thin IR excess emission at λ >= 24 μm consistent with debris disks. Few late-type, solar/subsolar-mass stars have primordial disks. The disk population around late-type stars is dominated by disks with inner holes (canonical "transition disks") and "homologously depleted" disks. Both types of disks represent an intermediate stage between primordial disks and debris disks. Thus, in agreement with previous results, we find that multiple paths for the primordial-to-debris disk transition exist. Because these "evolved primordial disks" greatly outnumber primordial disks, our results undermine standard arguments in favor of a lsim105 yr timescale for the transition based on data from Taurus-Auriga. Because the typical transition timescale is far longer than 105 yr, these data also appear to rule out standard ultraviolet photoevaporation scenarios as the primary mechanism to explain the transition. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant planet formation. Consistent with Currie et al., the luminosity of 24 μm emission in debris disks due to planet formation peaks at ≈10-20 Myr. If the gas and dust in disks evolve on similar timescales, the formation timescale for gas giant planets surrounding early-type, high/intermediate-mass (gsim1.4 M sun) stars is likely 1-5 Myr. Most solar/subsolar-mass stars detected by Spitzer have

  13. Filaments, ridges and a mini-starburst - HOBYS' view of high mass star formation with Herschel

    NASA Astrophysics Data System (ADS)

    Hill, T.; Motte, F.; Didelon, P.

    2012-03-01

    With its unprecedented spatial resolution and high sensitivity, Herschel is revolutionising our understanding of high mass star formation and the interstellar medium (ISM). In particular, Herschel is unveiling the filamentary structure and molecular cloud constituents of the ISM where star formation takes place. The Herschel Imaging Survey of OB Young Stellar objects (HOBYS; Motte, Zavagno, Bontemps, see http://www.herschel.fr/cea/hobys/en/index.php) key program targets burgeoning young stellar objects with the aim of characterising them and the environments in which they form. HOBYS has already proven fruitful with many clear examples of high-mass star formation in nearby molecular cloud complexes (e.g. Motte et al., 2010). Through multi-wavelength Herschel observations I will introduce select regions of the HOBYS program, including Vela C, M16 and W48 to start. These data are rich with filamentary structures and a wealth of sources which span a large mass range including, low, intermediate and high-mass objects in the pre-collapse or protostellar phase of formation, many of which will proceed to form stars. The natal filaments themselves come in many shapes and sizes, they can form thick ridge-like structures, be dispersed in low column density regions or cluster in higher density regions. In Vela C, high-mass star formation proceeds preferentially in high column density supercritical filaments, called ridges, which may result from the constructive convergence of flows (Hill et al., 2011). I will present other examples of ridges identified in HOBYS regions. In addition, I will present the latest results on the Eagle Nebula (M16). This region was made iconic by Hubble, but only Herschel can trace the cold, dense early prestellar phases of star formation, and their natal interstellar filaments, in this infamous star-forming complex. The cavity ionised by the nearby OB cluster in M16 serves to heat the Pillars of Creation and the surrounding interstellar filaments

  14. Measures of galaxy dust and gas mass with Herschel photometry and prospects for ALMA

    NASA Astrophysics Data System (ADS)

    Berta, S.; Lutz, D.; Genzel, R.; Förster-Schreiber, N. M.; Tacconi, L. J.

    2016-03-01

    Combining the deepest Herschel extragalactic surveys (PEP, GOODS-H, HerMES), and Monte Carlo mock catalogs, we explore the robustness of dust mass estimates based on modeling of broadband spectral energy distributions (SEDs) with two popular approaches: Draine & Li (2007, ApJ, 657, 810; DL07) and a modified blackbody (MBB). We analyze the cause, drivers, and trends of uncertainties and systematics in thorough detail. As long as the observed SED extends to at least 160-200 μm in the rest frame, Mdust can be recovered with a >3σ significance and without the occurrence of systematics. An average offset of a factor ~1.5 exists between DL07- and MBB-based dust masses, based on consistent dust properties. The performance of DL07 modeling turns out to be more robust than that of MBB since relative errors on Mdust are more mildly dependent on the maximum covered rest-frame wavelength and are less scattered. At the depth of the deepest Herschel surveys (in the GOODS-S field), it is possible to retrieve dust masses with a signal-to-noise ratio, S/N ≥ 3 for galaxies on the main sequence of star formation (MS) down to M∗ ~ 1010 [M⊙] up to z ~ 1. At higher redshift (z ≤ 2), the same result is only achieved for objects at the tip of the MS or for those objects lying above the tip owing to sensitivity and wavelength coverage limitations. Molecular gas masses, obtained by converting Mdust through the metallicity-dependent gas-to-dust ratio δGDR, are consistent with those based on the scaling of depletion time, τdep, and on CO sub-mm spectroscopy. Focusing on CO-detected galaxies at z> 1, the δGDR dependence on metallicity is consistent with the local relation, provided that a sufficient SED coverage is available. Once we established that Herschel-only and sub-mm-only estimates of dust masses can be affected by large uncertainties and possibly systematics in some cases, we combined far-IR Herschel data and sub-mm ALMA expected fluxes to study the advantages of a full

  15. Herschel observations of extraordinary sources: Analysis of the full Herschel/HIFI molecular line survey of sagittarius B2(N)

    SciTech Connect

    Neill, Justin L.; Bergin, Edwin A.; Crockett, Nathan R.; Favre, Cécile; Anderson, Dana E.; Burkhardt, Andrew M.; McNeill, Trevor D.; Lis, Dariusz C.; Emprechtinger, Martin; Monje, Raquel R.; Phillips, Thomas G.; Schilke, Peter; Comito, Claudia; Qin, Sheng-Li; Chen, Jo-Hsin; Harris, Brent J.; Steber, Amanda L.; Vasyunina, Tatiana; Lord, Steven D.; McGuire, Brett A. E-mail: ebergin@umich.edu; and others

    2014-07-01

    A sensitive broadband molecular line survey of the Sagittarius B2(N) star-forming region has been obtained with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on the Herschel Space Observatory, offering the first high spectral resolution look at this well-studied source in a wavelength region largely inaccessible from the ground (625-157 μm). From the roughly 8000 spectral features in the survey, a total of 72 isotopologues arising from 44 different molecules have been identified, ranging from light hydrides to complex organics, and arising from a variety of environments from cold and diffuse to hot and dense gas. We present a local thermodynamic equilibrium (LTE) model to the spectral signatures of each molecule, constraining the source sizes for hot core species with complementary Submillimeter Array interferometric observations and assuming that molecules with related functional group composition are cospatial. For each molecule, a single model is given to fit all of the emission and absorption features of that species across the entire 480-1910 GHz spectral range, accounting for multiple temperature and velocity components when needed to describe the spectrum. As with other HIFI surveys toward massive star-forming regions, methanol is found to contribute more integrated line intensity to the spectrum than any other species. We discuss the molecular abundances derived for the hot core where the LTE approximation is generally found to describe the spectrum well, in comparison to abundances derived for the same molecules in the Orion KL region from a similar HIFI survey. Notably, we find significantly higher abundances of amine- and amide-bearing molecules (CH{sub 3}NH{sub 2}, CH{sub 2}NH, and NH{sub 2}CHO) toward Sgr B2(N) than Orion KL and lower abundances of some complex oxygen-bearing molecules (CH{sub 3}OCHO in particular). In addition to information on the chemical composition of the hot core, the strong far-infrared dust continuum allows

  16. First Results from the Herschel Gould Belt Survey in Taurus and Comparison with Other Clouds

    NASA Astrophysics Data System (ADS)

    Kirk, Jason

    The unparalleled sensitivity and mapping speed of the ESA Herschel Space Observatory makes it possible to now map entire star formation regions in the time it would once have taken to map a single prestellar core. The Herschel Gould Belt Survey is a key program designed to fully map the clouds of the Gould Belt at five wavelengths between 70 and 500 μm. These clouds span a range of physical conditions from the sterility of Polaris to the active cluster forming complexes of Orion and Aquila. These clouds allow us to examine the genesis of the core mass function and how the history of star formation in different regions varies. The early results have demonstrated the markedly different populations of cores in these regions and have revealed the nearly ubiquitous relationship of those cores with dense filaments.

  17. Finite volume methods for submarine debris flow with Herschel-Bulkley rheology

    NASA Astrophysics Data System (ADS)

    Kim, Jihwan; Issler, Dieter

    2015-04-01

    Submarine landslides can impose great danger to the underwater structures and generate destructive waves. The Herschel-Bulkley rheological model is known to be appropriate for describing the nonlinear viscoplastic behavior of the debris flow. The numerical implementation of the depth-averaged Herschel-Bulkley models such as BING has so-far been limited to the 1-dimensional Lagrangian coordinate system. In this work, we develop numerical schemes with the finite volume methods in the Eulerian coordinates. We provide parameter sensitivity analysis and demonstrate how common ad-hoc assumptions such as including a minimum shear layer depth influence the modeling of the landslide dynamics. The possibility of adding hydrodynamic resistance forces, hydroplaning, and remolding into this Eulerian framework is also discussed. Finally, the possible extension to a two-dimensional operational model for coupling towards operational tsunami models is discussed.

  18. Analytical Modeling of Herschel-Quincke Concept Applied to Inlet Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Hallez, Raphael F.; Burdisso, Ricardo A.; Gerhold, Carl H. (Technical Monitor)

    2002-01-01

    This report summarizes the key results obtained by the Vibration and Acoustics Laboratories at Virginia Tech over the period from January 1999 to December 2000 on the project 'Investigation of an Adaptive Herschel-Quincke Tube Concept for the Reduction of Tonal and Broadband Noise from Turbofan Engines', funded by NASA Langley Research Center. The Herschel-Quincke (HQ) tube concept is a developing technique the consists of circumferential arrays of tubes around the duct. The analytical model is developed to provide prediction and design guidelines for application of the HQ concept to turbofan engine inlets. An infinite duct model is developed and used to provide insight into attenuation mechanisms and design strategies. Based on this early model, the NASA-developed TBIEM3D code is modified for the HQ system. This model allows for investigation of the HQ system combined with a passive liner.

  19. ALMA observation of high-z extreme star-forming environments discovered by Planck/Herschel

    NASA Astrophysics Data System (ADS)

    Kneissl, R.

    2016-05-01

    The Comic Microwave Background satellite Planck with its High Frequency Instrument has surveyed the mm/sub-mm sky in six frequency channels from 100 to 900 GHz. A sample of 228 cold sources of the Cosmic Infrared Background was observed in follow-up with Herschel SPIRE. The majority of sources appear to be over-densities of star-forming galaxies matching the size of high-z proto-cluster regions, while a 3% fraction are individual bright, lensed galaxies. A large observing program is underway with the aim of resolving the regions into the constituent members of the Planck sources. First ALMA data have been received on one Planck/Herschel proto-cluster candidate, showing the expected large over-abundance of bright mm/sub-mm sources within the cluster region. ALMA long baseline data of the brightest lensed galaxy in the sample with > 1 Jy at 350 μm are also forthcoming.

  20. Comet C/2013 A1 (Siding Spring) as seen with the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Kiss, Cs.; Müller, T. G.; Kidger, M.; Mattisson, P.; Marton, G.

    2015-02-01

    The thermal emission of comet C/2013 A1 (Siding Spring) was observed on March 31, 2013, at a heliocentric distance of 6.48 au using the PACS photometer camera of the Herschel Space Observatory. The comet was clearly active, showing a coma that could be traced to a distance of ~10'', i.e. ~50 000 km. Analysis of the radial intensity profiles of the coma provided a dust mass and dust production rate and the derived grain size distribution characteristics indicate an overabundance of large grains in the thermal emission. We estimate that activity started about 6 months before these observations at a heliocentric distance of ~8 au. Herschel is an ESA space observatory with science instruments provided by European-lead Principal Investigator consortia and with important participation from NASA.Appendix A is available in electronic form at http://www.aanda.org

  1. De Herschel à Alma. Les galaxies dévoilent enfin leurs secrets.

    NASA Astrophysics Data System (ADS)

    Elbaz, David

    2016-08-01

    With deep surveys, one can measure the amount of stars born in slices of the Universe and infer a "cosmic rate of star formation." The latest estimates from the Herschel satellite show a rapid drop of star formation in galaxies since ten billion years. To understand the cause of this fall, we can now measure the interstellar reservoirs of galaxies by combining observations from Herschel and the millimeter interferometer ALMA. Early results suggest that this fall comes from the rapid consumption of interstellar matter which served as reservoir to galaxies. Thanks to the technique of interferometry, ALMA can map interstellar dust within galaxies observed at the time of the peak of cosmic star formation, ten billion years ago. We discover that the stars of the most massive galaxies are born not only at very high rates but also with an extreme concentration.

  2. Experimental Investigation of the Herschel-Quincke Tube Concept on the Honeywell TFE731-60

    NASA Technical Reports Server (NTRS)

    Smith, Jerome P.; Burdisso, Ricardo A.; Gerhold, Carl H. (Technical Monitor)

    2002-01-01

    This report summarizes the key results obtained by the Vibration and Acoustics Laboratories at Virginia Tech over the period from January 1999 to December 2000 on the project 'Investigation of an Adaptive Herschel-Quincke Tube Concept for the Reduction of Tonal and Broadband Noise from Turbofan Engines', funded by NASA Langley Research Center. The Herschel-Quincke (HQ) tube concept is a developing technique that consists of circumferential arrays of tubes around the duct. A fixed array of tubes is installed on the inlet duct of the Honeywell TFE731-60 engine. Two array designs are incorporated into the inlet treatment, each designed for a different circumferential mode order which is expected to be cut on in the duct. Far field and in-duct noise measurement data are presented which demonstrate the effectiveness of the HQ concept for array 1, array 2, and both operating simultaneously.

  3. A Herschel Spectroscopic Survey of Warm Molecular Gas in Local Luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Lu, Nanyao Y.; Zhao, Y.; Xu, C. K.; Gao, Y.; Armus, L.; Appleton, P. N.; Charmandaris, V.; Diaz Santos, T.; Evans, A. S.; Howell, J.; Issak, K.; Iwasawa, K.; Leech, J.; Lord, S. D.; Mazzarella, J. M.; Petric, A.; Sanders, D. B.; Schulz, B.; Surace, J. A.; Van der Werf, P.

    2013-01-01

    We describe an on-going Herschel 194-671 micron spectroscopic survey of a flux-limited sample of 125 local luminous infrared galaxies (LIRGs), targeting primarily at the spectral line energy distribution (SLED) of the CO rotational line emission (from J=4-3 up to J=13-12) from warm and dense molecular gas, the [NII] 205 micron line from ionized gas, and the [CI] 370 and 609 micron lines arising mainly from less dense and colder molecular gas where the CO (J=1-0) line is also strong. We present observational results for the first set of 65 sample galaxies that are more or less point sources with respect to the Herschel beams, and show statistical correlations among the shape of the CO SLED, CO line luminosities, IR dust luminosity, and whether a target is known to harbor AGN or not.

  4. Herschel/HIFI-HRS observation of CH absorption in IRAS16293-2422

    NASA Astrophysics Data System (ADS)

    Bottinelli, S.; Caux, C.; Wakelam, V.; Ceccarelli, C.; Kahane, C.

    2011-05-01

    We present high spectral resolution observations of CH absorption towards the low-mass protostar IRAS16293-2422. The data were obtained with the High Resolution Spectrometer (HRS) module of the Heterodyne Instrument for the Far-Infrared (HIFI) on-board Herschel, as part of the CHESS (Chemical HErschel Surveys of Star-forming regions) guaranteed time key program. CH is well known for having column densities correlated with those of H_2 and for its role as a product in the ion-molecule gas-phase chemistry. We derive CH column densities in the envelope of IRAS16293-2422, and investigate the implications when comparing with column densities of H_2 and of other carbon species such as CN or CCH. We also discuss the non-detections of CD and CH^+.

  5. Observations of H2O in Titan's atmosphere with Herschel

    NASA Astrophysics Data System (ADS)

    Moreno, R.; Lellouch, E.; Lara, L. M.; Courtin, R.; Hartogh, P.; Rengel, M.

    2012-04-01

    Disk averaged observations of several H2O far infrared lines in Titan’s atmosphere were performed with the Herschel Space Observatory, as part of the guaranteed time key program "Water and related chemistry in the Solar System" (HssO, see Hartogh et al 2011). Two instruments were used: (i) HIFI, a heterodyne instrument (R~ 106 ) in the sub-millimeter, which measured the H2O(110-101) rotational transition at 557 GHz on June 10 and Dec. 31, 2010 (ii) PACS, a photoconductor spectrometer (R~103) which measured three water lines at 108.1, 75.4 and 66.4 microns on June 22, 2010. Additional PACS measurements at 66.4 microns on Dec. 15 and 22, 2010 and on July 09, 2011, do not show any significant line intensity variation with time, nor between the leading/trailing sides (i.e. longitude). Spectra were analyzed with a line-by-line radiative transfer code accounting for spherical geometry (Moreno et al. 2011). This model considers the H2O molecular opacity from JPL catalog (Pickett et al. 1998) and also includes collision-induced opacities N2-N2, N2-CH4 and CH4-CH4 (Borysow and Frommhold 1986, 1987, Borysow and Tang 1993). Far infrared aerosol opacities derived by CIRS were included, following Anderson and Samuelson (2011) for their vertical distribution and spectral dependencies. Analysis of the 557 GHz narrow line (FWHM ~ 2 MHz) indicates that it originates at altitudes above 300 km, while lines measured with PACS probe mainly deeper levels (80-150 km). The HIFI and PACS observations are fitted simultaneously, considering a vertical distribution of H2O mixing ratio which follows a power law dependency q=q0(P/P0)n, where q0 is the mixing ratio at some reference pressure level P0, taken near the expected condensation level. Model fits will be presented, and compared with previously proposed H2O vertical distributions. We show in particular that both the steep profile proposed by Lara et al. (1996) (and adopted by Coustenis et al. (1998) to model the first detection of H2O

  6. The raft of the Saint-Jean River, Gaspé (Québec, Canada): A dynamic feature trapping most of the wood transported from the catchment

    NASA Astrophysics Data System (ADS)

    Boivin, Maxime; Buffin-Bélanger, Thomas; Piégay, Hervé

    2015-02-01

    The rivers of the Gaspé Peninsula, Québec (Canada), a coastal drainage system of the St. Lawrence River, receive and transport vast quantities of large wood. The rapid rate of channel shifting caused by high-energy flows and noncohesive banks allows wood recruitment that in turn greatly influences river dynamics. The delta of the Saint-Jean River has accumulated wood since 1960, leading to frequent avulsions over that time period. The wood raft there is now more than 3-km in length, which is unusual but natural. This jam configuration allows a unique opportunity to estimate a wood budget at the scale of a long river corridor and to better understand the dynamics of large wood (LW) in rivers. A wood budget includes the evaluation of wood volumes (i) produced by bank erosion (input), (ii) still in transit in the river corridor (deposited on sand bars or channel edges), and (iii) accumulated in the delta (output). The budget is based on an analysis of aerial photos dating back to 1963 as well as surveys carried out in 2010, all of which were used to locate and describe large wood accumulations along a 60-km river section. The main results of this paper show that the raft formation in the delta is dynamic and can be massive, but it is a natural process. Considering the estimated wood volume trapped in the delta from 1963 to 2013 (≈ 25,000 m3), two important points are revealed by the quantification of the wood recruitment volume from 1963 to 2004 (≈ 27,000 m3 ± 400 m3) and of the wood volume stored on the bars in 2010 (≈ 5950 m3). First, the recruitment of large wood from lateral migration for the 40-year period can account for the volume of large wood in the delta and in transit. Second, the excess wood volume produced by lateral migration and avulsion represents a minimum estimation of the large wood trapped on the floodplain owing to wood volume that has decomposed and large wood that exited the river system. Rafts are major trapping structures that provide

  7. GASP: A computer code for calculating the thermodynamic and transport properties for ten fluids: Parahydrogen, helium, neon, methane, nitrogen, carbon monoxide, oxygen, fluorine, argon, and carbon dioxide. [enthalpy, entropy, thermal conductivity, and specific heat

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Baron, A. K.; Peller, I. C.

    1975-01-01

    A FORTRAN IV subprogram called GASP is discussed which calculates the thermodynamic and transport properties for 10 pure fluids: parahydrogen, helium, neon, methane, nitrogen, carbon monoxide, oxygen, fluorine, argon, and carbon dioxide. The pressure range is generally from 0.1 to 400 atmospheres (to 100 atm for helium and to 1000 atm for hydrogen). The temperature ranges are from the triple point to 300 K for neon; to 500 K for carbon monoxide, oxygen, and fluorine; to 600 K for methane and nitrogen; to 1000 K for argon and carbon dioxide; to 2000 K for hydrogen; and from 6 to 500 K for helium. GASP accepts any two of pressure, temperature and density as input conditions along with pressure, and either entropy or enthalpy. The properties available in any combination as output include temperature, density, pressure, entropy, enthalpy, specific heats, sonic velocity, viscosity, thermal conductivity, and surface tension. The subprogram design is modular so that the user can choose only those subroutines necessary to the calculations.

  8. Using Herschel Far-Infrared Photometry to Constrain Star Formation Rates in CLASH Cluster Galaxies

    NASA Astrophysics Data System (ADS)

    Larson, Rebecca L.; Postman, Marc; Fogarty, Kevin

    2016-01-01

    The Cluster Lensing And Supernova survey with Hubble (CLASH) program obtained broadband images of 25 massive galaxy clusters in 16 passbands from the UV to the near-IR. The data was taken with the Wide-field Camera 3 (WFC3), and the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). These 25 clusters have also been observed in the mid-IR by Spitzer IRAC, the far-IR by the Herschel Space Observatory PACS and SPIRE, and in the x-ray by the Chandra and XMM observatories. We focused on the two brightest cluster galaxies (BCGs) in the survey (MACS1931.8-2653 and RXJ1532.9+3021) that have reddening-corrected UV-derived star formation rates (SFRs) > 100 M⊙ yr-1 as measured by Fogarty et al (2015). The inclusion of Herschel data provides unique constraints on dust content and independent estimates of the star formation rates in these interesting galaxies. We performed photometry on the five Herschel bands (100-500μm), and removed any contamination from other cluster members. We fit a UV-FIR SED to each galaxy to measure the bolometric dust luminosity (Lbol), which we use to derive the FIR obscured SFR. We calculate the sum of the measured UV unobscured SFR from the HST photometry and the FIR obscured SFR from the Herschel photometry to get a total SFR for these two BCGs. We compared this to the reddening-corrected SFRs and found they were in agreement within error. This confirms that the Kennicutt and Calzetti methods for calculating star formation rates are both applicable for these highly star-forming massive cluster galaxies.

  9. Antecedents to Fechner's law: the astronomers J. Herschel, W. R. Dawes, and N. R. Pogson

    PubMed Central

    Pliskoff, Stanley S.

    1977-01-01

    The history of the stellar magnitude scale is briefly traced from the second century b.c. until the middle of the nineteenth century. It becomes clear that astronomers formulated “Fechner's Law” by about 1850. While Fechner is credited with the grander view of things, the contention is made that the astronomers John Herschel, W. R. Dawes, and N. R. Pogson have not been given their due by historians of psychology. PMID:16812026

  10. Star formation in z > 1 3CR host galaxies as seen by Herschel

    NASA Astrophysics Data System (ADS)

    Podigachoski, P.; Barthel, P. D.; Haas, M.; Leipski, C.; Wilkes, B.; Kuraszkiewicz, J.; Westhues, C.; Willner, S. P.; Ashby, M. L. N.; Chini, R.; Clements, D. L.; Fazio, G. G.; Labiano, A.; Lawrence, C.; Meisenheimer, K.; Peletier, R. F.; Siebenmorgen, R.; Verdoes Kleijn, G.

    2015-03-01

    We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z> 1 3CR sources, from the Herschel guaranteed time project The Herschel Legacy of distant radio-loud AGN. Combining these with existing Spitzer photometric data, we perform an infrared (IR) spectral energy distribution (SED) analysis of these landmark objects in extragalactic research to study the star formation in the hosts of some of the brightest active galactic nuclei (AGN) known at any epoch. Accounting for the contribution from an AGN-powered warm dust component to the IR SED, about 40% of our objects undergo episodes of prodigious, ULIRG-strength star formation, with rates of hundreds of solar masses per year, coeval with the growth of the central supermassive black hole. Median SEDs imply that the quasar and radio galaxy hosts have similar FIR properties, in agreement with the orientation-based unification for radio-loud AGN. The star-forming properties of the AGN hosts are similar to those of the general population of equally massive non-AGN galaxies at comparable redshifts, thus there is no strong evidence of universal quenching of star formation (negative feedback) within this sample. Massive galaxies at high redshift may be forming stars prodigiously, regardless of whether their supermassive black holes are accreting or not. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables 1, 2, 4 and Appendices are available in electronic form at http://www.aanda.org

  11. Results from the Herschel Gould Belt Survey in the Ophiuchus Main Cloud

    NASA Astrophysics Data System (ADS)

    Ladjelate, Bilal; André, Philippe; Könyves, Vera; Men'shchikov, Alexander

    2015-08-01

    Results from the Herschel Gould Belt Survey in the Ophiuchus Main CloudThe Ophiuchus Molecular Cloud is a well documented star-forming cloud located ~140 pc from the Sun. It is therefore an excellent laboratory for dense core search and classification. Harbouring low-mass star formation, its protostellar population have been studied for about three decades from the near infrared to the millimeter and radio range.As part of the Herschel Gould Belt Survey (http://www.herschel.fr/cea/gouldbelt/), extensive submillimeter images of the Ophiuchus Main Cloud (L1688) were produced and a deep census of both prestellar cores and young protostars was obtained using the multi-scale, multi-wavelength source extraction algorithm, getsources (Mensh'chikov et al. 2012).About 300 starless cores were extracted, including ~100 candidates gravitationally bound prestellar cores. The prestellar cores are primarily found in high column density filamentary structures above AV~7. Based on these data we discuss, the properties of the prestellar core mass function (CMF) as well as its variations in the various clumps of the cloud. The peak of the prestellar CMF appears to be close to 0.3 Solar masses in L1688.Conceptually, the low-mass end of the prestellar CMF is populated by pre-brown dwarf cores, the prototype of which is Oph-B11, a 20 Jovian masses object identified with SCUBA and IRAM (Greaves et al. 2003, André et al. 2012). Our Herschel census of dense cores in L1688 contains a few other candidate ultra low-mass cores under the hydrogen-burning limit (0.08 M⊙) which will be discussed.

  12. Temporal stereophotogrammetric analysis of retrogressive thaw slumps on Herschel Island, Yukon Territory

    NASA Astrophysics Data System (ADS)

    Lantuit, H.; Pollard, W. H.

    2005-05-01

    The western Canadian Arctic is identified as an area of potentially significant global warming. Thawing permafrost, sea level rise, changing sea ice conditions and increased wave activity will result in accelerated rates of coastal erosion and thermokarst activity in areas of ice-rich permafrost. The Yukon Coastal Plain is widely recognized as one of the most ice-rich and thaw-sensitive areas in the Canadian Arctic. In particular, Herschel Island displays extensive coastal thermokarst. Retrogressive thaw slumps are a common thermokarst landform along the Herschel Island coast that have been increasing in both frequency and extent have in recent years due to increased thawing of massive ground ice and coastal erosion. The volume of sediment and ground ice eroded by retrogressive slump activity and the potential release of climate change related materials like organic carbon, carbon dioxide and methane are largely unknown. The remote setting of Herschel Island, and the Arctic in general, make direct observation of this type of erosion and the analysis of potential climate feedbacks extremely problematic. Remote sensing provides possibly the best solution to this problem. This study looks at two retrogressive thaw slumps located on the western shore of Herschel Island and using stereophotogrammetric methods attempts to (1) develop the first three-dimensional geomorphic analysis of this type of landform, and (2) provide an estimation of the volume of sediment/ground ice eroded through back wasting thermokarst activity. Digital Elevation Models were extracted for the years 1952, 1970 and 2004 and validated using data collected in the field using Kinematic Differential Global Positioning System. Estimates of sediment volumes eroded from retrogressive thaw slumps were found to vary greatly. In one case the total volume of material lost for the 1970-2004 period was approximately 1560000m3. The estimated volume of sediment alone was 360000m3. The temporal analysis of the

  13. VizieR Online Data Catalog: Herschel far-IR counterparts of SDSS galaxies (Dominguez+, 2014)

    NASA Astrophysics Data System (ADS)

    Dominguez Sanchez, H.; Bongiovanni, A.; Lara-Lopez, M. A.; Oteo, I.; Cepa, J.; Perez Garcia, A. M.; Sanchez-Portal, M.; Ederoclite, A.; Lutz, D.; Cresci, G.; Delvecchio, I.; Berta, S.; Magnelli, B.; Popesso, P.; Pozzi, F.; Riguccini, L.

    2015-01-01

    In this paper, we present results for galaxies from the SDSS-DR7, with a counterpart from the PEP (Lutz et al., 2011, Cat. J/A+A/532/A90) Herschel survey in two different fields: the COSMOS field (Scoville et al. 2007ApJS..172....1S) and the Lockman Hole (LH hereafter; Lockman, Jahoda & McCammon 1986ApJ...302..432L). (1 data file).

  14. New HErschel Multi-wavelength Extragalactic Survey of Edge-on Spirals (NHEMESES)

    NASA Astrophysics Data System (ADS)

    Holwerda, B. W.; Bianchi, S.; Baes, M.; de Jong, R. S.; Dalcanton, J. J.; Radburn-Smith, D.; Gordon, K.; Xilouris, M.

    2012-08-01

    Edge-on spiral galaxies offer a unique perspective on the vertical structure of spiral disks, both stars and the iconic dark dustlanes. The thickness of these dustlanes can now be resolved for the first time with Herschel in far-infrared and sub-mm emission. We present NHEMESES, an ongoing project that targets 12 edge-on spiral galaxies with the PACS and SPIRE instruments on Herschel. These vertically resolved observations of edge-on spirals will impact on several current topics. First and foremost, these Herschel observations will settle whether or not there is a phase change in the vertical structure of the ISM with disk mass. Previously, a dramatic change in dustlane morphology was observed as in massive disks the dust collapses into a thin lane. If this is the case, the vertical balance between turbulence and gravity dictates the ISM structure and consequently star-formation and related phenomena (spiral arms, bars etc.). We specifically target lower mass nearby edge-ons to complement existing Herschel observations of high-mass edge-on spirals (the HEROES project). Secondly, the combined data-set, together with existing Spitzer observations, will drive a new generation of spiral disk Spectral Energy Distribution models. These model how dust reprocesses starlight to thermal emission but the dust geometry remains the critical unknown. And thirdly, the observations will provide an accurate and unbiased census of the cold dusty structures occasionally seen extending out of the plane of the disk, when backlit by the stellar disk. To illustrate the NHEMESES project, we present early results on NGC 4244 and NGC 891, two well studies examples of a low and high-mass edge-on spiral.

  15. Evolution of interstellar dust with Herschel. First results in the photodissociation regions of NGC 7023

    NASA Astrophysics Data System (ADS)

    Abergel, A.; Arab, H.; Compiègne, M.; Kirk, J. M.; Ade, P.; Anderson, L. D.; André, P.; Baluteau, J.-P.; Bernard, J.-P.; Blagrave, K.; Bontemps, S.; Boulanger, F.; Cohen, M.; Cox, P.; Dartois, E.; Davis, G.; Emery, R.; Fulton, T.; Gry, C.; Habart, E.; Huang, M.; Joblin, C.; Jones, S. C.; Lagache, G.; Lim, T.; Madden, S.; Makiwa, G.; Martin, P.; Miville-Deschênes, M.-A.; Molinari, S.; Moseley, H.; Motte, F.; Naylor, D.; Okumura, K.; Pinheiro Gonçalves, D.; Polehampton, E.; Rodon, J.; Russeil, D.; Saraceno, P.; Sauvage, M.; Sidher, S.; Spencer, L.; Swinyard, B.; Ward-Thompson, D.; White, G. J.; Zavagno, A.

    2010-07-01

    Context. In photodissociation regions (PDRs), the physical conditions and the excitation evolve on short spatial scales as a function of depth within the cloud, providing a unique opportunity to study how the dust and gas populations evolve with the excitation and physical conditions. The mapping of the PDRs in NGC 7023 performed during the science demonstration phase of Herschel is part of the “Evolution of interstellar dust” key program. The goal of this project is to build a coherent database on interstellar dust emission from diffuse clouds to the sites of star formation. Aims: We study the far-infrared/submillimeter emission of the PDRs and their fainter surrounding regions. We combine the Herschel and Spitzer maps to derive at each position the full emission spectrum of all dust components, which we compare to dust and radiative transfer models in order to learn about the spatial variations in both the excitation conditions and the dust properties. Methods: We adjust the emission spectra derived from PACS and SPIRE maps using modified black bodies to derive the temperature and the emissivity index β of the dust in thermal equilibrium with the radiation field. We present a first modeling of the NGC 7023-E PDR with standard dust properties and abundances. Results: At the peak positions, a value of β equal to 2 is compatible with the data. The detected spectra and the spatial structures are strongly influenced by radiative transfer effects. We are able to reproduce the spectra at the peak positions deduced from Herschel maps and emitted by dust particles at thermal equilibrium, and also the evolution of the spatial structures observed from the near infrared to the submillimeter. On the other hand, the emission of the stochastically heated smaller particles is overestimated by a factor ~2. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  16. A COOL DUST FACTORY IN THE CRAB NEBULA: A HERSCHEL STUDY OF THE FILAMENTS

    SciTech Connect

    Gomez, H. L.; Clark, C. J. R.; Gomez, E. L.; Gear, W. K.; Krause, O.; Besel, M.-A.; Bouwman, J.; Henning, Th.; Barlow, M. J.; Swinyard, B. M.; Owen, P. J.; Matsuura, M.; Rho, J.; Ivison, R. J.; Sibthorpe, B.; Polehampton, E. T.

    2012-11-20

    Whether supernovae are major sources of dust in galaxies is a long-standing debate. We present infrared and submillimeter photometry and spectroscopy from the Herschel Space Observatory of the Crab Nebula between 51 and 670 {mu}m as part of the Mass Loss from Evolved StarS program. We compare the emission detected with Herschel with multiwavelength data including millimeter, radio, mid-infrared, and archive optical images. We carefully remove the synchrotron component using the Herschel and Planck fluxes measured in the same epoch. The contribution from line emission is removed using Herschel spectroscopy combined with Infrared Space Observatory archive data. Several forbidden lines of carbon, oxygen, and nitrogen are detected where multiple velocity components are resolved, deduced to be from the nitrogen-depleted, carbon-rich ejecta. No spectral lines are detected in the SPIRE wavebands; in the PACS bands, the line contribution is 5% and 10% at 70 and 100 {mu}m and negligible at 160 {mu}m. After subtracting the synchrotron and line emission, the remaining far-infrared continuum can be fit with two dust components. Assuming standard interstellar silicates, the mass of the cooler component is 0.24{sup +0.32} {sub -0.08} M {sub Sun} for T = 28.1{sup +5.5} {sub -3.2} K. Amorphous carbon grains require 0.11 {+-} 0.01 M {sub Sun} of dust with T = 33.8{sup +2.3} {sub -1.8} K. A single temperature modified blackbody with 0.14 M {sub Sun} and 0.08 M {sub Sun} for silicate and carbon dust, respectively, provides an adequate fit to the far-infrared region of the spectral energy distribution but is a poor fit at 24-500 {mu}m. The Crab Nebula has condensed most of the relevant refractory elements into dust, suggesting the formation of dust in core-collapse supernova ejecta is efficient.

  17. Herschel-Resolved Outer Belts of Two-Belt Debris Disks--Evidence of Icy Grains

    NASA Astrophysics Data System (ADS)

    Morales, Farisa Y.; Bryden, Geoffrey; Werner, Michael W.; Stapelfeldt, Karl

    2015-12-01

    We present dual-band Herschel/PACS imaging for 57 main sequence stars (42 A-type and 15 solar-type) with previously known warm dust (Twarm ~200K) detected and characterized by Spitzer. About half of the star-disk systems in our sample have spectral energy distributions (SEDs) that suggest two-ring disk architectures that mirror that of the asteroid-Kuiper belt geometry of our own solar system. The Herschel observations at 70 and/or 100 micron spatially resolve the cold/outer dust component for 18 two-belt debris systems (15 for the first time; 10 are also resolved at 160 micron), finding evidence of planetesimals at >100 AU, i.e. larger size than assumed from a simple blackbody fit to the SED. By breaking the degeneracy between the grain properties and the dust's radial location, the resolved images help constrain the grain size distribution and hint at the dust's composition for each system. Based on the combined Spitzer/IRS+MIPS (5 to 70 micron), the Herschel/PACS (70 and/or 100 and 160 micron) dataset, and under the assumption of idealized spherical grains, we find that the majority of resolved cold/outer belts of star+disk systems are well fit with a mixed ice/rock composition, rather than pure rocky grains. In the absence of spectral features for ice, we find that the behavior of the continuum can help constrain the composition of the grains well (of icy nature and not pure rocky material) given the Herschel-resolved locations of the cold/outer dust belts. We have also begin to identify the presence of candidate companions via Keck direct imaging, which may be interacting with the observed dust.

  18. Herschel Far-IR Observations of the Giant H II Region NGC 3603

    NASA Astrophysics Data System (ADS)

    Di Cecco, Alessandra; Faustini, Fabiana; Paresce, Francesco; Correnti, Matteo; Calzoletti, Luca

    2015-01-01

    We observed the giant H II region around the NGC 3603 YC with the five broad bands (70, 160, 250, 350, 500 μm) of the SPIRE and PACS instruments, on board the Herschel Space Observatory. Together with what is currently known of the stellar, atomic, molecular, and warm dust components, this additional and crucial information should allow us to better understand the details of the star-formation history in this region. The main objective of the investigation is to study, at high spatial resolution, the distribution and main physical characteristics of the cold dust. By reconstructing the temperature and density maps, we found, respectively, a mean value of 36 K and log10 N H = 22.0 ± 0.1 cm-2. We carried out a photometric analysis detecting 107 point-like sources, mostly confined to the north and south of the cluster. By comparing our data with spectral energy distribution models, we found that 35 sources are well represented by young stellar objects in early evolutionary phases, from Class 0 to Class I. The Herschel detections also provided far-IR counterparts for 4 H2O masers and 11 objects previously known from mid-IR observations. The existence of so many embedded sources confirms the hypothesis of intense and ongoing star-formation activity in the region around NGC 3603 YC. Herschel is an ESA space observatory with science instruments provided by European-led principal investigator consortia and with important participation from NASA.

  19. Recent Star Formation in the Lupus Clouds as Seen by Herschel

    NASA Astrophysics Data System (ADS)

    Rygl, Kazi L. J.; Benedettini, Milena

    We present a study of the star formation histories of the Lupus I, III, and IV clouds using the Herschel 70-500 μm maps obtained by the Herschel Gould Belt Survey Key-Project. By combining the new Herschel data with the existing Spitzer catalog we obtained an unprecedented census of prestellar sources and young stellar objects in the Lupus clouds, which allowed us to study the overall star formation rate (SFR) and efficiency (SFE). The high SFE of Lupus III and its decreasing SFR suggest that Lupus III is the most evolved cloud, that after having experienced a major star formation event, is now approaching the end of its current star-forming cycle. Lupus I is currently undergoing a large star formation event, apparent by the increasing SFR. Also Lupus IV has an increasing SFR, however, the relative number of prestellar sources is much lower than in Lupus I, suggesting that its star formation has not yet reached its peak.

  20. LENS MODELS OF HERSCHEL-SELECTED GALAXIES FROM HIGH-RESOLUTION NEAR-IR OBSERVATIONS

    SciTech Connect

    Calanog, J. A.; Cooray, A.; Ma, B.; Casey, C. M.; Fu, Hai; Wardlow, J.; Amber, S.; Baker, A. J.; Baes, M.; Bock, J.; Bourne, N.; Dye, S.; Bussmann, R. S.; Chapman, S. C.; Clements, D. L.; Conley, A.; Dannerbauer, H.; Dunne, L.; Eales, S.; and others

    2014-12-20

    We present Keck-Adaptive Optics and Hubble Space Telescope high resolution near-infrared (IR) imaging for 500 μm bright candidate lensing systems identified by the Herschel Multi-tiered Extragalactic Survey and Herschel Astrophysical Terahertz Large Area Survey. Out of 87 candidates with near-IR imaging, 15 (∼17%) display clear near-IR lensing morphologies. We present near-IR lens models to reconstruct and recover basic rest-frame optical morphological properties of the background galaxies from 12 new systems. Sources with the largest near-IR magnification factors also tend to be the most compact, consistent with the size bias predicted from simulations and previous lensing models for submillimeter galaxies (SMGs). For four new sources that also have high-resolution submillimeter maps, we test for differential lensing between the stellar and dust components and find that the 880 μm magnification factor (μ{sub 880}) is ∼1.5 times higher than the near-IR magnification factor (μ{sub NIR}), on average. We also find that the stellar emission is ∼2 times more extended in size than dust. The rest-frame optical properties of our sample of Herschel-selected lensed SMGs are consistent with those of unlensed SMGs, which suggests that the two populations are similar.

  1. Properties of interstellar filaments derived from Herschel, Planck, and molecular line observations

    NASA Astrophysics Data System (ADS)

    Arzoumanian, Doris

    2015-08-01

    The highly filamentary structure of the interstellar medium (ISM) is now impressively revealed by Herschel and Planck images. Previous observations have shown that clouds are filamentary, however, only recently the mapping capabilities of Herscheland Planck have discovered their ubiquity in the ISM. In particular, Herschel images, with their high spatial and intensity dynamic ranges, show that dense filaments are associated with the main sites of star formation, demonstrating their key role in the star formation process.The analysis of the column density profiles of filaments indicates that they all share a common central width of 0.1pc, while they span a wide range in length, column density, mass per unit length. The results derived from observations tracing cold dust and gas emission, in total and polarised intensity, suggest that filaments can be divided into two families: On the one hand, low column density, unbound, and quiescent filaments mostly aligned with the magnetic field orientation, and on the other hand, dense, self-gravitating filaments, which fragment into star forming cores.I will present the properties of the filamentary structures derived from Herschel, Planck, and molecular line observations, and I will discuss the observational constraints on the formation and evolution of interstellar filaments.

  2. HERSCHEL AND SPITZER OBSERVATIONS OF SLOWLY ROTATING, NEARBY ISOLATED NEUTRON STARS

    SciTech Connect

    Posselt, B.; Pavlov, G. G.; Popov, S.; Wachter, S.

    2014-11-01

    Supernova fallback disks around neutron stars have been suspected to influence the evolution of the diverse neutron star populations. Slowly rotating neutron stars are the most promising places to find such disks. Searching for the cold and warm debris of old fallback disks, we carried out Herschel PACS (70 μm, 160 mu m) and Spitzer IRAC (3.6 μm, 4.5 μm) observations of eight slowly rotating (P ≈ 3-11 s) nearby (<1 kpc) isolated neutron stars. Herschel detected 160 μm emission (>5σ) at locations consistent with the positions of the neutron stars RX J0806.4-4123 and RX J2143.0+0654. No other significant infrared emission was detected from the eight neutron stars. We estimate probabilities of 63%, 33%, and 3% that, respectively, none, one, or both Herschel PACS 160 μm detections are unrelated excess sources due to background source confusion or an interstellar cirrus. If the 160 μm emission is indeed related to cold (10-22 K) dust around the neutron stars, this dust is absorbing and re-emitting ∼10% to ∼20% of the neutron stars' X-rays. Such high efficiencies would be at least three orders of magnitude larger than the efficiencies of debris disks around nondegenerate stars. While thin dusty disks around the neutron stars can be excluded as counterparts of the 160 μm emission, dusty asteroid belts constitute a viable option.

  3. HERSCHEL FAR-INFRARED AND SUBMILLIMETER PHOTOMETRY FOR THE KINGFISH SAMPLE OF NEARBY GALAXIES

    SciTech Connect

    Dale, D. A.; Aniano, G.; Draine, B. T.; Engelbracht, C. W.; Hinz, J. L.; Montiel, E. J.; Krause, O.; Groves, B. A.; Roussel, H.; Appleton, P. N.; Armus, L.; Beirao, P.; Bolatto, A. D.; Brandl, B. R.; Calzetti, D.; Crocker, A. F.; Croxall, K. V.; Galametz, M.; Gordon, K. D.; Hao, C.-N.; and others

    2012-01-20

    New far-infrared and submillimeter photometry from the Herschel Space Observatory is presented for 61 nearby galaxies from the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel (KINGFISH) sample. The spatially integrated fluxes are largely consistent with expectations based on Spitzer far-infrared photometry and extrapolations to longer wavelengths using popular dust emission models. Dwarf irregular galaxies are notable exceptions, as already noted by other authors, as their 500 {mu}m emission shows evidence for a submillimeter excess. In addition, the fraction of dust heating attributed to intense radiation fields associated with photodissociation regions is found to be (21 {+-} 4)% larger when Herschel data are included in the analysis. Dust masses obtained from the dust emission models of Draine and Li are found to be on average nearly a factor of two higher than those based on single-temperature modified blackbodies, as single blackbody curves do not capture the full range of dust temperatures inherent to any galaxy. The discrepancy is largest for galaxies exhibiting the coolest far-infrared colors.

  4. Herschel and Spitzer Observations of Slowly Rotating, Nearby Isolated Neutron Stars

    NASA Astrophysics Data System (ADS)

    Posselt, B.; Pavlov, G. G.; Popov, S.; Wachter, S.

    2014-11-01

    Supernova fallback disks around neutron stars have been suspected to influence the evolution of the diverse neutron star populations. Slowly rotating neutron stars are the most promising places to find such disks. Searching for the cold and warm debris of old fallback disks, we carried out Herschel PACS (70 μm, 160 μm) and Spitzer IRAC (3.6 μm, 4.5 μm) observations of eight slowly rotating (P ≈ 3-11 s) nearby (<1 kpc) isolated neutron stars. Herschel detected 160 μm emission (>5σ) at locations consistent with the positions of the neutron stars RX J0806.4-4123 and RX J2143.0+0654. No other significant infrared emission was detected from the eight neutron stars. We estimate probabilities of 63%, 33%, and 3% that, respectively, none, one, or both Herschel PACS 160 μm detections are unrelated excess sources due to background source confusion or an interstellar cirrus. If the 160 μm emission is indeed related to cold (10-22 K) dust around the neutron stars, this dust is absorbing and re-emitting ~10% to ~20% of the neutron stars' X-rays. Such high efficiencies would be at least three orders of magnitude larger than the efficiencies of debris disks around nondegenerate stars. While thin dusty disks around the neutron stars can be excluded as counterparts of the 160 μm emission, dusty asteroid belts constitute a viable option.

  5. Report of Some Comets: The Discovery of Uranus and Comets by William, Caroline, and John Herschel

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.; Olson, R. J. M.

    2011-01-01

    We report on the discovery and drawings of comets by William, Caroline, and John Herschel. The first discovery, by William Herschel, in 1781 from Bath, published in the Philosophical Transactions of the Royal Society with the title "Report of a Comet," turned out to be Uranus, the first planet ever discovered, Mercury through Saturn having been known since antiquity. William's sister Caroline was given duties of sweeping the skies and turned out to be a discoverer of 8 comets in her own right, in addition to keeping William's notes. Caroline's comets were discovered from Slough between 1786 and 1797. In the process, we also discuss original documents from the archives of the Royal Society and of the Royal Astronomical Society. We conclude by showing comet drawings that we have recently attributed to John Herschel, including Halley's Comet from 1836, recently located in the Ransom Center of the University of Texas at Austin. Acknowledgments: Planetary astronomy at Williams College is supported in part by grant NNX08AO50G from NASA Planetary Astronomy. We thank Peter Hingley of the Royal Astronomical Society and Richard Oram of the Harry Ransom Center of The University of Texas at Austin for their assistance.

  6. Herschel far-infrared observations of the Carina Nebula complex - The embedded young stellar and protostellar population

    NASA Astrophysics Data System (ADS)

    Gaczkowski, Benjamin; Preibisch, Thomas; Ratzka, Thorsten; Roccatagliata, Veronica; Ohlendorf, Henrike; Pekruhl, Stephanie

    2013-07-01

    At a distance of 2.3 kpc, the Carina Nebula is the nearest southern region with a large enough massive stellar population to sample the top of the IMF and displays all phenomena of massive star formation. We have performed a 9 square-degree Herschel far-infrared survey of the Carina Nebula complex (CNC) which revealed, for the first time, the very complex and filamentary small-scale structure of the dense clouds. We discovered 642 objects that are independently detected as point-like sources in at least two of the five Herschel bands. About 75% of these are Class 0 protostars with masses between about one and ten solar masses estimated from radiative transfer modeling. Taking the observational limits into account and extrapolating the observed number of Herschel-detected protostars over the stellar initial mass function suggests that the star formation rate of the CNC is about 0.017 solar masses per year. The spatial distribution of the Herschel young stellar objects (YSO) candidates is highly inhomogeneous and does not follow the distribution of cloud mass. Rather, most Herschel YSO candidates are found at the irradiated edges of clouds and pillars. The currently ongoing star formation process forms only low-mass and intermediate-mass stars, but no massive stars. The characteristic spatial configuration of the YSOs provides support to the picture that the formation of this latest stellar generation is triggered by the advancing ionization fronts. Around the bubble-shaped HII region Gum 31 (containing the young stellar cluster NGC 3324) in the north-western part of the CNC we identified 752 candidate YSOs from Spitzer, WISE, and Herschel data and analyzed their spectral energy distributions. Their location in the rim of the bubble is suggestive of their being triggered by a 'collect and collapse' scenario, which agrees well with the observed parameters of the region which we obtained from density and temperature maps from our Herschel data.

  7. Imaging Fourier Transform Spectroscopy from a Space Based Platform -- The Herschel/SPIRE Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Spencer, Locke Dean

    The Herschel Space Observatory (Herschel), a flagship mission of the European Space Agency (ESA), is comprised of three cryogenically cooled instruments commissioned to explore the far-infrared/submillimetre universe. Herschel's remote orbit at the second Lagrangian point (L2) of the Sun-Earth system, and its cryogenic payload, impose a need for thorough instrument characterization and rigorous testing as there will be no possibility for any servicing after launch. The Spectral and Photometric Imaging Receiver (SPIRE) is one of the instrument payloads aboard Herschel and consists of a three band imaging photometer and a two band imaging spectrometer. The imaging spectrometer on SPIRE consists of a Mach-Zehnder (MZ)-Fourier transform spectrometer (FTS) coupled with bolometric detector arrays to form an imaging FTS (IFTS). This thesis presents experiments conducted to verify the performance of an IFTS system from a space based platform, Le. the use of the SPIRE IFTS within the Herschel space observatory. Prior to launch, the SPIRE instrument has undergone a series of performance verification tests conducted at the Rutherford Appleton Laboratory (RAL) near Oxford, UK. Canada is involved in the SPIRE project through provision of instrument development hardware and software, mission flight software, and support personnel. Through this thesis project I have been stationed at RAL for a period spanning fifteen months to participate in the development, performance verification, and characterization of both the SPIRE FTS and photometer instruments. This thesis discusses Fourier transform spectroscopy and related FTS data processing (Chapter 2). Detailed discussions are included on the spectral phase related to the FTS beamsplitter (Chapter 3), the imaging aspects of the SPIRE IFTS instrument (Chapter 4), and the noise characteristics of the SPIRE bolometer detector arrays as measured using the SPIRE IFTS (Chapter 5). This thesis presents results from experiments performed

  8. A Cool Dust Factory in the Crab Nebula: A Herschel Study of the Filaments

    NASA Astrophysics Data System (ADS)

    Gomez, H. L.; Krause, O.; Barlow, M. J.; Swinyard, B. M.; Owen, P. J.; Clark, C. J. R.; Matsuura, M.; Gomez, E. L.; Rho, J.; Besel, M.-A.; Bouwman, J.; Gear, W. K.; Henning, Th.; Ivison, R. J.; Polehampton, E. T.; Sibthorpe, B.

    2012-11-01

    Whether supernovae are major sources of dust in galaxies is a long-standing debate. We present infrared and submillimeter photometry and spectroscopy from the Herschel Space Observatory of the Crab Nebula between 51 and 670 μm as part of the Mass Loss from Evolved StarS program. We compare the emission detected with Herschel with multiwavelength data including millimeter, radio, mid-infrared, and archive optical images. We carefully remove the synchrotron component using the Herschel and Planck fluxes measured in the same epoch. The contribution from line emission is removed using Herschel spectroscopy combined with Infrared Space Observatory archive data. Several forbidden lines of carbon, oxygen, and nitrogen are detected where multiple velocity components are resolved, deduced to be from the nitrogen-depleted, carbon-rich ejecta. No spectral lines are detected in the SPIRE wavebands; in the PACS bands, the line contribution is 5% and 10% at 70 and 100 μm and negligible at 160 μm. After subtracting the synchrotron and line emission, the remaining far-infrared continuum can be fit with two dust components. Assuming standard interstellar silicates, the mass of the cooler component is 0.24+0.32 - 0.08 M ⊙ for T = 28.1+5.5 - 3.2 K. Amorphous carbon grains require 0.11 ± 0.01 M ⊙ of dust with T = 33.8+2.3 - 1.8 K. A single temperature modified blackbody with 0.14 M ⊙ and 0.08 M ⊙ for silicate and carbon dust, respectively, provides an adequate fit to the far-infrared region of the spectral energy distribution but is a poor fit at 24-500 μm. The Crab Nebula has condensed most of the relevant refractory elements into dust, suggesting the formation of dust in core-collapse supernova ejecta is efficient. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  9. Upper atmosphere pollution measurements (GASP)

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Holdeman, J. D.

    1975-01-01

    The environmental effects are discussed of engine effluents of future large fleets of aircraft operating in the stratosphere. Topics discussed include: atmospheric properties, aircraft engine effluents, upper atmospheric measurements, global air sampling, and data reduction and analysis

  10. HERSCHEL FINDS EVIDENCE FOR STELLAR WIND PARTICLES IN A PROTOSTELLAR ENVELOPE: IS THIS WHAT HAPPENED TO THE YOUNG SUN?

    SciTech Connect

    Ceccarelli, C.; López-Sepulcre, A.; Dominik, C.; Kama, M.; Padovani, M.; Caux, E.; Caselli, P.

    2014-07-20

    There is evidence that the young Sun emitted a high flux of energetic (≥10 MeV) particles. The collisions of these particles with the material at the inner edge of the Protosolar Nebula disk induced spallation reactions that formed short-lived radionuclei, like {sup 10}Be, whose trace is now visible in some meteorites. However, it is poorly known exactly when this happened, and whether and how it affected the solar system. Here, we present indirect evidence for an ejection of energetic particles in the young protostar, OMC-2 FIR 4, similar to that experienced by the young solar system. In this case, the energetic particles collide with the material in the protostellar envelope, enhancing the abundance of two molecular ions, HCO{sup +} and N{sub 2}H{sup +}, whose presence is detected via Herschel observations. The flux of energetic particles at a distance of 1 AU from the emitting source, estimated from the measured abundance ratio of HCO{sup +} and N{sub 2}H{sup +}, can easily account for the irradiation required by meteoritic observations. These new observations demonstrate that the ejection of ≥10 MeV particles is a phenomenon occurring very early in the life of a protostar, before the disappearance of the envelope from which the future star accretes. The whole envelope is affected by the event, which sets constraints on the magnetic field geometry in the source and opens up the possibility that the spallation reactions are not limited to the inner edge of the Protosolar Nebula disk.

  11. TNOs are cool: A survey of the trans-Neptunian region. V. Physical characterization of 18 Plutinos using Herschel-PACS observations

    NASA Astrophysics Data System (ADS)

    Mommert, M.; Harris, A. W.; Kiss, C.; Pál, A.; Santos-Sanz, P.; Stansberry, J.; Delsanti, A.; Vilenius, E.; Müller, T. G.; Peixinho, N.; Lellouch, E.; Szalai, N.; Henry, F.; Duffard, R.; Fornasier, S.; Hartogh, P.; Mueller, M.; Ortiz, J. L.; Protopapa, S.; Rengel, M.; Thirouin, A.

    2012-05-01

    Context. The Herschel open time key programme TNOs are Cool: A survey of the trans-Neptunian region aims to derive physical and thermal properties for a set of ~140 Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. One goal of the project is to determine albedo and size distributions for specific classes and the overall population of TNOs. Aims: We present Herschel-PACS photometry of 18 Plutinos and determine sizes and albedos for these objects using thermal modeling. We analyze our results for correlations, draw conclusions on the Plutino size distribution, and compare to earlier results. Methods: Flux densities are derived from PACS mini scan-maps using specialized data reduction and photometry methods. In order to improve the quality of our results, we combine our PACS data with existing Spitzer MIPS data where possible, and refine existing absolute magnitudes for the targets. The physical characterization of our sample is done using a thermal model. Uncertainties of the physical parameters are derived using customized Monte Carlo methods. The correlation analysis is performed using a bootstrap Spearman rank analysis. Results: We find the sizes of our Plutinos to range from 150 to 730 km and geometric albedos to vary between 0.04 and 0.28. The average albedo of the sample is 0.08 ± 0.03, which is comparable to the mean albedo of Centaurs, Jupiter family comets and other TNOs. We were able to calibrate the Plutino size scale for the first time and find the cumulative Plutino size distribution to be best fit using a cumulative power law with q = 2 at sizes ranging from 120-400 km and q = 3 at larger sizes. We revise the bulk density of 1999 TC36 and find ρ = 0.64-0.11+0.15 g cm-3. On the basis of a modified Spearman rank analysis technique our Plutino sample appears to be biased with respect to object size but unbiased with respect to albedo. Furthermore, we find biases based on geometrical aspects

  12. Herschel HIFI observations of the Sgr A +50 km s-1 Cloud. Deep searches for O2 in emission and foreground absorption

    NASA Astrophysics Data System (ADS)

    Sandqvist, Aa.; Larsson, B.; Hjalmarson, Å.; Encrenaz, P.; Gerin, M.; Goldsmith, P. F.; Lis, D. C.; Liseau, R.; Pagani, L.; Roueff, E.; Viti, S.

    2015-12-01

    Context. The Herschel Oxygen Project (HOP) is an open time key program, awarded 140 h of observing time to search for molecular oxygen (O2) in a number of interstellar sources. To date O2 has definitely been detected in only two sources, namely ρ Oph A and Orion, reflecting the extremely low abundance of O2 in the interstellar medium. Aims: One of the sources in the HOP program is the +50 km s-1 Cloud in the Sgr A Complex in the centre of the Milky Way. Its environment is unique in the Galaxy and this property is investigated to see if it is conducive to the presence of O2. Methods: The Herschel Heterodyne Instrument for the Far Infrared (HIFI) is used to search for the 487 and 774 GHz emission lines of O2. Results: No O2 emission is detected towards the Sgr A +50 km s-1 Cloud, but a number of strong emission lines of methanol (CH3OH) and absorption lines of chloronium (H2Cl+) are observed. Conclusions: A 3σ upper limit for the fractional abundance ratio of [O2]/[H2] in the Sgr A +50 km s-1 Cloud is found to be X(O2) ≤ 5 × 10-8. However, since we can find no other realistic molecular candidate than O2 itself, we very tentatively suggest that two weak absorption lines at 487.261 and 487.302 GHz may be caused by the 487 GHz line of O2 in two foreground spiral arm clouds. By considering that the absorption may only be apparent, the estimated upper limit to the O2 abundance of ≤ (10-20) × 10-6 in these foreground clouds is very high, as opposed to the upper limit in the Sgr A +50 km s-1 Cloud itself, but similar to what has been reached in recent chemical shock models for Orion. This abundance limit was determined also using Odin non-detection limits, and assumes that O2 fills the beam. If the absorption is due to a differential Herschel OFF-ON emission, the O2 fractional abundance may be of the order of ≈ (5-10) × 10-6. With the assumption of pure absorption by foreground clouds, the unreasonably high abundance of (1.4-2.8) × 10-4 was obtained. The

  13. HERschel key program heritage: A far-infrared source catalog for the Magellanic Clouds

    SciTech Connect

    Seale, Jonathan P.; Meixner, Margaret; Sewiło, Marta; Babler, Brian; Engelbracht, Charles W.; Misselt, Karl; Montiel, Edward; Gordon, Karl; Roman-Duval, Julia; Hony, Sacha; Okumura, Koryo; Panuzzo, Pasquale; Sauvage, Marc; Chen, C.-H. Rosie; Indebetouw, Remy; Matsuura, Mikako; Oliveira, Joana M.; Loon, Jacco Th. van; Srinivasan, Sundar; and others

    2014-12-01

    Observations from the HERschel Inventory of the Agents of Galaxy Evolution (HERITAGE) have been used to identify dusty populations of sources in the Large and Small Magellanic Clouds (LMC and SMC). We conducted the study using the HERITAGE catalogs of point sources available from the Herschel Science Center from both the Photodetector Array Camera and Spectrometer (PACS; 100 and 160 μm) and Spectral and Photometric Imaging Receiver (SPIRE; 250, 350, and 500 μm) cameras. These catalogs are matched to each other to create a Herschel band-merged catalog and then further matched to archival Spitzer IRAC and MIPS catalogs from the Spitzer Surveying the Agents of Galaxy Evolution (SAGE) and SAGE-SMC surveys to create single mid- to far-infrared (far-IR) point source catalogs that span the wavelength range from 3.6 to 500 μm. There are 35,322 unique sources in the LMC and 7503 in the SMC. To be bright in the FIR, a source must be very dusty, and so the sources in the HERITAGE catalogs represent the dustiest populations of sources. The brightest HERITAGE sources are dominated by young stellar objects (YSOs), and the dimmest by background galaxies. We identify the sources most likely to be background galaxies by first considering their morphology (distant galaxies are point-like at the resolution of Herschel) and then comparing the flux distribution to that of the Herschel Astrophysical Terahertz Large Area Survey (ATLAS) survey of galaxies. We find a total of 9745 background galaxy candidates in the LMC HERITAGE images and 5111 in the SMC images, in agreement with the number predicted by extrapolating from the ATLAS flux distribution. The majority of the Magellanic Cloud-residing sources are either very young, embedded forming stars or dusty clumps of the interstellar medium. Using the presence of 24 μm emission as a tracer of star formation, we identify 3518 YSO candidates in the LMC and 663 in the SMC. There are far fewer far-IR bright YSOs in the SMC than the LMC

  14. Herschel observations of extended atomic gas in the core of the Perseus cluster

    NASA Astrophysics Data System (ADS)

    Mittal, Rupal; Oonk, J. B. Raymond; Ferland, Gary J.; Edge, Alastair C.; O'Dea, Christopher P.; Baum, Stefi A.; Whelan, John T.; Johnstone, Roderick M.; Combes, Francoise; Salomé, Philippe; Fabian, Andy C.; Tremblay, Grant R.; Donahue, Megan; Russell, Helen

    2012-11-01

    We present Herschel observations of the core of the Perseus cluster of galaxies. Especially intriguing is the network of filaments that surround the brightest cluster galaxy, NGC 1275, previously imaged extensively in Hα and CO. In this work, we report detections of far-infrared (FIR) lines, in particular, [C II] 158, [O I] 63, [N II] 122, [O IB] 145 and [O III] 88 μm, with Herschel. All lines are spatially extended, except [O III], with the [C II] line emission extending up to 25 kpc from the core. [C II] emission is found to be co-spatial with Hα and CO. Furthermore, [C II] shows a similar velocity distribution to CO, which has been shown in previous studies to display a close association with the Hα kinematics. The spatial and kinematical correlation among [C II], Hα and CO gives us confidence to model the different components of the gas with a common heating model. With the help of FIR continuum Herschel measurements, together with a suite of coeval radio, sub-millimetre and IR data from other observatories, we performed a spectral energy distribution fitting of NGC 1275 using a model that contains contributions from dust emission as well as synchrotron active galactic nucleus emission. This has allowed us to accurately estimate the dust parameters. The data indicate a low dust emissivity index, β ≈ 1, a total dust mass close to 107 M⊙, a cold dust component with temperature 38 ± 2 K and a warm dust component with temperature 116 ± 9 K. The FIR-derived star formation rate is 24 ± 1 M⊙ yr-1, which is in agreement with the far-ultraviolet-derived star formation rate in the core, determined after applying corrections for both Galactic and internal reddening. The total IR luminosity in the range 8-1000 μm is inferred to be 1.5 × 1011 L⊙, making NGC 1275 a luminous IR galaxy. We investigated in detail the source of the Herschel FIR and Hα emissions emerging from a core region 4 kpc in radius. Based on simulations conducted using the radiative

  15. Protostars, multiplicity, and disk evolution in the Corona Australis region: a Herschel Gould Belt Study

    NASA Astrophysics Data System (ADS)

    Sicilia-Aguilar, A.; Henning, T.; Linz, H.; André, P.; Stutz, A.; Eiroa, C.; White, G. J.

    2013-03-01

    Context. The CrA region and the Coronet cluster form a nearby (138 pc), young (1-2 Myr) star-forming region that hosts a moderate population of Class I, II, and III objects. Aims: We study the structure of the cluster and the properties of the protostars and protoplanetary disks in the region. Methods: We present Herschel PACS photometry at 100 and 160 μm, obtained as part of the Herschel Gould Belt Survey. The Herschel maps reveal the cluster members within the cloud with high sensitivity and high dynamic range. Results: Many of the cluster members are detected, including some embedded, very low-mass objects, several protostars (some of them extended), and substantial emission from the surrounding molecular cloud. Herschel also reveals some striking structures, such as bright filaments around the IRS 5 protostar complex and a bubble-shaped rim associated with the Class I object IRS 2. The disks around the Class II objects display a wide range of mid- and far-IR excesses consistent with different disk structures. We have modeled the disks with the RADMC radiative transfer code to quantify their properties. Some of them are consistent with flared, massive, relatively primordial disks (S CrA, T CrA). Others display significant evidence for inside-out evolution, consistent with the presence of inner holes/gaps (G-85, G-87). Finally, we found disks with a dramatic small dust depletion (G-1, HBC 677) that, in some cases, could be related to truncation or to the presence of large gaps in a flared disk (CrA-159). The derived masses for the disks around the low-mass stars are found to be below the typical values in Taurus, in agreement with previous Spitzer observations. Conclusions: The Coronet cluster presents itself as an interesting compact region that contains both young protostars and very evolved disks. The Herschel data provide sufficient spatial resolution to detect small-scale details, such as filamentary structures or spiral arms associated with multiple star

  16. Herschel Key Program Heritage: a Far-Infrared Source Catalog for the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Seale, Jonathan P.; Meixner, Margaret; Sewiło, Marta; Babler, Brian; Engelbracht, Charles W.; Gordon, Karl; Hony, Sacha; Misselt, Karl; Montiel, Edward; Okumura, Koryo; Panuzzo, Pasquale; Roman-Duval, Julia; Sauvage, Marc; Boyer, Martha L.; Chen, C.-H. Rosie; Indebetouw, Remy; Matsuura, Mikako; Oliveira, Joana M.; Srinivasan, Sundar; van Loon, Jacco Th.; Whitney, Barbara; Woods, Paul M.

    2014-12-01

    Observations from the HERschel Inventory of the Agents of Galaxy Evolution (HERITAGE) have been used to identify dusty populations of sources in the Large and Small Magellanic Clouds (LMC and SMC). We conducted the study using the HERITAGE catalogs of point sources available from the Herschel Science Center from both the Photodetector Array Camera and Spectrometer (PACS; 100 and 160 μm) and Spectral and Photometric Imaging Receiver (SPIRE; 250, 350, and 500 μm) cameras. These catalogs are matched to each other to create a Herschel band-merged catalog and then further matched to archival Spitzer IRAC and MIPS catalogs from the Spitzer Surveying the Agents of Galaxy Evolution (SAGE) and SAGE-SMC surveys to create single mid- to far-infrared (far-IR) point source catalogs that span the wavelength range from 3.6 to 500 μm. There are 35,322 unique sources in the LMC and 7503 in the SMC. To be bright in the FIR, a source must be very dusty, and so the sources in the HERITAGE catalogs represent the dustiest populations of sources. The brightest HERITAGE sources are dominated by young stellar objects (YSOs), and the dimmest by background galaxies. We identify the sources most likely to be background galaxies by first considering their morphology (distant galaxies are point-like at the resolution of Herschel) and then comparing the flux distribution to that of the Herschel Astrophysical Terahertz Large Area Survey (ATLAS) survey of galaxies. We find a total of 9745 background galaxy candidates in the LMC HERITAGE images and 5111 in the SMC images, in agreement with the number predicted by extrapolating from the ATLAS flux distribution. The majority of the Magellanic Cloud-residing sources are either very young, embedded forming stars or dusty clumps of the interstellar medium. Using the presence of 24 μm emission as a tracer of star formation, we identify 3518 YSO candidates in the LMC and 663 in the SMC. There are far fewer far-IR bright YSOs in the SMC than the LMC

  17. High-J CO Intensity Measurements for Galaxies Observed by the Herschel FTS

    NASA Astrophysics Data System (ADS)

    Kamenetzky, Julia; Rangwala, Naseem; Glenn, Jason; Maloney, Philip; Conley, Alex

    2015-08-01

    Molecular gas is the raw material for star formation and is commonly traced by the carbon monoxide (CO) molecule. The atmosphere blocks all but the lowest-J transitions of CO for observatories on the ground, but the launch of the Herschel Space Observatory revealed the CO emission of nearby galaxies from J=4-3 to J=13-12. Herschel showed that mid- and high-J CO lines in nearby galaxies are emitted from warm gas, accounting for approximately 10% of the molecular mass, but the majority of the CO luminosity. The energy budget of this warm, highly-excited gas is a significant window into the feedback interactions among molecular gas, star formation, and galaxy evolution. Likely, mechanical heating is required to explain the excitation. Such gas has also been observed in star forming regions within our galaxy.We have examined all ~ 300 spectra of galaxies from the Herschel Fourier Transform Spectrometer and measured line fluxes or upper limits for the CO J=4-3 to J=13-12, [CI], and [NII] 205 micron lines in ~ 200 galaxies, taking systematic effects of the FTS into account. We will present our line fitting method, illustrate trends available so far in this large sample, and preview the full 2-component radiative transfer likelihood modeling of the CO emission using an illustrative sample of 20 galaxies, including comparisons to well-resolved galactic regions. This work is a comprehensive study of mid- and high-J CO emission among a variety of galaxy types, and can be used as a resource for future (sub)millimeter studies of galaxies with ground-based instruments.

  18. Insights into the earliest stages of star cluster formationfrom Herschel Gould Belt survey observations

    NASA Astrophysics Data System (ADS)

    André, Philippe; Ladjelate, Bilal; Könyves, Vera

    2015-08-01

    For a long time, the conventional wisdom has been that "clustered star formation" and "isolated (or distributed) star formation" represent two fundamentally distinct modes of the star formation process. Recent detailed infrared studies of the spatial distribution of young stellar objects (YSOs) in the solar neighborhood, however, suggest that there is a continuous distribution of YSO surface densities from a diffuse population to the densest groups or clusters, with no evidence for discrete modes of star formation (e.g. Bressert et al. 2010). Based on the results of the Herschel Gould Belt survey (http://gouldbelt-herschel.cea.fr) toward the nearest regions of "clustered" and "distributed" star formation, including the Ophiuchus and Taurus clouds, we will show how these two seemingly opposing views can be reconciled.The Herschel results point to the key role of the quasi-universal filamentary structure pervading the cold ISM (cf. André et al. 2014, Protostars and Planets VI). Indeed, a large fraction of the dense molecular gas is found to be in the form of filaments and most prestellar cores are located within dense, "supercritical" filaments. To a large extent, therefore, the spatial distribution of YSOs is inherited from the filamentary texture of molecular clouds, which is partly hierarchical and shaped by a combination of turbulent, magnetic, and gravitational effects. Wherever gravity dominates on large scales, a "hub-filament" system develops (cf. Myers 2009) and a protocluster is generated at the "hub" or junction of a converging network of filaments. More distributed star formation occurs along individual filaments with marginally supercritical masses per unit length.

  19. Herschel-PACS imaging of protostars in the HH 1-2 outflow complex

    NASA Astrophysics Data System (ADS)

    Fischer, W. J.; Megeath, S. T.; Ali, B.; Tobin, J. J.; Osorio, M.; Allen, L. E.; Kryukova, E.; Stanke, T.; Stutz, A. M.; Bergin, E.; Calvet, N.; di Francesco, J.; Furlan, E.; Hartmann, L.; Henning, T.; Krause, O.; Manoj, P.; Maret, S.; Muzerolle, J.; Myers, P.; Neufeld, D.; Pontoppidan, K.; Poteet, C. A.; Watson, D. M.; Wilson, T.

    2010-07-01

    We present 70 and 160 μm Herschel science demonstration images of a field in the Orion A molecular cloud that contains the prototypical Herbig-Haro objects HH 1 and 2, obtained with the Photodetector Array Camera and Spectrometer (PACS). These observations demonstrate Herschel's unprecedented ability to study the rich population of protostars in the Orion molecular clouds at the wavelengths where they emit most of their luminosity. The four protostars previously identified by Spitzer 3.6-40 μm imaging and spectroscopy are detected in the 70 μm band, and three are clearly detected at 160 μm. We measure photometry of the protostars in the PACS bands and assemble their spectral energy distributions (SEDs) from 1 to 870 μm with these data, Spitzer spectra and photometry, 2MASS data, and APEX sub-mm data. The SEDs are fit to models generated with radiative transfer codes. From these fits we can constrain the fundamental properties of the protostars. We find luminosities in the range 12-84 L⊙ and envelope densities spanning over two orders of magnitude. This implies that the four protostars have a wide range of envelope infall rates and evolutionary states: two have dense, infalling envelopes, while the other two have only residual envelopes. We also show the highly irregular and filamentary structure of the cold dust and gas surrounding the protostars as traced at 160 μm. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. This work includes data acquired with the Atacama Pathfinder Experiment (APEX; E-082.F-9807, E-284.C-5015). APEX is a collaboration between the Max-Planck-Institut für Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory.Figures 2 and 3 are only available in electronic format at http://www.aanda.org

  20. The Search for Molecular Outflows in Local Volume AGNs with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Stone, M.; Veilleux, S.; Meléndez, M.; Sturm, E.; Graciá-Carpio, J.; González-Alfonso, E.

    2016-08-01

    We present the results from a systematic search for galactic-scale, molecular (OH 119 μm) outflows in a sample of 52 Local Volume (d\\lt 50 Mpc) Burst Alert Telescope detected active galactic nuclei (BAT AGNs) with Herschel-PACS. We combine the results from our analysis of the BAT AGNs with the published Herschel/PACS data of 43 nearby (z\\lt 0.3) galaxy mergers, mostly ultra-luminous infrared galaxies (ULIRGs) and QSOs. The objects in our sample of BAT AGNs have, on average, ˜ 10{--}100 times lower AGN luminosities, star formation rates, and stellar masses than those of the ULIRG and QSO samples. OH 119 μm is detected in 42 of our BAT AGN targets. Evidence for molecular outflows (i.e., OH absorption profiles with median velocities more blueshifted than ‑50 km s‑1 and/or blueshifted wings with 84% velocities less than ‑300 km s‑1) is seen in only four BAT AGNs (NGC 7479 is the most convincing case). Evidence for molecular inflows (i.e., OH absorption profiles with median velocities more redshifted than 50 km s‑1) is seen in seven objects, although an inverted P-Cygni profile is detected unambiguously in only one object (Circinus). Our data show that both the starburst and AGN contribute to driving OH outflows, but the fastest OH winds require AGNs with quasar-like luminosities. We also confirm that the total absorption strength of OH 119 μm is a good proxy for dust optical depth as it correlates strongly with the 9.7 μm silicate absorption feature, a measure of obscuration originating in both the nuclear torus and host galaxy disk. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. Herschel-ATLAS: the surprising diversity of dust-selected galaxies in the local submillimetre Universe

    NASA Astrophysics Data System (ADS)

    Clark, C. J. R.; Dunne, L.; Gomez, H. L.; Maddox, S.; De Vis, P.; Smith, M. W. L.; Eales, S. A.; Baes, M.; Bendo, G. J.; Bourne, N.; Driver, S. P.; Dye, S.; Furlanetto, C.; Grootes, M. W.; Ivison, R. J.; Schofield, S. P.; Robotham, A. S. G.; Rowlands, K.; Valiante, E.; Vlahakis, C.; van der Werf, P.; Wright, A. H.; de Zotti, G.

    2015-09-01

    We present the properties of the first 250 μm blind sample of nearby galaxies (15 < D < 46 Mpc) containing 42 objects from the Herschel Astrophysical Terahertz Large Area Survey. Herschel's sensitivity probes the faint end of the dust luminosity function for the first time, spanning a range of stellar mass (7.4 < M⋆ < 11.3 log10 M⊙), star formation activity (-11.8 < SSFR < -8.9 log10 yr-1), gas fraction (3-96 per cent), and colour (0.6 < FUV-KS < 7.0 mag). The median cold dust temperature is 14.6 K, colder than in the Herschel Reference Survey (18.5 K) and Planck Early Release Compact Source Catalogue (17.7 K). The mean dust-to-stellar mass ratio in our sample is higher than these surveys by factors of 3.7 and 1.8, with a dust mass volume density of (3.7 ± 0.7) × 105 M⊙ Mpc-3. Counter-intuitively, we find that the more dust rich a galaxy, the lower its UV attenuation. Over half of our dust-selected sample are very blue in FUV-KS colour, with irregular and/or highly flocculent morphology; these galaxies account for only 6 per cent of the sample's stellar mass but contain over 35 per cent of the dust mass. They are the most actively star-forming galaxies in the sample, with the highest gas fractions and lowest UV attenuation. They also appear to be in an early stage of converting their gas into stars, providing valuable insights into the chemical evolution of young galaxies.

  2. HerMES: Candidate High-redshift Galaxies Discovered with Herschel/SPIRE

    NASA Astrophysics Data System (ADS)

    Dowell, C. Darren; Conley, A.; Glenn, J.; Arumugam, V.; Asboth, V.; Aussel, H.; Bertoldi, F.; Béthermin, M.; Bock, J.; Boselli, A.; Bridge, C.; Buat, V.; Burgarella, D.; Cabrera-Lavers, A.; Casey, C. M.; Chapman, S. C.; Clements, D. L.; Conversi, L.; Cooray, A.; Dannerbauer, H.; De Bernardis, F.; Ellsworth-Bowers, T. P.; Farrah, D.; Franceschini, A.; Griffin, M.; Gurwell, M. A.; Halpern, M.; Hatziminaoglou, E.; Heinis, S.; Ibar, E.; Ivison, R. J.; Laporte, N.; Marchetti, L.; Martínez-Navajas, P.; Marsden, G.; Morrison, G. E.; Nguyen, H. T.; O'Halloran, B.; Oliver, S. J.; Omont, A.; Page, M. J.; Papageorgiou, A.; Pearson, C. P.; Petitpas, G.; Pérez-Fournon, I.; Pohlen, M.; Riechers, D.; Rigopoulou, D.; Roseboom, I. G.; Rowan-Robinson, M.; Sayers, J.; Schulz, B.; Scott, Douglas; Seymour, N.; Shupe, D. L.; Smith, A. J.; Streblyanska, A.; Symeonidis, M.; Vaccari, M.; Valtchanov, I.; Vieira, J. D.; Viero, M.; Wang, L.; Wardlow, J.; Xu, C. K.; Zemcov, M.

    2014-01-01

    We present a method for selecting z > 4 dusty, star-forming galaxies (DSFGs) using Herschel/Spectral and Photometric Imaging Receiver 250/350/500 μm flux densities to search for red sources. We apply this method to 21 deg2 of data from the HerMES survey to produce a catalog of 38 high-z candidates. Follow-up of the first five of these sources confirms that this method is efficient at selecting high-z DSFGs, with 4/5 at z = 4.3-6.3 (and the remaining source at z = 3.4), and that they are some of the most luminous dusty sources known. Comparison with previous DSFG samples, mostly selected at longer wavelengths (e.g., 850 μm) and in single-band surveys, shows that our method is much more efficient at selecting high-z DSFGs, in the sense that a much larger fraction are at z > 3. Correcting for the selection completeness and purity, we find that the number of bright (S 500 μm >= 30 mJy), red Herschel sources is 3.3 ± 0.8 deg-2. This is much higher than the number predicted by current models, suggesting that the DSFG population extends to higher redshifts than previously believed. If the shape of the luminosity function for high-z DSFGs is similar to that at z ~ 2, rest-frame UV based studies may be missing a significant component of the star formation density at z = 4-6, even after correction for extinction. . Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. OT1_nlu_1: Herschel Spectroscopic Survey of Warm Molecular Gas in Local Luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Lu, N.

    2010-07-01

    We propose to survey CO spectral line energy distribution (SLED), from J=4-3 up to J=13-12, on 93 local luminous infrared galaxies (LIRGs; L_{IR} > 1.0E11 L_{sun}) with Herschel SPIRE FTS spectrometer. These galaxies, plus 32 additional LIRGs that will have similar data from existing Herschel programs (mainly the HerCULES project), form a flux-limited subset of the Great Observatories All-Sky LIRGs Survey (GOALS) sample. Our proposal is built on the legacy of GOALS and extends beyond the existing Herschel HerCULES program, which emphasizes more on ULIRGs, to a much needed sample coverage of the more numerous and diverse population of less luminous LIRGs. The data from the proposed observations will not only provide much needed local LIRG templates for future ALMA studies of high-redshift counterparts, but also lend us a powerful diagnostic tool to probe the warm and dense molecular gas that are more closely related to the starburst or AGN activity in the nuclei of LIRGs. The data from this proposal will provide important statistical clues to the interplay between the cold and warm molecular gas, IR luminosity, star formation rate and efficiency, and the diverse properties of LIRGs. Specifically, using the homogeneous CO SLED data from this proposal, together with ground-base, low-order CO line data (mainly J=1-0) and other data that have been compiled for the GOALS sample, we will address the following questions: (1) What is the dominant nuclear power source in individual sample galaxy: starburst or AGN? (2) What are the typical physical properties of warm molecular gas in the nuclei of LIRGs? (3) How do the nuclear warm gas components correlate to the cold gas component, star formation rate and efficiency, dust temperature, etc? and (4) How does molecular gas excitation change along a merger sequence?

  4. The Search for Molecular Outflows in Local Volume AGNs with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Stone, M.; Veilleux, S.; Meléndez, M.; Sturm, E.; Graciá-Carpio, J.; González-Alfonso, E.

    2016-08-01

    We present the results from a systematic search for galactic-scale, molecular (OH 119 μm) outflows in a sample of 52 Local Volume (d\\lt 50 Mpc) Burst Alert Telescope detected active galactic nuclei (BAT AGNs) with Herschel-PACS. We combine the results from our analysis of the BAT AGNs with the published Herschel/PACS data of 43 nearby (z\\lt 0.3) galaxy mergers, mostly ultra-luminous infrared galaxies (ULIRGs) and QSOs. The objects in our sample of BAT AGNs have, on average, ∼ 10{--}100 times lower AGN luminosities, star formation rates, and stellar masses than those of the ULIRG and QSO samples. OH 119 μm is detected in 42 of our BAT AGN targets. Evidence for molecular outflows (i.e., OH absorption profiles with median velocities more blueshifted than ‑50 km s‑1 and/or blueshifted wings with 84% velocities less than ‑300 km s‑1) is seen in only four BAT AGNs (NGC 7479 is the most convincing case). Evidence for molecular inflows (i.e., OH absorption profiles with median velocities more redshifted than 50 km s‑1) is seen in seven objects, although an inverted P-Cygni profile is detected unambiguously in only one object (Circinus). Our data show that both the starburst and AGN contribute to driving OH outflows, but the fastest OH winds require AGNs with quasar-like luminosities. We also confirm that the total absorption strength of OH 119 μm is a good proxy for dust optical depth as it correlates strongly with the 9.7 μm silicate absorption feature, a measure of obscuration originating in both the nuclear torus and host galaxy disk. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  5. Insights into the origin of the stellar initial mass function from Herschel Gould Belt survey observations

    NASA Astrophysics Data System (ADS)

    André, Philippe; Roy, Arabindo; Arzoumanian, Doris

    2015-08-01

    The origin of the stellar initial mass function (IMF) is one of the most debated issues in astrophysics. Two major features of the IMF are 1) a fairly robust power-law slope at the high-mass end known since Salpeter (1955), and 2) a broad peak below 1 Mo corresponding to a characteristic stellar mass scale. In recent years, the dominant theoretical model proposed to account for these features has been the "gravo-turbulent fragmentation" picture, whereby the properties of interstellar turbulence lead to the Salpeter power law and gravity sets the characteristic mass scale (Jeans mass). I will discuss modifications to this picture based on extensive submillimeter imaging observations of nearby molecular clouds with the Herschel Space Observatory which set strong constraints on the formation process of prestellar cores.The Herschel results point to the key role of the quasi-universal filamentary structure pervading the cold interstellar medium and support a scenario in which star formation occurs in two main steps: first, the dissipation of kinetic energy in large-scale MHD flows (turbulent or not) generates ~ 0.1 pc-wide filaments in the cold ISM; second, the densest filaments grow and fragment into prestellar cores (and ultimately protostars) by gravitational instability above a critical threshold ~ 16 Mo/pc in mass per unit length or ~ 160 Mo/pc2 in gas surface density (AV ~ 8).In our observationally-driven scenario, the dense cores making up the peak of the prestellar core mass function (CMF) - likely responsible for the characteristic IMF mass scale - result from gravitational fragmentation of filaments near the critical threshold for global gravitational instability. The power-law tail of the CMF/IMF arises either from the characteristic power spectrum of initial density fluctuations measured along the Herschel filaments (Roy et al. submitted) or from the power-law distribution of masses per unit length observed for supercritical filaments.

  6. Herschel/PACS spectroscopy of trace gases of the stratosphere of Titan

    NASA Astrophysics Data System (ADS)

    Rengel, M.; Sagawa, H.; Hartogh, P.; Lellouch, E.; Feuchtgruber, H.; Moreno, R.; Jarchow, C.; Courtin, R.; Cernicharo, J.; Lara, L. M.

    2014-01-01

    Aims: We investigate the composition of Titan's stratosphere from new medium-resolution far-infrared observations performed with the full range of Herschel's Photodetector Array Camera and Spectrometer (PACS) (51-220 μm at a resolution λ/Δλ ranging from 950 to 5500 depending on wavelength and grating order). Methods: Using PACS, we obtained the spectral emission of several features of the Titan's stratosphere. We used a line-by-line radiative transfer code and the least-squares fitting technique to infer the abundances of the trace constituents. Results: Numerous spectral features attributable to CH4, CO, HCN, and H2O are present. From the flux density spectrum measured and by a detailed comparison with synthetic spectra, we constrain the stratospheric abundance of CH4, which is assumed to be constant with altitude, to be 1.29 ± 0.03%. Similarly, we constrain the abundance of CO to be 50 ± 2 ppm, and the HCN vertical distribution consistent with an increase from 40 ppb at ~100 km to ~4 ppm at ~200 km, which is an altitude region where the HCN signatures are sensitive. Measurements of three H2O rotational lines confirm the H2O distribution profile recently obtained with Herschel. Furthermore, we determine the isotopic ratios 12C/13C in CO and HCN to be 124 ± 58, and 66 ± 35, respectively. Comparisons between our results and the values derived with other instruments show that our results are consistent with the vertical distributions and isotopic ratios in previous studies, except for the HCN distribution obtained with Cassini/CIRS, which does not agree with the PACS lines at the 1-σ confidence interval. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  7. Multi-wavelength seds of Herschel-selected galaxies in the cosmos field

    SciTech Connect

    Lee, Nicholas; Sanders, D. B.; Casey, Caitlin M.; Hung, Chao-Ling; Scoville, N. Z.; Capak, Peter; Bock, J.; Le Floc'h, Emeric; Aussel, Hervé; Ilbert, Olivier; Kartaltepe, Jeyhan S.; Roseboom, Isaac; Oliver, S. J.; Salvato, Mara; Aravena, M.; Berta, S.; Riguccini, L.; Symeonidis, M.

    2013-12-01

    We combine Herschel Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging Receiver maps of the full 2 deg{sup 2} Cosmic Evolution Survey (COSMOS) field with existing multi-wavelength data to obtain template and model-independent optical-to-far-infrared spectral energy distributions (SEDs) for 4218 Herschel-selected sources with log(L {sub IR}/L {sub ☉}) = 9.4-13.6 and z = 0.02-3.54. Median SEDs are created by binning the optical to far-infrared (FIR) bands available in COSMOS as a function of infrared luminosity. Herschel probes rest-frame wavelengths where the bulk of the infrared radiation is emitted, allowing us to more accurately determine fundamental dust properties of our sample of infrared luminous galaxies. We find that the SED peak wavelength (λ{sub peak}) decreases and the dust mass (M {sub dust}) increases with increasing total infrared luminosity (L {sub IR}). In the lowest infrared luminosity galaxies (log(L {sub IR}/L {sub ☉}) = 10.0-11.5), we see evidence of polycyclic aromatic hydrocarbon (PAH) features (λ ∼ 7-9 μm), while in the highest infrared luminosity galaxies (L {sub IR} > 10{sup 12} L {sub ☉}) we see an increasing contribution of hot dust and/or power-law emission, consistent with the presence of heating from an active galactic nucleus (AGN). We study the relationship between stellar mass and star formation rate of our sample of infrared luminous galaxies and find no evidence that Herschel-selected galaxies follow the SFR/M {sub *} 'main sequence' as previously determined from studies of optically selected, star-forming galaxies. Finally, we compare the mid-infrared to FIR properties of our infrared luminous galaxies using the previously defined diagnostic, IR8 ≡ L {sub IR}/L {sub 8}, and find that galaxies with L {sub IR} ≳ 10{sup 11.3} L {sub ☉} tend to systematically lie above (× 3-5) the IR8 'infrared main sequence', suggesting either suppressed PAH emission or an increasing contribution from

  8. The Herschel ATLAS: Evolution of the 250 Micrometer Luminosity Function Out to z = 0.5

    NASA Technical Reports Server (NTRS)

    Dye, S.; Dunne, L.; Eales, S.; Smith, D. J. B.; Amblard, A.; Auld, R.; Baes, M.; Baldry, I. K.; Bamford, S.; Blain, A. W.; Bonfield, D. G.; Bremer, M.; Burgarella, D.; Buttiglione, S.; Cameron, E.; Cava, A.; Clements, D. L.; Cooray, A.; Croom, S.; Dariush, A.; de Zotti, G.; Driver, S.; Dunlop, J. S.; Frayer, D.; Leeuw, L.

    2010-01-01

    We have determined the luminosity function of 250 micrometer-selected galaxies detected in the approximately equal to 14 deg(sup 2) science demonstration region of the Herschel-ATLAS project out to a redshift of z = 0.5. Our findings very clearly show that the luminosity function evolves steadily out to this redshift. By selecting a sub-group of sources within a fixed luminosity interval where incompleteness effects are minimal, we have measured a smooth increase in the comoving 250 micrometer luminosity density out to z = 0.2 where it is 3.6(sup +1.4) (sub -0.9) times higher than the local value.

  9. Herschel/HIFI observations of the circumstellar ammonia lines in IRC+10216

    NASA Astrophysics Data System (ADS)

    Schmidt, M. R.; He, J. H.; Szczerba, R.; Bujarrabal, V.; Alcolea, J.; Cernicharo, J.; Decin, L.; Justtanont, K.; Teyssier, D.; Menten, K. M.; Neufeld, D. A.; Olofsson, H.; Planesas, P.; Marston, A. P.; Sobolev, A. M.; de Koter, A.; Schöier, F. L.

    2016-08-01

    Context. A discrepancy exists between the abundance of ammonia (NH3) derived previously for the circumstellar envelope (CSE) of IRC+10216 from far-IR submillimeter rotational lines and that inferred from radio inversion or mid-infrared (MIR) absorption transitions. Aims: To address the discrepancy described above, new high-resolution far-infrared (FIR) observations of both ortho- and para-NH3 transitions toward IRC+10216 were obtained with Herschel, with the goal of determining the ammonia abundance and constraining the distribution of NH3 in the envelope of IRC+10216. Methods: We used the Heterodyne Instrument for the Far Infrared (HIFI) on board Herschel to observe all rotational transitions up to the J = 3 level (three ortho- and six para-NH3 lines). We conducted non-LTE multilevel radiative transfer modelling, including the effects of near-infrared (NIR) radiative pumping through vibrational transitions. The computed emission line profiles are compared with the new HIFI data, the radio inversion transitions, and the MIR absorption lines in the ν2 band taken from the literature. Results: We found that NIR pumping is of key importance for understanding the excitation of rotational levels of NH3. The derived NH3 abundances relative to molecular hydrogen were (2.8 ± 0.5) × 10-8 for ortho-NH3 and for para-NH3, consistent with an ortho/para ratio of 1. These values are in a rough agreement with abundances derived from the inversion transitions, as well as with the total abundance of NH3 inferred from the MIR absorption lines. To explain the observed rotational transitions, ammonia must be formed near to the central star at a radius close to the end of the wind acceleration region, but no larger than about 20 stellar radii (1σ confidence level). Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. HIFI is the Herschel Heterodyne Instrument for the Far

  10. The Herschel cold debris disks: Confusion with the extragalactic background at 160 μm

    SciTech Connect

    Gáspár, András; Rieke, George H.

    2014-03-20

    The Herschel 'DUst around NEarby Stars' (DUNES) survey has found a number of debris disk candidates that are apparently very cold, with temperatures near 22 K. It has proven difficult to fit their spectral energy distributions with conventional models for debris disks. Given this issue, we carefully examine the alternative explanation that the detections arise from confusion with infrared cirrus and/or background galaxies that are not physically associated with the foreground stars. We find that such an explanation is consistent with all of these detections.

  11. The effect of sideband ratio on line intensity for Herschel/HIFI

    NASA Astrophysics Data System (ADS)

    Higgins, Ronan; Teyssier, David; Borys, Colin; Braine, Jonathan; Comito, Claudia; Delforge, Bertrand; Helmich, Frank; Olberg, Michael; Ossenkopf, Volker; Pearson, John; Shipman, Russell

    2014-07-01

    The Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory is composed of a set of fourteen double sideband mixers. We discuss the general problem of the sideband ratio (SBR) determination and the impact of an imbalanced sideband ratio on the line calibration in double sideband heterodyne receivers. The HIFI SBR is determined from a combination of data taken during pre-launch gas cell tests and in-flight. The results and some of the calibration artefacts discovered in the gas cell test data are presented here along with some examples of how these effects appear in science data taken in orbit.

  12. The Herschel Virgo Cluster Survey. XVIII. Star-forming dwarf galaxies in a cluster environment

    NASA Astrophysics Data System (ADS)

    Grossi, M.; Hunt, L. K.; Madden, S. C.; Hughes, T. M.; Auld, R.; Baes, M.; Bendo, G. J.; Bianchi, S.; Bizzocchi, L.; Boquien, M.; Boselli, A.; Clemens, M.; Corbelli, E.; Cortese, L.; Davies, J.; De Looze, I.; di Serego Alighieri, S.; Fritz, J.; Pappalardo, C.; Pierini, D.; Rémy-Ruyer, A.; Smith, M. W. L.; Verstappen, J.; Viaene, S.; Vlahakis, C.

    2015-02-01

    To assess the effects of the cluster environment on the different components of the interstellar medium, we analyse the far-infrared (FIR) and submillimetre (submm) properties of a sample of star-forming dwarf galaxies detected by the Herschel Virgo Cluster Survey (HeViCS). We determine dust masses and dust temperatures by fitting a modified black body function to the spectral energy distributions (SEDs). Stellar and gas masses, star formation rates (SFRs), and metallicities are obtained from the analysis of a set of ancillary data. Dust is detected in 49 out of a total 140 optically identified dwarfs covered by the HeViCS field; considering only dwarfs brighter than mB = 18 mag, this gives a detection rate of 43%. After evaluating different emissivity indices, we find that the FIR-submm SEDs are best-fit by β = 1.5, with a median dust temperature Td = 22.4 K. Assuming β = 1.5, 67% of the 23 galaxies detected in all five Herschel bands show emission at 500 μm in excess of the modified black-body model. The fraction of galaxies with a submillimetre excess decreases for lower values of β, while a similarly high fraction (54%) is found if a β-free SED modelling is applied. The excess is inversely correlated with SFR and stellar masses. To study the variations in the global properties of our sample that come from environmental effects, we compare the Virgo dwarfs to other Herschel surveys,such as the Key Insights into Nearby Galaxies: Far-Infrared Survey with Herschel (KINGFISH), the Dwarf Galaxy Survey (DGS), and the HeViCS Bright Galaxy Catalogue (BGC). We explore the relations between stellar mass and Hi fraction, specific star formation rate, dust fraction, gas-to-dust ratio over a wide range of stellar masses (from 107 to 1011 M⊙) for both dwarfs and spirals. Highly Hi-deficient Virgo dwarf galaxies are mostly characterised by quenched star formation activity and lower dust fractions giving hints for dust stripping in cluster dwarfs. However, to explain the

  13. VizieR Online Data Catalog: Deep Herschel PACS point spread functions (Bocchio+, 2016)

    NASA Astrophysics Data System (ADS)

    Bocchio, M.; Bianchi, A.; Abergel, S.

    2016-06-01

    Herschel PACS dedicated PSF observations are scanmaps centred on various objects taken at 70 (blue channel), 100 (green channel) and 160 (red channel) um. The core of the PSF is best characterised observing faint objects (e.g. the asteroid Vesta), while the wings of the PSF can only be seen in observations of bright objects (e.g. Mars). Using a combination of images of bright and faint objects it is therefore possible to have a good characterisation of the PACS PSFs. (2 data files).

  14. CSI L2 - Reconstructing Herschel/Planck, Anomalies on the Avionics Bench

    NASA Astrophysics Data System (ADS)

    Bacchetta, Andrea; Cocito, Andrea; Oort, Marc; Procopio, Dorico

    2010-08-01

    One year after the launch of Herschel and Planck it is time to show the issues which occurred in-flight that have required dedicated analyses. In particular, the role played by the Avionics Test Bench in investigating the anomalies involving the Attitude Control is presented. This verification set-up has been used extensively initially for reproducing the observed behavior and then to validate the various solutions that have been identified and implemented. Different entities, from the equipment suppliers up to the final customer, have been involved in this process and their role is presented.

  15. The on-board software of the HERSCHEL/PACS instrument: three successful years of in-flight operations

    NASA Astrophysics Data System (ADS)

    Pezzuto, Stefano; Ottensamer, Roland; Mazy, Alain; Feuchtgruber, Helmut; Di Giorgio, Anna Maria; Vandenbussche, Bart; Benedettini, Milena; Liu, Scige John; Molinari, Sergio; Schito, Daniele

    2012-09-01

    PACS is one of the three instruments of the ESA space mission Herschel. Its warm electronics consists of 4 computers connected through 1355 links. Each computer is equipped with a DSP-21020 microprocessor, each running its own software. In this poster we describe the main features of the dierent software with some emphasis on the FDIR (Failure Detection Isolation and Recovery) procedures implemented on-board: we describe the FDIR design and we show how the few anomalies that occurred since the Herschel launch three years ago, have been succesfully handled autonomously by the instrument.

  16. Tracing Protostellar Envelope Evolution with HOPS, the Herschel Orion Protostar Survey

    NASA Astrophysics Data System (ADS)

    Fischer, Will; Megeath, Tom; Furlan, Elise; Ali, Babar; Stutz, Amy; Booker, Joseph; Tobin, John; Stanke, Thomas; Osorio, Mayra

    2013-07-01

    HOPS, the Herschel Orion Protostar Survey, is an unprecedented program of large surveys with the Herschel, Spitzer, Hubble, and APEX observatories, as well as near-IR observations from the IRTF and other telescopes. Together these are providing a comprehensive observational assessment of protostellar evolution, from the earliest phases (see poster by A. Stutz) through the dissipation of the protostellar envelope. The BLT (bolometric luminosity and temperature) diagram for the ˜300 HOPS protostars resembles those constructed for other nearby star-forming regions. We fit the 1-870 um SEDs of the protostars with our grid of radiative transfer models to determine their luminosities, envelope densities, cavity angles, and inclinations (see poster by E. Furlan). High-resolution HST images of the scattered light nebulae provide additional constraints on envelope density, disk geometry, cavity geometry, and inclination angle (see poster by J. Booker). Finally, near-IR atomic hydrogen lines provide independent estimates of reddening and accretion luminosity in the less embedded sources. This multi-pronged modeling approach provides a more reliable assessment of envelope evolution than raw observational diagnostics like the bolometric temperature. We will compare the distributions of envelope densities and protostellar luminosities to the predictions of star-formation models.

  17. The Stratospheric Observatory for Infrared Astronomy (SOFIA) - next step after Spitzer/Herschel

    NASA Astrophysics Data System (ADS)

    Zinnecker, Hans

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a Boeing 747B fitted with a powerful 2.5m infrared telescope that operates at altitudes of 12-14km and observes light from the near-IR to the far-IR wavelength range that is blocked to reach the ground by the Earth's atmosphere (mainly due to water vapor). SOFIA is a joint project between NASA and the German Aerospace Agency (DLR). This new airborne Observatory started early science observations in 2010 and has recently reached full operational capability, with a suite fo currently 4 instruments (and two more to be commissioned) in Cycle 2. Scientific highlights will be presented which include mid-IR broad-band imaging and far-IR high-resolution spectroscopic results which go beyond those of Spitzer and Herschel (star formation studies and astrochemistry). SOFIA will have a projected lifetime of 20 yrs and will be the premier mid- and far-infrared facility in the post-Spitzer and post-Herschel era for many years to come.

  18. Candidate Gravitationally Lensed Dusty Star-forming Galaxies in the Herschel Wide Area Surveys

    NASA Astrophysics Data System (ADS)

    Nayyeri, H.; Keele, M.; Cooray, A.; Riechers, D. A.; Ivison, R. J.; Harris, A. I.; Frayer, D. T.; Baker, A. J.; Chapman, S. C.; Eales, S.; Farrah, D.; Fu, H.; Marchetti, L.; Marques-Chaves, R.; Martinez-Navajas, P. I.; Oliver, S. J.; Omont, A.; Perez-Fournon, I.; Scott, D.; Vaccari, M.; Vieira, J.; Viero, M.; Wang, L.; Wardlow, J.

    2016-05-01

    We present a list of candidate gravitationally lensed dusty star-forming galaxies (DSFGs) from the HerMES Large Mode Survey and the Herschel Stripe 82 Survey. Together, these partially overlapping surveys cover 372 deg2 on the sky. After removing local spiral galaxies and known radio-loud blazars, our candidate list of lensed DSFGs is composed of 77 sources with 500 μm flux densities (S 500) greater than 100 mJy. Such sources are dusty starburst galaxies similar to the first bright sub-millimeter galaxies (SMGs) discovered with SCUBA. We expect a large fraction of this list to be strongly lensed, with a small fraction made up of bright SMG–SMG mergers that appear as hyper-luminous infrared galaxies ({L}{IR}\\gt {10}13 {L}ȯ ). Thirteen of the 77 candidates have spectroscopic redshifts from CO spectroscopy with ground-based interferometers, putting them at z\\gt 1 and well above the redshift of the foreground lensing galaxies. The surface density of our sample is 0.21 ± 0.03 deg‑2. We present follow-up imaging of a few of the candidates to confirm their lensing nature. The sample presented here is an ideal tool for higher-resolution imaging and spectroscopic observations to understand the detailed properties of starburst phenomena in distant galaxies. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  19. A Search for the Far-Infrared Ghost of C/2010 X1 (Elenin) with Herschel

    NASA Astrophysics Data System (ADS)

    Kidger, Mark R.; Altieri, Bruno; Müller, Thomas; Gracia, Javier

    2016-04-01

    Observations of Comet C/2010 X1 (Elenin) in August 2011 showed a pattern of evolution of coma morphology into an expanding, amorphous cloud of rapidly decreasing surface brightness shortly before perihelion passage, similar to C/1999 S4 (LINEAR) in 2000. However, the comet's difficult viewing geometry at the time of disruption made it impossible to study the event using high-resolution imaging techniques and, in particular, to measure the ratio of dust to cometessimals which gives information on the internal structure of the nucleus before disruption. We report Herschel/PACS observations of the defunct Comet C/2010 X1 (Elenin), aimed at detecting its infrared ghost: the debris cloud and any remaining inert, or low-activity cometessimals that may have been released in the break-up of the nucleus, taking advantage of the comet's close pass to Earth in mid-October 2011. These observations would have allowed us to detect, potentially, both individual surviving inert fragments of the nucleus of ≈260 m diameter (and significantly smaller, active cometessimals) and the expanding dust cloud, being particularly sensitive to coarse dust and boulders in the millimetre to metre size range. No discrete bodies were detected by Herschel to this limiting size.

  20. Growing evidence for a core formation threshold traced in Herschel Gould Belt survey clouds

    NASA Astrophysics Data System (ADS)

    Könyves , V.; André, Ph.; Schneider, N.; Palmeirim, P.; Arzoumanian, D.; Men'shchikov, A.

    2013-11-01

    It has already been suggested that a threshold in column density - or in visual extinction - may need to be exceeded to form dense cores and then protostars. Based on Herschel Gould Belt survey results in the Aquila and Orion B molecular cloud complexes we observe clear connection between the locations of the detected prestellar cores and their background column density values. This finding appears to support a core formation scenario where such threshold corresponds to the extinction above which interstellar filaments become gravitationally unstable and fragment into cores. In these two actively star-forming regions we find the vast majority of the gravitationally bound prestellar cores above a high column density of about (6-7) × 1021 cm-2 (AV ˜ 6-7). This limit similarly appears in the column density probability distribution function (PDF) of the regions as well. The spatial distribution of the protostars and young stellar objects (YSOs) also shows a tight connection with the densest sites of both clouds, as more than 70 % of them appear above the mentioned AV thresholds. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. HERSCHEL FAR-IR OBSERVATIONS OF THE GIANT H II REGION NGC 3603

    SciTech Connect

    Cecco, Alessandra Di; Faustini, Fabiana; Calzoletti, Luca; Paresce, Francesco; Correnti, Matteo

    2015-01-20

    We observed the giant H II region around the NGC 3603 YC with the five broad bands (70, 160, 250, 350, 500 μm) of the SPIRE and PACS instruments, on board the Herschel Space Observatory. Together with what is currently known of the stellar, atomic, molecular, and warm dust components, this additional and crucial information should allow us to better understand the details of the star-formation history in this region. The main objective of the investigation is to study, at high spatial resolution, the distribution and main physical characteristics of the cold dust. By reconstructing the temperature and density maps, we found, respectively, a mean value of 36 K and log{sub 10} N {sub H} = 22.0 ± 0.1 cm{sup –2}. We carried out a photometric analysis detecting 107 point-like sources, mostly confined to the north and south of the cluster. By comparing our data with spectral energy distribution models, we found that 35 sources are well represented by young stellar objects in early evolutionary phases, from Class 0 to Class I. The Herschel detections also provided far-IR counterparts for 4 H{sub 2}O masers and 11 objects previously known from mid-IR observations. The existence of so many embedded sources confirms the hypothesis of intense and ongoing star-formation activity in the region around NGC 3603 YC.

  2. New constraints on the CH4 vertical profile in Uranus and Neptune from Herschel observations

    NASA Astrophysics Data System (ADS)

    Lellouch, E.; Moreno, R.; Orton, G. S.; Feuchtgruber, H.; Cavalié, T.; Moses, J. I.; Hartogh, P.; Jarchow, C.; Sagawa, H.

    2015-07-01

    Dedicated line observations of CH4 rotational lines performed with Herschel/PACS and HIFI in 2009-2011 provide new inferences of the mean methane profile in the upper tropospheres and stratospheres of Uranus and Neptune. At Uranus, CH4 is found to be near saturation, with a ~9 × 10-4 tropopause/lower stratosphere mole fraction. This is nominally six times larger than inferred from Spitzer in 2007, although reconciliation may be possible if the CH4 abundance decreases sharply from ~100 to 2 mbar. This unexpected situation might reflect heterogeneous conditions in Uranus' stratosphere, with local CH4 depletions and heating associated with downwelling motions. Higher CH4 abundances compared to values inferred under solstitial conditions by Voyager in 1989 suggest that atmospheric mixing is effectively subdued at high latitudes and/or is time-variable. At Neptune, the mid-stratosphere CH4 abundance is (1.15 ± 0.10) × 10-3, in agreement with earlier determinations and indicative of either leakage through a warmer polar region or upwelling at low or middle latitudes. On both planets, spatially resolved observations of temperature and methane in the stratosphere are needed to further identify the physical processes at work. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. Cryogenic far-infrared laser absorptivity measurements of the Herschel Space Observatory telescope mirror coatings.

    PubMed

    Fischer, Jacqueline; Klaassen, Tjeerd; Hovenier, Niels; Jakob, Gerd; Poglitsch, Albrecht; Sternberg, Oren

    2004-07-01

    Far-infrared laser calorimetry was used to measure the absorptivity, and thus the emissivity, of aluminum-coated silicon carbide mirror samples produced during the coating qualification run of the Herschel Space Observatory telescope to be launched by the European Space Agency in 2007. The samples were measured at 77 K to simulate the operating temperature of the telescope in its planned orbit about the second Lagrangian point, L2, of the Earth-Sun system. Together, the telescope's equilibrium temperature in space and the emissivity of the mirror surfaces will determine the far-infrared-submillimeter background and thus the sensitivity of two of the three astronomical instruments aboard the observatory if stray-light levels can be kept low relative to the mirror emission. Absorptivities of both clean and dust-contaminated samples were measured at 70, 118, 184, and 496 microm. Theoretical fits to the data predict absorptivities of 0.2-0.4% for the clean sample and 0.2-0.8% for the dusty sample, over the spectral range of the Herschel Space Observatory instruments. PMID:15250543

  4. Herschel/HIFI line surveys: Discovery of interstellar chloronium (H2Cl+)

    NASA Astrophysics Data System (ADS)

    Lis, Dariusz C.

    2015-01-01

    Prior to the launch of Herschel, HCl was the only chlorine-containing molecule detected in the interstellar medium (ISM). However, chemical models have identified chloronium, H2Cl+, as a relatively abundant species that is potentially detectable. H2Cl+ was predicted to be most abundant in the environments where the ultraviolet radiation is strong: in diffuse clouds, or near the surfaces of dense clouds illuminated by nearby O and B stars. The HIFI instrument on Herschel provided the first detection of H2Cl+ in the ISM. The 212-101 lines of ortho-H235Cl+ and ortho-H237Cl+ were detected in absorption toward NGC 6334I, and the 111-000 transition of para-H235Cl+ was detected in absorption toward NGC 6334I and Sgr B2(S). The derived HCl / H2Cl+ column density ratios, ˜1-10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H2Cl+ column densities, in excess of 1013 cm-2, are significantly higher than the model predictions. These observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models.

  5. MODELING THE HD 32297 DEBRIS DISK WITH FAR-INFRARED HERSCHEL DATA

    SciTech Connect

    Donaldson, J. K.; Lebreton, J.; Augereau, J.-C.; Krivov, A. V.

    2013-07-20

    HD 32297 is a young A-star ({approx}30 Myr) 112 pc away with a bright edge-on debris disk that has been resolved in scattered light. We observed the HD 32297 debris disk in the far-infrared and sub-millimeter with the Herschel Space Observatory PACS and SPIRE instruments, populating the spectral energy distribution (SED) from 63 to 500 {mu}m. We aimed to determine the composition of dust grains in the HD 32297 disk through SED modeling, using geometrical constraints from the resolved imaging to break the degeneracies inherent in SED modeling. We found the best fitting SED model has two components: an outer ring centered around 110 AU, seen in the scattered light images, and an inner disk near the habitable zone of the star. The outer disk appears to be composed of grains >2 {mu}m consisting of silicates, carbonaceous material, and water ice with an abundance ratio of 1:2:3 respectively and 90% porosity. These grains appear consistent with cometary grains, implying the underlying planetesimal population is dominated by comet-like bodies. We also discuss the 3.7{sigma} detection of [C II] emission at 158 {mu}m with the Herschel PACS instrument, making HD 32297 one of only a handful of debris disks with circumstellar gas detected.

  6. The data processing pipeline for the Herschel SPIRE Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Fulton, T.; Naylor, D. A.; Polehampton, E. T.; Valtchanov, I.; Hopwood, R.; Lu, N.; Baluteau, J.-P.; Mainetti, G.; Pearson, C.; Papageorgiou, A.; Guest, S.; Zhang, L.; Imhof, P.; Swinyard, B. M.; Griffin, M. J.; Lim, T. L.

    2016-05-01

    We present the data processing pipeline to generate calibrated data products from the Spectral and Photometric Imaging Receiver (SPIRE) imaging Fourier Transform Spectrometer on the Herschel Space Observatory. The pipeline processes telemetry from SPIRE observations and produces calibrated spectra for all resolution modes. The spectrometer pipeline shares some elements with the SPIRE photometer pipeline, including the conversion of telemetry packets into data timelines and calculation of bolometer voltages. We present the following fundamental processing steps unique to the spectrometer: temporal and spatial interpolation of the scan mechanism and detector data to create interferograms; Fourier transformation; apodization; and creation of a data cube. We also describe the corrections for various instrumental effects including first- and second-level glitch identification and removal, correction of the effects due to emission from the Herschel telescope and from within the spectrometer instrument, interferogram baseline correction, temporal and spatial phase correction, non-linear response of the bolometers, and variation of instrument performance across the focal plane arrays. Astronomical calibration is based on combinations of observations of standard astronomical sources and regions of space known to contain minimal emission.

  7. Towards a Complete Census of High-z ULIRGs with Herschel

    NASA Astrophysics Data System (ADS)

    Magdis, G. E.; Elbaz, D.; Hwang, H. S.; Pep Team; Hermes Team

    2011-10-01

    Using Herschel PACS and SPIRE observations as part of the HerMES, we explore the far-IR properties of a sample of mid-IR selected starburst dominated ultra-luminous infrared galaxies (ULIRGs) at z ˜ 2. We derive robust estimates of infrared luminosities (LIR) and dust temperatures (Td) of the population and find that galaxies in our sample range from those that are as cold as high-z sub-millimeter galaxies (SMGs) to those that are as warm as optically faint radio galaxies (OFRGs) and local ULIRGs. We also demonstrate that a significant fraction of our sample would be missed from ground based (sub)mm surveys (850-1200μm) showing that the latter introduce a bias towards the detection of colder sources. Similarly, based on PACS data as part of the PEP project, we construct for the first time the full average SED of a sub-sample of infrared luminous Lyman break galaxies at z˜3, and find them to have higher Td when compared to that of SMGs with comparable LIR. We conclude that high-z ULIRGs span a wide range of dust temperatures, larger than that seen in local ULIRGs, and that Herschel data provide the means to characterize the bulk of the ULIRG population, free from selection biases introduced by ground based (sub)mm surveys.

  8. What exactly was William Herschel's Milky Way and how did he construct it?

    NASA Astrophysics Data System (ADS)

    Sullivan, Woodruff T.; Sharma, R.

    2014-01-01

    William Herschel is famous for his "Construction of the Heavens," his pioneering quantitative view of the Milky Way based on extensive star counts ("gages") carried out while sweeping with his 20-ft telescope in the early 1780s. In 1785 he presented his main result in a single iconic diagram - a view of the Milky Way that was to dominate for over a century until "Kapteyn's Universe" finally overtook it in the early 20th century. In this paper we analyze the entire data sample of Herschel's published and unpublished star gages in order better to understand the nature of the data and how he used them. We examine such issues as his method of observing, his limiting magnitude, his consistency in star counting, his sky coverage, and his distance scaling (in units of "visual rays"). We also discuss how representative was his lone published 2-D slice through his model Milky Way, and the effects of his basic assumptions (such as a uniform density of stars). Where insight can be gained, we make comparisons with modern star counts (such as those of the HST Guide Star Catalog). To assist in this effort we have employed 3-D visualization software, as well as a plastic model (to be exhibited) constructed by a 3-D printer illustrating many aspects of the Herschelian Milky Way.

  9. A Herschel-Resolved Debris Disk Around the Nearby G Star HIP 32480

    NASA Technical Reports Server (NTRS)

    Stapelfeldt, K.

    2011-01-01

    The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a G0 star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grainsize of approximately 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

  10. DISCOVERY OF A MULTIPLY LENSED SUBMILLIMETER GALAXY IN EARLY HerMES HERSCHEL/SPIRE DATA

    SciTech Connect

    Conley, A.; Cooray, A.; Kim, S.; Amblard, A.; Vieira, J. D.; Blain, A.; Bock, J.; Bradford, C. M.; Bridge, C.; Carpenter, J. M.; Solares, E. A. Gonzalez; Aguirre, J. E.; Auld, R.; Baker, A. J.; Beelen, A.; Blundell, R.; Brisbin, D.; Burgarella, D.; Chanial, P.

    2011-05-10

    We report the discovery of a bright (f(250 {mu}m)>400 mJy), multiply lensed submillimeter galaxy HERMES J105751.1+573027 in Herschel/SPIRE Science Demonstration Phase data from the HerMES project. Interferometric 880 {mu}m Submillimeter Array observations resolve at least four images with a large separation of {approx}9''. A high-resolution adaptive optics K{sub p} image with Keck/NIRC2 clearly shows strong lensing arcs. Follow-up spectroscopy gives a redshift of z = 2.9575, and the lensing model gives a total magnification of {mu} {approx} 11 {+-} 1. The large image separation allows us to study the multi-wavelength spectral energy distribution (SED) of the lensed source unobscured by the central lensing mass. The far-IR/millimeter-wave SED is well described by a modified blackbody fit with an unusually warm dust temperature, 88 {+-} 3 K. We derive a lensing-corrected total IR luminosity of (1.43 {+-} 0.09) x 10{sup 13} L{sub sun}, implying a star formation rate of {approx}2500 M{sub sun} yr{sup -1}. However, models primarily developed from brighter galaxies selected at longer wavelengths are a poor fit to the full optical-to-millimeter SED. A number of other strongly lensed systems have already been discovered in early Herschel data, and many more are expected as additional data are collected.

  11. Dark cloud chemistry of nitrogen hydrides with the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Le Gal, R.; Hily-Blant, P.; Faure, A.

    2014-12-01

    Stars form in dark clouds. A complete knowledge of dark cloud chemical composition can be helpful to understand star- and planet-formation processes. Nitrogen is the sixth most abundant interstellar element, and also a basic component of prebiotic molecules. Yet, the reservoir of gaseous nitrogen in dark clouds is not precisely known. It is expected to be mainly N and/or N_2, but both are unobservable in dark gas. Their abundances therefore derive indirectly from those of other N-bearing species through chemical modelling. In this context, our work focuses on a revision of the nitrogen-hydride chemistry in dark clouds using fundamental rotational transitions of NH, NH_2, and NH_3 observed with Herschel/HIFI towards a sample of low-mass protostellar objects. To this purpose, we update and upgrade a chemical network containing the chemistry of the ortho and para forms of nitrogen-hydride molecules, allowing to reproduce the NH:NH_2:NH_3 ratios observed with Herschel/HIFI towards IRAS 16293-2422, putting constraints on the budget of gas-phase carbon, oxygen and sulphur. Furthermore, our results explain the non-thermodynamical ortho-to-para ratio of ammonia observed in cold diffuse gas.

  12. Investigating star formation properties of galaxies in massive clusters with Herschel and ALMA

    NASA Astrophysics Data System (ADS)

    Wu, John F.; Baker, Andrew J.; Aguirre, Paula; Barkats, D.; Halpern, Mark; Hilton, Matt; Hughes, John Patrick; Infante, Leopoldo; Lindner, Robert; Marriage, Tobias; Menanteau, Felipe; Sifon, Cristobal; Weiss, Axel; ACT Collaboration

    2016-01-01

    I will present results from an investigation of star formation properties of galaxies residing in two massive z ~ 1 clusters (including the 'El Gordo' merger) that were initially selected via their Sunyaev-Zeldovich decrements by the Atacama Cosmology Telescope (ACT) southern survey. This study uses new Herschel Space Observatory and Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 2 observations, which provide information about the dust and cold gas content of galaxies in our targeted clusters. We have detected CO (4-3) and [CI] in individual star-forming cluster galaxies, and also measured stacked continuum and spectral line fluxes at long (e.g., far-infrared, submillimeter, and radio) wavelengths. We use these results to explore the relations between star formation and local environment and cluster dynamical state.This work has been supported by (i) an award issued by JPL/Caltech in association with Herschel, which is a European Space Agency Cornerstone Mission with significant participation by NASA, and (ii) the National Science Foundation through award GSSP SOSPA2-018 from the National Radio Astronomy Observatory, which is operated under cooperative agreement by Associated Universities, Inc.

  13. Thermal and shape properties of asteroid (21) Lutetia from Herschel observations around the Rosetta flyby

    NASA Astrophysics Data System (ADS)

    O'Rourke, L.; Müller, T.; Valtchanov, I.; Altieri, B.; González-Garcia, B. M.; Bhattacharya, B.; Jorda, L.; Carry, B.; Küppers, M.; Groussin, O.; Altwegg, K.; Barucci, M. A.; Bockelee-Morvan, D.; Crovisier, J.; Dotto, E.; Garcia-Lario, P.; Kidger, M.; Llorente, A.; Lorente, R.; Marston, A. P.; Sanchez Portal, M.; Schulz, R.; Sierra, M.; Teyssier, D.; Vavrek, R.

    2012-06-01

    Prior to and around the Rosetta flyby of (21) Lutetia, the Herschel Space Observatory performed a collaborative observation campaign with its two photometers observing the asteroid in the far infrared, at wavelengths not covered by Rosetta's instruments. The Herschel observations, fed into a thermophysical model (TPM) using as input a shape model based on in-situ images, were also further correlated with ˜70 multi-wavelength observations of Lutetia. We confirm the geometric albedo measured by Rosetta, derive a H-mag value based upon the effective diameter of the asteroid and point to (21) Lutetia having an extremely low thermal inertia (5 J m-2 s-0.5 K-1). This thermal inertia is only possible through the existence of a significant amount of small scale roughness which is not directly observable by the OSIRIS (Optical, Spectroscopic, and Infrared Imaging System) instrument on-board Rosetta. In addition, our results point to the existence of a hill/crater surface feature located on the asteroids southern region not observed by Rosetta. From our results, we conclude that only through the merging of in situ and remote sensing observations can a true global picture be obtained of this asteroid.

  14. The Herschel-ATLAS: Extragalatic Number Counts from 250 to 500 Microns

    NASA Technical Reports Server (NTRS)

    Clements, D. L.; Rigby, E.; Maddox, S.; Dunne, L.; Mortier, A.; Amblard, A.; Auld, R.; Bonfield, D.; Cooray, A.; Dariush, A.; Dye, S.; Eales, S.; Gardner, Jonathan P.; Ibar, E.; Ivison, R.; Leeuw, L.; Sibthorpe, B.; Smith, D. J. B.; Temi, P.; Pascale, E.; Pohlen, M.

    2010-01-01

    Aims.The Herschel-ATLAS survey (H-ATLAS) will be the largest area survey to be undertaken by the Herschel Space Observatory. It will cover 550 sq. deg. of extragalactic sky at wavelengths of 100, 160, 250, 350 and 500 microns when completed, reaching flux limits (50-) from 32 to 145mJy. We here present galaxy number counts obtained for SPIRE observations of the first -14 sq. deg. observed at 250, 350 and 500 m. Methods. Number counts are a fundamental tool in constraining models of galaxy evolution. We use source catalogs extracted from the H-ATLAS maps as the basis for such an analysis. Correction factors for completeness and flux boosting are derived by applying our extraction method to model catalogs and then applied to the raw observational counts. Results. We find a steep rise in the number counts at flux levels of 100-200mJy in all three SPIRE bands, consistent with results from BLAST. The counts are compared to a range of galaxy evolution models. None of the current models is an ideal fit to the data but all ascribe the steep rise to a population of luminous, rapidly evolving dusty galaxies at moderate to high redshift.

  15. HELP: The Herschel Extragalactic Legacy Project and The Coming of Age of Multi-wavelength Astrophysics

    NASA Astrophysics Data System (ADS)

    Vaccari, M.

    How did galaxies form and evolve? This is one of the most challenging questions in astronomy today. Answering it requires a careful combination of observational and theoretical work to reliably determine the observed properties of cosmic bodies over large portions of the distant Universe on the one hand, and accurately model the physical processes driving their evolution on the other. Most importantly, it requires bringing together disparate multi-wavelength and multi-resolution spectro-photometric datasets in an homogeneous and well-characterized manner so that they are suitable for a rigorous statistical analysis. The Herschel Extragalactic Legacy Project (HELP) funded by the EC FP7 SPACE program aims to achieve this goal by combining the expertise of optical, infrared and radio astronomers to provide a multi-wavelength database for the distant Universe as an accessible value-added resource for the astronomical community. It will do so by bringing together multi-wavelength datasets covering the 1,000 deg2 mapped by Herschel extragalactic surveys in an homogeneous and well-characterized manner, creating a joint lasting legacy from several ambitious sky surveys.

  16. Modeling the HD 32297 Debris Disk With Far-Infrared Herschel Data

    NASA Technical Reports Server (NTRS)

    Donaldson, J.K.; Lebreton, J.; Roberge, A.; Augereau, J.-C.; Krivov, A. V.

    2013-01-01

    HD 32297 is a young A-star (approx. 30 Myr) 112 pc away with a bright edge-on debris disk that has been resolved in scattered light. We observed the HD 32297 debris disk in the far-infrared and sub-millimeter with the Herschel Space Observatory PACS and SPIRE instruments, populating the spectral energy distribution (SED) from 63 to 500 micron..We aimed to determine the composition of dust grains in the HD 32297 disk through SED modeling, using geometrical constraints from the resolved imaging to break the degeneracies inherent in SED modeling. We found the best fitting SED model has two components: an outer ring centered around 110 AU, seen in the scattered light images, and an inner disk near the habitable zone of the star. The outer disk appears to be composed of grains>2 micron consisting of silicates, carbonaceous material, and water ice with an abundance ratio of 1:2:3 respectively and 90% porosity. These grains appear consistent with cometary grains, implying the underlying planetesimal population is dominated by comet-like bodies. We also discuss the 3.7 sigma detection of [C ii] emission at 158 micron with the Herschel PACS instrument, making HD 32297 one of only a handful of debris disks with circumstellar gas detected

  17. The bolometric and UV attenuation in normal spiral galaxies of the Herschel Reference Survey

    NASA Astrophysics Data System (ADS)

    Viaene, S.; Baes, M.; Bendo, G.; Boquien, M.; Boselli, A.; Ciesla, L.; Cortese, L.; De Looze, I.; Eales, S.; Fritz, J.; Karczewski, O. Ł.; Madden, S.; Smith, M. W. L.; Spinoglio, L.

    2016-02-01

    The dust in nearby galaxies absorbs a fraction of the UV-optical-near-infrared radiation produced by stars. This energy is consequently re-emitted in the infrared. We investigate the portion of the stellar radiation absorbed by spiral galaxies from the Herschel Reference Survey (HRS) by modelling their UV-to-submillimetre spectral energy distributions. Our models provide an attenuated and intrinsic spectral energy distribution (SED), from which we find that on average 32% of all starlight is absorbed by dust. We define the UV heating fraction as the percentage of dust luminosity that comes from absorbed UV photons and find this to be 56%, on average. This percentage varies with morphological type, with later types having significantly higher UV heating fractions. We find a strong correlation between the UV heating fraction and specific star formation rate and provide a power-law fit. Our models allow us to revisit the IRX - AFUV relations, and derive these quantities directly within a self-consistent framework. We calibrate this relation for different bins of NUV - r colour and provide simple relations to relate these parameters. We investigated the robustness of our method and conclude that the derived parameters are reliable within the uncertainties that are inherent to the adopted SED model. This calls for a deeper investigation of how well extinction and attenuation can be determined through panchromatic SED modelling. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  18. Lessons learned from the microbial analysis of the Herschel spacecraft during assembly, integration, and test operations.

    PubMed

    Moissl-Eichinger, Christine; Pukall, Rüdiger; Probst, Alexander J; Stieglmeier, Michaela; Schwendner, Petra; Mora, Maximilian; Barczyk, Simon; Bohmeier, Maria; Rettberg, Petra

    2013-12-01

    Understanding microbial diversity in spacecraft assembly clean rooms is of major interest with respect to planetary protection considerations. A coordinated screening of different clean rooms in Europe and South America by three German institutes [Deutsches Zentrum für Luft- und Raumfahrt (DLR), Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), and the Institute of Microbiology and Archaea Center, University of Regensburg] took place during the assembly, test, and launch operations of the Herschel spacecraft in 2006-2009. Through this campaign, we retrieved critical information regarding the microbiome within these clean rooms and on the Herschel spacecraft, which served as a model for upcoming ESA mission preparations. This "lessons learned" document summarizes and discusses the data we obtained during this sampling campaign. Additionally, we have taken the opportunity to create a database that includes all 16S rRNA gene sequences ever retrieved from molecular and cultivable diversity studies of spacecraft assembly clean rooms to compare the microbiomes of US, European, and South American facilities. PMID:24313230

  19. Herschel photometric observations of the low metallicity dwarf galaxy NGC 1705

    NASA Astrophysics Data System (ADS)

    O'Halloran, B.; Galametz, M.; Madden, S. C.; Auld, R.; Baes, M.; Barlow, M. J.; Bendo, G. J.; Bock, J. J.; Boselli, A.; Bradford, M.; Buat, V.; Castro-Rodriguez, N.; Chanial, P.; Charlot, S.; Ciesla, L.; Clements, D. L.; Cormier, D.; Cooray, A.; Cortese, L.; Davies, J. I.; Dwek, E.; Eales, S. A.; Elbaz, D.; Galliano, F.; Gear, W. K.; Glenn, J.; Gomez, H. L.; Hony, S.; Isaak, K. G.; Levenson, L. R.; Lu, N.; Okumura, K.; Oliver, S.; Page, M. J.; Panuzzo, P.; Papageorgiou, A.; Parkin, T. J.; Perez-Fournon, I.; Pohlen, M.; Rangwala, N.; Rigby, E. E.; Roussel, H.; Rykala, A.; Sacchi, N.; Sauvage, M.; Schulz, B.; Schirm, M. R. P.; Smith, M. W. L.; Spinoglio, L.; Srinivasan, S.; Stevens, J. A.; Symeonidis, M.; Trichas, M.; Vaccari, M.; Vigroux, L.; Wilson, C. D.; Wozniak, H.; Wright, G. S.; Zeilinger, W. W.

    2010-07-01

    We present Herschel SPIRE and PACS photometeric observations of the low metallicity (Z ~ 0.35 Z⊙) nearby dwarf galaxy, NGC 1705, in six wavelength bands as part of the Dwarf Galaxy Survey guaranteed time Herschel key program. We confirm the presence of two dominant circumnuclear IR-bright regions surrounding the central super star cluster that had been previously noted at mid-IR wavelengths and in the sub-mm by LABOCA. On constructing a global spectral energy distribution using the SPIRE and PACS photometry, in conjunction with archival IR measurements, we note the presence of an excess at sub-mm wavelengths. This excess suggests the presence of a signiPcant cold dust component within NGC 1705 and was modeled as an additional cold component in the SED. Although alternative explanations for the sub-mm excess beyond 350 μm, such as changes to the dust emissivity cannot be ruled out, the most likely explanation for the observed submillimetre excess is that of an additional cold dust component.

  20. The Herschel Virgo Cluster Survey . VII. Dust in cluster dwarf elliptical galaxies

    NASA Astrophysics Data System (ADS)

    De Looze, I.; Baes, M.; Zibetti, S.; Fritz, J.; Cortese, L.; Davies, J. I.; Verstappen, J.; Bendo, G. J.; Bianchi, S.; Clemens, M.; Bomans, D. J.; Boselli, A.; Corbelli, E.; Dariush, A.; di Serego Alighieri, S.; Fadda, D.; Garcia-Appadoo, D. A.; Gavazzi, G.; Giovanardi, C.; Grossi, M.; Hughes, T. M.; Hunt, L. K.; Jones, A. P.; Madden, S.; Pierini, D.; Pohlen, M.; Sabatini, S.; Smith, M. W. L.; Vlahakis, C.; Xilouris, E. M.

    2010-07-01

    We use the science demonstration phase data of the Herschel Virgo Cluster Survey to search for dust emission of early-type dwarf galaxies in the central regions of the Virgo cluster as an alternative way of identifying the interstellar medium. We present the first possible far-infrared detection of cluster early-type dwarf galaxies: VCC 781 and VCC 951 are detected at the 10σ level in the SPIRE 250 μm image. Both detected galaxies have dust masses of the order of 105 M_⊙ and average dust temperatures ≈20 K. The detection rate (less than 1%) is quite high compared to the 1.7% detection rate for Hi emission, considering that dwarfs in the central regions are more Hi deficient. We conclude that the removal of interstellar dust from dwarf galaxies resulting from ram pressure stripping, harassment, or tidal effects must be as efficient as the removal of interstellar gas. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. OT2_bsmith_3: Spirals, Bridges, and Tails: The Herschel View of Dust in Interacting Galaxies

    NASA Astrophysics Data System (ADS)

    Smith, B.

    2011-09-01

    The tidal features produced by gravitational interactions between galaxies may contribute significantly to the enrichment of the intergalactic medium in dust and heavy elements. However, at the present time little is known about the dust content and properties of tidal structures. To address this lack, we propose to use the PACS and SPIRE instruments on Herschel to image a sample of nine nearby interacting galaxies in six far-infrared/submm broadband filters. We will map the dust column density and temperature in the main bodies and tidal features of these galaxies, and compare the far-infrared/submm properties of these features with those of normal spirals and dwarf galaxies. We will compare the Herschel maps with already acquired GALEX UV, Spitzer IR, and ground-based optical data, and with population synthesis and radiative transfer codes, to investigate dust heating mechanisms and extinction in these galaxies. We will compare with available radio maps to investigate dust/gas ratios and star formation triggering mechanisms, and compare with numerical simulations of the interactions. Our sample includes the closest and best-studied examples of tidal dwarf galaxies and accretion-driven star formation. These will provide a good testbed for interpreting high redshift systems.

  2. Probing the molecular interstellar medium of M82 with Herschel-SPIRE spectroscopy

    NASA Astrophysics Data System (ADS)

    Panuzzo, P.; Rangwala, N.; Rykala, A.; Isaak, K. G.; Glenn, J.; Wilson, C. D.; Auld, R.; Baes, M.; Barlow, M. J.; Bendo, G. J.; Bock, J. J.; Boselli, A.; Bradford, M.; Buat, V.; Castro-Rodríguez, N.; Chanial, P.; Charlot, S.; Ciesla, L.; Clements, D. L.; Cooray, A.; Cormier, D.; Cortese, L.; Davies, J. I.; Dwek, E.; Eales, S. A.; Elbaz, D.; Fulton, T.; Galametz, M.; Galliano, F.; Gear, W. K.; Gomez, H. L.; Griffin, M.; Hony, S.; Levenson, L. R.; Lu, N.; Madden, S.; O'Halloran, B.; Okumura, K.; Oliver, S.; Page, M. J.; Papageorgiou, A.; Parkin, T. J.; Pérez-Fournon, I.; Pohlen, M.; Polehampton, E. T.; Rigby, E. E.; Roussel, H.; Sacchi, N.; Sauvage, M.; Schulz, B.; Schirm, M. R. P.; Smith, M. W. L.; Spinoglio, L.; Stevens, J. A.; Srinivasan, S.; Symeonidis, M.; Swinyard, B.; Trichas, M.; Vaccari, M.; Vigroux, L.; Wozniak, H.; Wright, G. S.; Zeilinger, W. W.

    2010-07-01

    We present the observations of the starburst galaxy M82 taken with the Herschel SPIRE Fourier-transform spectrometer. The spectrum (194-671 μm) shows a prominent CO rotational ladder from J = 4-3 to 13-12 emitted by the central region of M82. The fundamental properties of the gas are well constrained by the high J lines observed for the first time. Radiative transfer modeling of these high-S/N 12CO and 13CO lines strongly indicates a very warm molecular gas component at ~500 K and pressure of ~3×106 K cm-3, in good agreement with the H2 rotational lines measurements from Spitzer and ISO. We suggest that this warm gas is heated by dissipation of turbulence in the interstellar medium (ISM) rather than X-rays or UV flux from the straburst. This paper illustrates the promise of the SPIRE FTS for the study of the ISM of nearby galaxies. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. Herschel+Hubble Observations of a Multiply-Lensed Sub-millimeter Galaxy at z~3

    NASA Astrophysics Data System (ADS)

    Nayyeri, Hooshang; Cooray, Asantha R.; Calanog, Jae Alyson B.; Riechers, Dominik A.; Frayer, David T.; Herschel HERMES, H-ATLAS

    2016-01-01

    We present the results of our deep Keck/NIRC2 and Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) observations of an extremely star forming lensed dusty Sub-Millimeter Galaxy (SMG) identified from the Herschel Astrohysical Terahertz Large Area Survey (H-ATLAS). The object under study forms a complex lensing system that consists of four foreground aligned galaxies at z ~ 1 (measured from Keck/DEIMOS observations) with multiple lensing features that consist of giant arcs and counter images. Molecular line observations of the background source with Green Bank Telescope (GBT) and Combined Array for Research in Millimeter-wave Astronomy (CARMA) put it at a redshift of 2.685. Multi-band data from Keck, HST and Herschel yields a Star Formation Rate in excess of 1000 Solar masses per year putting this system among the most intensely star forming systems at z>2. The measured SFR puts this system well above the main sequence of star forming galaxies at z ~ 3. The measured gas fraction and molecular gas surface density measurements from long wavelength observations are consistent with theoretical models and observational trends of gas rich SMGs at high redshifts.

  4. An External Origin for Carbon Monoxide on Uranus from Herschel/SPIRE?

    NASA Astrophysics Data System (ADS)

    Teanby, N. A.; Irwin, P. G. J.

    2013-10-01

    Previous studies have demonstrated an external source of CO on Jupiter, Saturn, and Neptune. However, it has not been possible to demonstrate this on Uranus because of its low CO abundance, low upper-tropospheric temperatures, and low stratospheric thermal gradient, which make detection very challenging. Here we use 17 Herschel/SPIRE observation sequences spanning 3 yr (2009-2012), which cover 14.6-51.8 cm-1 with a combined integration time of 5 hr. These spectra were originally taken for routine calibration purposes, so were corrected for continuum offsets prior to analysis. The final stacked spectra had an extremely low noise level of 10-50 pW cm-2 sr-1/cm-1. Despite this, CO was not observed, but we were able to obtain stringent 3σ upper limits at the 0.1-0.2 bar level of 2.1 ppb for a uniform profile, and 9.4 ppb for a stratosphere-only profile—an order of magnitude improvement over previous studies. Comparison with observed CO fluorescence by Encrenaz et al. suggests the majority of Uranus' stratospheric CO has an external origin. It thus appears that external supply of oxygen species—via comets, micrometeorites, or dust—is an important process on all giant planets in our solar system. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  5. Wideband ultra-low noise cryogenic InP IF amplifiers for the Herschel mission radiometers

    NASA Astrophysics Data System (ADS)

    Lopez-Fernandez, Isaac; Gallego-Puyol, Juan D.; Diez, Carmen; Barcia, Alberto; Martin-Pintado, Jesus

    2003-02-01

    The sub-millimeter radiometers of the Herschel mission have very stringent requirements. The scientific goals require an instantaneous bandwidth of four GHz with very low noise, flat gain and low power dissipation. Short-term gain stability of the amplifier is important, because gain fluctuations could limit the sensitivity of the instrument. Besides, a highly reliable, low weight unit is required to be compatible with the space instrumentation standards. The amplifiers will be used in conjunction with HEB and SIS mixers in all 7 channels of the instrument. This paper describes the design, the special construction techniques and the results of the amplifiers built by Centro Astronómico de Yebes for the development model of the Herschel Heterodyne Instrument. The average noise temperature obtained in the 4-8 GHz band is 3.5 K, with a gain of 27 +/-1.1 dB at an ambient temperature of 15 K and keeping the total power dissipation below the allowed 4 mW. Normalized gain fluctuations were carefully measured, being lower than 1.5·10-4 Hz-1/2 @ 1 Hz. Space qualification of the design is in progress.

  6. VizieR Online Data Catalog: Panchromatic SED of Herschel sources (Berta+, 2013)

    NASA Astrophysics Data System (ADS)

    Berta, S.; Lutz, D.; Santini, P.; Wuyts, S.; Rosario, D.; Brisbin, D.; Cooray, A.; Franceschini, A.; Gruppioni, C.; Hatziminaoglou, E.; Hwang, H. S.; Le Floc'h, E.; Magnelli, B.; Nordon, R.; Oliver, S.; Page, M. J.; Popesso, P.; Pozzetti, L.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Roseboom, I.; Scott, D.; Symeonidis, M.; Valtchanov, I.; Viero, M.; Wang, L.

    2016-06-01

    Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S and COSMOS fields, it is possible to sample the 8-500 micron spectral energy distributions of galaxies with at least 7-10 bands. Extending to the UV, optical, and near- infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected 10 restframe color space, based on this rich data-set, using a superposition of multi-variate Gaussian modes. We use this model to classify galaxies and build median spectral energy distributions (SEDs) of each class, which are then fitted with a modified version of the MAGPHYS code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an Active Galactic Nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6-9 classes, spanning a large range of far- to near-IR luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z~1 Lyα-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eight other popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10-20%, the scatter being dominated more by fine tuning of the codes, rather

  7. VizieR Online Data Catalog: Panchromatic SED of Herschel sources (Berta+, 2013)

    NASA Astrophysics Data System (ADS)

    Berta, S.; Lutz, D.; Santini, P.; Wuyts, S.; Rosario, D.; Brisbin, D.; Cooray, A.; Franceschini, A.; Gruppioni, C.; Hatziminaoglou, E.; Hwang, H. S.; Le Floc'h, E.; Magnelli, B.; Nordon, R.; Oliver, S.; Page, M. J.; Popesso, P.; Pozzetti, L.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Roseboom, I.; Scott, D.; Symeonidis, M.; Valtchanov, I.; Viero, M.; Wang, L.

    2013-01-01

    Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S and COSMOS fields, it is possible to sample the 8-500 micron spectral energy distributions of galaxies with at least 7-10 bands. Extending to the UV, optical, and near- infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected 10 restframe color space, based on this rich data-set, using a superposition of multi-variate Gaussian modes. We use this model to classify galaxies and build median spectral energy distributions (SEDs) of each class, which are then fitted with a modified version of the MAGPHYS code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an Active Galactic Nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6-9 classes, spanning a large range of far- to near-IR luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z~1 Lyα-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eight other popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10-20%, the scatter being dominated more by fine tuning of the codes, rather

  8. Nondimensional quasi-steady analysis of magnetorheological dampers utilizing a Herschel-Bulkley model with preyield viscosity

    NASA Astrophysics Data System (ADS)

    John, Shaju; Wereley, Norman M.

    2003-07-01

    Dampers based on electrorheological (ER) and magnetorheolgical (MR) fluids can be analyzed under assumptions of quasi-steady, fully developed flow behavior. Models that have been used to characterize ER and MR dampers include the Bingham-plastic, the Herschel-Bulkley and biviscous models. In the Bingham-plastic and the Herschel-Bulkley models, the fluid exhibits rigid behavior in the preyield flow region. The difference between these two models lie in the modeling of the postyield behavior. In the case of the Bingham-plastic model, the postyield behavior is such that the shear stress is proportional to the shear rate. In contrast, the Herschel-Bulkley model assumes that the shear stress is proportional to a power law of the shearrate. In the biciscous model, the relationship between the shear stres and shear rate is linear in both the preyield and postyield regions with constant values of viscosities for the two regions. However, the preyield flow behavior exhibits a much high viscosity than that in the postyield. In the propose model, the assumption of preyield rigid behavior within the Herschel-Bulkley model has been relaxed while the postyield relationship based on the power law has been retained. Here the fluid undergoes Newtonian preyield viscous flow and has a non-Newtonian postyield behavior. Based on this model, we have analyzed the performance of a rectangular duct ER or MR valve. Typical results include shear stress and velocity profiles across the valve gap, equivalent damping and damping coefficients.

  9. William Herschel during the 1780-1810 era: A natural historian studies "maturation" of stars over immeasurable time

    NASA Astrophysics Data System (ADS)

    Sullivan, Woody

    2015-01-01

    (A) William Herschel (1738-1822) considered himself a natural historian, different only from the usual natural historians in that his focus was on stars and nebulae rather than plants, animals, and minerals. In this regard, he developed ideas concerning changes over very long times, inferred from his catalogues of 2500 star clusters and nebulae. By assuming that all the observed types of star clusters and morphologies of nebulae represented different stages in the formation of stars and clusters under the action of gravity, Herschel argued for a sequence of "maturation," or evolution as we would call it. He could put no definite time scale on these dynamic processes, but inspired by contemporary geologists such as James Hutton and John Michell (yes, he was a geologist, too!), he felt that the time scales must be very long. In further support, he photometrically estimated that the very faintest stars that he could see in his giant 40-ft telescope were about two million light-years distant. Herschel's findings on the structure and age of the Milky Way system, his "construction of the heavens," were also influenced by geological notions of the formation and subsequent warping of strata over long times, and the geologists' attempts to uncover the interior and distant past of the Earth. (B) Herschel was a very successful professional musician for two decades, primarily in the fashionable resort city of Bath, England. And then he discovered Uranus in 1781 at age 43, an event that catapulted him into celebrity and allowed him immediately to transform himself into a full-time astronomer. He composed over twenty symphonies, many concertos, and a large number of organ and choral works. During this session, a chorus of University of Washington students will present a short concert featuring Herschel's most popular composition, a novelty number called "The Eccho Catch," as well as contemporary pieces with astronomical themes by other composers.

  10. HERschel Observations of Edge-on Spirals (HEROES). I. Far-infrared morphology and dust mass determination

    NASA Astrophysics Data System (ADS)

    Verstappen, J.; Fritz, J.; Baes, M.; Smith, M. W. L.; Allaert, F.; Bianchi, S.; Blommaert, J. A. D. L.; De Geyter, G.; De Looze, I.; Gentile, G.; Gordon, K. D.; Holwerda, B. W.; Viaene, S.; Xilouris, E. M.

    2013-08-01

    Context. Edge-on spiral galaxies with prominent dust lanes provide us with an excellent opportunity to study the distribution and properties of the dust within them. The HEROES project was set up to observe a sample of seven large edge-on galaxies across various wavelengths for this investigation. Aims: Within this first paper, we present the Herschel observations and perform a qualitative and quantitative analysis on them, and we derive some global properties of the far infrared and submillimetre emission. Methods: We determine horizontal and vertical profiles from the Herschel observations of the galaxies in the sample and describe the morphology. Modified black-body fits to the global fluxes, measured using aperture photometry, result in dust temperatures and dust masses. The latter values are compared to those that are derived from radiative transfer models taken from the literature. Results: On the whole, our Herschel flux measurements agree well with archival values. We find that the exponential horizontal dust distribution model often used in the literature generally provides a good description of the observed horizontal profiles. Three out of the seven galaxies show signatures of extended vertical emission at 100 and 160 μm at the 5σ level, but in two of these it is probably due to deviations from an exactly edge-on orientation. Only for NGC 4013, a galaxy in which vertically extended dust has already been detected in optical images, we can detect vertically extended dust, and the derived scaleheight agrees with the value estimated through radiative transfer modelling. Our analysis hints at a correlation between the dust scaleheight and its degree of clumpiness, which we infer from the difference between the dust masses as calculated from modelling of optical data and from fitting the spectral energy distribution of Herschel datapoints. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia

  11. Identification of z ≳ 2 Herschel 500 μM Sources Using Color Deconfusion

    NASA Astrophysics Data System (ADS)

    Shu, X. W.; Elbaz, D.; Bourne, N.; Schreiber, C.; Wang, T.; Dunlop, J. S.; Fontana, A.; Leiton, R.; Pannella, M.; Okumura, K.; Michałowski, M. J.; Santini, P.; Merlin, E.; Buitrago, F.; Bruce, V. A.; Amorin, R.; Castellano, M.; Derriere, S.; Comastri, A.; Cappelluti, N.; Wang, J. X.; Ferguson, H. C.

    2016-01-01

    We present a new method to search for candidate z ≳ 2 Herschel 500 μm sources in the Great Observatories Origins Deep Survey-North field using a S500 μm/S24 μm “color deconfusion” technique. Potential high-z sources are selected against low-redshift ones from their large 500 to 24 μm flux density ratios. By effectively reducing the contribution from low-redshift populations to the observed 500 μm emission, we are able to identify counterparts to high-z 500 μm sources whose 24 μm fluxes are relatively faint. The recovery of known z ≳ 4 starbursts confirms the efficiency of this approach in selecting high-z Herschel sources. The resulting sample consists of 34 dusty star-forming galaxies at z ≳ 2. The inferred infrared luminosities are in the range 1.5 × 1012-1.8 × 1013 L⊙, corresponding to dust-obscured star formation rates (SFRs) of ˜260-3100 M⊙ yr-1 for a Salpeter initial mass function. Comparison with previous SCUBA 850 μ {{m}}-selected galaxy samples shows that our method is more efficient at selecting high-z dusty galaxies, with a median redshift of z=3.07+/- 0.83 and with 10 of the sources at z ≳ 4. We find that at a fixed luminosity, the dust temperature is ˜5 K cooler than that expected from the {T}d-{L}{{IR}} relation at z\\quad ≲ 1, though different temperature selection effects should be taken into account. The radio-detected subsample (excluding three strong active galactic nucleus) follows the far-infrared (far-IR)/radio correlation at lower redshifts, and no evolution with redshift is observed out to z˜ 5, suggesting that the far-IR emission is star formation dominated. The contribution of the high-z Herschel 500 μm sources to the cosmic SFR density is comparable to that of (sub)millimeter galaxy populations at z˜ 2.5 and at least 40% of the extinction-corrected UV samples at z˜ 4. Further investigation into the nature of these high-z dusty galaxies will be crucial for our understanding of the star formation histories

  12. FAR-INFRARED LINE SPECTRA OF SEYFERT GALAXIES FROM THE HERSCHEL-PACS SPECTROMETER

    SciTech Connect

    Spinoglio, Luigi; Pereira-Santaella, Miguel; Busquet, Gemma; Dasyra, Kalliopi M.; Calzoletti, Luca; Malkan, Matthew A.; Tommasin, Silvia

    2015-01-20

    We observed the far-IR fine-structure lines of 26 Seyfert galaxies with the Herschel-PACS spectrometer. These observations are complemented with Spitzer Infrared Spectrograph and Herschel SPIRE spectroscopy. We used the ionic lines to determine electron densities in the ionized gas and the [C I] lines, observed with SPIRE, to measure the neutral gas densities, while the [O I] lines measure the gas temperature, at densities below ∼10{sup 4} cm{sup –3}. Using the [O I]145 μm/63 μm and [S III]33/18 μm line ratios, we find an anti-correlation of the temperature with the gas density. Various fine-structure line ratios show density stratifications in these active galaxies. On average, electron densities increase with the ionization potential of the ions. The infrared lines arise partly in the narrow line region, photoionized by the active galactic nucleus (AGN), partly in H II regions photoionized by hot stars, and partly in photo-dissociated regions. We attempt to separate the contributions to the line emission produced in these different regions by comparing our observed emission line ratios to theoretical values. In particular, we tried to separate the contribution of AGNs and star formation by using a combination of Spitzer and Herschel lines, and we found that besides the well-known mid-IR line ratios, the line ratio of [O III]88 μm/[O IV]26 μm can reliably discriminate the two emission regions, while the far-IR line ratio of [C II]157 μm/[O I]63 μm is only able to mildly separate the two regimes. By comparing the observed [C II]157 μm/[N II]205 μm ratio with photoionization models, we also found that most of the [C II] emission in the galaxies we examined is due to photodissociation regions.

  13. Herschel view of the large-scale structure in the Chamaeleon dark clouds

    NASA Astrophysics Data System (ADS)

    Alves de Oliveira, C.; Schneider, N.; Merín, B.; Prusti, T.; Ribas, Á.; Cox, N. L. J.; Vavrek, R.; Könyves, V.; Arzoumanian, D.; Puga, E.; Pilbratt, G. L.; Kóspál, Á.; André, Ph.; Didelon, P.; Men'shchikov, A.; Royer, P.; Waelkens, C.; Bontemps, S.; Winston, E.; Spezzi, L.

    2014-08-01

    Context. The Chamaeleon molecular cloud complex is one of the nearest star-forming sites and encompasses three molecular clouds (Cha I, II, and III) that have a different star-formation history, from quiescent (Cha III) to actively forming stars (Cha II), and one that reaches the end of star-formation (Cha I). Aims: We aim at characterising the large-scale structure of the three sub-regions of the Chamaeleon molecular cloud complex by analysing new far-infrared images taken with the Herschel Space Observatory. Methods: We derived column density and temperature maps using PACS and SPIRE observations from the Herschel Gould Belt Survey and applied several tools, such as filament tracing, power-spectra, Δ-variance, and probability distribution functions (PDFs) of the column density, to derive the physical properties. Results: The column density maps reveal a different morphological appearance for each of the three clouds, with a ridge-like structure for Cha I, a clump-dominated regime for Cha II, and an intricate filamentary network for Cha III. The filament width is measured to be about 0.12 ± 0.04 pc in the three clouds, and the filaments are found to be gravitationally unstable in Cha I and II, but mostly subcritical in Cha III. Faint filaments (striations) are prominent in Cha I and are mostly aligned with the large-scale magnetic field. The PDFs of all regions show a lognormal distribution at low column densities. For higher densities, the PDF of Cha I shows a turnover indicative of an extended higher density component and culminates in a power-law tail. Cha II shows a power-law tail with a slope characteristic of gravity. The PDF of Cha III can be best fit by a single lognormal. Conclusions: The turbulence properties of the three regions are found to be similar, pointing towards a scenario where the clouds are impacted by large-scale processes. The magnetic field might possibly play an important role for the star formation efficiency in the Chamaeleon clouds

  14. VizieR Online Data Catalog: NGC 891 Herschel PACS and SPIRE spectroscopy (Hughes+, 2015)

    NASA Astrophysics Data System (ADS)

    Hughes, T. M.; Foyle, K.; Schirm, M. R. P.; Parkin, T. J.; de Looze, I.; Wilson, C. D.; Bendo, G. J.; Baes, M.; Fritz, J.; Boselli, A.; Cooray, A.; Cormier, D.; Karczewski, O. L.; Lebouteiller, V.; Lu, N.; Madden, S. C.; Spinoglio, L.; Viaene, S.

    2014-10-01

    We present Herschel PACS spectroscopic observations of the [CII] 158, [NII] 122, [OI] 63, 145, and [OIII] 88 micron fine-structure lines in NGC 891 taken has part of the Very Nearby Galaxy Survey (P.I.: C. Wilson). Observations were taken on the 28th February and 1st March, 2011, using the unchopped grating scan mode. They were processed from Level 0 to Level 1 using the Herschel Interactive Processing Environment (HIPE) v.9.2 with calibration files FM,41, following the standard pipeline reduction steps for the unchopped observing mode. Level 1 cubes were exported to PACSman v.3.5.2 (Lebouteiller, 2012A&A...548A..91L), where each individual spaxel's spectrum is fit with a Gaussian function and second order polynomial for the line and continuum baseline, respectively. Intensity maps of the integrated flux are created from the individual rasters, also using PACSman, by projecting the rasters onto a common, over-sampled grid with a 3.133 arcsec pixel size. Complete details on the data reduction may be found in the paper. Our data files are summarised in cubes.dat. Each file is a FITS cube with 8 planes, where each plane contains the following maps: (1.) integrated intensity map in units of W/m2/sr, (2.) integrated intensity error map in units of W/m2/sr, (3.) velocity map in units of km/s, (4.) velocity error map in units of km/s, (5.) full-width at half-maximum map of the line fit in units of km/s, (6.) full-width at half-maximum error map in units of km/s, (7.) continuum map in Jy, and (8.) continuum error map in units of Jy. Please note that the observations consist of raster maps and strips for the [CII], [NII] and [OI] 63 micron lines, and only strips for the remaining lines. The raw data can be retrieved from the Herschel Science Archive (ESA) with the stated OBSIDs. (2 data files).

  15. The pattern of extreme star formation events in SDSS quasar hosts in Herschel fields

    NASA Astrophysics Data System (ADS)

    Pitchford, Lura Katherine; Hatziminaoglou, Evanthia; Feltre, Anna; Clarke, Charlotte; Farrah, Duncan; Harris, Kathryn Amy; Hurley, Peter; Oliver, Sebastian; Page, Mat; Wang, Lingyu

    2016-01-01

    Using a sample of ~500 quasars up to redshifts of ~4 detected by the Sloan Digital Sky Survey (SDSS) and the Spectral and Photometric Imaging Receiver (SPIRE) instrument of Herschel, we describe the behavior of intense starbursts in luminous quasars and how it correlates with the properties of the active galactic nuclei (AGN). We select our objects in the Herschel Stripe 82 Survey (HerS) and in the largest fields of the Herschel Multi-tiered Extragalactic Survey (HerMES), including the HerMES Large Mode Survey (HeLMS).The far-infrared (FIR) emission of our objects is quantified using a spectral energy distribution (SED) fitting technique. As our sources are individually detected in the SPIRE bands, they are bright in the FIR, exhibiting typical star formation rates (SFRs) of order of 1000 M⊙yr-1. We find the SFR to increase by a factor of nearly ten from z~0.5 to z~3, in line with the increasing comoving SFR density over a similar redshift range. The SFR, however, is shown to remain constant with increasing quasar luminosity for quasars with IR luminosities above 1012L⊙, indicating a self-regulating star formation process rather than a suppression effect due to the presence of powerful AGN. We find no further proof of a causal relation between star formation and accretion onto the central black hole, as the SFR and the Eddington ratio, λEdd, are found to be uncorrelated.We then compare the broad absorption line (BAL) quasars to the rest of the quasar population, as they are candidates for outflows in action from which shorter-term feedback effects could be sought. We find the accretion luminosities and λEdd values of BAL quasars to be drawn from the same population as those of the non-BAL quasars; further, the host SFRs are statistically similar among the two populations, all of which argue against feedback effects. These similarities also oppose an evolutionary scenario, as a different evolutionary stage would imply differences in either the accretion state

  16. Spatial distribution of water in the stratosphere of Jupiter from observations with the Herschel space observatory

    NASA Astrophysics Data System (ADS)

    Cavalié, T.; Feuchtgruber, H.; Lellouch, E.; de Val-Borro, M.; Jarchow, C.; Moreno, R.; Hartogh, P.; Orton, G.; Greathouse, T. K.; Billebaud, F.; Dobrijevic, M.; Lara, L. M.; Gonzalez, A.; Sagawa, H.

    2013-09-01

    Water in the atmospheres of the outer planets has both an internal and an external source (e.g., [1] and [2] for Jupiter). These sources are separated by a condensation layer, the tropopause cold trap, which acts as a transport barrier between the troposphere and the stratosphere. Thus, the water vapor observed by the Infrared Space Observatory (ISO) in the stratosphere of the giant planets has an external origin [3]. This external supply of water may have several sources: (i) a permanent flux from interplanetary dust particles produced from asteroid collisions and from comet activity [4], (ii) local sources from planetary environments (rings, satellites) [5], (iii) cometary "Shoemaker-Levy 9 (SL9) type" impacts [6]. In the past 15 years, several studies suggested that water in the stratosphere of Jupiter originated from the SL9 comet impacts in July 1994, but a direct proof was missing. We will report the first high S/N spatially resolved mapping observations of water in Jupiter's stratosphere carried out with the Heterodyne Instrument for the Far Infrared (HIFI) [7] and Photodetector Array Camera and Spectrometer (PACS) [8] instruments onboard the ESA Herschel Space Observatory [9]. These observations have been obtained in the framework of the Guaranteed Time Key Program "Water and related chemistry in the Solar System", also known as "Herschel Solar System Observations" (HssO) [10]. In parallel, we have monitored Jupiter's stratospheric temperature with the NASA Infrared Telescope Facility (IRTF) to separate temperature from water variability. We will present the results recently published by our team [11]. Water is found to be restricted to pressures lower than 2mbar. Its column density decreases by a factor of 2-3 between southern and northern latitudes (see Fig. 1), consistently between the HIFI and the PACS 66.4μm maps. Latitudinal temperature variability cannot explain the global north-south asymmetry in the water maps. From the latitudinal and vertical

  17. Direct estimate of cirrus noise in Herschel Hi-GAL images

    NASA Astrophysics Data System (ADS)

    Martin, P. G.; Miville-Deschênes, M.-A.; Roy, A.; Bernard, J.-P.; Molinari, S.; Billot, N.; Brunt, C.; Calzoletti, L.; Digiorgio, A. M.; Elia, D.; Faustini, F.; Joncas, G.; Mottram, J. C.; Natoli, P.; Noriega-Crespo, A.; Paladini, R.; Robitaille, J. F.; Strafella, F.; Traficante, A.; Veneziani, M.

    2010-07-01

    In Herschel images of the Galactic plane and many star forming regions, a major factor limiting our ability to extract faint compact sources is cirrus confusion noise, operationally defined as the “statistical error to be expected in photometric measurements due to confusion in a background of fluctuating surface brightness”. The histogram of the flux densities of extracted sources shows a distinctive faint-end cutoff below which the catalog suffers from incompleteness and the flux densities become unreliable. This empirical cutoff should be closely related to the estimated cirrus noise and we show that this is the case. We compute the cirrus noise directly, both on Herschel images from which the bright sources have been removed and on simulated images of cirrus with statistically similar fluctuations. We connect these direct estimates with those from power spectrum analysis, which has been used extensively to predict the cirrus noise and provides insight into how it depends on various statistical properties and photometric operational parameters. We report multi-wavelength power spectra of diffuse Galactic dust emission from Hi-GAL observations at 70 to 500 μm within Galactic plane fields at l = 30 °and l = 59 °. We find that the exponent of the power spectrum is about -3. At 250 μm, the amplitude of the power spectrum increases roughly as the square of the median brightness of the map and so the expected cirrus noise scales linearly with the median brightness. For a given region, the wavelength dependence of the amplitude can be described by the square of the spectral energy distribution (SED) of the dust emission. Generally, the confusion noise will be a worse problem at longer wavelengths, because of the combination of lower angular resolution and the rising power spectrum of cirrus toward lower spatial frequencies, but the photometric signal to noise will also depend on the relative SED of the source compared to the cirrus. Herschel is an ESA space

  18. Pillars and globules at the edges of H ii regions. Confronting Herschel observations and numerical simulations

    NASA Astrophysics Data System (ADS)

    Tremblin, P.; Minier, V.; Schneider, N.; Audit, E.; Hill, T.; Didelon, P.; Peretto, N.; Arzoumanian, D.; Motte, F.; Zavagno, A.; Bontemps, S.; Anderson, L. D.; André, Ph.; Bernard, J. P.; Csengeri, T.; Di Francesco, J.; Elia, D.; Hennemann, M.; Könyves, V.; Marston, A. P.; Nguyen Luong, Q.; Rivera-Ingraham, A.; Roussel, H.; Sousbie, T.; Spinoglio, L.; White, G. J.; Williams, J.

    2013-12-01

    Context. Herschel far-infrared imaging observations have revealed the density structure of the interface between H ii regions and molecular clouds in great detail. In particular, pillars and globules are present in many high-mass star-forming regions, such as the Eagle nebula (M 16) and the Rosette molecular cloud, and understanding their origin will help characterize triggered star formation. Aims: The formation mechanisms of these structures are still being debated. The initial morphology of the molecular cloud and its turbulent state are key parameters since they generate deformations and curvatures of the shell during the expansion of the H ii region. Recent numerical simulations have shown how pillars can arise from the collapse of the shell in on itself and how globules can be formed from the interplay of the turbulent molecular cloud and the ionization from massive stars. The goal here is to test this scenario through recent observations of two massive star-forming regions, M 16 and the Rosette molecular cloud. Methods: First, the column density structure of the interface between molecular clouds and associated H ii regions was characterized using column density maps obtained from far-infrared imaging of the Herschel HOBYS key programme. Then, the DisPerSe algorithm was used on these maps to detect the compressed layers around the ionized gas and pillars in different evolutionary states. Column density profiles were constructed. Finally, their velocity structure was investigated using CO data, and all observational signatures were tested against some distinct diagnostics established from simulations. Results: The column density profiles have revealed the importance of compression at the edge of the ionized gas. The velocity properties of the structures, i.e. pillars and globules, are very close to what we predict from the numerical simulations. We have identified a good candidate of a nascent pillar in the Rosette molecular cloud that presents the velocity

  19. The Herschel-SPIRE instrument and its in-flight performance

    NASA Astrophysics Data System (ADS)

    Griffin, M. J.; Abergel, A.; Abreu, A.; Ade, P. A. R.; André, P.; Augueres, J.-L.; Babbedge, T.; Bae, Y.; Baillie, T.; Baluteau, J.-P.; Barlow, M. J.; Bendo, G.; Benielli, D.; Bock, J. J.; Bonhomme, P.; Brisbin, D.; Brockley-Blatt, C.; Caldwell, M.; Cara, C.; Castro-Rodriguez, N.; Cerulli, R.; Chanial, P.; Chen, S.; Clark, E.; Clements, D. L.; Clerc, L.; Coker, J.; Communal, D.; Conversi, L.; Cox, P.; Crumb, D.; Cunningham, C.; Daly, F.; Davis, G. R.; de Antoni, P.; Delderfield, J.; Devin, N.; di Giorgio, A.; Didschuns, I.; Dohlen, K.; Donati, M.; Dowell, A.; Dowell, C. D.; Duband, L.; Dumaye, L.; Emery, R. J.; Ferlet, M.; Ferrand, D.; Fontignie, J.; Fox, M.; Franceschini, A.; Frerking, M.; Fulton, T.; Garcia, J.; Gastaud, R.; Gear, W. K.; Glenn, J.; Goizel, A.; Griffin, D. K.; Grundy, T.; Guest, S.; Guillemet, L.; Hargrave, P. C.; Harwit, M.; Hastings, P.; Hatziminaoglou, E.; Herman, M.; Hinde, B.; Hristov, V.; Huang, M.; Imhof, P.; Isaak, K. J.; Israelsson, U.; Ivison, R. J.; Jennings, D.; Kiernan, B.; King, K. J.; Lange, A. E.; Latter, W.; Laurent, G.; Laurent, P.; Leeks, S. J.; Lellouch, E.; Levenson, L.; Li, B.; Li, J.; Lilienthal, J.; Lim, T.; Liu, S. J.; Lu, N.; Madden, S.; Mainetti, G.; Marliani, P.; McKay, D.; Mercier, K.; Molinari, S.; Morris, H.; Moseley, H.; Mulder, J.; Mur, M.; Naylor, D. A.; Nguyen, H.; O'Halloran, B.; Oliver, S.; Olofsson, G.; Olofsson, H.-G.; Orfei, R.; Page, M. J.; Pain, I.; Panuzzo, P.; Papageorgiou, A.; Parks, G.; Parr-Burman, P.; Pearce, A.; Pearson, C.; Pérez-Fournon, I.; Pinsard, F.; Pisano, G.; Podosek, J.; Pohlen, M.; Polehampton, E. T.; Pouliquen, D.; Rigopoulou, D.; Rizzo, D.; Roseboom, I. G.; Roussel, H.; Rowan-Robinson, M.; Rownd, B.; Saraceno, P.; Sauvage, M.; Savage, R.; Savini, G.; Sawyer, E.; Scharmberg, C.; Schmitt, D.; Schneider, N.; Schulz, B.; Schwartz, A.; Shafer, R.; Shupe, D. L.; Sibthorpe, B.; Sidher, S.; Smith, A.; Smith, A. J.; Smith, D.; Spencer, L.; Stobie, B.; Sudiwala, R.; Sukhatme, K.; Surace, C.; Stevens, J. A.; Swinyard, B. M.; Trichas, M.; Tourette, T.; Triou, H.; Tseng, S.; Tucker, C.; Turner, A.; Vaccari, M.; Valtchanov, I.; Vigroux, L.; Virique, E.; Voellmer, G.; Walker, H.; Ward, R.; Waskett, T.; Weilert, M.; Wesson, R.; White, G. J.; Whitehouse, N.; Wilson, C. D.; Winter, B.; Woodcraft, A. L.; Wright, G. S.; Xu, C. K.; Zavagno, A.; Zemcov, M.; Zhang, L.; Zonca, E.

    2010-07-01

    The Spectral and Photometric Imaging REceiver (SPIRE), is the Herschel Space Observatory`s submillimetre camera and spectrometer. It contains a three-band imaging photometer operating at 250, 350 and 500 μm, and an imaging Fourier-transform spectrometer (FTS) which covers simultaneously its whole operating range of 194-671 μm (447-1550 GHz). The SPIRE detectors are arrays of feedhorn-coupled bolometers cooled to 0.3 K. The photometer has a field of view of 4´× 8´, observed simultaneously in the three spectral bands. Its main operating mode is scan-mapping, whereby the field of view is scanned across the sky to achieve full spatial sampling and to cover large areas if desired. The spectrometer has an approximately circular field of view with a diameter of 2.6´. The spectral resolution can be adjusted between 1.2 and 25 GHz by changing the stroke length of the FTS scan mirror. Its main operating mode involves a fixed telescope pointing with multiple scans of the FTS mirror to acquire spectral data. For extended source measurements, multiple position offsets are implemented by means of an internal beam steering mirror to achieve the desired spatial sampling and by rastering of the telescope pointing to map areas larger than the field of view. The SPIRE instrument consists of a cold focal plane unit located inside the Herschel cryostat and warm electronics units, located on the spacecraft Service Module, for instrument control and data handling. Science data are transmitted to Earth with no on-board data compression, and processed by automatic pipelines to produce calibrated science products. The in-flight performance of the instrument matches or exceeds predictions based on pre-launch testing and modelling: the photometer sensitivity is comparable to or slightly better than estimated pre-launch, and the spectrometer sensitivity is also better by a factor of 1.5-2. Herschel is an ESA space observatory with science instruments provided by European-led Principal

  20. Far Infrared Variability of Sagittarius A*: 25.5 hr of Monitoring with Herschel

    NASA Astrophysics Data System (ADS)

    Stone, Jordan M.; Marrone, D. P.; Dowell, C. D.; Schulz, B.; Heinke, C. O.; Yusef-Zadeh, F.

    2016-07-01

    Variable emission from Sgr A*, the luminous counterpart to the super-massive black hole at the center of our Galaxy, arises from the innermost portions of the accretion flow. Better characterization of the variability is important for constraining models of the low-luminosity accretion mode powering Sgr A*, and could further our ability to use variable emission as a probe of the strong gravitational potential in the vicinity of the 4× {10}6{M}ȯ black hole. We use the Herschel Spectral and Photometric Imaging Receiver (SPIRE) to monitor Sgr A* at wavelengths that are difficult or impossible to observe from the ground. We find highly significant variations at 0.25, 0.35, and 0.5 mm, with temporal structure that is highly correlated across these wavelengths. While the variations correspond to \\lt 1 % changes in the total intensity in the Herschel beam containing Sgr A*, comparison to independent, simultaneous observations at 0.85 mm strongly supports the reality of the variations. The lowest point in the light curves, ∼0.5 Jy below the time-averaged flux density, places a lower bound on the emission of Sgr A* at 0.25 mm, the first such constraint on the THz portion of the spectral energy distribution. The variability on few hour timescales in the SPIRE light curves is similar to that seen in historical 1.3 mm data, where the longest time series is available, but the distribution of variations in the sub-mm do not show a tail of large-amplitude variations seen at 1.3 mm. Simultaneous X-ray photometry from XMM-Newton shows no significant variation within our observing period, which may explain the lack of very large submillimeter variations in our data if X-ray and submillimeter flares are correlated. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. A REDSHIFT SURVEY OF HERSCHEL FAR-INFRARED SELECTED STARBURSTS AND IMPLICATIONS FOR OBSCURED STAR FORMATION

    SciTech Connect

    Casey, C. M.; Budynkiewicz, J.; Berta, S.; Lutz, D.; Magnelli, B.; Bethermin, M.; Le Floc'h, E.; Magdis, G.; Burgarella, D.; Chapin, E.; Chapman, S. C.; Clements, D. L.; Conley, A.; Conselice, C. J.; Cooray, A.; Farrah, D.; Hatziminaoglou, E.; Ivison, R. J.; and others

    2012-12-20

    We present Keck spectroscopic observations and redshifts for a sample of 767 Herschel-SPIRE selected galaxies (HSGs) at 250, 350, and 500 {mu}m, taken with the Keck I Low Resolution Imaging Spectrometer and the Keck II DEep Imaging Multi-Object Spectrograph. The redshift distribution of these SPIRE sources from the Herschel Multitiered Extragalactic Survey peaks at z = 0.85, with 731 sources at z < 2 and a tail of sources out to z {approx} 5. We measure more significant disagreement between photometric and spectroscopic redshifts (({Delta}z/(1 + z{sub spec})) = 0.29) than is seen in non-infrared selected samples, likely due to enhanced star formation rates and dust obscuration in infrared-selected galaxies. The infrared data are used to directly measure integrated infrared luminosities and dust temperatures independent of radio or 24 {mu}m flux densities. By probing the dust spectral energy distribution (SED) at its peak, we estimate that the vast majority (72%-83%) of z < 2 Herschel-selected galaxies would drop out of traditional submillimeter surveys at 0.85-1 mm. We find that dust temperature traces infrared luminosity, due in part to the SPIRE wavelength selection biases, and partially from physical effects. As a result, we measure no significant trend in SPIRE color with redshift; if dust temperature were independent of luminosity or redshift, a trend in SPIRE color would be expected. Composite infrared SEDs are constructed as a function of infrared luminosity, showing the increase in dust temperature with luminosity, and subtle change in near-infrared and mid-infrared spectral properties. Moderate evolution in the far-infrared (FIR)/radio correlation is measured for this partially radio-selected sample, with q{sub IR}{proportional_to}(1 + z){sup -0.30{+-}0.02} at z < 2. We estimate the luminosity function and implied star formation rate density contribution of HSGs at z < 1.6 and find overall agreement with work based on 24 {mu}m extrapolations of the LIRG

  2. A POPULATION OF z > 2 FAR-INFRARED HERSCHEL-SPIRE-SELECTED STARBURSTS

    SciTech Connect

    Casey, C. M.; Berta, S.; Lutz, D.; Magnelli, B.; Bethermin, M.; Floc'h, E. le; Magdis, G.; Burgarella, D.; Chapin, E.; Chapman, S. C.; Clements, D. L.; Conley, A.; Conselice, C. J.; Farrah, D.; Hatziminaoglou, E.; Ivison, R. J.; Oliver, S. J.; and others

    2012-12-20

    We present spectroscopic observations for a sample of 36 Herschel-SPIRE 250-500 {mu}m selected galaxies (HSGs) at 2 < z < 5 from the Herschel Multi-tiered Extragalactic Survey. Redshifts are confirmed as part of a large redshift survey of Herschel-SPIRE-selected sources covering {approx}0.93 deg{sup 2} in six extragalactic legacy fields. Observations were taken with the Keck I Low Resolution Imaging Spectrometer and the Keck II DEep Imaging Multi-Object Spectrograph. Precise astrometry, needed for spectroscopic follow-up, is determined by identification of counterparts at 24 {mu}m or 1.4 GHz using a cross-identification likelihood matching method. Individual source luminosities range from log (L{sub IR}/L{sub Sun }) = 12.5-13.6 (corresponding to star formation rates (SFRs) 500-9000 M{sub Sun} yr{sup -1}, assuming a Salpeter initial mass function), constituting some of the most intrinsically luminous, distant infrared galaxies discovered thus far. We present both individual and composite rest-frame ultraviolet spectra and infrared spectral energy distributions. The selection of these HSGs is reproducible and well characterized across large areas of the sky in contrast to most z > 2 HyLIRGs in the literature, which are detected serendipitously or via tailored surveys searching only for high-z HyLIRGs; therefore, we can place lower limits on the contribution of HSGs to the cosmic star formation rate density (SFRD) at (7 {+-} 2) Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1} h {sup 3} Mpc{sup -3} at z {approx} 2.5, which is >10% of the estimated total SFRD of the universe from optical surveys. The contribution at z {approx} 4 has a lower limit of 3 Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1} h {sup 3} Mpc{sup -3}, {approx}>20% of the estimated total SFRD. This highlights the importance of extremely infrared-luminous galaxies with high SFRs to the buildup of stellar mass, even at the earliest epochs.

  3. Molecule survival in magnetized protostellar disk winds. II. Predicted H2O line profiles versus Herschel/HIFI observations

    NASA Astrophysics Data System (ADS)

    Yvart, W.; Cabrit, S.; Pineau des Forêts, G.; Ferreira, J.

    2016-01-01

    Context. The origin of molecular protostellar jets and their role in extracting angular momentum from the accreting system are important open questions in star formation research. In the first paper of this series we showed that a dusty magneto-hydrodynamic (MHD) disk wind appeared promising to explain the pattern of H2 temperature and collimation in the youngest jets. Aims: We wish to see whether the high-quality H2O emission profiles of low-mass protostars, observed for the first time by the HIFI spectrograph on board the Herschel satellite, remain consistent with the MHD disk wind hypothesis, and which constraints they would set on the underlying disk properties. Methods: We present synthetic H2O line profiles predictions for a typical MHD disk wind solution with various values of disk accretion rate, stellar mass, extension of the launching area, and view angle. We compare them in terms of line shapes and intensities with the HIFI profiles observed by the WISH key program towards a sample of 29 low-mass Class 0 and Class 1 protostars. Results: A dusty MHD disk wind launched from 0.2-0.6 AU AU to 3-25 AU can reproduce to a remarkable degree the observed shapes and intensities of the broad H2O component observed in low-mass protostars, both in the fundamental 557 GHz line and in more excited lines. Such a model also readily reproduces the observed correlation of 557 GHz line luminosity with envelope density, if the infall rate at 1000 AU is 1-3 times the disk accretion rate in the wind ejection region. It is also compatible with the typical disk size and bolometric luminosity in the observed targets. However, the narrower line profiles in Class 1 sources suggest that MHD disk winds in these sources, if present, would have to be slower and/or less water rich than in Class 0 sources. Conclusions: MHD disk winds appear as a valid (though not unique) option to consider for the origin of the broad H2O component in low-mass protostars. ALMA appears ideally suited to

  4. Coastal Hazard Vulnerability Assessment: A Case Study of Erosion and Flooding on Herschel Island, Yukon Territory, Canada

    NASA Astrophysics Data System (ADS)

    Radosavljevic, B.; Lantuit, H.; Overduin, P. P.; Fritz, M.

    2015-12-01

    Coastal infrastructure, cultural, and archeological sites are increasingly vulnerable to erosion and flooding along permafrost coasts. Amplified warming of the Arctic, sea level rise, lengthening of the open water period, and a predicted increase in frequency of major storms compound these threats. Mitigation necessitates decision-making tools at an appropriate scale. We present a study of coastal erosion combining it with a flooding risk assessment for the culturally important historic settlement on Herschel Island, a UNESCO World Heritage candidate site. The resulting map may help local stakeholders devise management strategies to cope with rapidly changing environmental conditions. We analyzed shoreline movement using the Digital Shoreline Analysis System (DSAS) after digitizing shorelines from 1952, 1970, and 2011. Using these data, forecasts of shoreline positions were made for 20 and 50 years into the future. Flooding risk was assessed using a cost-distance map based on a high-resolution Light Detection and Ranging (LiDAR) dataset and current Intergovernmental Panel on Climate Change sea level estimates. Widespread erosion characterizes the study area. The rate of shoreline movement for different periods of the study ranges from -5.5 to 2.7 m·a-1 (mean -0.6 m·a-1). Mean coastal retreat decreased from -0.6 m·a-1 to -0.5 m·a-1, for 1952-1970 and 1970-2000, respectively, and increased to -1.3 m·a-1 in the period 2000-2011. Ice-rich coastal sections, and coastal sections most exposed to wave attack exhibited the highest rates of coastal retreat. The geohazard map resulting from shoreline projections and flood risk analysis indicates that most of the area occupied by the historic settlement is at extreme or very high risk of flooding, and some buildings are vulnerable to coastal erosion. The results of this study indicate a greater threat by coastal flooding than erosion. Our assessment may be applied in other locations where limited data are available.

  5. The Herschel-PACS grating drive mechanism: design status and prototype results

    NASA Astrophysics Data System (ADS)

    Renotte, E.; Gillis, J.-M.; Jamar, C.; Marquet, B.; Plesseria, J.-Y.; Collin, B.; Delrez, C.

    2001-09-01

    The Photodetector Array Camera and Spectrometer (PACS) is an imaging spectrometer-photometer which forms part of the science payload of the Herschel Space Observatory (formerly called FIRST), an ESA cornerstone mission (CS4) to be launched in 2007 on Ariane 5. This paper reports the present design of the motorised grating assembly for the PACS spectrometer. The PACS grating shall be capable of accurate positioning (4 arcsec) within a large angular throw (40 arcdeg) in cryogenic environment (4K). The drive mechanism is remotely controlled from the "Detector and Mechanism Controller" (DEC/MEC). Technologies of actuators, position sensors, pivots, lubricants, servo-control and cryogenic test set-up are discussed in this paper.

  6. ON THE MULTIPLICITY OF THE ZERO-AGE MAIN-SEQUENCE O STAR HERSCHEL 36

    SciTech Connect

    Arias, Julia I.; Barba, Rodolfo H.; Gamen, Roberto C.; Apellaniz, Jesus MaIz; Alfaro, Emilio J.; Sota, Alfredo; Bidin, Christian Moni

    2010-02-10

    We present the analysis of high-resolution optical spectroscopic observations of the zero-age main-sequence O star Herschel 36 spanning six years. This star is definitely a multiple system, with at least three components detected in its spectrum. Based on our radial-velocity (RV) study, we propose a picture of a close massive binary and a more distant companion, most probably in wide orbit about each other. The orbital solution for the binary, whose components we identify as O9 V and B0.5 V, is characterized by a period of 1.5415 {+-} 0.0006 days. With a spectral type O7.5 V, the third body is the most luminous component of the system and also presents RV variations with a period close to 498 days. Some possible hypotheses to explain the variability are briefly addressed and further observations are suggested.

  7. Herschel photometry of disks around low-mass stars in the R CrA cloud

    SciTech Connect

    Harvey, Paul M.; Henning, Thomas; Liu, Yao; Wolf, Sebastian E-mail: nje@astro.as.utexas.edu E-mail: yliu@pmo.ac.cn E-mail: yliu@pmo.ac.cn

    2014-11-01

    We report photometric results from a subset of a Herschel-PACS program to observe cool dust in disks around low-mass stars as a complement to our earlier program to measure far-infrared emission from brown dwarfs. In this latest study we observed five low-mass objects in the nearby R Corona Australis region and detected at least three at 70 μm. Using a Monte Carlo radiative transfer code we have investigated the disk masses and geometry based on detailed spectral energy distribution (SED) modeling, and we compare these new results to those from our earlier larger sample of brown dwarfs. In particular, our SED analysis for these five objects shows again that disk geometries of brown dwarfs or low-mass stars are generally similar to their higher mass counterparts like T Tauri disks, but the range of disk mass extends to well below the value found in T Tauri stars.

  8. Preliminary Results of the Herschel Gould Belt Survey in the Orion B Complex

    NASA Astrophysics Data System (ADS)

    Könyves, Vera; André, Philippe; Palmeirim, Pedro; Schneider, Nicola; Arzoumanian, Doris; Men'shchikov, Alexander

    As a preliminary result of the Herschel Gould Belt survey (André et al. 2010) in the Orion B cloud complex we find a clear connection between the locations of the detected prestellar cores and the column density values. We find that the vast majority of the gravitationally bound prestellar cores are detected above a high column density of about 6-7 × 1021 cm-2 (A V ˜ 6-7). This is in very good agreement with dense core formation thresholds found in other regions. For Orion B, a similar limit appears both in the distribution of background column density values of the prestellar cores, and in the column density PDF of the region. Within our core formation scenario, the found threshold can be translated as the column density above which the filaments become gravitationally unstable and fragment into cores.

  9. DISENTANGLING THE ENVIRONMENT OF THE FU ORIONIS CANDIDATE HBC 722 WITH HERSCHEL

    SciTech Connect

    Green, Joel D.; Evans, Neal J. II; Merello, Manuel; Pooley, David; Kospal, Agnes; Van Kempen, Tim A.; Van Dishoeck, Ewine; Herczeg, Gregory; Quanz, Sascha P.; Henning, Thomas; Bouwman, Jeroen; Lee, Jeong-Eun; Dunham, Michael M.; Meeus, Gwendolyn; Chen, Jo-Hsin; Guedel, Manuel; Skinner, Stephen L.; Rebull, Luisa M.; Guieu, Sylvain

    2011-04-20

    We analyze the submillimeter emission surrounding the new FU Orionis-type object, HBC 722. We present the first epoch of observations of the active environs of HBC 722, with imaging and spectroscopy from PACS, SPIRE, and HIFI on board the Herschel Space Observatory, as well as CO J = 2-1 and 350 {mu}m imaging (SHARC-II) with the Caltech Submillimeter Observatory. The primary source of submillimeter continuum emission in the region-2MASS 20581767+4353310-is located 16'' south-southeast of the optical flaring source while the optical and near-infrared emission is dominated by HBC 722. A bipolar outflow extends over HBC 722; the most likely driver is the submillimeter source. We detect warm (100 K) and hot (246 K) CO emission in the surrounding region, evidence of outflow-driven heating in the vicinity. The region around HBC 722 itself shows little evidence of heating driven by the new outbursting source itself.

  10. THE HERSCHEL REFERENCE SURVEY: DUST IN EARLY-TYPE GALAXIES AND ACROSS THE HUBBLE SEQUENCE

    SciTech Connect

    Smith, M. W. L.; Gomez, H. L.; Eales, S. A.; Davies, J. I.; Gear, W. K.; Ciesla, L.; Boselli, A.; Cortese, L.; Bendo, G. J.; Baes, M.; De Looze, I.; Fritz, J.; Bianchi, S.; Di Serego Alighieri, S.; Clemens, M.; Clements, D. L.; Cooray, A. R.; Gavazzi, G.; Madden, S.; and others

    2012-04-01

    We present Herschel observations of 62 early-type galaxies (ETGs), including 39 galaxies morphologically classified as S0+S0a and 23 galaxies classified as ellipticals using SPIRE at 250, 350, and 500 {mu}m as part of the volume-limited Herschel Reference Survey (HRS). We detect dust emission in 24% of the ellipticals and 62% of the S0s. The mean temperature of the dust is (T{sub d} ) = 23.9 {+-} 0.8 K, warmer than that found for late-type galaxies in the Virgo Cluster. The mean dust mass for the entire detected early-type sample is logM{sub d} = 6.1 {+-} 0.1 M{sub Sun} with a mean dust-to-stellar-mass ratio of log(M{sub d} /M{sub *}) = -4.3 {+-} 0.1. Including the non-detections, these parameters are logM{sub d} = 5.6 {+-} 0.1 and log(M{sub d} /M{sub *}) = -5.1 {+-} 0.1, respectively. The average dust-to-stellar-mass ratio for the early-type sample is fifty times lower, with larger dispersion, than the spiral galaxies observed as part of the HRS, and there is an order-of-magnitude decline in M{sub d} /M{sub *} between the S0s and ellipticals. We use UV and optical photometry to show that virtually all the galaxies lie close to the red sequence yet the large number of detections of cool dust, the gas-to-dust ratios, and the ratios of far-infrared to radio emission all suggest that many ETGs contain a cool interstellar medium similar to that in late-type galaxies. We show that the sizes of the dust sources in S0s are much smaller than those in early-type spirals and the decrease in the dust-to-stellar-mass ratio from early-type spirals to S0s cannot simply be explained by an increase in the bulge-to-disk ratio. These results suggest that the disks in S0s contain much less dust (and presumably gas) than the disks of early-type spirals and this cannot be explained simply by current environmental effects, such as ram-pressure stripping. The wide range in the dust-to-stellar-mass ratio for ETGs and the lack of a correlation between dust mass and optical luminosity

  11. A Herschel view of the far-infrared properties of submillimetre galaxies

    NASA Astrophysics Data System (ADS)

    Magnelli, B.; Lutz, D.; Santini, P.; Saintonge, A.; Berta, S.; Albrecht, M.; Altieri, B.; Andreani, P.; Aussel, H.; Bertoldi, F.; Béthermin, M.; Bongiovanni, A.; Capak, P.; Chapman, S.; Cepa, J.; Cimatti, A.; Cooray, A.; Daddi, E.; Danielson, A. L. R.; Dannerbauer, H.; Dunlop, J. S.; Elbaz, D.; Farrah, D.; Förster Schreiber, N. M.; Genzel, R.; Hwang, H. S.; Ibar, E.; Ivison, R. J.; Le Floc'h, E.; Magdis, G.; Maiolino, R.; Nordon, R.; Oliver, S. J.; Pérez García, A.; Poglitsch, A.; Popesso, P.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Rosario, D.; Roseboom, I.; Salvato, M.; Sanchez-Portal, M.; Scott, D.; Smail, I.; Sturm, E.; Swinbank, A. M.; Tacconi, L. J.; Valtchanov, I.; Wang, L.; Wuyts, S.

    2012-03-01

    We study a sample of 61submillimetre galaxies (SMGs) selected from ground-based surveys, with known spectroscopic redshifts and observed with the Herschel Space Observatory as part of the PACS Evolutionary Probe (PEP) and the Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time key programmes. Our study makes use of the broad far-infrared and submillimetre wavelength coverage (100-600 μm) only made possible by the combination of observations from the PACS and SPIRE instruments aboard the Herschel Space Observatory. Using a power-law temperature distribution model to derive infrared luminosities and dust temperatures, we measure a dust emissivity spectral index for SMGs of β = 2.0 ± 0.2. Our results unambiguously unveil the diversity of the SMG population. Some SMGs exhibit extreme infrared luminosities of s1013{L⊙} and relatively warm dust components, while others are fainter (a few times 1012 L⊙) and are biased towards cold dust temperatures. Although at zs2 classical SMGs (>5 mJy at 850 μm) have large infrared luminosities (s1013 L⊙), objects only selected on their submm flux densities (without any redshift informations) probe a large range in dust temperatures and infrared luminosities. The extreme infrared luminosities of some SMGs (LIR ≳ 1012.7 L⊙, 26/61 systems) imply star formation rates (SFRs) of >500 M⊙ yr-1 (assuming a Chabrier IMF and no dominant AGN contribution to the FIR luminosity). Such high SFRs are difficult to reconcile with a secular mode of star formation, and may instead correspond to a merger-driven stage in the evolution of these galaxies. Another observational argument in favour of this scenario is the presence of dust temperatures warmer than that of SMGs of lower luminosities (s40 K as opposed to s25 K), consistent with observations of local ultra-luminous infrared galaxies triggered by major mergers and with results from hydrodynamic simulations of major mergers combined with radiative transfer calculations

  12. Dust spectral energy distributions of nearby galaxies: an insight from the Herschel Reference Survey

    NASA Astrophysics Data System (ADS)

    Ciesla, L.; Boquien, M.; Boselli, A.; Buat, V.; Cortese, L.; Bendo, G. J.; Heinis, S.; Galametz, M.; Eales, S.; Smith, M. W. L.; Baes, M.; Bianchi, S.; De Looze, I.; di Serego Alighieri, S.; Galliano, F.; Hughes, T. M.; Madden, S. C.; Pierini, D.; Rémy-Ruyer, A.; Spinoglio, L.; Vaccari, M.; Viaene, S.; Vlahakis, C.

    2014-05-01

    Although it accounts only for a small fraction of the baryonic mass, dust has a profound impact on the physical processes at play in galaxies. Thus, to understand the evolution of galaxies, it is essential not only to characterize dust properties per se, but also in relation to global galaxy properties. To do so, we derive the dust properties of galaxies in a volume limited, K-band selected sample, the Herschel Reference Survey (HRS). We gather infrared photometric data from 8 μm to 500 μm from Spitzer, WISE, IRAS, and Herschel for all of the HRS galaxies. Draine & Li (2007, ApJ, 663, 866) models are fit to the data from which the stellar contribution has been carefully removed. We find that our photometric coverage is sufficient to constrain all of the parameters of the Draine & Li models and that a strong constraint on the 20-60 μm range is mandatory to estimate the relative contribution of the photo-dissociation regions to the infrared spectral energy distribution (SED). The SED models tend to systematically underestimate the observed 500 μm flux densities, especially for low-mass systems. We provide the output parameters for all of the galaxies, i.e., the minimum intensity of the interstellar radiation field, the fraction of polycyclic aromatic hydrocarbon (PAH), the relative contribution of PDR and evolved stellar population to the dust heating, the dust mass, and the infrared luminosity. For a subsample of gas-rich galaxies, we analyze the relations between these parameters and the main integrated properties of galaxies, such as stellar mass, star formation rate, infraredluminosity, metallicity, Hα and H-band surface brightness, and the far-ultraviolet attenuation. A good correlation between the fraction of PAH and the metallicity is found, implying a weakening of the PAH emission in galaxies with low metallicities and, thus, low stellar masses. The intensity of the diffuse interstellar radiation field and the H-band and Hα surface brightnesses are

  13. Warm Gas and Dust of Massive Young Stellar Objects Revealed by Herschel PACS Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kwon, Woojin; van der Tak, Floris; Karska, Agata; Herczeg, Gregory; Chavarria, Luis; Herpin, Fabrice; Wyrowski, Friedrich; Braine, Jonathan; van Dishoeck, Ewine

    2015-08-01

    We present results of Herschel PACS imaging spectroscopy data toward ten massive young stellar objects taken as part of the WISH project. Our sample consists of four high mass protostellar objects (HMPOs), two hot molecular cores (HMCs), and four ultracompact HII regions (UCHIIs), and the spectra cover a broad range of wavelengths (55 to 210 micron) presenting various atomic and molecular lines as well as excellent continua. By fitting the continua utilizing a modified black-body formula we estimate mass-weighted temperature and column density distributions of warm dust and find that UCHII regions are hottest and HMCs are most deeply embedded. We also estimate rotational temperature and column density distributions of warm CO gas using the rotational diagram analysis. In addition, based on the comparison of high J CO line fluxes to the RATRAN estimates of central heating envelope models, we find that majority of warm CO is originated from bipolar outflow shocks.

  14. High-J CO survey of low-mass protostars observed with Herschel-HIFI

    NASA Astrophysics Data System (ADS)

    Yıldız, U. A.; Kristensen, L. E.; van Dishoeck, E. F.; San José-García, I.; Karska, A.; Harsono, D.; Tafalla, M.; Fuente, A.; Visser, R.; Jørgensen, J. K.; Hogerheijde, M. R.

    2013-08-01

    Context. In the deeply embedded stage of star formation, protostars start to heat and disperse their surrounding cloud cores. The evolution of these sources has traditionally been traced through dust continuum spectral energy distributions (SEDs), but the use of CO excitation as an evolutionary probe has not yet been explored due to the lack of high-J CO observations. Aims: The aim is to constrain the physical characteristics (excitation, kinematics, column density) of the warm gas in low-mass protostellar envelopes using spectrally resolved Herschel data of CO and compare those with the colder gas traced by lower excitation lines. Methods: Herschel-HIFI observations of high-J lines of 12CO, 13CO, and C18O (up to Ju = 10, Eu up to 300 K) are presented toward 26 deeply embedded low-mass Class 0 and Class I young stellar objects, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. This is the first large spectrally resolved high-J CO survey conducted for these types of sources. Complementary lower J CO maps were observed using ground-based telescopes, such as the JCMT and APEX and convolved to matching beam sizes. Results: The 12CO 10-9 line is detected for all objects and can generally be decomposed into a narrow and a broad component owing to the quiescent envelope and entrained outflow material, respectively. The 12CO excitation temperature increases with velocity from ~60 K up to ~130 K. The median excitation temperatures for 12CO, 13CO, and C18O derived from single-temperature fits to the Ju = 2-10 integrated intensities are ~70 K, 48 K and 37 K, respectively, with no significant difference between Class 0 and Class I sources and no trend with Menv or Lbol. Thus, in contrast to the continuum SEDs, the spectral line energy distributions (SLEDs) do not show any evolution during the embedded stage. In contrast, the integrated line intensities of all CO isotopologs show a clear decrease with evolutionary stage as the envelope is

  15. A Herschel Spectroscopic Survey of Warm Molecular Gas in Local Infrared Luminous Galaxies

    NASA Astrophysics Data System (ADS)

    Lu, N.; Zhao, Y.; Xu, C. K.; Gao, Y.; GOALS FTS Team

    2013-03-01

    We describe an on-going 194-671 μm spectroscopic survey of a flux-limited sample of 125 local luminous infrared galaxies (LIRGs) with Herschel SPIRE Fourier Transform Spectrometer (FTS). The survey targets primarily the CO spectral line energy distribution (SLED), from J = 4-3 up to J = 13-12, to probe dense and warm molecular gas that should play an intimate role in star formation and/or active galactic nuclear activities in these galaxies. The program is about 75% finished. At S/N > 5, besides the CO lines, we also detected [N ii] 205 μm and [C i] 370 μm (3 P 2 - 3P1) lines in every target observed. In about half of the observed targets, we also detected [C i] 609 μm (3 P 1 - 3P0).

  16. The protostar OMC-2 FIR 4: Results from the CHESS Herschel/HIFI spectral survey

    NASA Astrophysics Data System (ADS)

    Kama, Mihkel; Lopez-Sepulcre, Ana; Ceccarelli, Cecilia; Dominik, Carsten; Caux, Emmanuel; Fuente, Asuncion

    2013-07-01

    The intermediate-mass protostar OMC-2 FIR 4 in Orion is the focus of several ongoing studies, including a CHESS key programme Herschel/HIFI spectral survey. In this poster, we review recent CHESS results on this source, including the properties of the central hot core, the presence of a compact outflow, the spatial variation of the chemical composition, and the discovery of a tenuous foreground cloud. The HIFI spectrum of FIR 4 contains 719 lines from 40 species and isotopologs. Cooling by lines detectable with our sensitivity contributes 2% of the total in the 480 to 1900 GHz range. The total line flux is dominated by CO, followed by H2O and CH3OH. Initial comparisons with spectral surveys of other sources will also be presented.

  17. CO luminosity function from Herschel-selected galaxies and the contribution of AGN

    NASA Astrophysics Data System (ADS)

    Vallini, L.; Gruppioni, C.; Pozzi, F.; Vignali, C.; Zamorani, G.

    2016-02-01

    We derive the carbon monoxide (CO) luminosity function (LF) for different rotational transitions [i.e. (1-0), (3-2), (5-4)] starting from the Herschel LF by Gruppioni et al. and using appropriate LCO-LIR conversions for different galaxy classes. Our predicted LFs fit the data so far available at z ≈ 0 and 2. We compare our results with those obtained by semi-analytical models (SAMs): while we find a good agreement over the whole range of luminosities at z ≈ 0, at z ≈ 1 and z ≈ 2, the tension between our LFs and SAMs in the faint and bright ends increases. We finally discuss the contribution of luminous active galactic nucleus (LX > 1044 erg s- 1) to the bright end of the CO LF concluding that they are too rare to reproduce the actual CO LF at z ≈ 2.

  18. New information on solar activity, 1779-1818, from Sir William Herschel's unpublished notebooks

    NASA Technical Reports Server (NTRS)

    Hoyt, Douglas V.; Schatten, Kenneth H.

    1992-01-01

    Herschel's observations are analyzed in order to determine the level of solar activity for solar cycle 5. It is concluded that solar cycle 5 may have peaked as early as 1801 based upon the average number of groups with a probable secondary maximum in 1804. Depending on the technique adopted, the peak for solar cycle 5 occurred sometime between 1801 and 1804, rather than 1805.2, as commonly assumed. Instead of a solar cycle of 17 yrs, a cycle length of 14 yrs is found. It is also found that the peak yearly mean sunspot number is only about 38 rather than 45, as deduced by Wolf (1855). A technique for making early solar observations homogeneous with modern sunspot observations is proposed.

  19. Herschel Legacy Survey of Hydrogen Fluoride and Water Towards Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Rodriguez Monje, Raquel

    Hydride molecules, molecules containing just one heavy element atom with one or more hydrogen atoms, play an importance role in interstellar chemistry, as they are often stable end points of chemical reactions, or represent important intermediate stages of the reaction chains theorized to form gas phase molecules. This makes hydride molecules a sensitive test of these chemical models, as well as potential tracers of molecular hydrogen. Due to the low moment of inertia, hydrides have their fundamental rotational transitions in the submillimeter band, blocked by the Earth's atmosphere and in most cases, only accessible with the past NASA mission, Herschel Space Observatory. Two of the key results from Herschel observations are: the first detection of the fundamental J = 1 - 0 rotational transition of hydrogen fluoride (HF) at 1.232 THz (243 μm) and the discovery of HF's ubiquitous nature in the Milky Way. HF has not only been observed toward almost every bright continuum source in the Galactic plane, but also in some nearby ultra luminous galaxies, establishing its importance outside the Milky Way as well. Despite fluorine's (F) relative low abundance in the interstellar medium (ISM) (about four times lower than carbon), F plays an important role in the interstellar chemistry due to the unique thermochemistry of the reaction between F and molecular hydrogen (H2). F is the only atom that reacts exothermically with H2, to form the compound HF. Once formed, HF becomes the main reservoir of fluorine in the ISM, with a strong bond only destroyed by reactions with low abundance ions H3+, C+ and He+, or photodissociation. This unusual stability allows the build up of large amounts of HF in the ISM, which has now been confirmed by Herschel. Chemical model predicted that the ground state rotational transition line of HF J = 1 - 0 would yield an extremely sensitive probe of the diffuse molecular gas along the line-of-sight to background far-infrared continuum sources and a

  20. GT1_mbaes_1: HERschel Observations of Edge-on Spirals (HEROES)

    NASA Astrophysics Data System (ADS)

    Baes, M.

    2010-03-01

    We propose to use PACS and SPIRE to map the dust distribution in a sample of seven large edge-on spiral galaxies with regular dust lanes. We will look for the presence of cold dust at large galactocentric radii and investigate the link between dust, gas and metallicity as a function of radius. We will also constrain the vertical distribution of the dust and particularly look for dust emission at large heights above the plane of the galaxies. We will compare the observed Herschel maps with simulated maps resulting from detailed radiative transfer models based on optical and near-infrared images. This will enable us to investigate whether we can confirm the existence of a dust energy balance problem suggested by previous observations (the dust seen in absorption in optical maps underestimates the dust seen in emission) and investigate possible ways to alleviate this potential problem.

  1. Development of Cryogenic Filter Wheels for the HERSCHEL Photodetector Array Camera & Spectrometer (PACS)

    NASA Technical Reports Server (NTRS)

    Koerner, Christian; Kampf, Dirk; Poglitsch, Albrecht; Schubert, Josef; Ruppert, U.; Schoele, M.

    2014-01-01

    This paper describes the two PACS Filter Wheels that are direct-drive rotational mechanisms operated at a temperature below 5K inside the PACS focal plane unit of the Herschel Satellite. The purpose of the mechanisms is to switch between filters. The rotation axis is pivoted to the support structure via a slightly preloaded pair of ball bearings and driven by a Cryotorquer. Position sensing is realized by a pair of Hall effect sensors. Powerless positioning at the filter positions is achieved by a magnetic ratchet system. The key technologies are the Cryotorquer design and the magnetic ratchet design in the low temperature range. Furthermore, we will report on lessons learned during the development and qualification of the mechanism and the paint.

  2. Anomalously Broad Diffuse Interstellar Bands and Excited CH+ Absorption in the Spectrum of Herschel 36

    NASA Astrophysics Data System (ADS)

    York, D. G.; Dahlstrom, J.; Welty, D. E.; Oka, T.; Hobbs, L. M.; Johnson, S.; Friedman, S. D.; Jiang, Z.; Rachford, B. L.; Snow, T. P.; Sherman, R.; Sonnentrucker, P.

    2014-02-01

    Anomalously broad diffuse interstellar bands (DIBs) at 5780.5, 5797.1, 6196.0, and 6613.6 Å are found in absorption along the line of sight to Herschel 36, an O star system next to the bright Hourglass nebula of the Hii region Messier 8. Excited lines of CH and CH+ are seen as well. We show that the region is very compact and itemize other anomalies of the gas. An infrared-bright star within 400 AU is noted. The combination of these effects produces anomalous DIBs, interpreted by Oka et al. (2013, see also this volume) as being caused predominantly by infrared pumping of rotational levels of relatively small molecules.

  3. AN ANALYSIS OF THE ENVIRONMENTS OF FU ORIONIS OBJECTS WITH HERSCHEL

    SciTech Connect

    Green, Joel D.; Evans, Neal J. II; Merello, Manuel; Kospal, Agnes; Herczeg, Gregory; Quanz, Sascha P.; Henning, Thomas; Bouwman, Jeroen; Van Kempen, Tim A.; Lee, Jeong-Eun; Dunham, Michael M.; Meeus, Gwendolyn; Chen, Jo-hsin; Guedel, Manuel; Liebhart, Armin; Skinner, Stephen L.

    2013-08-01

    We present Herschel-HIFI, SPIRE, and PACS 50-670 {mu}m imaging and spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735 Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date from 1936 to 2010, from the 'FOOSH' (FU Orionis Objects Surveyed with Herschel) program, as well as ancillary results from Spitzer Infrared Spectrograph and the Caltech Submillimeter Observatory. In their system properties (L{sub bol}, T{sub bol}, and line emission), we find that FUors are in a variety of evolutionary states. Additionally, some FUors have features of both Class I and II sources: warm continuum consistent with Class II sources, but rotational line emission typical of Class I, far higher than Class II sources of similar mass/luminosity. Combining several classification techniques, we find an evolutionary sequence consistent with previous mid-IR indicators. We detect [O I] in every source at luminosities consistent with Class 0/I protostars, much greater than in Class II disks. We detect transitions of {sup 13}CO (J{sub up} of 5-8) around two sources (V1735 Cyg and HBC 722) but attribute them to nearby protostars. Of the remaining sources, three (FU Ori, V1515 Cyg, and V1331 Cyg) exhibit only low-lying CO, but one (V1057 Cyg) shows CO up to J = 23 {yields} 22 and evidence for H{sub 2}O and OH emission, at strengths typical of protostars rather than T Tauri stars. Rotational temperatures for 'cool' CO components range from 20 to 81 K, for {approx} 10{sup 50} total CO molecules. We detect [C I] and [N II] primarily as diffuse emission.

  4. The Photodetector Array Camera and Spectrometer (PACS) for the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Poglitsch, A.; Waelkens, C.; Bauer, O. H.; Cepa, J.; Henning, T.; van Hoof, C.; Katterloher, R.; Kerschbaum, F.; Lemke, D.; Renotte, E.; Rodriguez, L..; Royer, P.; Saraceno, P.

    2004-05-01

    The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments for ESA's far infrared and submillimetre observatory Herschel. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16 × 25 pixels, each, and two filled Si bolometer arrays with 16 × 32 and 32 × 64 pixels, respectively, to perform imaging line spectroscopy and imaging photometry in the 60-210 μ m wavelength band. In photometry mode, it will simultaneously image two bands, 60-85 or 85-130μ m and 130-210μ m, over a field of view of /sim 1.75'× 3.5', with full beam sampling in each band. In spectroscopy mode, it will image a field of ˜ 50''× 50'', resolved into 5 × 5 pixels, with an instantaneous spectral coverage of ˜ 1500km/s and a spectral resolution of ˜ 175km/s. In both modes background-noise limited peformance is expected, with sensitivities (5 σ in 1h) of 3-10× 10-18 W/m2, respectively. We describe the design of the instrument and its observing modes, report first results from instrument level tests of the Qualification Model, and give examples of the observing capabilities of PACS onboard Herschel for several key questions of modern astronomy, illustrated by examples from the emerging Guaranteed Time Programmme of the PACS consortium. This work is supported by the following funding agencies: ASI (Italy), BMVIT (Austria), CEA/CNES (France), DLR (Germany), ESA-PRODEX (Begium), and CDTI (Spain).

  5. Herschel/HIFI observation of highly excited rotational lines of HNC toward IRC +10 216

    NASA Astrophysics Data System (ADS)

    Daniel, F.; Agúndez, M.; Cernicharo, J.; De Beck, E.; Lombaert, R.; Decin, L.; Kahane, C.; Guélin, M.; Müller, H. S. P.

    2012-06-01

    We report the detection in emission of various highly excited rotational transitions of HNC (J = 6-5 through J = 12-11) toward the carbon-star envelope IRC +10 216 using the HIFI instrument on-board the Herschel Space Observatory. Observations of the J = 1-0 and J = 3-2 lines of HNC with the IRAM 30-m telescope are also presented. The lines observed with HIFI have upper level energies corresponding to temperatures between 90 and 340 degrees Kelvin, and trace a warm and smaller circumstellar region than that seen in the interferometric maps of the J = 1-0 transition, whose emission extends up to a radius of 20''. After a detailed chemical and radiative transfer modeling, we find that the presence of HNC in the circumstellar envelope of IRC +10 216 is consistent with formation from the precursor ion HCNH+, which in turn is produced through several proton transfer reactions which are triggered by cosmic-ray ionization. We also find that the radiative pumping through λ 21 μm photons to the first excited state of the bending mode ν2 plays a crucial role to populate the high-J HNC levels involved in the transitions observed with HIFI. Emission in these high-J rotational transitions of HNC is expected to be strong in regions which are warm and dense and/or have an intense infrared flux at wavelengths around 21 μm. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Based on observations carried out with the IRAM 30-m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  6. Angular Cross-correlation of Spitzer IRAC and Herschel Spire Sources

    NASA Astrophysics Data System (ADS)

    Mitchell-Wynne, Ketron; Cooray, A.; Wang, L.; HerMES Consortium

    2011-01-01

    The Spitzer Deep Wide-Field Survey (SDWFS) and the Herschel Multi-tiered Extragalactic Survey (HerMES) each provide deep and wide coverage, centered on the Bootes field, at infrared and sub-millimeter wavelengths. The SDWFS covers approximately 8.5 square degrees with sensitivities of galaxies out to z 3. From the public SDWFS source catalog, we remove stars and contaminants by concentration, using selection methods based on IRAC and optical colors; optical photometry is provided by the NOAO Deep Wide-Field Survey. Photometric redshifts of detected IRAC sources are then determined using the 1.6 micron spectral feature (or 'bump'). We classify three different kinds of bumps, (bump 1- bump 3), with redshifts ranging approximately from 0-1.3, 1.3-2, and 2-3 respectively. The number of bump 1 sources in the SDWFS catalogs were found to be in excess of 25,000 at the 5 sigma detection limit of the 3.6 micron channel of the IRAC instrument. Bump 2 and bump 3 source identification yielded similar, but slightly fewer counts. We also extract a separate catalog of 2500 or so dust-obscured galaxies (DOGs) at z 2 using 24 micron and r-band fluxes. As part of HerMES observations with SPIRE, the Bootes field contain more than 15,000 clearly detected SPIRE sources at 250 microns, In this paper we report on the cross correlation function of these bump sources with the source catalogs from three bands of the SPIRE instrument onboard Herschel. The aim is to broadly reconstruct the redshift distribution of SPIRE sources using redshift distributions of bump and DOGs in the bootes field and the relative clustering strengths.

  7. A HERSCHEL AND APEX CENSUS OF THE REDDEST SOURCES IN ORION: SEARCHING FOR THE YOUNGEST PROTOSTARS

    SciTech Connect

    Stutz, Amelia M.; Robitaille, Thomas; Henning, Thomas; Krause, Oliver; Tobin, John J.; Stanke, Thomas; Megeath, S. Thomas; Fischer, William J.; Ali, Babar; Furlan, Elise; Hartmann, Lee; Osorio, Mayra; Wilson, Thomas L.; Allen, Lori; Manoj, P.

    2013-04-10

    We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using data obtained with the PACS instrument on board the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar candidates are detected at 70 {mu}m and 160 {mu}m that are either too faint (m{sub 24} > 7 mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS 24 {mu}m band. We find that the 11 reddest protostar candidates with log {lambda}F{sub {lambda}}70/{lambda}F{sub {lambda}}24 > 1.65 are free of contamination and can thus be reliably explained as protostars. The remaining 44 sources have less extreme 70/24 colors, fainter 70 {mu}m fluxes, and higher levels of contamination. Taking the previously known sample of Spitzer protostars and the new sample together, we find 18 sources that have log {lambda}F{sub {lambda}}70/{lambda}F{sub {lambda}}24 > 1.65; we name these sources 'PACS Bright Red sources', or PBRs. Our analysis reveals that the PBR sample is composed of Class 0 like sources characterized by very red spectral energy distributions (SEDs; T{sub bol} < 45 K) and large values of sub-millimeter fluxes (L{sub smm}/L{sub bol} > 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2-2 M{sub Sun} and luminosities of 0.7-10 L{sub Sun }. Based on these properties, and a comparison of the SEDs with radiative transfer models of protostars, we conclude that the PBRs are most likely extreme Class 0 objects distinguished by higher than typical envelope densities and hence, high mass infall rates.

  8. Herschel/HIFI line surveys: Discovery of interstellar chloronium (H{sub 2}Cl{sup +})

    SciTech Connect

    Lis, Dariusz C.

    2015-01-22

    Prior to the launch of Herschel, HCl was the only chlorine-containing molecule detected in the interstellar medium (ISM). However, chemical models have identified chloronium, H{sub 2}Cl{sup +}, as a relatively abundant species that is potentially detectable. H{sub 2}Cl{sup +} was predicted to be most abundant in the environments where the ultraviolet radiation is strong: in diffuse clouds, or near the surfaces of dense clouds illuminated by nearby O and B stars. The HIFI instrument on Herschel provided the first detection of H{sub 2}Cl{sup +} in the ISM. The 2{sub 12}-1{sub 01} lines of ortho-H{sub 2}{sup 35}Cl{sup +} and ortho-H{sub 2}{sup 37}Cl{sup +} were detected in absorption toward NGC 6334I, and the 1{sub 11}-0{sub 00} transition of para-H{sub 2}{sup 35}Cl{sup +} was detected in absorption toward NGC 6334I and Sgr B2(S). The derived HCl/H{sub 2}Cl{sup +} column density ratios, ∼1-10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H{sub 2}Cl{sup +} column densities, in excess of 10{sup 13} cm{sup −2}, are significantly higher than the model predictions. These observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models.

  9. Herschel-Planck dust optical depth and column density maps. II. Perseus

    NASA Astrophysics Data System (ADS)

    Zari, Eleonora; Lombardi, Marco; Alves, João; Lada, Charles J.; Bouy, Hervé

    2016-03-01

    We present optical depth and temperature maps of the Perseus molecular cloud, obtained combining dust emission data from the Herschel and Planck satellites and 2MASS/NIR dust extinction maps. The maps have a resolution of 36 arcsec in the Herschel regions, and of 5 arcmin elsewhere. The dynamic range of the optical depth map ranges from 1 × 10-2 mag up to 20 mag in the equivalent K-band extinction. We also evaluate the ratio between the 2.2 μm extinction coefficient and the 850 μm opacity. The value we obtain is close to the one found in the Orion B molecular cloud. We show that the cumulative and the differential area function of the data (which is proportional to the probability distribution function of the cloud column density) follow power laws with an index of respectively ≃-2, and ≃-3. We use WISE data to improve current YSO catalogs based mostly on Spitzer data and we build an up-to-date selection of Class I/0 objects. Using this selection, we evaluate the local Schmidt law, ΣYSO ∝ Σgasβ, showing that β = 2.4 ± 0.6. Finally, we show that the area-extinction relation is important for determining the star-formation rate in the cloud, which is in agreement with other recent works. The optical depth and temperature maps (FITS files) are 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/A106

  10. Spatially resolved imaging of the two-component η Crv debris disk with Herschel

    SciTech Connect

    Duchêne, G.; Arriaga, P.; Kalas, P.; Wyatt, M.; Kennedy, G.; Sibthorpe, B.; Lisse, C.; Holland, W.; Wisniewski, J.; Clampin, M.; Pinte, C.; Booth, M.; Horner, J.; Matthews, B.; Greaves, J.

    2014-04-01

    We present far-infrared and submillimeter images of the η Crv debris disk system obtained with Herschel and SCUBA-2, as well as Hubble Space Telescope visible and near-infrared coronagraphic images. In the 70 μm Herschel image, we clearly separate the thermal emission from the warm and cold belts in the system, find no evidence for a putative dust population located between them, and precisely determine the geometry of the outer belt. We also find marginal evidence for azimuthal asymmetries and a global offset of the outer debris ring relative to the central star. Finally, we place stringent upper limits on the scattered light surface brightness of the outer ring. Using radiative transfer modeling, we find that it is impossible to account for all observed properties of the system under the assumption that both rings contain dust populations with the same properties. While the outer belt is in reasonable agreement with the expectations of steady-state collisional cascade models, albeit with a minimum grain size that is four times larger than the blow-out size, the inner belt appears to contain copious amounts of small dust grains, possibly below the blow-out size. This suggests that the inner belt cannot result from a simple transport of grains from the outer belt and rather supports a more violent phenomenon as its origin. We also find that the emission from the inner belt has not declined over three decades, a much longer timescale than its dynamical timescale, which indicates that the belt is efficiently replenished.

  11. The gas-to-dust mass ratio of Centaurus A as seen by Herschel

    NASA Astrophysics Data System (ADS)

    Parkin, T. J.; Wilson, C. D.; Foyle, K.; Baes, M.; Bendo, G. J.; Boselli, A.; Boquien, M.; Cooray, A.; Cormier, D.; Davies, J. I.; Eales, S. A.; Galametz, M.; Gomez, H. L.; Lebouteiller, V.; Madden, S.; Mentuch, E.; Page, M. J.; Pohlen, M.; Remy, A.; Roussel, H.; Sauvage, M.; Smith, M. W. L.; Spinoglio, L.

    2012-05-01

    We present photometry of the nearby galaxy NGC 5128 (Centaurus A) observed with the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on board the Herschel Space Observatory, at 70, 160, 250, 350 and 500 μm, as well as new CO J= 3-2 observations taken with the HARP-B instrument on the James Clerk Maxwell Telescope (JCMT). Using a single-component modified blackbody, we model the dust spectral energy distribution within the disc of the galaxy using all five Herschel wavebands and find dust temperatures of ˜30 K towards the centre of the disc and a smoothly decreasing trend to ˜20 K with increasing radius. We find a total dust mass of (1.59 ± 0.05) × 107 M⊙ and a total gas mass of (2.7 ± 0.2) × 109 M⊙. The average gas-to-dust mass ratio is 103 ± 8, but we find an interesting increase in this ratio to approximately 275 towards the centre of Cen A. We discuss several possible physical processes that may be causing this effect, including dust sputtering, jet entrainment and systematic variables such as the XCO factor. Dust sputtering by X-rays originating in the active galactic nucleus or the removal of dust by the jets is our most favoured explanation. a PACS values are divisive and SPIRE values are multiplicative. b These uncertainties are for the pixels at their native pixel scale, as listed in this table. c We have ignored the fact that the SPIRE calibration errors are correlated between all three bands and our total 7 per cent error comprises 5 per cent correlated error and 5 per cent uncorrelated error.

  12. The enigmatic nature of the circumstellar envelope and bow shock surrounding Betelgeuse as revealed by Herschel

    NASA Astrophysics Data System (ADS)

    Decin, L.; Cox, N. L. J.; Royer, P.; van Marle, A. J.; Vandenbussche, B.

    2013-05-01

    The interaction between stellar winds and the interstellar medium (ISM) can create complex bow shocks. We have studied the bow shock region around Betelgeuse using Herschel PACS images at 70, 100, and 160 μm and SPIRE images at 250, 350, and 500 μm. These data were complemented with ultraviolet GALEX data, near-infrared WISE data, and radio 21 cm GALFA-HI data. The infrared Herschel images of the environment around Betelgeuse are spectacular, showing the occurrence of multiple arcs at ~6-7' from the central target and the presence of a linear bar at ~9'. Remarkably, no large-scale instabilities are seen in the outer arcs and linear bar. The dust temperature in the outer arcs varies between 40 and 140 K, with the linear bar having the same colour temperature as the arcs. The inner envelope shows clear evidence of a non-homogeneous clumpy structure (beyond 15''). The non-homogeneous distribution of the material even persists until the collision with the ISM. A strong variation in brightness of the inner clumps at a radius of ~2' suggests a drastic change in mean gas and dust density ~32 000 yr ago. Using hydrodynamical simulations (see van Marle & Decin, these proceedings), we try to explain the observed morphology of the bow shock around Betelgeuse. Different hypotheses, based on observational and theoretical constraints, are formulated to explain the origin of the multiple arcs and the linear bar and the fact that no large-scale instabilities are visible in the bow shock region. We infer that the two main ingredients for explaining these phenomena are a non-homogeneous mass-loss process and the influence of the Galactic magnetic field. The linear bar is probably an interstellar structure illuminated by Betelgeuse itself.

  13. High-J CO Sleds in Nearby Infrared Bright Galaxies Observed By Herschel/PACS

    NASA Astrophysics Data System (ADS)

    Mashian, N.; Sturm, E.; Sternberg, A.; Janssen, A.; Hailey-Dunsheath, S.; Fischer, J.; Contursi, A.; González-Alfonso, E.; Graciá-Carpio, J.; Poglitsch, A.; Veilleux, S.; Davies, R.; Genzel, R.; Lutz, D.; Tacconi, L.; Verma, A.; Weiß, A.; Polisensky, E.; Nikola, T.

    2015-04-01

    We report the detection of far-infrared (FIR) CO rotational emission from nearby active galactic nuclei (AGNs) and starburst galaxies, as well as several merging systems and Ultra-Luminous Infrared Galaxies (ULIRGs). Using the Herschel Photodetector Array Camera and Spectrometer (PACS), we have detected transitions in the Jupp = 14-30 range. The PACS CO data obtained here provide the first reference of well-sampled FIR extragalactic CO spectral line energy distributions (SLEDs) for this range. We find a large range in the overall SLED shape, even among galaxies of similar type, demonstrating the uncertainties in relying solely on high-J CO diagnostics to characterize the excitation source of a galaxy. Combining our data with low-J line intensities taken from the literature, we present a CO ratio-ratio diagram and discuss its value in distinguishing excitation sources and physical properties of the molecular gas. The position of a galaxy on such a diagram is less a signature of its excitation mechanism, than an indicator of the presence of warm, dense molecular gas. We then quantitatively analyze the CO emission from a subset of the detected sources with single-component and two-component large velocity gradient (LVG) radiative transfer models to fit the CO SLEDs. From these fits we derive the molecular gas mass and the corresponding CO-to-H2 conversion factor, {{α }CO}, for each respective source. For the ULIRGs we find α values in the canonical range 0.4- 5M⊙ (K km s-1 pc2)-1, while for the other objects, α varies between 0.2 and 14. Finally, we compare our best-fit LVG model results with previous studies of the same galaxies and comment on any differences. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  14. Exploring the Dust Content of Galactic Winds with Herschel. I. NGC 4631

    NASA Astrophysics Data System (ADS)

    Meléndez, M.; Veilleux, S.; Martin, C.; Engelbracht, C.; Bland-Hawthorn, J.; Cecil, G.; Heitsch, F.; McCormick, A.; Müller, T.; Rupke, D.; Teng, S. H.

    2015-05-01

    We present a detailed analysis of deep far-infrared observations of the nearby edge-on star-forming galaxy NGC 4631 obtained with the Herschel Space Observatory. Our Photodetector Array Camera and Spectrometer (PACS) images at 70 and 160 μm show a rich complex of filaments and chimney-like features that extends up to a projected distance of 6 kpc above the plane of the galaxy. The PACS features often match extraplanar Hα, radio-continuum, and soft X-ray features observed in this galaxy, pointing to a tight disk-halo connection regulated by star formation. On the other hand, the morphology of the colder dust component detected on a larger scale in the Spectral and Photometric Imaging Receiver 250, 350, and 500 μm data matches the extraplanar H I streams previously reported in NGC 4631 and suggests a tidal origin. The PACS 70/160 μm ratios are elevated in the central ˜3.0 kpc region above the nucleus of this galaxy (the “superbubble”). A pixel-by-pixel analysis shows that dust in this region has a higher temperature and/or an emissivity with a steeper spectral index (β \\gt 2) than the dust in the disk, possibly the result of the harsher environment in the superbubble. Star formation in the disk seems energetically insufficient to lift the material out of the disk, unless it was more active in the past or the dust-to-gas ratio in the superbubble region is higher than the Galactic value. Some of the dust in the halo may also have been tidally stripped from nearby companions or lifted from the disk by galaxy interactions. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  15. WHAT DETERMINES THE DENSITY STRUCTURE OF MOLECULAR CLOUDS? A CASE STUDY OF ORION B WITH HERSCHEL

    SciTech Connect

    Schneider, N.; Andre, Ph.; Koenyves, V.; Motte, F.; Arzoumanian, D.; Didelon, P.; Hennemann, M.; Hill, T.; Palmeirim, P.; Peretto, N.; Roy, A.; Ward-Thompson, D.; Benedettini, M.; Pezzuto, S.; Rygl, K. L. J.; Bressert, E.; Di Francesco, J.; Griffin, M.; and others

    2013-04-01

    A key parameter to the description of all star formation processes is the density structure of the gas. In this Letter, we make use of probability distribution functions (PDFs) of Herschel column density maps of Orion B, Aquila, and Polaris, obtained with the Herschel Gould Belt survey (HGBS). We aim to understand which physical processes influence the PDF shape, and with which signatures. The PDFs of Orion B (Aquila) show a lognormal distribution for low column densities until A{sub V} {approx} 3 (6), and a power-law tail for high column densities, consistent with a {rho}{proportional_to}r {sup -2} profile for the equivalent spherical density distribution. The PDF of Orion B is broadened by external compression due to the nearby OB stellar aggregates. The PDF of a quiescent subregion of the non-star-forming Polaris cloud is nearly lognormal, indicating that supersonic turbulence governs the density distribution. But we also observe a deviation from the lognormal shape at A{sub V} > 1 for a subregion in Polaris that includes a prominent filament. We conclude that (1) the point where the PDF deviates from the lognormal form does not trace a universal A{sub V} -threshold for star formation, (2) statistical density fluctuations, intermittency, and magnetic fields can cause excess from the lognormal PDF at an early cloud formation stage, (3) core formation and/or global collapse of filaments and a non-isothermal gas distribution lead to a power-law tail, and (4) external compression broadens the column density PDF, consistent with numerical simulations.

  16. Search for signatures of dust in the Pluto-Charon system using Herschel/PACS observations

    NASA Astrophysics Data System (ADS)

    Marton, G.; Kiss, Cs.; Balog, Z.; Lellouch, E.; Verebélyi, E.; Klaas, U.

    2015-07-01

    In this letter we explore the environment of Pluto and Charon in the far infrared with the main aim of identifying the signs of any possible dust ring, should it exist in the system. Our study is based on observations performed at 70 μm with the PACS instrument onboard the Herschel Space Observatory at nine epochs between March 14 and 19, 2012. The far-infrared images of the Pluto-Charon system are compared to those of the point spread function (PSF) reference quasar 3C 454.3. The deviation between the observed Pluto-Charon and reference PSFs are less then 1σ, indicating that clear evidence for an extended dust ring around the system was not found. Our method is capable of detecting a hypothetical ring with a total flux of ~3.3 mJy at a distance of ~153 000 km (~8.2 Pluto-Charon distances) from the system's barycentre. We place upper limits on the total disk mass and on the column density in a reasonable disk configuration and analyse the hazard during the flyby of NASA's New Horizons in July 2015. This realistic model configuration predicts a column density of 8.7 × 10-10 g cm-2 along the path of the probe and an impactor mass of 8.7 × 10-5 g. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  17. The Herschel Orion Protostar Survey: Spectral Energy Distributions and Fits Using a Grid of Protostellar Models

    NASA Astrophysics Data System (ADS)

    Furlan, E.; Fischer, W. J.; Ali, B.; Stutz, A. M.; Stanke, T.; Tobin, J. J.; Megeath, S. T.; Osorio, M.; Hartmann, L.; Calvet, N.; Poteet, C. A.; Booker, J.; Manoj, P.; Watson, D. M.; Allen, L.

    2016-05-01

    We present key results from the Herschel Orion Protostar Survey: spectral energy distributions (SEDs) and model fits of 330 young stellar objects, predominantly protostars, in the Orion molecular clouds. This is the largest sample of protostars studied in a single, nearby star formation complex. With near-infrared photometry from 2MASS, mid- and far-infrared data from Spitzer and Herschel, and submillimeter photometry from APEX, our SEDs cover 1.2–870 μm and sample the peak of the protostellar envelope emission at ∼100 μm. Using mid-IR spectral indices and bolometric temperatures, we classify our sample into 92 Class 0 protostars, 125 Class I protostars, 102 flat-spectrum sources, and 11 Class II pre-main-sequence stars. We implement a simple protostellar model (including a disk in an infalling envelope with outflow cavities) to generate a grid of 30,400 model SEDs and use it to determine the best-fit model parameters for each protostar. We argue that far-IR data are essential for accurate constraints on protostellar envelope properties. We find that most protostars, and in particular the flat-spectrum sources, are well fit. The median envelope density and median inclination angle decrease from Class 0 to Class I to flat-spectrum protostars, despite the broad range in best-fit parameters in each of the three categories. We also discuss degeneracies in our model parameters. Our results confirm that the different protostellar classes generally correspond to an evolutionary sequence with a decreasing envelope infall rate, but the inclination angle also plays a role in the appearance, and thus interpretation, of the SEDs.

  18. A Herschel and APEX Census of the Reddest Sources in Orion: Searching for the Youngest Protostars

    NASA Astrophysics Data System (ADS)

    Stutz, Amelia M.; Tobin, John J.; Stanke, Thomas; Megeath, S. Thomas; Fischer, William J.; Robitaille, Thomas; Henning, Thomas; Ali, Babar; di Francesco, James; Furlan, Elise; Hartmann, Lee; Osorio, Mayra; Wilson, Thomas L.; Allen, Lori; Krause, Oliver; Manoj, P.

    2013-04-01

    We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using data obtained with the PACS instrument on board the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar candidates are detected at 70 μm and 160 μm that are either too faint (m 24 > 7 mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS 24 μm band. We find that the 11 reddest protostar candidates with log λF λ70/λF λ24 > 1.65 are free of contamination and can thus be reliably explained as protostars. The remaining 44 sources have less extreme 70/24 colors, fainter 70 μm fluxes, and higher levels of contamination. Taking the previously known sample of Spitzer protostars and the new sample together, we find 18 sources that have log λF λ70/λF λ24 > 1.65; we name these sources "PACS Bright Red sources," or PBRs. Our analysis reveals that the PBR sample is composed of Class 0 like sources characterized by very red spectral energy distributions (SEDs; T bol < 45 K) and large values of sub-millimeter fluxes (L smm/L bol > 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2-2 M ⊙ and luminosities of 0.7-10 L ⊙. Based on these properties, and a comparison of the SEDs with radiative transfer models of protostars, we conclude that the PBRs are most likely extreme Class 0 objects distinguished by higher than typical envelope densities and hence, high mass infall rates.

  19. The Herschel view of the nebula around the luminous blue variable star AG Carinae

    NASA Astrophysics Data System (ADS)

    Vamvatira-Nakou, C.; Hutsemékers, D.; Royer, P.; Cox, N. L. J.; Nazé, Y.; Rauw, G.; Waelkens, C.; Groenewegen, M. A. T.

    2015-06-01

    Far-infrared Herschel PACS imaging and spectroscopic observations of the nebula around the luminous blue variable (LBV) star AG Car have been obtained along with optical imaging in the Hα+[ N ii ] filter. In the infrared light, the nebula appears as a clumpy ring shell that extends up to 1.2 pc with an inner radius of 0.4 pc. It coincides with the Hα nebula, but extends further out. Dust modeling of the nebula was performed and indicates the presence of large grains. The dust mass is estimated to be ~0.2 M⊙. The infrared spectrum of the nebula consists of forbidden emission lines over a dust continuum. Apart from ionized gas, these lines also indicate the existence of neutral gas in a photodissociation region that surrounds the ionized region. The abundance ratios point towards enrichment by processed material. The total mass of the nebula ejected from the central star amounts to ~15 M⊙, assuming a dust-to-gas ratio typical of LBVs. The abundances and the mass-loss rate were used to constrain the evolutionary path of the central star and the epoch at which the nebula was ejected, with the help of available evolutionary models. This suggests an ejection during a cool LBV phase for a star of ~55 M⊙ with little rotation. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Based in part on observations collected at the European Southern Observatory, La Silla, Chile.Appendices are available in electronic form at http://www.aanda.org

  20. Far-infrared photometric observations of the outer planets and satellites with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Müller, T. G.; Balog, Z.; Nielbock, M.; Moreno, R.; Klaas, U.; Moór, A.; Linz, H.; Feuchtgruber, H.

    2016-04-01

    We present all Herschel-PACS photometer observations of Mars, Saturn, Uranus, Neptune, Callisto, Ganymede, and Titan. All measurements were carefully inspected for quality problems, were reduced in a (semi-)standard way, and were calibrated. The derived flux densities are tied to the standard PACS photometer response calibration, which is based on repeated measurements of five fiducial stars. The overall absolute flux uncertainty is dominated by the estimated 5% model uncertainty of the stellar models in the PACS wavelength range between 60 and 210 μm. A comparison with the corresponding planet and satellite models shows excellent agreement for Uranus, Neptune, and Titan, well within the specified 5%. Callisto is brighter than our model predictions by about 4-8%, Ganymede by about 14-21%. We discuss possible reasons for the model offsets. The measurements of these very bright point-like sources, together with observations of stars and asteroids, demonstrate the high reliability of the PACS photometer observations and the linear behavior of the PACS bolometer source fluxes over more than four orders of magnitude (from mJy levels up to more than 1000 Jy). Our results show the great potential of using the observed solar system targets for cross-calibration purposes with other ground-based, airborne, and space-based instruments and projects. At the same time, the PACS results will lead to improved model solutions for future calibration applications. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. HerMES: Candidate high-redshift galaxies discovered with Herschel/Spire

    SciTech Connect

    Dowell, C. Darren; Bock, J.; Bridge, C.; Cooray, A.; Conley, A.; Glenn, J.; Arumugam, V.; Asboth, V.; Aussel, H.; Béthermin, M.; Boselli, A.; Buat, V.; Burgarella, D.; Cabrera-Lavers, A.; Casey, C. M.; Chapman, S. C.; Clements, D. L.; Conversi, L.; Dannerbauer, H.; and others

    2014-01-01

    We present a method for selecting z > 4 dusty, star-forming galaxies (DSFGs) using Herschel/Spectral and Photometric Imaging Receiver 250/350/500 μm flux densities to search for red sources. We apply this method to 21 deg{sup 2} of data from the HerMES survey to produce a catalog of 38 high-z candidates. Follow-up of the first five of these sources confirms that this method is efficient at selecting high-z DSFGs, with 4/5 at z = 4.3-6.3 (and the remaining source at z = 3.4), and that they are some of the most luminous dusty sources known. Comparison with previous DSFG samples, mostly selected at longer wavelengths (e.g., 850 μm) and in single-band surveys, shows that our method is much more efficient at selecting high-z DSFGs, in the sense that a much larger fraction are at z > 3. Correcting for the selection completeness and purity, we find that the number of bright (S {sub 500} {sub μm} ≥ 30 mJy), red Herschel sources is 3.3 ± 0.8 deg{sup –2}. This is much higher than the number predicted by current models, suggesting that the DSFG population extends to higher redshifts than previously believed. If the shape of the luminosity function for high-z DSFGs is similar to that at z ∼ 2, rest-frame UV based studies may be missing a significant component of the star formation density at z = 4-6, even after correction for extinction.

  2. Far-infrared colours of nearby late-type galaxies in the Herschel Reference Survey

    NASA Astrophysics Data System (ADS)

    Boselli, A.; Ciesla, L.; Cortese, L.; Buat, V.; Boquien, M.; Bendo, G. J.; Boissier, S.; Eales, S.; Gavazzi, G.; Hughes, T. M.; Pohlen, M.; Smith, M. W. L.; Baes, M.; Bianchi, S.; Clements, D. L.; Cooray, A.; Davies, J.; Gear, W.; Madden, S.; Magrini, L.; Panuzzo, P.; Remy, A.; Spinoglio, L.; Zibetti, S.

    2012-04-01

    We study the far infrared (60-500 μm) colours of late-type galaxies in the Herschel Reference Survey, a K-band selected, volume limited sample of nearby galaxies. The far infrared colours are correlated with each other, with tighter correlations for the indices that are closer in wavelength. We also compare the different colour indices to various tracers of the physical properties of the target galaxies, such as the surface brightness of the ionising and non-ionising stellar radiation, the dust attenuation and the metallicity. The emission properties of the cold dust dominating the far infrared spectral domain are regulated by the properties of the interstellar radiation field. Consistent with that observed in nearby, resolved galaxies, our analysis shows that the ionising and the non-ionising stellar radiation, including that emitted by the most evolved, cold stars, both contribute to the heating of the cold dust component. This work also shows that metallicity is another key parameter characterising the cold dust emission of normal, late-type galaxies. A single modified black body with a grain emissivity index β = 1.5 better fits the observed SPIRE flux density ratios S250/S350 vs. S350/S500 than β = 2, although values of β ≃ 2 are possible in metal rich, high surface brightness galaxies. Values of β ≲ 1.5 better represent metal poor, lowsurface brightness objects. This observational evidence provides strong constraints for dust emission models of normal, late type galaxies. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  3. Star Formation in the Perseus Molecular Cloud: A Detailed Look at Star-Forming Clumps with Herschel

    NASA Astrophysics Data System (ADS)

    Sadavoy, Sarah I.

    2013-08-01

    This dissertation presents new Herschel observations at 70 micron, 160 micron, 250 micron, 350 micron, and 500 micron of the Perseus molecular cloud from the Herschel Gould Belt Survey. The Perseus molecular cloud is a nearby star-forming region consisting of seven main star-forming clumps. The Herschel observations are used to characterize and contrast the properties of these clumps, and to study their embedded core populations. First, we probed the exceptionally young clump, B1-E. Using complementary molecular line data, we demonstrate that B1-E is likely fragmenting into a first generation of dense cores in relative isolation. Such a core formation region has never been observed before. Second, we use complementary long wavelength observations at 850 micron to study the dust properties in the larger, more active B1 clump. We find that Herschel data alone cannot constrain well the dust properties of cold dust emission and that long wavelength observations are needed. Additionally, we find evidence of dust grain growth towards the dense cores in B1, where the dust emissivity index, beta, varies from the often assumed value of beta = 2. In the absence of long wavelength observations, however, assuming beta = 2 is preferable over measuring beta with the Herschel-only bands. Finally, we use the source extraction code, getsources, to identify the core populations within each clump from the Herschel data. In addition, we use complementary archival infrared observations to study their populations of young stellar objects (YSOs). We find that the more massive clumps have an excess of older stage YSOs, suggesting that these regions contracted first. Starless cores are typically associated with peaks in the column density, where those found towards regions of higher column density also have higher average densities and colder temperatures. Starless cores associated with a strong, local interstellar radiation field, however, have higher temperatures. We find that the clumps

  4. Spitzer/IRAC Imaging of Exceptionally Bright Cluster-Lensed Submillimeter Galaxies Discovered by the Herschel Lensing Survey

    NASA Astrophysics Data System (ADS)

    Egami, Eiichi; Ebeling, Harald; Rawle, Timothy; Clement, Benjamin; Walth, Gregory; Pereira, Maria; Richard, Johan; Kneib, Jean-Paul

    2012-12-01

    Over the last few years, discoveries of exceptionally bright (e.g., observed S_peak > 100 mJy in the Herschel/SPIRE bands) gravitationally lensed submillimeter galaxies (SMGs) have generated great excitement. This is because these gravitationally lensed SMGs are so bright that they enable us to perform a variety of follow-up observations using a suite of observing facilities in the submillimeter, millimeter, and radio now available on the ground. Using Herschel, our team has been conducting a survey of such bright lensed galaxies in the fields of massive galaxy clusters: ``The Herschel Lensing Survey (HLS)'' (PI: Egami; 419 hours). This large Herschel program targets a total of 581 X-ray/SZ-selected massive clusters, and is currently 80% complete. Cluster lenses are often more powerful than galaxy lenses, producing larger magnifications. For example, typical magnification factors for galaxy-lensed Herschel sources are x10 or less while cluster-lensed systems can often produce magnification factors of x20-30 and even above x100. Cluster lenses will therefore allow us to detect and study intrinsically less-luminous and/or more distant sources with the ability to provide a view of finer-scale (i.e., sub-kpc) structures. Here, we propose to conduct Spitzer/IRAC imaging of 56 bright lensed SMG candidates we have identified in the ~470 HLS cluster fields observed so far. The main scientific goal is twofold: (1) to locate the underlying stellar component, and (2) to study its properties (e.g., stellar mass, specific star-formation rate) by constraining the rest-frame near-infrared SED and comparing with the Herschel and other submillimeter/millimeter data (e.g., SMA, PdB, ALMA, etc.). These rare bright lensed SMGs will allow us to probe the population of heavily dust-obscured vigorously star-forming galaxies at high redshift (z>1), which is thought to play an important role in the cosmic star-formation history of the Universe and yet has been difficult to study due to the

  5. THE HERSCHEL AND JCMT GOULD BELT SURVEYS: CONSTRAINING DUST PROPERTIES IN THE PERSEUS B1 CLUMP WITH PACS, SPIRE, AND SCUBA-2

    SciTech Connect

    Sadavoy, S. I.; Di Francesco, J.; Johnstone, D.; Fallscheer, C.; Matthews, B.; Currie, M. J.; Jenness, T.; Drabek, E.; Hatchell, J.; Nutter, D.; Andre, Ph.; Hennemann, M.; Hill, T.; Koenyves, V.; Benedettini, M.; Bernard, J.-P.; Duarte-Cabral, A.; Friesen, R.; Greaves, J.; Collaboration: JCMT and Herschel Gould Belt Survey teams; and others

    2013-04-20

    We present Herschel observations from the Herschel Gould Belt Survey and SCUBA-2 science verification observations from the JCMT Gould Belt Survey of the B1 clump in the Perseus molecular cloud. We determined the dust emissivity index using four different techniques to combine the Herschel PACS+SPIRE data at 160-500 {mu}m with the SCUBA-2 data at 450 {mu}m and 850 {mu}m. Of our four techniques, we found that the most robust method was filtering out the large-scale emission in the Herschel bands to match the spatial scales recovered by the SCUBA-2 reduction pipeline. Using this method, we find {beta} Almost-Equal-To 2 toward the filament region and moderately dense material and lower {beta} values ({beta} {approx}> 1.6) toward the dense protostellar cores, possibly due to dust grain growth. We find that {beta} and temperature are more robust with the inclusion of the SCUBA-2 data, improving estimates from Herschel data alone by factors of {approx}2 for {beta} and by {approx}40% for temperature. Furthermore, we find core mass differences of {approx}< 30% compared to Herschel-only estimates with an adopted {beta} = 2, highlighting the necessity of long-wavelength submillimeter data for deriving accurate masses of prestellar and protostellar cores.

  6. Revealing the ISM in high redshift starburst galaxies: An analysis of Herschel PACS and SPIRE FTS spectroscopic observations of HerMES and H-ATLAS-selected lensed galaxies

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha

    In the quest to develop a fundamental understanding of galaxy formation and evolution, observations of dusty star-forming galaxies (DSFGs) promise significant progress this decade. The importance of DSFGs is highlighted by the fact that half of the energy emitted by extragalactic sources emerges as dust-reprocessed light at infrared (IR) to sub millimeter wavelength. In the post-herschel\\ era, we are now at a unique position to tackle some of the key questions on galaxy formation and evolution because of the large area Herschel's Key Project surveys (HerMES and H-ATLAS). In particular those surveys have allowed us to identify a sample of 250 strongly gravitationally lensed DSFGs at z > 1. They give us a unique opportunity to dissect the detailed structures and kinematics of DSFGs. The Herschel Science Archive also contains individual follow up data on 44 and 25 of the brightest sources with SPIRE-FTS and PACS, respectively, in the spectroscopy mode, taking over 250 hours in four open-time programs. Only one of the 44 SPIRE FTS targets has yet to appear in the published literature. One of the four include an open-time 2 PACS spectroscopy program that was led at UCI by a former postdoc from the PI's group. That program was initially approved at Priority 2 in 2011, but was triggered in late 2012 and achieved 100% completion during the last two weeks of Herschel lifetime in May 2013. This archival analysis, interpretation, and modeling program involves two parts: (i) PACS spectroscopy in 50 to 200 microns of 25 lensed galaxies in the fine-structure emission lines [SiII]34, [SIII]33, [OIV]26, [OIII]52, [NIII]57 and [OI]63, and the molecular hydrogen H_2 S(0) and S(1). (ii) SPIRE FTS spectroscopy of 44 lensed galaxies, including above 25, over the wavelength range of 200 to 600 microns targeting [CII]158, [OIII]88, [OI]63/145, and [NI]122. The analysis will lead to a better understanding of the ISM of starbursting galaxies that span 1 < z < 3.1 range in redshift and a

  7. TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70-500 μm

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lellouch, E.; Müller, T.; Santos-Sanz, P.; Panuzzo, P.; Kiss, C.; Lim, T.; Mommert, M.; Bockelée-Morvan, D.; Vilenius, E.; Stansberry, J.; Tozzi, G. P.; Mottola, S.; Delsanti, A.; Crovisier, J.; Duffard, R.; Henry, F.; Lacerda, P.; Barucci, A.; Gicquel, A.

    2013-07-01

    Aims: Trans-Neptunian objects (TNOs) are bodies populating the Kuiper belt and they are believed to retain the most pristine and least altered material of the solar system. The Herschel open time key programme entitled "TNOs are Cool: A survey of the trans-Neptunian region" has been awarded 373 h to investigate the albedo, size distribution and thermal properties of TNOs and Centaurs. Here we focus on the brightest targets observed by both the PACS and SPIRE multiband photometers: the dwarf planet Haumea, six TNOs (Huya, Orcus, Quaoar, Salacia, 2002 UX25, and 2002 TC302), and two Centaurs (Chiron and Chariklo). Methods: Flux densities are derived from PACS and SPIRE instruments using optimised data reduction methods. The spectral energy distribution obtained with the Herschel PACS and SPIRE instruments over 6 bands (centred at 70, 100, 160, 250, 350, and 500 μm), with Spitzer-MIPS at 23.7 and 71.4 μm, and with WISE at 11.6 and 22.1 μm in the case of 10199 Chariklo, has been modelled with the NEATM thermal model in order to derive the albedo, diameter, and beaming factor. For the Centaurs Chiron and Chariklo and for the 1000 km sized Orcus and Quaoar, a thermophysical model was also run to better constrain their thermal properties. Results: We derive the size, albedo, and thermal properties, including thermal inertia and surface emissivity, for the 9 TNOs and Centaurs. Several targets show a significant decrease in their spectral emissivity longwards of ~300 μm and especially at 500 μm. Using our size estimations and the mass values available in the literature, we also derive the bulk densities for the binaries Quaoar/Weywot (2.18-0.36+0.43 g/cm3), Orcus/Vanth (1.53-0.13+0.15 g/cm3), and Salacia/Actea (1.29-0.23+0.29 g/cm3). Quaoar's density is similar to that of the other dwarf planets Pluto and Haumea, and its value implies high contents of refractory materials mixed with ices. Herschel is an ESA space observatory with science instruments provided by European

  8. The Herschel Exploitation of Local Galaxy Andromeda (HELGA). VI. The Distribution and Properties of Molecular Cloud Associations in M31

    NASA Astrophysics Data System (ADS)

    Kirk, J. M.; Gear, W. K.; Fritz, J.; Smith, M. W. L.; Ford, G.; Baes, M.; Bendo, G. J.; De Looze, I.; Eales, S. A.; Gentile, G.; Gomez, H. L.; Gordon, K.; O'Halloran, B.; Madden, S. C.; Roman-Duval, J.; Verstappen, J.; Viaene, S.; Boselli, A.; Cooray, A.; Lebouteiller, V.; Spinoglio, L.

    2015-01-01

    In this paper we present a catalog of giant molecular clouds (GMCs) in the Andromeda (M31) galaxy extracted from the Herschel Exploitation of Local Galaxy Andromeda (HELGA) data set. GMCs are identified from the Herschel maps using a hierarchical source extraction algorithm. We present the results of this new catalog and characterize the spatial distribution and spectral energy properties of its clouds based on the radial dust/gas properties found by Smith et al. A total of 326 GMCs in the mass range 104-107 M ⊙ are identified; their cumulative mass distribution is found to be proportional to M -2.34, in agreement with earlier studies. The GMCs appear to follow the same correlation of cloud mass to L CO observed in the Milky Way. However, comparison between this catalog and interferometry studies also shows that the GMCs are substructured below the Herschel resolution limit, suggesting that we are observing associations of GMCs. Following Gordon et al., we study the spatial structure of M31 by splitting the observed structure into a set of spiral arms and offset rings. We fit radii of 10.3 and 15.5 kpc to the two most prominent rings. We then fit a logarithmic spiral with a pitch angle of 8.°9 to the GMCs not associated with either ring. Last, we comment on the effects of deprojection on our results and investigate the effect different models for M31's inclination will have on the projection of an unperturbed spiral arm system. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  9. Matching dust emission structures and magnetic field in high-latitude cloud L1642: comparing Herschel and Planck maps★

    NASA Astrophysics Data System (ADS)

    Malinen, J.; Montier, L.; Montillaud, J.; Juvela, M.; Ristorcelli, I.; Clark, S. E.; Berné, O.; Bernard, J.-Ph.; Pelkonen, V.-M.; Collins, D. C.

    2016-05-01

    The nearby cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. It is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g., of the effect of magnetic fields. We compare Herschel dust emission structures and magnetic field orientation revealed by Planck polarization maps in L1642. The high-resolution (˜20″) Herschel data reveal a complex structure including a dense, compressed central clump, and low density striations. The Planck polarization data (at 10' resolution) reveal an ordered magnetic field pervading the cloud and aligned with the surrounding striations. There is a complex interplay between the cloud structure and large scale magnetic field. This suggests that the magnetic field is closely linked to the formation and evolution of the cloud. CO rotational emission confirms that the striations are connected with the main clumps and likely to contain material either falling into or flowing out of the clumps. There is a clear transition from aligned to perpendicular structures approximately at a column density of NH = 1.6 × 1021 cm-2. Comparing the Herschel maps with the Planck polarization maps shows the close connection between the magnetic field and cloud structure even in the finest details of the cloud.

  10. Comparing Herschel dust emission structures, magnetic fields observed by Planck, and dynamics: high-latitude star forming cloud L1642

    NASA Astrophysics Data System (ADS)

    Malinen, Johanna

    2016-01-01

    The nearby high-latitude cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. This cloud is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g., of the effect of magnetic fields. We compare Herschel dust emission structures and magnetic field orientation revealed by Planck polarization maps in L1642, and also combine these with dynamic information from molecular line observations. The high-resolution Herschel data reveal a complex structure including a dense, compressed central blob with elongated extensions, low density striations, "fishbone" like structures with a spine and perpendicular striations, and a spiraling "tail". The Planck polarization data reveal an ordered magnetic field that pervades the cloud and is aligned with the surrounding low density striations. We show that there is a complex interplay between the cloud structure and large scale magnetic fields revealed by Planck polarization data at 10' resolution. This suggests that the magnetic field is closely linked to the formation and evolution of the cloud. We see a clear transition from aligned to perpendicular structures approximately at a column density of NH = 2x10^21 cm-2. We conclude that Planck polarization data revealing the large scale magnetic field orientation can be very useful even when comparing to the finest structures in higher resolution data, e.g. Herschel at ~18" resolution.

  11. Matching dust emission structures and magnetic field in high-latitude cloud L1642: comparing Herschel and Planck maps★

    NASA Astrophysics Data System (ADS)

    Malinen, J.; Montier, L.; Montillaud, J.; Juvela, M.; Ristorcelli, I.; Clark, S. E.; Berné, O.; Bernard, J.-Ph.; Pelkonen, V.-M.; Collins, D. C.

    2016-08-01

    The nearby cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. It is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g. of the effect of magnetic fields. We compare Herschel dust emission structures and magnetic field orientation revealed by Planck polarization maps in L1642. The high-resolution (˜20 arcsec) Herschel data reveal a complex structure including a dense, compressed central clump, and low-density striations. The Planck polarization data (at 10 arcmin resolution) reveal an ordered magnetic field pervading the cloud and aligned with the surrounding striations. There is a complex interplay between the cloud structure and large-scale magnetic field. This suggests that the magnetic field is closely linked to the formation and evolution of the cloud. CO rotational emission confirms that the striations are connected with the main clumps and likely to contain material either falling into or flowing out of the clumps. There is a clear transition from aligned to perpendicular structures approximately at a column density of NH = 1.6 × 1021 cm-2. Comparing the Herschel maps with the Planck polarization maps shows the close connection between the magnetic field and cloud structure even in the finest details of the cloud.

  12. Herschel-HIFI view of mid-IR quiet massive protostellar objects

    NASA Astrophysics Data System (ADS)

    Herpin, F.; Chavarría, L.; Jacq, T.; Braine, J.; van der Tak, F.; Wyrowski, F.; van Dishoeck, E. F.; Baudry, A.; Bontemps, S.; Kristensen, L.; Schmalzl, M.; Mata, J.

    2016-03-01

    Aims: We present Herschel/HIFI observations of 14 water lines in a small sample of Galactic massive protostellar objects: NGC 6334I(N), DR21(OH), IRAS 16272-4837, and IRAS 05358+3543. Using water as a tracer of the structure and kinematics, we individually study each of these objects with the aim to estimate the amount of water around them, but to also to shed light on the high-mass star formation process. Methods: We analyzed the gas dynamics from the line profiles using Herschel-HIFI observations acquired as part of the WISH key-project of 14 far-IR water lines (H_216O, H_217O, H_218O) and several other species. Then through modeling the observations using the RATRAN radiative transfer code, we estimated outflow, infall, turbulent velocities, and molecular abundances and investigated the correlation with the evolutionary status of each source. Results: The four sources (and the previously studied W43-MM1) have been ordered in terms of evolution based on their spectral energy distribution from youngest to older: 1) NGC 64334I(N); 2) W43-MM1; 3) DR21(OH); 4) IRAS 16272-4837; 5) IRAS 05358+3543. The molecular line profiles exhibit a broad component coming from the shocks along the cavity walls that is associated with the protostars, and an infalling (or expanding, for IRAS 05358+3543) and passively heated envelope component, with highly supersonic turbulence that probably increases with the distance from the center. Accretion rates between 6.3 × 10-5 and 5.6 × 10-4M⊙ yr-1 are derived from the infall observed in three of our sources. The outer water abundance is estimated to be at the typical value of a few 10-8, while the inner abundance varies from 1.7 × 10-6 to 1.4 × 10-4 with respect to H2 depending on the source. Conclusions: We confirm that regions of massive star formation are highly turbulent and that the turbulence probably increases in the envelope with the distance to the star. The inner abundances are lower than the expected, 10-4, perhaps because

  13. The Herschel Virgo Cluster Survey. XVII. SPIRE point-source catalogs and number counts

    NASA Astrophysics Data System (ADS)

    Pappalardo, Ciro; Bendo, George J.; Bianchi, Simone; Hunt, Leslie; Zibetti, Stefano; Corbelli, Edvige; di Serego Alighieri, Sperello; Grossi, Marco; Davies, Jonathan; Baes, Maarten; De Looze, Ilse; Fritz, Jacopo; Pohlen, Michael; Smith, Matthew W. L.; Verstappen, Joris; Boquien, Médéric; Boselli, Alessandro; Cortese, Luca; Hughes, Thomas; Viaene, Sebastien; Bizzocchi, Luca; Clemens, Marcel

    2015-01-01

    Aims: We present three independent catalogs of point-sources extracted from SPIRE images at 250, 350, and 500 μm, acquired with the Herschel Space Observatory as a part of the Herschel Virgo Cluster Survey (HeViCS). The catalogs have been cross-correlated to consistently extract the photometry at SPIRE wavelengths for each object. Methods: Sources have been detected using an iterative loop. The source positions are determined by estimating the likelihood to be a real source for each peak on the maps, according to the criterion defined in the sourceExtractorSussextractor task. The flux densities are estimated using the sourceExtractorTimeline, a timeline-based point source fitter that also determines the fitting procedure with the width of the Gaussian that best reproduces the source considered. Afterwards, each source is subtracted from the maps, removing a Gaussian function in every position with the full width half maximum equal to that estimated in sourceExtractorTimeline. This procedure improves the robustness of our algorithm in terms of source identification. We calculate the completeness and the flux accuracy by injecting artificial sources in the timeline and estimate the reliability of the catalog using a permutation method. Results: The HeViCS catalogs contain about 52 000, 42 200, and 18 700 sources selected at 250, 350, and 500 μm above 3σ and are ~75%, 62%, and 50% complete at flux densities of 20 mJy at 250, 350, 500 μm, respectively. We then measured source number counts at 250, 350, and 500 μm and compare them with previous data and semi-analytical models. We also cross-correlated the catalogs with the Sloan Digital Sky Survey to investigate the redshift distribution of the nearby sources. From this cross-correlation, we select ~2000 sources with reliable fluxes and a high signal-to-noise ratio, finding an average redshift z ~ 0.3 ± 0.22 and 0.25 (16-84 percentile). Conclusions: The number counts at 250, 350, and 500 μm show an increase in

  14. The Cologne Database for Molecular Spectroscopy, Cdms, in Times of Herschel, SOFIA, and Alma

    NASA Astrophysics Data System (ADS)

    Müller, Holger S. P.; Stutzki, Jürgen; Schlemmer, Stephan

    2009-06-01

    The CDMS provides in its catalog section atomic and molecular line lists for species that have been or may be observed in space by radio astronomical means. The line list of each molecule is gathered in an individual entry; minor isotopologs have separate entries, and the same applies to excited vibrational states with the exception of some diatomic molecules. With 5 to 10 new or updated entries each month, the CDMS catalog has been growing rapidly over the past 10 years: since February 2009, there have been more than 500 entries in the CDMS - with many more entries to be created. Entries are generated from fitting (mostly) laboratory data to accepted Hamiltonian models. Despite many dedicated laboratory spectroscopic investigations in recent years, accurate data is still lacking frequently - in particular at higher frequencies, for minor isotopic species, for excited vibrational states, or for somewhat larger molecules. While high frequency data are of special concern for the Herschel satellite, scheduled to be launched in mid-April 2009, or for the Stratospheric Observatory For Infrared Astronomy (SOFIA), the remaining issues mentioned above are important especially for telecope arrays such as the Atacama Large Millimeter Array (ALMA). The main features of the CDMS catalog will be described, including recent developments concerning new entries as well as available and planned features. In particular, we will discuss issues relevant for generating a consolidated database that also takes into account information from other databases. Attention will be given to laboratory spectroscopic needs for missions such as Herschel and SOFIA on one hand and for ALMA, the Expanded Very Large Array (EVLA), and other facilities on the other, both, in terms of general aspects and in terms of specific examples. Selected contributions from the Cologne spectroscopy laboratories to address these needs will be presented. H. S. P. Müller, S. Thorwirth, D. A. Roth, G. Winnewisser

  15. Herschel observations of the debris cloud of C/2010 X1 (Elenin)

    NASA Astrophysics Data System (ADS)

    Kidger, Mark Richard; Altieri, Bruno

    2015-08-01

    We report Herschel observations of defunct Comet C/2010 X1 (Elenin), aimed at detecting its infrared ghost: the debris cloud and any remaining inert cometessimals that may have been released in the break-up of the nucleus, taking advantage of the comet’s very close pass to Earth in mid-October 2011. These observations would have allowed us to detect both individual surviving fragments of the nucleus of »100m diameter and the expanding dust cloud, being particularly sensitive to coarse dust and boulders in the millimetre to metre size range. No discrete bodies were detected by Herschel to this limiting size, although there is a possible, very low signal-to-noise, detection of the debris cloud.Although most comets exhibit a (relatively) predictable behaviour, a minority of objects deviate considerably from the norm, either by showing sudden outbursts in brightness or, more rarely, by fading unexpectedly. The archetypal event in this latter category was the intensely observed sudden disruption of Comet C/1999 S4 (LINEAR) in July 2000 as it passed perihelion: it was found to have disintegrated into a cloud of cometessimals plus an expanding dust cloud, which faded rapidly, becoming undetectable within 20 days of disruption. Observations of Comet C/2010 X1 (Elenin) in August 2011 showed a similar pattern of evolution of coma morphology into an expanding, amorphous cloud of rapidly decreasing surface brightness (Mattiazzo & McNaught, 2011, CBET 2801) shortly before perihelion passage. However, the comet’s difficult viewing geometry at the time of disruption made it impossible to study the event using high-resolution imaging techniques and, in particular, to measure the ratio of dust to cometessimals which gives information on the internal structure of the nucleus before disruption. Our observations allow us to put a strong upper limit on the maximum size of the building blocks of the nucleus and to contrast this with the predictions of the rubble pile model

  16. Shockingly low water abundances in Herschel/PACS observations of low-mass protostars in Perseus

    NASA Astrophysics Data System (ADS)

    Karska, A.; Kristensen, L. E.; van Dishoeck, E. F.; Drozdovskaya, M. N.; Mottram, J. C.; Herczeg, G. J.; Bruderer, S.; Cabrit, S.; Evans, N. J.; Fedele, D.; Gusdorf, A.; Jørgensen, J. K.; Kaufman, M. J.; Melnick, G. J.; Neufeld, D. A.; Nisini, B.; Santangelo, G.; Tafalla, M.; Wampfler, S. F.

    2014-12-01

    Context. Protostars interact with their surroundings through jets and winds impinging on the envelope and creating shocks, but the nature of these shocks is still poorly understood. Aims: Our aim is to survey far-infrared molecular line emission from a uniform and significant sample of deeply-embedded low-mass young stellar objects (YSOs) in order to characterize shocks and the possible role of ultraviolet radiation in the immediate protostellar environment. Methods: Herschel/PACS spectral maps of 22 objects in the Perseus molecular cloud were obtained as part of the William Herschel Line Legacy (WILL) survey. Line emission from H2O, CO, and OH is tested against shock models from the literature. Results: Observed line ratios are remarkably similar and do not show variations with physical parameters of the sources (luminosity, envelope mass). Most ratios are also comparable to those found at off-source outflow positions. Observations show good agreement with the shock models when line ratios of the same species are compared. Ratios of various H2O lines provide a particularly good diagnostic of pre-shock gas densities, nH ~ 105 cm-3, in agreement with typical densities obtained from observations of the post-shock gas when a compression factor on the order of 10 is applied (for non-dissociative shocks). The corresponding shock velocities, obtained from comparison with CO line ratios, are above 20 km s-1. However, the observations consistently show H2O-to-CO and H2O-to-OH line ratios that are one to two orders of magnitude lower than predicted by the existing shock models. Conclusions: The overestimated model H2O fluxes are most likely caused by an overabundance of H2O in the models since the excitation is well-reproduced. Illumination of the shocked material by ultraviolet photons produced either in the star-disk system or, more locally, in the shock, would decrease the H2O abundances and reconcile the models with observations. Detections of hot H2O and strong OH

  17. Disk radii and grain sizes in Herschel-resolved debris disks

    SciTech Connect

    Pawellek, Nicole; Krivov, Alexander V.; Marshall, Jonathan P.; Montesinos, Benjamin; Ábrahám, Péter; Moór, Attila; Bryden, Geoffrey; Eiroa, Carlos

    2014-09-01

    The radii of debris disks and the sizes of their dust grains are important tracers of the planetesimal formation mechanisms and physical processes operating in these systems. Here we use a representative sample of 34 debris disks resolved in various Herschel Space Observatory (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) programs to constrain the disk radii and the size distribution of their dust. While we modeled disks with both warm and cold components, and identified warm inner disks around about two-thirds of the stars, we focus our analysis only on the cold outer disks, i.e., Kuiper-belt analogs. We derive the disk radii from the resolved images and find a large dispersion for host stars of any spectral class, but no significant trend with the stellar luminosity. This argues against ice lines as a dominant player in setting the debris disk sizes, since the ice line location varies with the luminosity of the central star. Fixing the disk radii to those inferred from the resolved images, we model the spectral energy distribution to determine the dust temperature and the grain size distribution for each target. While the dust temperature systematically increases toward earlier spectral types, the ratio of the dust temperature to the blackbody temperature at the disk radius decreases with the stellar luminosity. This is explained by a clear trend of typical sizes increasing toward more luminous stars. The typical grain sizes are compared to the radiation pressure blowout limit s {sub blow} that is proportional to the stellar luminosity-to-mass ratio and thus also increases toward earlier spectral classes. The grain sizes in the disks of G- to A-stars are inferred to be several times s {sub blow} at all stellar luminosities, in agreement with collisional models of debris disks. The sizes, measured in the units of s {sub blow}, appear to decrease

  18. Herschel/PACS photometry of transiting-planet host stars with candidate warm debris disks

    NASA Astrophysics Data System (ADS)

    Merín, Bruno; Ardila, David R.; Ribas, Álvaro; Bouy, Hervé; Bryden, Geoffrey; Stapelfeldt, Karl; Padgett, Deborah

    2014-09-01

    Dust in debris disks is produced by colliding or evaporating planetesimals, which are remnants of the planet formation process. Warm dust disks, known by their emission at ≤24 μm, are rare (4% of FGK main sequence stars) and especially interesting because they trace material in the region likely to host terrestrial planets, where the dust has a very short dynamical lifetime. Statistical analyses of the source counts of excesses as found with the mid-IR Wide Field Infrared Survey Explorer (WISE) suggest that warm-dust candidates found for the Kepler transiting-planet host-star candidates can be explained by extragalactic or galactic background emission aligned by chance with the target stars. These statistical analyses do not exclude the possibility that a given WISE excess could be due to a transient dust population associated with the target. Here we report Herschel/PACS 100 and 160 micron follow-up observations of a sample of Kepler and non-Kepler transiting-planet candidates' host stars, with candidate WISE warm debris disks, aimed at detecting a possible cold debris disk in any one of them. No clear detections were found in any one of the objects at either wavelength. Our upper limits confirm that most objects in the sample do not have a massive debris disk like that in β Pic. We also show that the planet-hosting star WASP-33 does not have a debris disk comparable to the one around η Crv. Although the data cannot be used to rule out rare warm disks around the Kepler planet-hosting candidates, the lack of detections and the characteristics of neighboring emission found at far-IR wavelengths support an earlier result suggesting that most of the WISE-selected IR excesses around Kepler candidate host stars are likely due to either chance alignment with background IR-bright galaxies and/or to interstellar emission. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important

  19. Herschel/HIFI observations of ionised carbon in the β Pictoris debris disk

    NASA Astrophysics Data System (ADS)

    Cataldi, G.; Brandeker, A.; Olofsson, G.; Larsson, B.; Liseau, R.; Blommaert, J.; Fridlund, M.; Ivison, R.; Pantin, E.; Sibthorpe, B.; Vandenbussche, B.; Wu, Y.

    2014-03-01

    Context. The dusty debris disk around the ~20 Myr old main-sequence A-star β Pictoris is known to contain gas. Evidence points towards a secondary origin of the gas as opposed to being a direct remnant from the initial protoplanetary disk, although the dominant gas production mechanism is so far not identified. The origin of the observed overabundance of C and O compared with solar abundances of metallic elements such as Na and Fe is also unclear. Aims: Our goal is to constrain the spatial distribution of C in the disk, and thereby the gas origin and its abundance pattern. Methods: We used the HIFI instrument on board the Herschel Space Observatory to observe and spectrally resolve C ii emission at 158 μm from the β Pic debris disk. Assuming a disk in Keplerian rotation and a model for the line emission from the disk, we used the spectrally resolved line profile to constrain the spatial distribution of the gas. Results: We detect the C ii 158 μm emission. Modelling the shape of the emission line shows that most of the gas is located at about ~100 AU or beyond. We estimate a total C gas mass of 1.3-0.5+1.3 × 10-2 M⊕ (central 90% confidence interval). The data suggest that more gas is located on the south-west side of the disk than on the north-east side. The shape of the emission line is consistent with the hypothesis of a well mixed gas (constant C/Fe ratio throughout the disk). Assuming instead a spatial profile expected from a simplified accretion disk model, we found it to give a significantly poorer fit to the observations. Conclusions: Since the bulk of the gas is found outside 30 AU, we argue that the cometary objects known as "falling evaporating bodies" are probably not the dominant source of gas; production from grain-grain collisions or photodesorption seems more likely. The incompatibility of the observations with a simplified accretion disk model might favour a preferential depletion explanation for the overabundance of C and O, although it is

  20. HERSCHEL SEARCH FOR O{sub 2} TOWARD THE ORION BAR

    SciTech Connect

    Melnick, Gary J.; Tolls, Volker; Goldsmith, Paul F.; Kaufman, Michael J.; Hollenbach, David J.; Black, John H.; Hjalmarson, Ake; Liseau, Rene; Encrenaz, Pierre; Pagani, Laurent; Falgarone, Edith; Gerin, Maryvonne; Lis, Dariusz C.; Neufeld, David A.; Snell, Ronald L.; Van der Tak, Floris; Van Dishoeck, Ewine F.

    2012-06-10

    We report the results of a search for molecular oxygen (O{sub 2}) toward the Orion Bar, a prominent photodissociation region at the southern edge of the H II region created by the luminous Trapezium stars. We observed the spectral region around the frequency of the O{sub 2} N{sub J} = 3{sub 3}-1{sub 2} transition at 487 GHz and the 5{sub 4}-3{sub 4} transition at 774 GHz using the Heterodyne Instrument for the Far-Infrared on the Herschel Space Observatory. Neither line was detected, but the 3{sigma} upper limits established here translate to a total line-of-sight O{sub 2} column density <1.5 Multiplication-Sign 10{sup 16} cm{sup -2} for an emitting region whose temperature is between 30 K and 250 K, or <1 Multiplication-Sign 10{sup 16} cm{sup -2} if the O{sub 2} emitting region is primarily at a temperature of {approx}<100 K. Because the Orion Bar is oriented nearly edge-on relative to our line of sight, the observed column density is enhanced by a factor estimated to be between 4 and 20 relative to the face-on value. Our upper limits imply that the face-on O{sub 2} column density is less than 4 Multiplication-Sign 10{sup 15} cm{sup -2}, a value that is below, and possibly well below, model predictions for gas with a density of 10{sup 4}-10{sup 5} cm{sup -3} exposed to a far-ultraviolet flux 10{sup 4} times the local value, conditions inferred from previous observations of the Orion Bar. The discrepancy might be resolved if (1) the adsorption energy of O atoms to ice is greater than 800 K; (2) the total face-on A{sub V} of the Bar is less than required for O{sub 2} to reach peak abundance; (3) the O{sub 2} emission arises within dense clumps with a small beam filling factor; or (4) the face-on depth into the Bar where O{sub 2} reaches its peak abundance, which is density dependent, corresponds to a sky position different from that sampled by our Herschel beams.

  1. Herschel observations of the Marco Polo-R asteroid 175706 (1996 FG3).

    NASA Astrophysics Data System (ADS)

    O'Rourke, L.; Barucci, A.; Gònzalez-Garcìa, B.; Dotto, E.; Küppers, M.

    2012-09-01

    Background: The Marco Polo-R mission has been selected for the assessment study phase of the ESA M3 missions. This ESA-led sample return mission to the binary asteroid 1996 FG3 (launch window between 2020 and 2024) is proposed with a design that allows it to fit within the pre-defined cost cap of a M-class mission. The binary nature of the target will allow more precise measurements of mass, gravity, and density than for a single object, as well as additional insights into the geology and geophysics of the system. The asteroid has been classified by Binzel et al. [1] as a C-type. It is considered to be a typical example of a primitive object [2]. Dynamically, this is an Apollo asteroid with semimajor axis a of 1.054 AU, eccentricity e of 0.35, and and inclination i of 1.98 degrees. Measurements of the albedo derived from thermal infrared observations give a value of pV = 0.042 (+0.035 -0.017), and a combined diameter of D = 1.84 (+0.56 -0.47) km [3]. The Herschel observations : The MACH-11 (Measurements of 11 Asteroids & Comets) Programme observed this binary asteroid in two occasions in November of 2012. The observations performed had a duration of 0.6 hours with the asteroid pair moving rapidly at 6'/hr thus making removal of the background quite straightforward. The observations were performed in two observing blocks; the first block consisted of a 2 repetition blue/red map, the second block consisted of a 2 repetition green/red map, with the intention to observe the target at different phase angles. Our Results : Our measurements will serve to update the known radiometric properties for this binary asteroid through their inclusion into a thermophysical model (TPM) [4] which has been validated against a large database of asteroids including targets of other spacecraft mission e.g. Lutetia [5], Itokawa [6]. Using existing sets of published thermal observations (Spitzer, TNG NICS), combined with our Herschel observations, applied within this thermophysical model

  2. Herschel observations of Hickson compact groups of galaxies: Unveiling the properties of cold dust

    NASA Astrophysics Data System (ADS)

    Bitsakis, T.; Charmandaris, V.; Appleton, P. N.; Díaz-Santos, T.; Le Floc'h, E.; da Cunha, E.; Alatalo, K.; Cluver, M.

    2014-05-01

    We present a Herschel far-infrared and sub-millimetre (sub-mm) study of a sample of 120 galaxies in 28 Hickson compact groups (HCGs). Fitting their UV to sub-mm spectral energy distributions with the model of da Cunha et al. (2008), we accurately estimate the dust masses, luminosities, and temperatures of the individual galaxies. We find that nearly half of the late-type galaxies in dynamically "old" groups, those with more than 25% of early-type members and redder UV-optical colours, also have significantly lower dust-to-stellar mass ratios compared to those of actively star-forming galaxies of the same mass found both in HCGs and in the field. Examining their dust-to-gas mass ratios, we conclude that dust was stripped out of these systems as a result of the gravitational and hydrodynamic interactions, experienced owing to previous encounters with other group members. About 40% of the early-type galaxies (mostly lenticulars), in dynamically "old" groups, display dust properties similar to those of the UV-optical red late-type galaxies. Given their stellar masses, star formation rates, and UV-optical colours, we suggest that red late-type and dusty lenticular galaxies represent transition populations between blue star-forming disk galaxies and quiescent early-type ellipticals. On the other hand, both the complete absence of any correlation between the dust and stellar masses of the dusty ellipticals and their enhanced star formation activity, suggest the increase in their gas and dust content due to accretion and merging. Our deep Herschel observations also allow us to detect the presence of diffuse cold intragroup dust in 4 HCGs. We also find that the fraction of 250 μm emission that is located outside of the main bodies of both the red late-type galaxies and the dusty lenticulars is 15-20% of their integrated emission at this band. All these findings are consistent with an evolutionary scenario in which gas dissipation, shocks, and turbulence, in addition to

  3. Herschel-PACS observations of [OI] and H2O in Chamaeleon II

    NASA Astrophysics Data System (ADS)

    Riviere-Marichalar, P.; Bayo, A.; Kamp, I.; Vicente, S.; Williams, J. P.; Barrado, D.; Eiroa, C.; Duchêne, G.; Montesinos, B.; Mathews, G.; Podio, L.; Dent, W. R. F.; Huélamo, N.; Merín, B.

    2015-03-01

    Context. Gas plays a major role in the dynamical evolution of protoplanetary discs. Its coupling with the dust is the key to our understanding of planetary formation. Studying the gas content is therefore a crucial step towards understanding protoplanetary discs evolution. Such a study can be made through spectroscopic observations of emission lines in the FIR, where some of the most important gas coolants emit, such as the [OI] 3P1 → 3P2 transition at 63.18 μm. Aims: We aim at characterising the gas content of protoplanetary discs in the intermediate-aged (from the perspective of the disc lifetime) Chamaeleon II (Cha II) star forming region. We also aim at characterising the gaseous detection fractions within this age range, which is an essential step tracing gas evolution with age in different star forming regions. This evolutionary study can be used to tackle the problem of the gas dispersal timescale in future studies. Methods: We obtained Herschel-PACS line scan spectroscopic observations at 63 μm of 19 Cha II Class I and II stars. The observations were used to trace [OI] and o-H2O at 63 μm. The analysis of the spatial distribution of [OI], when extended, can be used to understand the origin of the emission. Results: We have detected [OI] emission toward seven out of the nineteen systems observed, and o-H2O emission at 63.32 μm in just one of them