Science.gov

Sample records for faint red sequence

  1. The faint end of the red sequence galaxy luminosity function: unveiling surface brightness selection effects with the CLASH clusters

    NASA Astrophysics Data System (ADS)

    Martinet, Nicolas; Durret, Florence; Adami, Christophe; Rudnick, Gregory

    2017-08-01

    Characterizing the evolution of the faint end of the cluster red sequence (RS) galaxy luminosity function (GLF) with redshift is a milestone in understanding galaxy evolution. However, the community is still divided in that respect, hesitating between an enrichment of the RS due to efficient quenching of blue galaxies from z 1 to present-day or a scenario in which the RS is built at a higher redshift and does not evolve afterwards. Recently, it has been proposed that surface brightness (SB) selection effects could possibly solve the literature disagreement, accounting for the diminishing RS faint population in ground-based observations. We investigate this hypothesis by comparing the RS GLFs of 16 CLASH clusters computed independently from ground-based Subaru/Suprime-Cam V and Ip or Ic images and space-based HST/ACS F606W and F814W images in the redshift range 0.187 ≤ z ≤ 0.686. We stack individual cluster GLFs in two redshift bins (0.187 ≤ z ≤ 0.399 and 0.400 ≤ z ≤ 0.686) and two mass (6 × 1014M⊙ ≤ M200< 1015M⊙ and 1015M⊙ ≤ M200) bins, and also measure the evolution with the enclosing radius from 0.5 Mpc up to the virial radius for the Subaru large field of view data. Finally, we simulate the low-redshift clusters at higher redshift to investigate SB dimming effects. We find similar RS GLFs for space- and ground-based data, with a difference of 0.2σ in the faint end parameter α when stacking all clusters together and a maximum difference of 0.9σ in the case of the high-redshift stack, demonstrating a weak dependence on the type of observation in the probed range of redshift and mass. When considering the full sample, we estimate α = - 0.76 ± 0.07 and α = - 0.78 ± 0.06 with HST and Subaru, respectively. We note a mild variation of the faint end between the high- and low-redshift subsamples at a 1.7σ and 2.6σ significance. We investigate the effect of SB dimming by simulating our low-redshift galaxies at high redshift. We measure an

  2. On the clustering of faint red galaxies

    NASA Astrophysics Data System (ADS)

    Xu, Haojie; Zheng, Zheng; Guo, Hong; Zhu, Ju; Zehavi, Idit

    2016-08-01

    Faint red galaxies in the Sloan Digital Sky Survey show a puzzling clustering pattern in previous measurements. In the two-point correlation function (2PCF), they appear to be strongly clustered on small scales, indicating a tendency to reside in massive haloes as satellite galaxies. However, their weak clustering on large scales suggests that they are more likely to be found in low-mass haloes. The interpretation of the clustering pattern suffers from the large sample variance in the 2PCF measurements, given the small volume of the volume-limited sample of such faint galaxies. We present improved clustering measurements of faint galaxies by making a full use of a flux-limited sample to obtain volume-limited measurements with an increased effective volume. In the improved 2PCF measurements, the fractional uncertainties on large scales drop by more than 40 per cent, and the strong contrast between small-scale and large-scale clustering amplitudes seen in previous work is no longer prominent. From halo occupation distribution modelling of the measurements, we find that a considerable fraction of faint red galaxies to be satellites in massive haloes, a scenario supported by the strong covariance of small-scale 2PCF measurements and the relative spatial distribution of faint red galaxies and luminous galaxies. However, the satellite fraction is found to be degenerate with the slope of the distribution profile of satellites in inner haloes. We compare the modelling results with semi-analytic model predictions and discuss the implications.

  3. Fainting

    MedlinePlus

    ... tunnel vision) or noises are fading into the background. Causes Fainting may occur while or after you: ... a seizure or heart rhythm disturbance), and to figure out the cause of the fainting episode. If ...

  4. Fainting

    MedlinePlus

    ... brain does not get enough oxygen. You lose consciousness, or “pass out,” for a brief time (usually ... syncope, exertional syncope, fainting, hyperventilation, hypovolemic syncope, lose consciousness, loss of consciousness, micturition syncope, orthostatic syncope, pass ...

  5. Faint Photoelectric Photometric Standard Star Sequences

    DTIC Science & Technology

    1988-07-15

    PHOTOELECTRIC PHOTOMETRIC STANDARD STAR SEQUENCES by Arlo U. Landolt Department of Physics and Astronomy Louisiana State University Baton Rouge, Louisiana 70803...portion of astronomy that is concerned with the measurement of the energy radiated by celestial objects at any point or points along the electromagnetic...astronomers. i. Two-Star Photometer Dr. Albert D. Grauer, Professor of Physics and Astronomy at the University of Arkansas in Little Rock (UALR) and

  6. Recognition of Distant Supergiants among Faint Red Stars in the Galactic Plane

    NASA Astrophysics Data System (ADS)

    MacConnell, Darrell J.; Wing, R. F.; Costa, E.

    2011-05-01

    Surveys along the Galactic plane at red and infrared wavelengths -- e.g. several objective-prism surveys in the photographic infrared, and the recent Spitzer/GLIMPSE survey in the 3-8μ region -- record large numbers of faint red stars. Some of these sources must be distant, heavily-reddened supergiants in remote spiral arms, and they would be valuable tracers if their distances could be estimated. Measurement of a TiO band and a color index -- show that the majority of the detected faint, red sources are stars of type M, reddened to different degrees. It is more difficult to distinguish bona fide supergiants from the more common giants (which are also likely to be reddened, but are not confined to spiral arms), and to obtain the luminosity classes needed for the determination of individual distances. We have developed two methods, one using slit spectroscopy and the other narrow-band photometry, for determining the luminosities of reddened M stars. Both methods depend primarily on the measurement of CN absorption in the 0.8μ region, often in the face of much stronger TiO bands. The spectroscopic method involves flattening the digital spectra and comparing program stars to standards of the same TiO strength to judge the amount of CN present. The narrow-band method involves fitting a blackbody curve to the calibrated photometry and defining a reddening-free CN index. This CN absorption is measurable in all giants and supergiants of types K and M and is stronger in supergiants. In fact, young, massive supergiants of classes Ia and Iab, which should be excellent spiral-arm tracers, can be distinguished from supergiants of class Ib, which may be older. We illustrate our procedures and apply them to a sample of GLIMPSE sources. We show that our methods give consistent results and can be used to identify distant supergiants among GLIMPSE sources.

  7. NOTE: Red, Gray, and Blue: Near Infrared Spectrophotometry of Faint Moons of Uranus and Neptune

    NASA Astrophysics Data System (ADS)

    Trilling, David E.; Brown, Robert H.

    2000-11-01

    Using the CoCo Cold Coronagraph at NASA's Infrared Telescope Facility on Mauna Kea, we observed the uranian satellites Miranda, Puck, Portia, and Rosalind and the neptunian satellite Proteus in the near infrared (JHK) to determine the albedos of those faint satellites. In V-J, all of Puck, Portia, Rosalind, and Proteus are very blue, similar to the colors of many icy satellites and of water ice. The satellites we observed have a wide range of J-H colors, with Miranda being blue, Proteus being gray, and Puck, Portia, and Rosalind being red. For the satellites for which we could determine H-K (Miranda, Puck, and Proteus), the colors are gray to red. As a whole, spectrally, these five satellites lie between icy Solar System satellites (e.g., saturnian satellites or the major uranian satellites) and Kuiper belt objects. The redness of Proteus and Puck and perhaps other satellites suggests the presence of organic material, although the redness is also similar to that of C- and D-class asteroids and some outer jovian moons. In all cases, diagnostic spectral features could be masked by broadband photometry.

  8. The red-sequence of 72 WINGS local galaxy clusters

    NASA Astrophysics Data System (ADS)

    Valentinuzzi, T.; Poggianti, B. M.; Fasano, G.; D'Onofrio, M.; Moretti, A.; Ramella, M.; Biviano, A.; Fritz, J.; Varela, J.; Bettoni, D.; Vulcani, B.; Moles, M.; Couch, W. J.; Dressler, A.; Kjærgaard, P.; Omizzolo, A.; Cava, A.

    2011-12-01

    We study the color - magnitude red sequence and blue fraction of 72 X-ray selected galaxy clusters at z = 0.04-0.07 from the WINGS survey, searching for correlations between the characteristics of the red sequence (RS) and the environment. We consider the slope and scatter of the red sequence, the number ratio of red luminous-to-faint galaxies, the blue fraction, and the fractions of ellipticals, S0s, and spirals that compose the RS. None of these quantities correlate with the cluster velocity dispersion, X-ray luminosity, number of cluster substructures, BCG prevalence over next brightest galaxies, and the spatial concentration of ellipticals. The properties of the RS, instead, depend strongly on local galaxy density. Higher density regions have a smaller RS scatter, a higher luminous-to-faint ratio, a lower blue fraction, and a lower spiral fraction on the RS. Our results clearly illustrate the prominent effect of the local density in setting the epoch when galaxies become passive and join the red sequence, as opposed to the mass of the galaxy host structure.

  9. The accelerated build-up of the red sequence in high-redshift galaxy clusters

    NASA Astrophysics Data System (ADS)

    Cerulo, P.; Couch, W. J.; Lidman, C.; Demarco, R.; Huertas-Company, M.; Mei, S.; Sánchez-Janssen, R.; Barrientos, L. F.; Muñoz, R. P.

    2016-04-01

    We analyse the evolution of the red sequence in a sample of galaxy clusters at redshifts 0.8 < z < 1.5 taken from the HAWK-I Cluster Survey (HCS). The comparison with the low-redshift (0.04 < z < 0.08) sample of the WIde-field Nearby Galaxy-cluster Survey (WINGS) and other literature results shows that the slope and intrinsic scatter of the cluster red sequence have undergone little evolution since z = 1.5. We find that the luminous-to-faint ratio and the slope of the faint end of the luminosity distribution of the HCS red sequence are consistent with those measured in WINGS, implying that there is no deficit of red galaxies at magnitudes fainter than M_V^{ast } at high redshifts. We find that the most massive HCS clusters host a population of bright red sequence galaxies at MV < -22.0 mag, which are not observed in low-mass clusters. Interestingly, we also note the presence of a population of very bright (MV < -23.0 mag) and massive (log (M*/M⊙) > 11.5) red sequence galaxies in the WINGS clusters, which do not include only the brightest cluster galaxies and which are not present in the HCS clusters, suggesting that they formed at epochs later than z = 0.8. The comparison with the luminosity distribution of a sample of passive red sequence galaxies drawn from the COSMOS/UltraVISTA field in the photometric redshift range 0.8 < zphot < 1.5 shows that the red sequence in clusters is more developed at the faint end, suggesting that halo mass plays an important role in setting the time-scales for the build-up of the red sequence.

  10. The faint intergalactic-medium red-shifted emission balloon: future UV observations with EMCCDs

    NASA Astrophysics Data System (ADS)

    Kyne, Gillian; Hamden, Erika T.; Lingner, Nicole; Morrissey, Patrick; Nikzad, Shouleh; Martin, D. Christopher

    2016-08-01

    We present the latest developments in our joint NASA/CNES suborbital project. This project is a balloon-borne UV multi-object spectrograph, which has been designed to detect faint emission from the circumgalactic medium (CGM) around low redshift galaxies. One major change from FIREBall-1 has been the use of a delta-doped Electron Multiplying CCD (EMCCD). EMCCDs can be used in photon-counting (PC) mode to achieve extremely low readout noise (¡ 1e-). Our testing initially focused on reducing clock-induced-charge (CIC) through wave shaping and well depth optimisation with the CCD Controller for Counting Photons (CCCP) from Nüvü. This optimisation also includes methods for reducing dark current, via cooling and substrate voltage adjustment. We present result of laboratory noise measurements including dark current. Furthermore, we will briefly present some initial results from our first set of on-sky observations using a delta-doped EMCCD on the 200 inch telescope at Palomar using the Palomar Cosmic Web Imager (PCWI).

  11. Abundance ratios of red giants in low-mass ultra-faint dwarf spheroidal galaxies

    NASA Astrophysics Data System (ADS)

    François, P.; Monaco, L.; Bonifacio, P.; Moni Bidin, C.; Geisler, D.; Sbordone, L.

    2016-04-01

    Context. Low-mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used to better understand their star formation and chemical evolution. Aims: We report on the analysis of a sample of 11 stars belonging to five different ultra-faint dwarf spheroidal galaxies (UfDSph) that is based on X-Shooter spectra obtained at the VLT. Methods: Medium-resolution spectra have been used to determine the detailed chemical composition of their atmosphere. We performed a standard 1D LTE analysis to compute the abundances. Results: Considering all the stars as representative of the same population of low-mass galaxies, we found that the [α/Fe] ratios vs.s [Fe/H] decreases as the metallicity of the star increases in a way similar to that which is found for the population of stars that belong to dwarf spheroidal galaxies. The main difference is that the solar [α/Fe] is reached at a much lower metallicity for the UfDSph than for the dwarf spheroidal galaxies. We report for the first time the abundance of strontium in CVn II. The star we analyzed in this galaxy has a very high [Sr/Fe] and a very low upper limit of barium which makes it a star with an exceptionally high [Sr/Ba] ratio.

  12. VizieR Online Data Catalog: Kepler faint red giants (Mathur+, 2016)

    NASA Astrophysics Data System (ADS)

    Mathur, S.; Garcia, R. A.; Huber, D.; Regulo, C.; Stello, D.; Beck, P. G.; Houmani, K.; Salabert, D.

    2016-11-01

    From the H14 catalog (Huber+, 2014, J/ApJS/211/2), we selected GKM dwarfs according to the following criteria: logg>=4.25 and Teff<=5500K. We also added a few tens of stars from the asteroseismic sample of solar-like stars from Chaplin et al. (2011ApJ...732...54C) where red-giant-like oscillations were detected. These additional stars have Teff>5500K. (4 data files).

  13. Infra-Red Characteristics of Faint Galactic Carbon Stars from the First Byurakan Spectral Sky Survey

    NASA Astrophysics Data System (ADS)

    Kostandyan, G. R.; Gigoyan, K. S.

    2017-07-01

    Infra-Red (IR) astronomical databases, namely, IRAS, 2MASS, WISE, and Spitzer, are used to analyze photometric data of 126 carbon (C) stars whose spectra are visible in the First Byurakan Survey (FBS) (Markarian et al. 1989) low-resolution (lr) spectral plates. In this work several IR color-color diagrams are studied. Early and late-type C stars are separated in the JHK Near-Infra-Red (NIR) color-color plots, as well as in the WISE W3-W4 versus W1-W2 diagram. Late N-type Asymptotic Giant Branch (AGB) stars are redder in W1-W2, while early-types (CH and R giants) are redder in W3-W4 as expected. Objects with W2-W3 > 1.0m show double-peaked spectral energy distribution (SED), indicating the existence of the circumstellar envelopes around them. 26 N-type stars have IRAS Point Source Catalog (PSC) associations. The reddest object among the targets is N-type C star FBS 2213+421, which belong to the group of the cold post-AGB R Coronae Borealis (R CrB) variables (Rossi et al. 2016).

  14. The Growth Of The Red-sequence In Clusters Since z≈1

    NASA Astrophysics Data System (ADS)

    Munoz, Roberto P.; Barrientos, L. F.; Gladders, M. D.; Koester, B. P.; Gilbank, D. G.; Yee, H. K. C.

    2010-05-01

    Galaxy clusters are gravitationally bounded structures in the Universe, which are inhabited by several thousands of galaxies in a very small region in the sky. The central megaparsec of clusters is dominated by early type galaxies, which are observed to obey tight empirical scaling relations as the fundamental plane and the red-sequence. In this work, we present deep Js and Ks-band imaging of 15 galaxy clusters at z≈1, which were discovered in the Red-Sequence Cluster Survey (RCS-1) and followed up using the VLT/ISAAC instrument. We built the Ks-band luminosity function for the composite cluster down to M*+2.5 through the application of a background subtraction method, and we found that it can be described by a Schechter function with Ks*=18.82 and α=-0.42. Furthermore, we built the background subtracted color-magnitude diagram for the composite cluster and measured for the first time the ratio of luminous-to-faint red-sequence galaxies at z=1 from a large ensemble of clusters. We found an increase of 100% in this ratio from z=0.45 to 1.0, that can be explained by a simple evolutionary model developed in this work consisting in an early truncation of the star formation for bright cluster galaxies and a delayed truncation for faint cluster galaxies. Our results suggest that bright cluster galaxies formed most of their stellar content at z=3, that faint cluster galaxies are still forming stars at z=1, and that the red-sequence is not yet fully in place at z=1. RPM was supported by a Proyecto MECESUP PUC609, Fondo Gemini 2008 Nº 32080004 and Fondo ALMA-CONICYT Nº 31070007.

  15. mufasa: the assembly of the red sequence

    NASA Astrophysics Data System (ADS)

    Davé, Romeel; Rafieferantsoa, Mika H.; Thompson, Robert J.

    2017-10-01

    We examine the growth and evolution of quenched galaxies in the mufasa cosmological hydrodynamic simulations that include an evolving halo mass-based quenching prescription, with galaxy colours computed accounting for line-of-sight extinction to individual star particles. mufasa reproduces the observed present-day red sequence reasonably well, including its slope, amplitude and scatter. In mufasa, the red sequence slope is driven entirely by the steep stellar mass-stellar metallicity relation, which independently agrees with observations. High-mass star-forming galaxies blend smoothly on to the red sequence, indicating the lack of a well-defined green valley at M* ≳ 1010.5 M⊙. The most massive galaxies quench the earliest and then grow very little in mass via dry merging; they attain their high masses at earlier epochs when cold inflows more effectively penetrate hot haloes. To higher redshifts, the red sequence becomes increasingly contaminated with massive dusty star-forming (SF) galaxies; UVJ selection subtly but effectively separates these populations. We then examine the evolution of the mass functions of central and satellite galaxies split into passive and star-forming via UVJ. Massive quenched systems show good agreement with observations out to z ∼ 2, despite not including a rapid early quenching mode associated with mergers. However, low-mass quenched galaxies are far too numerous at z ≲ 1 in mufasa, indicating that mufasa strongly overquenches satellites. A challenge for hydrodynamic simulations is to devise a quenching model that produces enough early massive quenched galaxies and keeps them quenched to z = 0, while not being so strong as to overquench satellites; mufasa's current scheme fails at the latter.

  16. The built-up of the red sequence in the Hercules cluster

    NASA Astrophysics Data System (ADS)

    Agulli, I.; Aguerri, J. A. L.; Dominguez Palmero, L.; Diaferio, A.

    2016-09-01

    We present the study of the colour-magnitude diagram of the cluster Abell 2151 (A 2151), with a particular focus on the low-mass end. The deep spectroscopy with AF2/WYFFOS@WHT and the caustic method enable us to obtain 360 members within 1.3 R200 and absolute magnitude M_r ≲ M_r^{ast }+6. This nearby cluster shows a well defined red sequence up to Mr ˜ -18.5; at fainter magnitudes only 36 per cent of the galaxies lie on the extrapolation of the red sequence. We compare the red sequences of A 2151 and Abell 85, which is another nearby cluster with similar spectroscopic data, but with different mass and dynamical state. Both clusters show similar red sequences at the bright end (Mr ≤ -19.5), whereas large differences appear at the faint end. This result suggests that the reddening of bright galaxies is independent of environment, unlike the dwarf population (Mr ≥ -18.0).

  17. RED: the analysis, management and dissemination of expressed sequence tags.

    PubMed

    Everitt, R; Minnema, S E; Wride, M A; Koster, C S; Hance, J E; Mansergh, F C; Rancourt, D E

    2002-12-01

    The Rancourt EST Database (RED) is a web-based system for the analysis, management, and dissemination of expressed sequence tags (ESTs). RED represents a flexible template DNA sequence database that can be easily manipulated to suit the needs of other laboratories undertaking mid-size sequencing projects.

  18. Fainting (Syncope)

    MedlinePlus

    ... Adults Making Your Wishes Known Home & Community Home › Aging & Health A to Z › Fainting (Syncope) Font size A A A Print Share Glossary Basic Facts & Information Causes & Symptoms Diagnosis & Tests Care & Treatment Lifestyle & Management Other Resources Caregiving How ...

  19. The Nature of Red-Sequence Cluster Spiral Galaxies

    NASA Astrophysics Data System (ADS)

    Kashur, Lane; Barkhouse, Wayne; Sultanova, Madina; Kalawila Vithanage, Sandanuwa; Archer, Haylee; Foote, Gregory; Mathew, Elijah; Rude, Cody; Lopez-Cruz, Omar

    2017-01-01

    Preliminary analysis of the red-sequence galaxy population from a sample of 57 low-redshift galaxy clusters observed using the KPNO 0.9m telescope and 74 clusters from the WINGS dataset, indicates that a small fraction of red-sequence galaxies have a morphology consistent with spiral systems. For spiral galaxies to acquire the color of elliptical/S0s at a similar luminosity, they must either have been stripped of their star-forming gas at an earlier epoch, or contain a larger than normal fraction of dust. To test these ideas we have compiled a sample of red-sequence spiral galaxies and examined their infrared properties as measured by 2MASS, WISE, Spitzer, and Herschel. These IR data allows us to estimate the amount of dust in each of our red-sequence spiral galaxies. We compare the estimated dust mass in each of these red-sequence late-type galaxies with spiral galaxies located in the same cluster field but having colors inconsistent with the red-sequence. We thus provide a statistical measure to discriminate between purely passive spiral galaxy evolution and dusty spirals to explain the presence of these late-type systems in cluster red-sequences.

  20. A TALE OF DWARFS AND GIANTS: USING A z = 1.62 CLUSTER TO UNDERSTAND HOW THE RED SEQUENCE GREW OVER THE LAST 9.5 BILLION YEARS

    SciTech Connect

    Rudnick, Gregory H.; Tran, Kim-Vy; Papovich, Casey; Momcheva, Ivelina; Willmer, Christopher

    2012-08-10

    We study the red sequence in a cluster of galaxies at z = 1.62 and follow its evolution over the intervening 9.5 Gyr to the present day. Using deep YJK{sub s} imaging with the HAWK-I instrument on the Very Large Telescope, we identify a tight red sequence and construct its rest-frame i-band luminosity function (LF). There is a marked deficit of faint red galaxies in the cluster that causes a turnover in the LF. We compare the red-sequence LF to that for clusters at z < 0.8, correcting the luminosities for passive evolution. The shape of the cluster red-sequence LF does not evolve between z = 1.62 and z = 0.6 but at z < 0.6 the faint population builds up significantly. Meanwhile, between z = 1.62 and 0.6 the inferred total light on the red sequence grows by a factor of {approx}2 and the bright end of the LF becomes more populated. We construct a simple model for red-sequence evolution that grows the red sequence in total luminosity and matches the constant LF shape at z > 0.6. In this model the cluster accretes blue galaxies from the field whose star formation is quenched and who are subsequently allowed to merge. We find that three to four mergers among cluster galaxies during the 4 Gyr between z = 1.62 and z = 0.6 match the observed LF evolution between the two redshifts. The inferred merger rate is consistent with other studies of this cluster. Our result supports the picture that galaxy merging during the major growth phase of massive clusters is an important process in shaping the red-sequence population at all luminosities.

  1. A Tale of Dwarfs and Giants: Using a z = 1.62 Cluster to Understand How the Red Sequence Grew over the Last 9.5 Billion Years

    NASA Astrophysics Data System (ADS)

    Rudnick, Gregory H.; Tran, Kim-Vy; Papovich, Casey; Momcheva, Ivelina; Willmer, Christopher

    2012-08-01

    We study the red sequence in a cluster of galaxies at z = 1.62 and follow its evolution over the intervening 9.5 Gyr to the present day. Using deep YJKs imaging with the HAWK-I instrument on the Very Large Telescope, we identify a tight red sequence and construct its rest-frame i-band luminosity function (LF). There is a marked deficit of faint red galaxies in the cluster that causes a turnover in the LF. We compare the red-sequence LF to that for clusters at z < 0.8, correcting the luminosities for passive evolution. The shape of the cluster red-sequence LF does not evolve between z = 1.62 and z = 0.6 but at z < 0.6 the faint population builds up significantly. Meanwhile, between z = 1.62 and 0.6 the inferred total light on the red sequence grows by a factor of ~2 and the bright end of the LF becomes more populated. We construct a simple model for red-sequence evolution that grows the red sequence in total luminosity and matches the constant LF shape at z > 0.6. In this model the cluster accretes blue galaxies from the field whose star formation is quenched and who are subsequently allowed to merge. We find that three to four mergers among cluster galaxies during the 4 Gyr between z = 1.62 and z = 0.6 match the observed LF evolution between the two redshifts. The inferred merger rate is consistent with other studies of this cluster. Our result supports the picture that galaxy merging during the major growth phase of massive clusters is an important process in shaping the red-sequence population at all luminosities. Based on observations obtained at the European Southern Observatory using the ESO Very Large Telescope on Cerro Paranal through ESO program 386.A-0514(A).

  2. Insertion sequences enrichment in extreme Red sea brine pool vent.

    PubMed

    Elbehery, Ali H A; Aziz, Ramy K; Siam, Rania

    2017-03-01

    Mobile genetic elements are major agents of genome diversification and evolution. Limited studies addressed their characteristics, including abundance, and role in extreme habitats. One of the rare natural habitats exposed to multiple-extreme conditions, including high temperature, salinity and concentration of heavy metals, are the Red Sea brine pools. We assessed the abundance and distribution of different mobile genetic elements in four Red Sea brine pools including the world's largest known multiple-extreme deep-sea environment, the Red Sea Atlantis II Deep. We report a gradient in the abundance of mobile genetic elements, dramatically increasing in the harshest environment of the pool. Additionally, we identified a strong association between the abundance of insertion sequences and extreme conditions, being highest in the harshest and deepest layer of the Red Sea Atlantis II Deep. Our comparative analyses of mobile genetic elements in secluded, extreme and relatively non-extreme environments, suggest that insertion sequences predominantly contribute to polyextremophiles genome plasticity.

  3. Cloning of intronic sequence within DsRed2 increased the number of cells expressing red fluorescent protein.

    PubMed

    Pisal, Rishikaysh V; Hrebikova, Hana; Chvatalova, Jana; Soukup, Tomas; Stanislav, Filip; Mokry, Jaroslav

    2017-08-24

    Cloning of artificial intronic sequence within the open reading frame (ORF) of DsRed2 gene. Splice prediction software was used to analyze DsRed2 sequence to find an ideal site for cloning artificial intronic sequence. Intron was cloned within DsRed2 using cyclic ligation assembly. Flow cytometry was used to quantify the number of cells expressing red fluorescence. Sequencing data confirmed precise cloning of intron at the desired position using cyclic ligation assembly. Successful expression of red fluorescence after cloning of intron confirmed successful intron recognition and splicing by host cell line. Cloning of intron increased the number of cells expressing red fluorescent protein. Cloning of intronic sequence within DsRed2 has helped to increase the number of cells expressing red fluorescence by approximately four percent.

  4. MODELING THE RED SEQUENCE: HIERARCHICAL GROWTH YET SLOW LUMINOSITY EVOLUTION

    SciTech Connect

    Skelton, Rosalind E.; Bell, Eric F.; Somerville, Rachel S.

    2012-07-01

    We explore the effects of mergers on the evolution of massive early-type galaxies by modeling the evolution of their stellar populations in a hierarchical context. We investigate how a realistic red sequence population set up by z {approx} 1 evolves under different assumptions for the merger and star formation histories, comparing changes in color, luminosity, and mass. The purely passive fading of existing red sequence galaxies, with no further mergers or star formation, results in dramatic changes at the bright end of the luminosity function and color-magnitude relation. Without mergers there is too much evolution in luminosity at a fixed space density compared to observations. The change in color and magnitude at a fixed mass resembles that of a passively evolving population that formed relatively recently, at z {approx} 2. Mergers among the red sequence population ('dry mergers') occurring after z = 1 build up mass, counteracting the fading of the existing stellar populations to give smaller changes in both color and luminosity for massive galaxies. By allowing some galaxies to migrate from the blue cloud onto the red sequence after z = 1 through gas-rich mergers, younger stellar populations are added to the red sequence. This manifestation of the progenitor bias increases the scatter in age and results in even smaller changes in color and luminosity between z = 1 and z = 0 at a fixed mass. The resultant evolution appears much slower, resembling the passive evolution of a population that formed at high redshift (z {approx} 3-5), and is in closer agreement with observations. We conclude that measurements of the luminosity and color evolution alone are not sufficient to distinguish between the purely passive evolution of an old population and cosmologically motivated hierarchical growth, although these scenarios have very different implications for the mass growth of early-type galaxies over the last half of cosmic history.

  5. Modeling the Red Sequence: Hierarchical Growth yet Slow Luminosity Evolution

    NASA Astrophysics Data System (ADS)

    Skelton, Rosalind E.; Bell, Eric F.; Somerville, Rachel S.

    2012-07-01

    We explore the effects of mergers on the evolution of massive early-type galaxies by modeling the evolution of their stellar populations in a hierarchical context. We investigate how a realistic red sequence population set up by z ~ 1 evolves under different assumptions for the merger and star formation histories, comparing changes in color, luminosity, and mass. The purely passive fading of existing red sequence galaxies, with no further mergers or star formation, results in dramatic changes at the bright end of the luminosity function and color-magnitude relation. Without mergers there is too much evolution in luminosity at a fixed space density compared to observations. The change in color and magnitude at a fixed mass resembles that of a passively evolving population that formed relatively recently, at z ~ 2. Mergers among the red sequence population ("dry mergers") occurring after z = 1 build up mass, counteracting the fading of the existing stellar populations to give smaller changes in both color and luminosity for massive galaxies. By allowing some galaxies to migrate from the blue cloud onto the red sequence after z = 1 through gas-rich mergers, younger stellar populations are added to the red sequence. This manifestation of the progenitor bias increases the scatter in age and results in even smaller changes in color and luminosity between z = 1 and z = 0 at a fixed mass. The resultant evolution appears much slower, resembling the passive evolution of a population that formed at high redshift (z ~ 3-5), and is in closer agreement with observations. We conclude that measurements of the luminosity and color evolution alone are not sufficient to distinguish between the purely passive evolution of an old population and cosmologically motivated hierarchical growth, although these scenarios have very different implications for the mass growth of early-type galaxies over the last half of cosmic history.

  6. OBSERVATIONAL CONSTRAINTS ON RED AND BLUE HELIUM BURNING SEQUENCES

    SciTech Connect

    McQuinn, Kristen B. W.; Skillman, Evan D.; Dalcanton, Julianne J.; Weisz, Daniel R.; Williams, Benjamin F.; Dolphin, Andrew E.; Holtzman, Jon

    2011-10-10

    We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical isochrones from Padova stellar evolution models across metallicities from Z = 0.001 to 0.009. We find that the observational data and the theoretical isochrones for both blue and red HeB populations overlap in optical luminosities and colors and the observed and predicted blue to red HeB ratios agree for stars older than 50 Myr over the time bins studied. These findings confirm the usefulness of applying isochrones to interpret observations of HeB populations. However, there are significant differences, especially for the red HeB population. Specifically, we find (1) offsets in color between the observations and theoretical isochrones of order 0.15 mag (0.5 mag) for the blue (red) HeB populations brighter than M{sub V} {approx} -4 mag, which cannot be solely due to differential extinction; (2) blue HeB stars fainter than M{sub V} {approx} -3 mag are bluer than predicted; (3) the slope of the red HeB sequence is shallower than predicted by a factor of {approx}3; and (4) the models overpredict the ratio of the most luminous blue to red HeB stars corresponding to ages {approx}< 50 Myr. Additionally, we find that for the more metal-rich galaxies in our sample (Z {approx}> 0.5 Z{sub sun}), the red HeB stars overlap with the red giant branch stars in the color-magnitude diagrams, thus reducing their usefulness as indicators of star formation for ages {approx}> 100 Myr.

  7. PRIMUS: OBSCURED STAR FORMATION ON THE RED SEQUENCE

    SciTech Connect

    Zhu Guangtun; Blanton, Michael R.; Burles, Scott M.; Coil, Alison L.; Moustakas, John; Aird, James; Cool, Richard J.; Eisenstein, Daniel J.; Wong, Kenneth C.

    2011-01-10

    We quantify the fraction of galaxies at moderate redshifts (0.1 < z < 0.5) that appear red-and-dead in the optical, but in fact contain obscured star formation detectable in the infrared (IR), with the PRIsm MUlti-object Survey (PRIMUS). PRIMUS has measured {approx}120,000 robust redshifts with a precision of {sigma}{sub z}/(1 + z) {approx} 0.5% over 9.1 deg{sup 2} of the sky to the depth of i {approx} 23 (AB), up to redshift z {approx} 1. We specifically targeted 6.7 deg{sup 2} fields with existing deep IR imaging from the Spitzer Space Telescope from the SWIRE and S-COSMOS surveys. We select in these fields an i-band flux-limited sample (i < 20 mag in the SWIRE fields and i < 21 mag in the S-COSMOS field) of 3310 red-sequence galaxies at 0.1 < z < 0.5 for which we can reliably classify obscured star-forming (SF) and quiescent galaxies using IR color. Our sample constitutes the largest galaxy sample at intermediate redshift to study obscured star formation on the red sequence, and we present the first quantitative analysis of the fraction of obscured SF galaxies as a function of luminosity. We find that on average, at L {approx} L*, about 15% of red-sequence galaxies have IR colors consistent with SF galaxies. The percentage of obscured SF galaxies increases by {approx}8% per mag with decreasing luminosity from the highest luminosities to L {approx} 0.2 L*. Our results suggest that a significant fraction of red-sequence galaxies have ongoing star formation and that galaxy evolution studies based on optical color therefore need to account for this complication.

  8. A Tale of Giants and Dwarfs: How the Red Sequence in Clusters Grew Over The Last 9.5 Gyr.

    NASA Astrophysics Data System (ADS)

    Rudnick, Gregory; Tran, K.; Papovich, C.

    2012-01-01

    Understanding how star formation was turned off in galaxies over time and how these passive galaxies then evolve is a major focus of galaxy evolution studies. Equally important is uncovering what role environmental processes play. Here we discuss the evolution of the red sequence in galaxy clusters over the past 9.5 Gyr of cosmic time, as revealed by deep YJK imaging with HAWK-I/VLT of a confirmed massive cluster at z=1.62. We use these data to measure the luminosity function (LF) of red sequence galaxies and chart the growth of the passive sequence. We compare the shape of the LF and the total light on the red sequence in the z=1.62 cluster with clusters at 0.4faint magnitudes consistent with seen at z=0.7 in EDisCS clusters. Interestingly, there is an apparent deficit of bright red galaxies in the z=1.62 cluster when compared to likely descendant clusters at lower redshift. After correcting for the evolving mass to light ratio, we find that the total amount of stellar mass on the red sequence increases rapidly from z=1.62 to z=0.7 and then increases more slowly to z=0. We will discuss scenarios for how the rapid growth in the total light over a period of 3.2 Gyr can be reconciled with the lack of evolution in the shape of the luminosity function. One possibility is that galaxies are added to the red sequence, but that other processes, e.g. dry merging, must be at play to explain the lack of evolution in the LF shape and to populate the bright end. At z<0.7 the amount of merging in the deep cluster potential well decreases and the LF shape begins to rapidly evolve.

  9. RCSLenS: The Red Cluster Sequence Lensing Survey

    NASA Astrophysics Data System (ADS)

    Hildebrandt, H.; Choi, A.; Heymans, C.; Blake, C.; Erben, T.; Miller, L.; Nakajima, R.; van Waerbeke, L.; Viola, M.; Buddendiek, A.; Harnois-Déraps, J.; Hojjati, A.; Joachimi, B.; Joudaki, S.; Kitching, T. D.; Wolf, C.; Gwyn, S.; Johnson, N.; Kuijken, K.; Sheikhbahaee, Z.; Tudorica, A.; Yee, H. K. C.

    2016-11-01

    We present the Red Cluster Sequence Lensing Survey (RCSLenS), an application of the methods developed for the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) to the ˜785 deg2, multi-band imaging data of the Red-sequence Cluster Survey 2. This project represents the largest public, sub-arcsecond seeing, multi-band survey to date that is suited for weak gravitational lensing measurements. With a careful assessment of systematic errors in shape measurements and photometric redshifts, we extend the use of this data set to allow cross-correlation analyses between weak lensing observables and other data sets. We describe the imaging data, the data reduction, masking, multi-colour photometry, photometric redshifts, shape measurements, tests for systematic errors, and a blinding scheme to allow for more objective measurements. In total, we analyse 761 pointings with r-band coverage, which constitutes our lensing sample. Residual large-scale B-mode systematics prevent the use of this shear catalogue for cosmic shear science. The effective number density of lensing sources over an unmasked area of 571.7 deg2 and down to a magnitude limit of r ˜ 24.5 is 8.1 galaxies per arcmin2 (weighted: 5.5 arcmin-2) distributed over 14 patches on the sky. Photometric redshifts based on four-band griz data are available for 513 pointings covering an unmasked area of 383.5 deg2. We present weak lensing mass reconstructions of some example clusters as well as the full survey representing the largest areas that have been mapped in this way. All our data products are publicly available through Canadian Astronomy Data Centre at http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/en/community/rcslens/query.html in a format very similar to the CFHTLenS data release.

  10. Dizziness and Fainting Spells

    MedlinePlus

    ... or Animals Genitals and Urinary Tract Glands & Growth Head Neck & Nervous System Heart Infections Learning Disabilities Obesity Orthopedic ... Vaccine Preventable Diseases Healthy Children > Health Issues > Conditions > Head Neck & Nervous System > Dizziness and Fainting Spells Health Issues ...

  11. Fainting: First Aid

    MedlinePlus

    ... brain is momentarily inadequate, causing you to lose consciousness. This loss of consciousness is usually brief. Fainting can have no medical ... be a serious disorder. Therefore, treat loss of consciousness as a medical emergency until the signs and ...

  12. The Next Generation Virgo Cluster Survey (NGVS). XXIV. The Red Sequence to ~106 L ⊙ and Comparisons with Galaxy Formation Models

    NASA Astrophysics Data System (ADS)

    Roediger, Joel C.; Ferrarese, Laura; Côté, Patrick; MacArthur, Lauren A.; Sánchez-Janssen, Rúben; Blakeslee, John P.; Peng, Eric W.; Liu, Chengze; Munoz, Roberto; Cuillandre, Jean-Charles; Gwyn, Stephen; Mei, Simona; Boissier, Samuel; Boselli, Alessandro; Cantiello, Michele; Courteau, Stéphane; Duc, Pierre-Alain; Lançon, Ariane; Mihos, J. Christopher; Puzia, Thomas H.; Taylor, James E.; Durrell, Patrick R.; Toloba, Elisa; Guhathakurta, Puragra; Zhang, Hongxin

    2017-02-01

    We use deep optical photometry from the Next Generation Virgo Cluster Survey (NGVS) to investigate the color–magnitude diagram for the galaxies inhabiting the core of this cluster. The sensitivity of the NGVS imaging allows us to continuously probe galaxy colors over a factor of ∼2 × 105 in luminosity, from brightest cluster galaxies to scales overlapping classical satellites of the Milky Way ({M}g\\prime ∼ ‑9 M * ∼ 106 M ⊙), within a single environment. Remarkably, we find the first evidence that the red sequence (RS) flattens in all colors at the faint-magnitude end (starting between ‑14 ≤ {M}g\\prime ≤ ‑13, around M * ∼ 4 × 107 M ⊙), with the slope decreasing to ∼60% or less of its value at brighter magnitudes. This could indicate that the stellar populations of faint dwarfs in Virgo’s core share similar characteristics (e.g., constant mean age) over ∼3 mag in luminosity, suggesting that these galaxies were quenched coevally, likely via pre-processing in smaller hosts. We also compare our results to galaxy formation models, finding that the RS in model clusters have slopes at intermediate magnitudes that are too shallow, and in the case of semianalytic models, do not reproduce the flattening seen at both extremes (bright/faint) of the Virgo RS. Deficiencies in the chemical evolution of model galaxies likely contribute to the model-data discrepancies at all masses, while overly efficient quenching may also be a factor at dwarf scales. Deep UV and near-IR photometry are required to unambiguously diagnose the cause of the faint-end flattening.

  13. Precision Measurements of the Cluster Red Sequence using an Error Corrected Gaussian Mixture Model

    SciTech Connect

    Hao, Jiangang; Koester, Benjamin P.; Mckay, Timothy A.; Rykoff, Eli S.; Rozo, Eduardo; Evrard, August; Annis, James; Becker, Matthew; Busha, Michael; Gerdes, David; Johnston, David E.; /Northwestern U. /Brookhaven

    2009-07-01

    The red sequence is an important feature of galaxy clusters and plays a crucial role in optical cluster detection. Measurement of the slope and scatter of the red sequence are affected both by selection of red sequence galaxies and measurement errors. In this paper, we describe a new error corrected Gaussian Mixture Model for red sequence galaxy identification. Using this technique, we can remove the effects of measurement error and extract unbiased information about the intrinsic properties of the red sequence. We use this method to select red sequence galaxies in each of the 13,823 clusters in the maxBCG catalog, and measure the red sequence ridgeline location and scatter of each. These measurements provide precise constraints on the variation of the average red galaxy populations in the observed frame with redshift. We find that the scatter of the red sequence ridgeline increases mildly with redshift, and that the slope decreases with redshift. We also observe that the slope does not strongly depend on cluster richness. Using similar methods, we show that this behavior is mirrored in a spectroscopic sample of field galaxies, further emphasizing that ridgeline properties are independent of environment. These precise measurements serve as an important observational check on simulations and mock galaxy catalogs. The observed trends in the slope and scatter of the red sequence ridgeline with redshift are clues to possible intrinsic evolution of the cluster red-sequence itself. Most importantly, the methods presented in this work lay the groundwork for further improvements in optically-based cluster cosmology.

  14. POST-MERGER SIGNATURES OF RED-SEQUENCE GALAXIES IN RICH ABELL CLUSTERS AT z {approx}< 0.1

    SciTech Connect

    Sheen, Yun-Kyeong; Yi, Sukyoung K.; Lee, Jaehyun; Ree, Chang H.

    2012-09-15

    We have investigated the post-merger signatures of red-sequence galaxies in rich Abell clusters at z {approx}< 0.1: A119, A2670, A3330, and A389. Deep images in u', g', r', and medium-resolution galaxy spectra were taken using MOSAIC II CCD and Hydra MOS mounted on a Blanco 4 m telescope at Cerro Tololo Inter-American Observatory. Post-merger features are identified by visual inspection based on asymmetric disturbed features, faint structures, discontinuous halo structures, rings, and dust lanes. We found that {approx}25% of bright (M{sub r} < -20) cluster red-sequence galaxies show post-merger signatures in four clusters consistently. Most ({approx}71%) of the featured galaxies were found to be bulge dominated, and for the subsample of bulge-dominated red-sequence galaxies, the post-merger fraction rises to {approx}38%. We also found that roughly 4% of bulge-dominated red-sequence galaxies interact (ongoing merger). A total of 42% (38% post-merger, 4% ongoing merger) of galaxies show merger-related features. Compared to a field galaxy study with a similar limiting magnitude by van Dokkum in 2005, our cluster study presents a similar post-merger fraction but a markedly lower ongoing merger fraction. The merger fraction derived is surprisingly high for the high density of our clusters, where the fast internal motions of galaxies are thought to play a negative role in galaxy mergers. The fraction of post-merger and ongoing merger galaxies can be explained as follows. Most of the post-merger galaxies may have carried over their merger features from their previous halo environment, whereas interacting galaxies interact in the current cluster in situ. According to our semi-analytic calculation, massive cluster halos may very well have experienced tens of halo mergers over the last 4-5 Gyr; post-merger features last that long, allowing these features to be detected in our clusters today. The apparent lack of dependence of the merger fraction on the clustocentric distance

  15. WHAT DOES CLUSTERING TELL US ABOUT THE BUILDUP OF THE RED SEQUENCE?

    SciTech Connect

    Tinker, Jeremy L.; Wetzel, Andrew R.

    2010-08-10

    We analyze the clustering of red and blue galaxies from four samples spanning a redshift range of 0.4 < z < 2.0 to test the various scenarios by which galaxies evolve onto the red sequence. The data are taken from the UKIDSS Ultra Deep Survey, DEEP2, and COMBO-17. The use of clustering allows us to determine what fraction of the red sequence is made up of central galaxies and satellite galaxies. At all redshifts, including z = 0, the data are consistent with {approx}60% of satellite galaxies being red or quenched, implying that {approx}1/3 of the red sequence is comprised of satellite galaxies. More than three-fourths of red satellite galaxies were moved to the red sequence after they were accreted onto a larger halo. The constant fraction of satellite galaxies that are red yields a quenching time for satellite galaxies that depends on redshift in the same way as halo dynamical times: t{sub Q} {approx} (1 + z){sup -1.5}. In three of the four samples, the data favor a model in which red central galaxies are a random sample of all central galaxies; there is no preferred halo mass scale at which galaxies make the transition from star-forming to red and dead. The large errors on the fourth sample inhibit any conclusions. Theoretical models in which star formation is quenched above a critical halo mass are excluded by these data. A scenario in which mergers create red central galaxies imparts a weaker correlation between halo mass and central galaxy color, but even the merger scenario creates tension with red galaxy clustering at redshifts above 0.5. These results suggest that the mechanism by which central galaxies become red evolves from z = 0.5 to z = 0.

  16. Cosmological Constraints from the Red-Sequence Cluster Survey

    NASA Astrophysics Data System (ADS)

    Gladders, Michael D.; Yee, H. K. C.; Majumdar, Subhabrata; Barrientos, L. Felipe; Hoekstra, Henk; Hall, Patrick B.; Infante, Leopoldo

    2007-01-01

    We present a first cosmological analysis of a refined cluster catalog from the Red-Sequence Cluster Survey (RCS). The input cluster sample is derived from the deepest 72.07 deg2 of the RCS images, which probe to the highest redshift and lowest mass limits. The catalog contains 956 clusters over 0.35

  17. Can the magnetic susceptibility record of Chinese Red Clay sequence be used for palaeomonsoon reconstructions?

    NASA Astrophysics Data System (ADS)

    Zhao, Guoyong; Han, Yan; Liu, Xiuming; Chang, Liao; Lü, Bin; Chen, Qu; Guo, Xuelian; Yan, Junhui; Yan, Jun

    2016-03-01

    Red Clay underlying the loess-palaeosol sequences on the Chinese Loess Plateau is an eolian deposit. There is a controversy over whether magnetic susceptibility (χ) variations in Red Clay sequence can be used as an indicator of summer palaeomonsoon intensity. This study investigates the magnetic mineralogy, magnetic concentration and magnetic grain size distribution of Jiaxian Red Clay with multimagnetic methods. Our results indicate that the magnetic properties of Jiaxian Red Clay are similar to those of the Quaternary loess-palaeosol sequences, and ultrafine ferrimagnetic grains produced during pedogenesis are responsible for an increase in susceptibility, therefore the χ enhancement mechanism of Red Clay is similar to that of the overlying loess-palaeosol sequences. This paper explores χ variations in the Red Clay sequence through spatial and temporal analysis. The susceptibility variation of six sites along a NNE to SSW transect correlate to palaeoclimatic cycles, so χ can be used to trace the summer palaeomonsoon intensity from a spatial perspective. However, a simple loess-derived calibration function cannot be used to quantitative reconstruct the palaeomonsoon intensity variations thought time. An adjusted calibration function for palaeosols from Red Clay sequence needs to be developed, so that χ can be used to quantitative reconstruct palaeomonsoon intensity. Further study is necessary to develop such a transfer function.

  18. Probing the Deep End of the Milky Way with Kepler: Asteroseismic Analysis of 854 Faint Red Giants Misclassified as Cool Dwarfs

    NASA Astrophysics Data System (ADS)

    Mathur, S.; García, R. A.; Huber, D.; Regulo, C.; Stello, D.; Beck, P. G.; Houmani, K.; Salabert, D.

    2016-08-01

    Asteroseismology has proven to be an excellent tool to determine not only global stellar properties with good precision, but also to infer the stellar structure, dynamics, and evolution for a large sample of Kepler stars. Prior to the launch of the mission, the properties of Kepler targets were inferred from broadband photometry, leading to the Kepler Input Catalog (KIC). The KIC was later revised in the Kepler Star Properties Catalog, based on literature values and an asteroseismic analysis of stars that were unclassified in the KIC. Here, we present an asteroseismic analysis of 45,400 stars that were classified as dwarfs in the Kepler Star Properties Catalog. We found that around 2% of the sample shows acoustic modes in the typical frequency range that put them in the red-giant category rather than the cool dwarf category. We analyze the asteroseismic properties of these stars, derive their surface gravities, masses, and radii, and present updated effective temperatures and distances. We show that the sample is significantly fainter than the previously known oscillating giants in the Kepler field, with the faintest stars reaching down to a Kepler magnitude of Kp ∼ 16. We demonstrate that 404 stars are at distances beyond 5 kpc and that the stars are significantly less massive than for the original Kepler red-giant sample, consistent with a population of distant halo giants. A comparison with a galactic population model shows that up to 40 stars might be genuine halo giants, which would increase the number of known asteroseismic halo stars by a factor of 4. The detections presented here will provide a valuable sample for galactic archeology studies.

  19. THE WiggleZ DARK ENERGY SURVEY: GALAXY EVOLUTION AT 0.25 {<=} z {<=} 0.75 USING THE SECOND RED-SEQUENCE CLUSTER SURVEY

    SciTech Connect

    Li, I. H.; Blake, Chris; Contreras, Carlos; Couch, Warrick J.; Glazebrook, Karl; Yee, H. K. C.; Brough, Sarah; Colless, Matthew; Croom, Scott M.; Jelliffe, Ben; Davis, Tamara; Drinkwater, Michael J.; Forster, Karl; Martin, D. Christopher; Gilbank, David G.; Gladders, M. G.; Hsieh, Bau-ching; Jurek, Russell J.; Madore, Barry; Pimbblet, Kevin; and others

    2012-03-10

    We study the evolution of galaxy populations around the spectroscopic WiggleZ sample of star-forming galaxies at 0.25 {<=} z {<=} 0.75 using the photometric catalog from the Second Red-Sequence Cluster Survey (RCS2). We probe the optical photometric properties of the net excess neighbor galaxies. The key concept is that the marker galaxies and their neighbors are located at the same redshift, providing a sample of galaxies representing a complete census of galaxies in the neighborhood of star-forming galaxies. The results are compared with those using the RCS WiggleZ Spare-Fibre (RCS-WSF) sample as markers, representing galaxies in cluster environments at 0.25 {<=} z {<=} 0.45. By analyzing the stacked color-color properties of the WiggleZ neighbor galaxies, we find that their optical colors are not a strong function of indicators of star-forming activities such as EW([O II]) or Galaxy Evolution Explorer (GALEX) near-UV luminosity of the markers. The galaxies around the WiggleZ markers exhibit a bimodal distribution on the color-magnitude diagram, with most of them located in the blue cloud. The optical galaxy luminosity functions (GLFs) of the blue neighbor galaxies have a faint-end slope {alpha} of {approx} - 1.3, similar to that for galaxies in cluster environments drawn from the RCS-WSF sample. The faint-end slope of the GLF for the red neighbors, however, is {approx} - 0.4, significantly shallower than the {approx} - 0.7 found for those in cluster environments. This suggests that the buildup of the faint end of the red sequence in cluster environments is in a significantly more advanced stage than that in the star-forming and lower galaxy density WiggleZ neighborhoods. We find that the red galaxy fraction (f{sub red}) around the star-forming WiggleZ galaxies has similar values from z {approx} 0.3 to z {approx} 0.6 with f{sub red} {approx} 0.28, but drops to f{sub red} {approx} 0.20 at z {approx}> 0.7. This change of f{sub red} with redshift suggests that there

  20. Draft Genome Sequence of Lactobacillus plantarum XJ25 Isolated from Chinese Red Wine

    PubMed Central

    Zhao, Meijing; Tian, Yu

    2016-01-01

    Here, we present the draft genome sequence of Lactobacillus plantarum XJ25, isolated from Chinese red wine that had undergone spontaneous malolactic fermentation, which consists of 25 contigs and is 3,218,018 bp long. PMID:27856576

  1. Galaxy Zoo Hubble: First results of the redshift evolution of disk fraction in the red sequence

    NASA Astrophysics Data System (ADS)

    Galloway, Melanie; Willett, Kyle; Fortson, Lucy; Scarlata, Claudia; Beck, Melanie; Masters, Karen; Melvin, Tom

    2016-01-01

    The transition of galaxies from the blue cloud to the red sequence is commonly linked to a morphological transformation from disk to elliptical structure. However, the correlation between color and morphology is not one-to-one, as evidenced by the existence of a significant population of red disks. As this stage in a galaxy's evolution is likely to be transitory, the mechanism by which red disks are formed offers insight to the processes that trigger quenching of star formation and the galaxy's position on the star-forming sequence. To study the population of disk galaxies in the red sequence as a function of cosmic time, we utilize data from the Galaxy Zoo: Hubble project, which uses crowdsourced visual classifications of images of galaxies selected from the AEGIS, COSMOS, GEMS, and GOODS surveys. We construct a large sample of over 10,000 disk galaxies spanning a wide (0 < z < 1.0) redshift range. We use this sample to examine the change in the fraction of disks in the red sequence with respect to all disks from z˜1 to the present day. Preliminary results confirm that the fraction of disks in the red sequence decreases as the Universe evolves. We discuss the quenching processes which may explain this trend, and which morphological transformations are most affected by it.

  2. Evolution of Group Galaxies from the First Red-Sequence Cluster Survey

    NASA Astrophysics Data System (ADS)

    Li, I. H.; Yee, H. K. C.; Hsieh, B. C.; Gladders, M.

    2012-04-01

    We study the evolution of the red-galaxy fraction (f red) in 905 galaxy groups with 0.15 <= z < 0.52. The galaxy groups are identified by the "probability friends-of-friends" algorithm from the first Red-Sequence Cluster Survey (RCS1) photometric-redshift sample. There is a high degree of uniformity in the properties of the red sequence of the group galaxies, indicating that the luminous red-sequence galaxies in the groups are already in place by z ~ 0.5 and that they have a formation epoch of z >~ 2. In general, groups at lower redshifts exhibit larger f red than those at higher redshifts, showing a group Butcher-Oemler effect. We investigate the evolution of f red by examining its dependence on four parameters, one of which can be classified as intrinsic and three of which can be classified as environmental: galaxy stellar mass (M *), total group stellar mass (M *, grp, a proxy for group halo mass), normalized group-centric radius (r grp), and local galaxy density (Σ5). We find that M * is the dominant parameter such that there is a strong correlation between f red and galaxy stellar mass. Furthermore, the dependence of f red on the environmental parameters is also a strong function of M *. Massive galaxies (M * >~ 1011 M ⊙) show little dependence of f red on r grp, M *, grp, and Σ5 over the redshift range. The dependence of f red on these parameters is primarily seen for galaxies with lower masses, especially for M * <~ 1010.6 M ⊙. We observe an apparent "group down-sizing" effect, in that galaxies in lower-mass halos, after controlling for galaxy stellar mass, have lower f red. We find a dependence of f red on both r grp and Σ5 after the other parameters are controlled. At a fixed r grp, there is a significant dependence of f red on Σ5, while r grp gradients of f red are seen for galaxies in similar Σ5 regions. This indicates that galaxy group environment has a residual effect over that of local galaxy density (or vice versa), and both parameters need

  3. Comparative analysis of myostatin gene and promoter sequences of Qinchuan and Red Angus cattle.

    PubMed

    He, Y L; Wu, Y H; Quan, F S; Liu, Y G; Zhang, Y

    2013-09-04

    To better understand the function of the myostatin gene and its promoter region in bovine, we amplified and sequenced the myostatin gene and promoter from the blood of Qinchuan and Red Angus cattle by using polymerase chain reaction. The sequences of Qinchuan and Red Angus cattle were compared with those of other cattle breeds available in GenBank. Exon splice sites were confirmed by mRNA sequencing. Compared to the published sequence (GenBank accession No. AF320998), 69 single nucleotide polymorphisms (SNPs) were identified in the Qinchuan myostatin gene, only one of which was an insertion mutation in Qinchuan cattle. There was a 16-bp insertion in the first 705-bp intron in 3 Qinchuan cattle. A total of 7 SNPs were identified in exon 3, in which the mutation occurred in the third base of the codon and was synonymous. On comparing the Qinchuan myostatin gene sequence to that of Red Angus cattle, a total of 50 SNPs were identified in the first and third exons. In addition, there were 18 SNPs identified in the Qinchuan cattle promoter region compared with those of other cattle compared to the Red Angus cattle myostatin promoter region. breeds (GenBank accession No. AF348479), but only 14 SNPs when compared to the Red Angus cattle myostatin promoter region.

  4. Evidence for the Universality of Properties of Red-sequence Galaxies in X-Ray- and Red-Sequence-Selected Clusters at z ~ 1

    NASA Astrophysics Data System (ADS)

    Foltz, R.; Rettura, A.; Wilson, G.; van der Burg, R. F. J.; Muzzin, A.; Lidman, C.; Demarco, R.; Nantais, Julie; DeGroot, A.; Yee, H.

    2015-10-01

    We study the slope, intercept, and scatter of the color-magnitude and color-mass relations for a sample of 10 infrared red-sequence-selected clusters at z ˜ 1. The quiescent galaxies in these clusters formed the bulk of their stars above z ≳ 3 with an age spread Δt ≳ 1 Gyr. We compare UVJ color-color and spectroscopic-based galaxy selection techniques, and find a 15% difference in the galaxy populations classified as quiescent by these methods. We compare the color-magnitude relations from our red-sequence selected sample with X-ray- and photometric-redshift-selected cluster samples of similar mass and redshift. Within uncertainties, we are unable to detect any difference in the ages and star formation histories of quiescent cluster members in clusters selected by different methods, suggesting that the dominant quenching mechanism is insensitive to cluster baryon partitioning at z ˜ 1.

  5. EVIDENCE FOR THE UNIVERSALITY OF PROPERTIES OF RED-SEQUENCE GALAXIES IN X-RAY- AND RED-SEQUENCE-SELECTED CLUSTERS AT z ∼ 1

    SciTech Connect

    Foltz, R.; Wilson, G.; DeGroot, A.; Rettura, A.; Van der Burg, R. F. J.; Lidman, C.; Demarco, R.; Nantais, Julie; Yee, H. E-mail: gillian.wilson@ucr.edu E-mail: arettura@astro.caltech.edu E-mail: avmuzzin@ast.cam.ac.uk E-mail: rdemarco@astro-udec.cl E-mail: hyee@astro.utoronto.ca

    2015-10-20

    We study the slope, intercept, and scatter of the color–magnitude and color–mass relations for a sample of 10 infrared red-sequence-selected clusters at z ∼ 1. The quiescent galaxies in these clusters formed the bulk of their stars above z ≳ 3 with an age spread Δt ≳ 1 Gyr. We compare UVJ color–color and spectroscopic-based galaxy selection techniques, and find a 15% difference in the galaxy populations classified as quiescent by these methods. We compare the color–magnitude relations from our red-sequence selected sample with X-ray- and photometric-redshift-selected cluster samples of similar mass and redshift. Within uncertainties, we are unable to detect any difference in the ages and star formation histories of quiescent cluster members in clusters selected by different methods, suggesting that the dominant quenching mechanism is insensitive to cluster baryon partitioning at z ∼ 1.

  6. Cyclostratigraphy for Chinese red clay sequences: Implications to changing previous age models and paleoclimate interpretations

    NASA Astrophysics Data System (ADS)

    Anwar, T.; Kravchinsky, V. A.; Zhang, R.

    2015-12-01

    The Chinese Loess Plateau contains red clay sequence which has continuous alternation of sedimentary cycles with recurrent paleoclimatic fluctuations. Absence of abundant fossils and inability of radiometric dating method made magnetostratigraphy a leading method to build age model for the red clay. Here magnetostratigraphic age model in red clay sequence is tested using cyclostratigraphy as orbital parameters of Earth are known. Milankovitch periodicities recorded in magnetic susceptibility and grain size in the Shilou red clay section are investigated and previously found age of 11 Ma for this section is re-evaluated. Magnetostratigraphy dating based on only visual correlation could potentially lead to erroneous age model. In this study the correlation is executed through the iteration procedure until it is supported by cyclostratigraphy; i.e. Milankovitch cycles are resolved in the best possible manner. Our new approach provides an age of 5.2 Ma for the Shilou profile. Wavelet analysis reveals that a 400 kyr eccentricity cycle is well preserved and the existence of a 100 kyr eccentricity in the red clay sequence on the eastern Chinese Loess Plateau suggests that eccentricity plays a vital role in Pliocene climate evolution. Paleomonsoon evolution is reconstructed and divided into three intervals (5.2-4.5 Ma, 4.5-3.6 Ma and 3.6-2.58 Ma). The earliest stage indicates that summer and winter monsoon cycles may rapidly alter, whereas the middle stage reflects an intensification of winter monsoon and aridification in Asia, and the youngest stage is characterized by relatively intensified summer monsoon. This study demonstrates that cyclostratigraphy can greatly assist magnetostratigraphy in dating the red clay sequences, and implies that many published age models for the red clay sequences should likely be re-assessed where possible. An evaluation of the monsoon system and climate change in eastern Asia might prominently benefit from this approach.

  7. Satellite DNA Sequences in Canidae and Their Chromosome Distribution in Dog and Red Fox.

    PubMed

    Vozdova, Miluse; Kubickova, Svatava; Cernohorska, Halina; Fröhlich, Jan; Rubes, Jiri

    2016-01-01

    Satellite DNA is a characteristic component of mammalian centromeric heterochromatin, and a comparative analysis of its evolutionary dynamics can be used for phylogenetic studies. We analysed satellite and satellite-like DNA sequences available in NCBI for 4 species of the family Canidae (red fox, Vulpes vulpes, VVU; domestic dog, Canis familiaris, CFA; arctic fox, Vulpes lagopus, VLA; raccoon dog, Nyctereutes procyonoides procyonoides, NPR) by comparative sequence analysis, which revealed 86-90% intraspecies and 76-79% interspecies similarity. Comparative fluorescence in situ hybridisation in the red fox and dog showed signals of the red fox satellite probe in canine and vulpine autosomal centromeres, on VVUY, B chromosomes, and in the distal parts of VVU9q and VVU10p which were shown to contain nucleolus organiser regions. The CFA satellite probe stained autosomal centromeres only in the dog. The CFA satellite-like DNA did not show any significant sequence similarity with the satellite DNA of any species analysed and was localised to the centromeres of 9 canine chromosome pairs. No significant heterochromatin block was detected on the B chromosomes of the red fox. Our results show extensive heterogeneity of satellite sequences among Canidae and prove close evolutionary relationships between the red and arctic fox. © 2017 S. Karger AG, Basel.

  8. Complete mitochondrial genome sequence of northeastern red deer (Cervus elaphus xanthopygus).

    PubMed

    Shao, Yuanchen; Su, Weilin; Liu, Huamiao; Zha, Daiming; Zhang, Ranran; Xing, Xiumei

    2016-01-01

    The complete mitochondrial genome of the northeastern red deer, Cervus elaphus xanthopygus, was determined by accurate polymerase chain reaction. The entire genome is 16,416 bp in length and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region, all of which are arranged in a typical vertebrate manner. The overall base composition of the northeastern red deer's mitochondrial genome is 33.3% of A, 24.3% of C, 28.9% of T and 13.5% of G. A termination-associated sequence and several conserved central sequence block domains were discovered within the control region.

  9. The complete mitochondrial genome sequence of the Tibetan red fox (Vulpes vulpes montana).

    PubMed

    Zhang, Jin; Zhang, Honghai; Zhao, Chao; Chen, Lei; Sha, Weilai; Liu, Guangshuai

    2015-01-01

    In this study, the complete mitochondrial genome of the Tibetan red fox (Vulpes Vulpes montana) was sequenced for the first time using blood samples obtained from a wild female red fox captured from Lhasa in Tibet, China. Qinghai--Tibet Plateau is the highest plateau in the world with an average elevation above 3500 m. Sequence analysis showed it contains 12S rRNA gene, 16S rRNA gene, 22 tRNA genes, 13 protein-coding genes and 1 control region (CR). The variable tandem repeats in CR is the main reason of the length variability of mitochondrial genome among canide animals.

  10. How Faint Can You Go?

    NASA Astrophysics Data System (ADS)

    Henden, Arne

    2017-06-01

    For many scientific projects, knowledge of the faint limit of your exposure can be extremely important. In addition, it can be just plain fun to know how faint your equipment can go under varying circumstances. This paper describes the concept and gives some guidance as to how to increase the scientific value of your reports.

  11. EVOLUTION OF GROUP GALAXIES FROM THE FIRST RED-SEQUENCE CLUSTER SURVEY

    SciTech Connect

    Li, I. H.; Yee, H. K. C.; Hsieh, B. C.; Gladders, M. E-mail: hyee@astro.utoronto.ca E-mail: gladders@oddjob.uchicago.edu

    2012-04-20

    We study the evolution of the red-galaxy fraction (f{sub red}) in 905 galaxy groups with 0.15 {<=} z < 0.52. The galaxy groups are identified by the 'probability friends-of-friends' algorithm from the first Red-Sequence Cluster Survey (RCS1) photometric-redshift sample. There is a high degree of uniformity in the properties of the red sequence of the group galaxies, indicating that the luminous red-sequence galaxies in the groups are already in place by z {approx} 0.5 and that they have a formation epoch of z {approx}> 2. In general, groups at lower redshifts exhibit larger f{sub red} than those at higher redshifts, showing a group Butcher-Oemler effect. We investigate the evolution of f{sub red} by examining its dependence on four parameters, one of which can be classified as intrinsic and three of which can be classified as environmental: galaxy stellar mass (M{sub *}), total group stellar mass (M{sub *,grp}, a proxy for group halo mass), normalized group-centric radius (r{sub grp}), and local galaxy density ({Sigma}{sub 5}). We find that M{sub *} is the dominant parameter such that there is a strong correlation between f{sub red} and galaxy stellar mass. Furthermore, the dependence of f{sub red} on the environmental parameters is also a strong function of M{sub *}. Massive galaxies (M{sub *} {approx}> 10{sup 11} M{sub Sun }) show little dependence of f{sub red} on r{sub grp}, M{sub *,grp}, and {Sigma}{sub 5} over the redshift range. The dependence of f{sub red} on these parameters is primarily seen for galaxies with lower masses, especially for M{sub *} {approx}< 10{sup 10.6} M{sub Sun }. We observe an apparent 'group down-sizing' effect, in that galaxies in lower-mass halos, after controlling for galaxy stellar mass, have lower f{sub red}. We find a dependence of f{sub red} on both r{sub grp} and {Sigma}{sub 5} after the other parameters are controlled. At a fixed r{sub grp}, there is a significant dependence of f{sub red} on {Sigma}{sub 5}, while r{sub grp

  12. RED-SEQUENCE GALAXIES AT HIGH REDSHIFT BY THE COMBO-17+4 SURVEY

    SciTech Connect

    Nicol, Marie-Helene; Meisenheimer, Klaus; Wolf, Christian; Tapken, Christian E-mail: meise@mpia.de E-mail: ctapken@aip.de

    2011-01-20

    We investigate the evolution of the galaxy population since redshift 2 with a focus on the color bimodality and mass density of the red sequence. We obtain precise and reliable photometric redshifts up to z = 2 by supplementing the optical survey COMBO-17 with observations in four near-infrared bands on 0.2 deg{sup 2} of the COMBO-17 A901-field. Our results are based on an H-band-selected catalog of 10,692 galaxies complete to H = 21fm7. We measure the rest-frame color (U{sub 280}-V) of each galaxy, which across the redshift range of our interest requires no extrapolation and is robust against moderate redshift errors by staying clear of the 4000 A break. We measure the color-magnitude relation of the red sequence as a function of look-back time from the peak in a color-error-weighted histogram, and thus trace the galaxy bimodality out to z {approx_equal} 1.65. The (U{sub 280}-V) of the red sequence is found to evolve almost linearly with look-back time. At high redshift, we find massive galaxies in both the red and the blue population. Red-sequence galaxies with log M{sub *}/M{sub sun}>11 increase in mass density by a factor of {approx}4 from z {approx} 2 to 1 and remain nearly constant at z < 1. However, some galaxies as massive as log M{sub *}/M{sub sun} = 11.5 are already in place at z {approx} 2.

  13. Faint Infrared-Excess Field Galaxies: FROGs

    NASA Astrophysics Data System (ADS)

    Moustakas, L. A.; Davis, M.; Zepf, S. E.; Bunker, A. J.

    Deep near-infrared and optical imaging surveys in the field reveal a curious population of galaxies that are infrared-bright (I-K>4), yet with relatively blue optical colors (V-I<2). Their surface density, several per square arcminute at K>20, is high enough that if placed at z>1 as our models suggest, their space densities are about one-tenth of phi-*. The colors of these ``faint red outlier galaxies'' (fROGs) may derive from exceedingly old underlying stellar populations, a dust-embedded starburst or AGN, or a combination thereof. Determining the nature of these fROGs, and their relation with the I-K>6 ``extremely red objects,'' has implications for our understanding of the processes that give rise to infrared-excess galaxies in general. We report on an ongoing study of several targets with HST & Keck imaging and Keck/LRIS multislit spectroscopy.

  14. Sequence analysis of a canine parvovirus isolated from a red panda (Ailurus fulgens) in China.

    PubMed

    Qin, Qin; Loeffler, I Kati; Li, Ming; Tian, Kegong; Wei, Fuwen

    2007-06-01

    Canine parvovirus (CPV) was first recognized in the late 1970 s in dogs and has mutated and spread throughout the world in canid and felid species since then. In this study, a novel CPV was isolated from the endangered red panda (Ailurus fulgens) in China. Nucleotide and phylogenetic analysis of the capsid protein VP2 gene classified the red panda parvovirus (RPPV) as a CPV-2a type. Substitution of Val for Gly at the conserved 300 residue in RPPV presents an unusual variation in the CPV-2a amino acid sequence and is further evidence for the continuing evolution of the virus. The 300 residue is important in distinguishing the antigenicity and host range of CPVs. The clinical significance and population impact of RPPV infection in captive red pandas in China is unknown and is an important topic for future research.

  15. Imaging stellar faint companions

    NASA Astrophysics Data System (ADS)

    Cagigal, Manuel P.; Canales, Vidal F.

    . The conclusion is that the use of the Dark Speckle technique in a compensated nulling interferometer could be a promising way to detect faint objects, although the application of the technique in the infrared range requires the development of appropriate detectors.

  16. Unmixing hysteresis loops of the late Miocene-early Pleistocene loess-red clay sequence

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Necula, C.; Heslop, D.; Nie, J.

    2016-12-01

    Magnetic paleoclimatic records often represent mixed environmental signals. Unmixing these signals may improve our understanding of the paleoenvironmental information contained within these records, but such a task is challenging. Here we report an example of numerical unmixing of magnetic hysteresis data obtained from Chinese loess and red clay sequences. We find that the mixed magnetic assemblages of the loess and red clay sediments both contain a component characterized by a narrow hysteresis loop, the abundance of which is positively correlated with magnetic susceptibility. This component has grain sizes close to the superparamagnetic/stable single domain boundary and is attributed to pedogenic activity. Furthermore, a wasp-waisted component is found in both the loess and red clay, however, the wasp-waisted form is more constricted in the red clay. We attribute this component to a mixture of detrital ferrimagnetic grains with pedogenic hematite. The abundance of this component decreases from the base to the top of the red clay, a pattern we attribute to decreased hematite production over the Chinese Loess Plateau (CLP) due to long-term climate cooling. This work demonstrates the potential of hysteresis loop unmixing to recover quantitative paleoclimatic information carried by both low and high coercivity magnetic minerals.

  17. Unmixing hysteresis loops of the late Miocene-early Pleistocene loess-red clay sequence

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Necula, Cristian; Heslop, David; Nie, Junsheng

    2016-07-01

    Magnetic paleoclimatic records often represent mixed environmental signals. Unmixing these signals may improve our understanding of the paleoenvironmental information contained within these records, but such a task is challenging. Here we report an example of numerical unmixing of magnetic hysteresis data obtained from Chinese loess and red clay sequences. We find that the mixed magnetic assemblages of the loess and red clay sediments both contain a component characterized by a narrow hysteresis loop, the abundance of which is positively correlated with magnetic susceptibility. This component has grain sizes close to the superparamagnetic/stable single domain boundary and is attributed to pedogenic activity. Furthermore, a wasp-waisted component is found in both the loess and red clay, however, the wasp-waisted form is more constricted in the red clay. We attribute this component to a mixture of detrital ferrimagnetic grains with pedogenic hematite. The abundance of this component decreases from the base to the top of the red clay, a pattern we attribute to decreased hematite production over the Chinese Loess Plateau (CLP) due to long-term climate cooling. This work demonstrates the potential of hysteresis loop unmixing to recover quantitative paleoclimatic information carried by both low and high coercivity magnetic minerals.

  18. Unmixing hysteresis loops of the late Miocene-early Pleistocene loess-red clay sequence.

    PubMed

    Zhang, Rui; Necula, Cristian; Heslop, David; Nie, Junsheng

    2016-07-08

    Magnetic paleoclimatic records often represent mixed environmental signals. Unmixing these signals may improve our understanding of the paleoenvironmental information contained within these records, but such a task is challenging. Here we report an example of numerical unmixing of magnetic hysteresis data obtained from Chinese loess and red clay sequences. We find that the mixed magnetic assemblages of the loess and red clay sediments both contain a component characterized by a narrow hysteresis loop, the abundance of which is positively correlated with magnetic susceptibility. This component has grain sizes close to the superparamagnetic/stable single domain boundary and is attributed to pedogenic activity. Furthermore, a wasp-waisted component is found in both the loess and red clay, however, the wasp-waisted form is more constricted in the red clay. We attribute this component to a mixture of detrital ferrimagnetic grains with pedogenic hematite. The abundance of this component decreases from the base to the top of the red clay, a pattern we attribute to decreased hematite production over the Chinese Loess Plateau (CLP) due to long-term climate cooling. This work demonstrates the potential of hysteresis loop unmixing to recover quantitative paleoclimatic information carried by both low and high coercivity magnetic minerals.

  19. Unmixing hysteresis loops of the late Miocene–early Pleistocene loess-red clay sequence

    PubMed Central

    Zhang, Rui; Necula, Cristian; Heslop, David; Nie, Junsheng

    2016-01-01

    Magnetic paleoclimatic records often represent mixed environmental signals. Unmixing these signals may improve our understanding of the paleoenvironmental information contained within these records, but such a task is challenging. Here we report an example of numerical unmixing of magnetic hysteresis data obtained from Chinese loess and red clay sequences. We find that the mixed magnetic assemblages of the loess and red clay sediments both contain a component characterized by a narrow hysteresis loop, the abundance of which is positively correlated with magnetic susceptibility. This component has grain sizes close to the superparamagnetic/stable single domain boundary and is attributed to pedogenic activity. Furthermore, a wasp-waisted component is found in both the loess and red clay, however, the wasp-waisted form is more constricted in the red clay. We attribute this component to a mixture of detrital ferrimagnetic grains with pedogenic hematite. The abundance of this component decreases from the base to the top of the red clay, a pattern we attribute to decreased hematite production over the Chinese Loess Plateau (CLP) due to long-term climate cooling. This work demonstrates the potential of hysteresis loop unmixing to recover quantitative paleoclimatic information carried by both low and high coercivity magnetic minerals. PMID:27389499

  20. The first symbiont-free genome sequence of marine red alga, Susabi-nori (Pyropia yezoensis).

    PubMed

    Nakamura, Yoji; Sasaki, Naobumi; Kobayashi, Masahiro; Ojima, Nobuhiko; Yasuike, Motoshige; Shigenobu, Yuya; Satomi, Masataka; Fukuma, Yoshiya; Shiwaku, Koji; Tsujimoto, Atsumi; Kobayashi, Takanori; Nakayama, Ichiro; Ito, Fuminari; Nakajima, Kazuhiro; Sano, Motohiko; Wada, Tokio; Kuhara, Satoru; Inouye, Kiyoshi; Gojobori, Takashi; Ikeo, Kazuho

    2013-01-01

    Nori, a marine red alga, is one of the most profitable mariculture crops in the world. However, the biological properties of this macroalga are poorly understood at the molecular level. In this study, we determined the draft genome sequence of susabi-nori (Pyropia yezoensis) using next-generation sequencing platforms. For sequencing, thalli of P. yezoensis were washed to remove bacteria attached on the cell surface and enzymatically prepared as purified protoplasts. The assembled contig size of the P. yezoensis nuclear genome was approximately 43 megabases (Mb), which is an order of magnitude smaller than the previously estimated genome size. A total of 10,327 gene models were predicted and about 60% of the genes validated lack introns and the other genes have shorter introns compared to large-genome algae, which is consistent with the compact size of the P. yezoensis genome. A sequence homology search showed that 3,611 genes (35%) are functionally unknown and only 2,069 gene groups are in common with those of the unicellular red alga, Cyanidioschyzon merolae. As color trait determinants of red algae, light-harvesting genes involved in the phycobilisome were predicted from the P. yezoensis nuclear genome. In particular, we found a second homolog of phycobilisome-degradation gene, which is usually chloroplast-encoded, possibly providing a novel target for color fading of susabi-nori in aquaculture. These findings shed light on unexplained features of macroalgal genes and genomes, and suggest that the genome of P. yezoensis is a promising model genome of marine red algae.

  1. The First Symbiont-Free Genome Sequence of Marine Red Alga, Susabi-nori (Pyropia yezoensis)

    PubMed Central

    Nakamura, Yoji; Sasaki, Naobumi; Kobayashi, Masahiro; Ojima, Nobuhiko; Yasuike, Motoshige; Shigenobu, Yuya; Satomi, Masataka; Fukuma, Yoshiya; Shiwaku, Koji; Tsujimoto, Atsumi; Kobayashi, Takanori; Nakayama, Ichiro; Ito, Fuminari; Nakajima, Kazuhiro; Sano, Motohiko; Wada, Tokio; Kuhara, Satoru; Inouye, Kiyoshi; Gojobori, Takashi; Ikeo, Kazuho

    2013-01-01

    Nori, a marine red alga, is one of the most profitable mariculture crops in the world. However, the biological properties of this macroalga are poorly understood at the molecular level. In this study, we determined the draft genome sequence of susabi-nori (Pyropia yezoensis) using next-generation sequencing platforms. For sequencing, thalli of P. yezoensis were washed to remove bacteria attached on the cell surface and enzymatically prepared as purified protoplasts. The assembled contig size of the P. yezoensis nuclear genome was approximately 43 megabases (Mb), which is an order of magnitude smaller than the previously estimated genome size. A total of 10,327 gene models were predicted and about 60% of the genes validated lack introns and the other genes have shorter introns compared to large-genome algae, which is consistent with the compact size of the P. yezoensis genome. A sequence homology search showed that 3,611 genes (35%) are functionally unknown and only 2,069 gene groups are in common with those of the unicellular red alga, Cyanidioschyzon merolae. As color trait determinants of red algae, light-harvesting genes involved in the phycobilisome were predicted from the P. yezoensis nuclear genome. In particular, we found a second homolog of phycobilisome-degradation gene, which is usually chloroplast-encoded, possibly providing a novel target for color fading of susabi-nori in aquaculture. These findings shed light on unexplained features of macroalgal genes and genomes, and suggest that the genome of P. yezoensis is a promising model genome of marine red algae. PMID:23536760

  2. Complete mitochondrial genome sequence of tarim red deer (Cervus elaphus yarkandensis).

    PubMed

    Shao, Yuanchen; Xing, Xiumei; Zha, Daiming; Yang, Fuhe

    2016-01-01

    The complete mitochondrial genome of the tarim red deer, Cervus elaphus yarkandensis, was determined by accurate polymerase chain reaction. The entire genome was 16,351 bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region, all of which were arranged in a typical vertebrate manner. The overall base composition of the northeast sika deer's mitochondrial genome was 33.3% of A, 24.4% of C, 28.9% of T and 13.4% of G. A termination-associated sequence and several conserved central sequence block domains were discovered within the control region.

  3. Implications of some flow sedimentary structures within Miocene evaporitic sequence, Red Sea, Egypt

    SciTech Connect

    Wali, A.

    1984-09-01

    Some typical flow sedimentary structures were clearly detected within the middle Miocene alternating gypsiferous and anhydritic clays of the evaporitic sequence in Ras Gemsa and Um El-Huweitat localities. Sedimentologic analyses of the different structural forms revealed that they were originally formed from unlithified sediments and due to submarine flowage. These structures were formed as a result of stress-load, compression, and rotation. Such a genetic approach is helpful in deducing the environmental conditions within which these sediments accumulated. Degrees of flowage and affected stresses on similar lithologic associations could be considered strong evidence for correlation within the extended Miocene evaporitic sequence along the Red Sea coast.

  4. Linkage Mapping and Comparative Genomics of Red Drum (Sciaenops ocellatus) Using Next-Generation Sequencing.

    PubMed

    Hollenbeck, Christopher M; Portnoy, David S; Wetzel, Dana; Sherwood, Tracy A; Samollow, Paul B; Gold, John R

    2017-03-10

    Developments in next-generation sequencing allow genotyping of thousands of genetic markers across hundreds of individuals in a cost-effective manner. Because of this, it is now possible to rapidly produce dense genetic linkage maps for nonmodel species. Here, we report a dense genetic linkage map for red drum, a marine fish species of considerable economic importance in the southeastern United States and elsewhere. We used a prior microsatellite-based linkage map as a framework and incorporated 1794 haplotyped contigs derived from high-throughput, reduced representation DNA sequencing to produce a linkage map containing 1794 haplotyped restriction-site associated DNA (RAD) contigs, 437 anonymous microsatellites, and 44 expressed sequence-tag-linked microsatellites (EST-SSRs). A total of 274 candidate genes, identified from transcripts from a preliminary hydrocarbon exposure study, were localized to specific chromosomes, using a shared synteny approach. The linkage map will be a useful resource for red drum commercial and restoration aquaculture, and for better understanding and managing populations of red drum in the wild.

  5. Linkage Mapping and Comparative Genomics of Red Drum (Sciaenops ocellatus) Using Next-Generation Sequencing

    PubMed Central

    Hollenbeck, Christopher M.; Portnoy, David S.; Wetzel, Dana; Sherwood, Tracy A.; Samollow, Paul B.; Gold, John R.

    2017-01-01

    Developments in next-generation sequencing allow genotyping of thousands of genetic markers across hundreds of individuals in a cost-effective manner. Because of this, it is now possible to rapidly produce dense genetic linkage maps for nonmodel species. Here, we report a dense genetic linkage map for red drum, a marine fish species of considerable economic importance in the southeastern United States and elsewhere. We used a prior microsatellite-based linkage map as a framework and incorporated 1794 haplotyped contigs derived from high-throughput, reduced representation DNA sequencing to produce a linkage map containing 1794 haplotyped restriction-site associated DNA (RAD) contigs, 437 anonymous microsatellites, and 44 expressed sequence-tag-linked microsatellites (EST-SSRs). A total of 274 candidate genes, identified from transcripts from a preliminary hydrocarbon exposure study, were localized to specific chromosomes, using a shared synteny approach. The linkage map will be a useful resource for red drum commercial and restoration aquaculture, and for better understanding and managing populations of red drum in the wild. PMID:28122951

  6. Genetic signatures of adaptation revealed from transcriptome sequencing of Arctic and red foxes.

    PubMed

    Kumar, Vikas; Kutschera, Verena E; Nilsson, Maria A; Janke, Axel

    2015-08-07

    The genus Vulpes (true foxes) comprises numerous species that inhabit a wide range of habitats and climatic conditions, including one species, the Arctic fox (Vulpes lagopus) which is adapted to the arctic region. A close relative to the Arctic fox, the red fox (Vulpes vulpes), occurs in subarctic to subtropical habitats. To study the genetic basis of their adaptations to different environments, transcriptome sequences from two Arctic foxes and one red fox individual were generated and analyzed for signatures of positive selection. In addition, the data allowed for a phylogenetic analysis and divergence time estimate between the two fox species. The de novo assembly of reads resulted in more than 160,000 contigs/transcripts per individual. Approximately 17,000 homologous genes were identified using human and the non-redundant databases. Positive selection analyses revealed several genes involved in various metabolic and molecular processes such as energy metabolism, cardiac gene regulation, apoptosis and blood coagulation to be under positive selection in foxes. Branch site tests identified four genes to be under positive selection in the Arctic fox transcriptome, two of which are fat metabolism genes. In the red fox transcriptome eight genes are under positive selection, including molecular process genes, notably genes involved in ATP metabolism. Analysis of the three transcriptomes and five Sanger re-sequenced genes in additional individuals identified a lower genetic variability within Arctic foxes compared to red foxes, which is consistent with distribution range differences and demographic responses to past climatic fluctuations. A phylogenomic analysis estimated that the Arctic and red fox lineages diverged about three million years ago. Transcriptome data are an economic way to generate genomic resources for evolutionary studies. Despite not representing an entire genome, this transcriptome analysis identified numerous genes that are relevant to arctic

  7. Isolation, cloning and sequencing of transferrins from red-eared turtle, African ostrich, and turkey.

    PubMed

    Ciuraszkiewicz, Justyna; Olczak, Mariusz; Watorek, Wiesław

    2006-07-01

    Transferrins form an important class of iron-binding proteins widely distributed in the physiological fluids of vertebrates and invertebrates. In vertebrates they are present mostly in serum as serotransferrins. In birds and reptiles transferrins are also found in eggs as ovotransferrins. However, until now only chicken and duck ovotransferrin sequences have been published. This paper presents data on the purification, biochemical analysis, cloning and sequencing of ovotransferrins from red-eared turtle, African ostrich and turkey, revealing their significant homology with other known ovotransferrin sequences. The proteins were purified by size-exclusion and anion-exchange chromatography. Isoelectric points, iron-saturated and iron-free spectra, as well as the mRNA nucleotide sequences of 2,409 nt (ORF: 2,106 nt encoding a 701-amino-acid polypeptide; ), 2,418 nt (ORF 2,118 nt encoding a 705-amino-acid polypeptide; ), and 2,397 nt (ORF: 2,118 nt encoding a 705-amino-acid polypeptide; ) were determined for ostrich (OtrF), red-eared turtle (TtrF), and turkey (MtrF) ovotransferrin, respectively.

  8. Sequencing and de novo assembly of the red cusk-eel (Genypterus chilensis) transcriptome.

    PubMed

    Aedo, J E; Maldonado, J; Estrada, J M; Fuentes, E N; Silva, H; Gallardo-Escarate, C; Molina, A; Valdés, J A

    2014-12-01

    The red cusk-eel (Genypterus chilensis) is an endemic fish species distributed along the coasts of the Eastern South Pacific. Biological studies on this fish are scarce, and genomic information for G. chilensis is practically non-existent. Thus, transcriptome information for this species is an essential resource that will greatly enrich molecular information and benefit future studies of red cusk-eel biology. In this work, we obtained transcriptome information of G. chilensis using the Illumina platform. The RNA sequencing generated 66,307,362 and 59,925,554 paired-end reads from skeletal muscle and liver tissues, respectively. De novo assembly using the CLC Genomic Workbench version 7.0.3 produced 48,480 contigs and created a reference transcriptome with a N50 of 846bp and average read coverage of 28.3×. By sequence similarity search for known proteins, a total of 21,272 (43.9%) contigs were annotated for their function. Out of these annotated contigs, 33.5% GO annotation results for biological processes, 32.6% GO annotation results for cellular components and 34.5% GO annotation results for molecular functions. This dataset represents the first transcriptomic resource for the red cusk-eel and for a member of the Ophidiimorpharia taxon. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Kinematics of faint white dwarfs.

    PubMed

    Luyten, W J

    1978-10-01

    An analysis has been made for solar motion for 128 very faint white dwarfs of color class b or a. While about 40% of these stars may be high-velocity objects, it seems definitely indicated that the luminosity of all of them is considerably lower than that for the "normal" white dwarf of the same color.

  10. Morphological evolution of cluster red sequence galaxies in the past 9 Gyr

    NASA Astrophysics Data System (ADS)

    De Propris, Roberto; Bremer, Malcolm N.; Phillipps, Steven

    2016-10-01

    Galaxies arrive on the red sequences of clusters at high redshift (z > 1) once their star formation is quenched and evolve passively thereafter. However, we have previously found that cluster red sequence galaxies (CRSGs) undergo significant morphological evolution subsequent to the cessation of star formation, at some point in the past 9-10 Gyr. Through a detailed study of a large sample of cluster red sequence galaxies spanning 0.2 < z < 1.4 we elucidate the details of this evolution. Below z ˜ 0.5-0.6 (in the last 5-6 Gyr) there is little or no morphological evolution in the population as a whole, unlike in the previous 4-5 Gyr. Over this earlier time (i) disc-like systems with Sérsic n < 2 progressively disappear, as (ii) the range of their axial ratios similarly decreases, removing the most elongated systems (those consistent with thin discs seen at an appreciable inclination angle) and (iii) radial colour gradients (bluer outwards) decrease in an absolute sense from significant age-related gradients to a residual level consistent with the metallicity-induced gradients seen in low-redshift cluster members. The distribution of their effective radii shows some evidence of evolution, consistent with growth of at most a factor <1.5 between z ˜ 1.4 and ˜0.5, significantly less than for comparable field galaxies, while the distribution of their central (<1 kpc) bulge surface densities shows no evolution at least at z < 1. A simple model involving the fading and thickening of a disc component after comparatively recent quenching (after z ˜ 1.5) around an otherwise passively evolving older spheroid component is consistent with all of these findings.

  11. Recent Galaxy Mergers and Residual Star Formation of Red Sequence Galaxies in Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Sheen, Yun-Kyeong; Yi, Sukyoung K.; Ree, Chang H.; Jaffé, Yara; Demarco, Ricardo; Treister, Ezequiel

    2016-08-01

    This study explored the Galaxy Evolution Explorer ultraviolet (UV) properties of optical red sequence galaxies in four rich Abell clusters at z≤slant 0.1. In particular, we tried to find a hint of merger-induced recent star formation (RSF) in red sequence galaxies. Using the NUV - r\\prime colors of the galaxies, RSF fractions were derived based on various criteria for post-merger galaxies and normal galaxies. Following k-correction, about 36% of the post-merger galaxies were classified as RSF galaxies with a conservative criterion (NUV - r\\prime ≤slant 5), and that number was doubled (˜72%) when using a generous criterion (NUV - r\\prime ≤slant 5.4). The trend was the same when we restricted the sample to galaxies within 0.5 × R 200. Post-merger galaxies with strong UV emission showed more violent, asymmetric features in the deep optical images. The RSF fractions did not show any trend along the clustocentric distance within R 200. We performed a Dressler-Shectman test to check whether the RSF galaxies had any correlation with the substructures in the galaxy clusters. Within R 200 of each cluster, the RSF galaxies did not appear to be preferentially related to the clusters’ substructures. Our results suggested that only 30% of RSF red sequence galaxies show morphological hints of recent galaxy mergers. This implies that internal processes (e.g., stellar mass loss or hot gas cooling) for the supply of cold gas to early-type galaxies may play a significant role in the residual star formation of early-type galaxies at a recent epoch.

  12. Insights into Korean red fox (Vulpes vulpes) based on mitochondrial cytochrome b sequence variation in East Asia.

    PubMed

    Yu, Jeong-Nam; Han, Sang-Hoon; Kim, Bang-Hwan; Kryukov, Alexey P; Kim, Soonok; Lee, Byoung-Yoon; Kwak, Myounghai

    2012-11-01

    The red fox (Vulpes vulpes) is the most widely distributed terrestrial carnivore in the world, occurring throughout most of North America, Europe, Asia, and North Africa. In South Korea, however, this species has been drastically reduced due to habitat loss and poaching. Consequently, it is classified as an endangered species in Korea. As a first step of a planned red fox restoration project, preserved red fox museum specimens were used to determine the genetic status of red foxes that had previously inhabited South Korea against red foxes from neighboring countries. Total eighty three mtDNA cytochrome b sequences, including 22 newly obtained East Asian red fox sequences and worldwide red fox sequences from NCBI, were clustered into three clades (i.e., I, II, and III) based on haplotype network and neighbor-joining trees. The mean genetic distance between clades was 2.0%. Clade III contained South Korean and other East Asian samples in addition to Eurasian and North Pacific individuals. In clade III, South Korean individuals were separated into two lineages of Eurasian and North Pacific groups, showing unclear phylogeographic structuring and admixture. This suggests that South Korean red fox populations may have been composed of individuals from these two different genetic lineages.

  13. A study on the multicolour evolution of red-sequence galaxy populations: insights from hydrodynamical simulations and semi-analytical models

    NASA Astrophysics Data System (ADS)

    Romeo, A. D.; Kang, Xi; Contini, E.; Sommer-Larsen, J.; Fassbender, R.; Napolitano, N. R.; Antonuccio-Delogu, V.; Gavignaud, I.

    2015-09-01

    Context. By means of our own cosmological-hydrodynamical simulation (SIM) and semi-analytical model (SAM), we studied galaxy population properties in clusters and groups, spanning over ten different bands from the ultraviolet to the near-infrared (NIR), and their evolution since redshift z = 2. Aims: We compare our results in terms of red/blue galaxy fractions and of the luminous-to-faint ratio (LFR) on the red sequence (RS) with recent observational data reaching beyond z = 1.5. Methods: Different selection criteria were tested to retrieve the galaxies that effectively belong to the RS: either by their quiescence degree measured from their specific star formation rate (sSFR; the so-called "dead sequence"), or by their position in a colour-colour plane, which is also a function of sSFR. In both cases, the colour cut and the lower limit magnitude thresholds were let to evolve with redshift so that they would follow the natural shift of the characteristic luminosity in the luminosity function (LF). Results: We find that the Butcher-Oemler effect is wavelength-dependent, with the fraction of blue galaxies increasing more steeply in optical-optical than in NIR-optical colours. Moreover, a steep trend in the blue fraction can only be reproduced when an optically fixed luminosity-selected sample is chosen, while the trend flattens when selecting samples by stellar mass or by an evolving magnitude limit. We also find that the RS-LFR behaviour, highly debated in the literature, is strongly dependent on the galaxy selection function: in particular, the very mild evolution that is recovered when using a mass-selected galaxy sample agrees with values reported for some of the highest redshift-confirmed (proto)clusters. For differences that are attributable to environments, we find that normal groups and (to a lesser extent) cluster outskirts present the highest values of both the star-forming fraction and LFR at low z, while fossil groups and cluster cores have the lowest

  14. THE MID-INFRARED AND NEAR-ULTRAVIOLET EXCESS EMISSIONS OF QUIESCENT GALAXIES ON THE RED SEQUENCE

    SciTech Connect

    Ko, Jongwan; Lee, Jong Chul; Hwang, Ho Seong; Sohn, Young-Jong

    2013-04-10

    We study the mid-infrared (IR) and near-ultraviolet (UV) excess emissions of spectroscopically selected quiescent galaxies on the optical red sequence. We use the Wide-field Infrared Survey Explorer mid-IR and Galaxy Evolution Explorer near-UV data for a spectroscopic sample of galaxies in the Sloan Digital Sky Survey Data Release 7 to study the possible connection between quiescent red-sequence galaxies with and without mid-IR/near-UV excess. Among 648 12 {mu}m detected quiescent red-sequence galaxies without H{alpha} emission, 26% and 55% show near-UV and mid-IR excess emissions, respectively. When we consider only bright (M{sub r} < -21.5) galaxies with an early-type morphology, the fraction of galaxies with recent star formation is still 39%. The quiescent red-sequence galaxies with mid-IR and near-UV excess emissions are optically fainter and have slightly smaller D{sub n} 4000 than those without mid-IR and near-UV excess emissions. We also find that mid-IR weighted mean stellar ages of quiescent red-sequence galaxies with mid-IR excess are larger than those with near-UV excess, and smaller than those without mid-IR and near-UV excess. The environmental dependence of the fraction of quiescent red-sequence galaxies with mid-IR and near-UV excess seems strong even though the trends of quiescent red-sequence galaxies with near-UV excess differ from those with mid-IR excess. These results indicate that the recent star formation traced by near-UV ({approx}< 1 Gyr) and mid-IR ({approx}< 2 Gyr) excess is not negligible among nearby, quiescent, red, early-type galaxies. We suggest a possible evolutionary scenario of quiescent red-sequence galaxies from quiescent red-sequence galaxies with near-UV excess to those with mid-IR excess to those without near-UV and mid-IR excess.

  15. The nature of faint emission-line galaxies

    NASA Technical Reports Server (NTRS)

    Smetanka, John J.

    1993-01-01

    One of the results of faint galaxy redshift surveys is the increased fraction of galaxies which have strong emission-line spectra. These faint surveys find that roughly 50 percent of the galaxies have an equivalent width of (OII), W sub 3727, greater than 20 A while this fraction is less than 20 percent in the DARS survey. This has been interpreted as evidence for strong evolution in the galaxy population at redshifts less than 0.5. In order to further investigate the properties of the galaxies in faint redshift surveys, two important factors must be addressed. The first is the observed correlation between color, luminosity, and W sub 3727. There is a correlation between color and the strength of emission lines, bluer galaxies having stronger emission features, as evident for Markarian galaxies and for galaxies in Kennicutt's spectrophotometric atlas. This correlation also applies galaxies in faint redshift surveys. In addition, low luminosity galaxies have a larger average W sub 3727 (and bluer colors) than higher luminosity galaxies. This is illustrated for Kennicutt's low z late-type galaxies, for the Durham Faint Surveys, and for galaxies in SA68. The second factor which must be incorporated into any interpretation of the faint emission galaxies is the different luminosity functions for galaxies depending on color. This is usually modeled by varying M* for different color classes (or morphological types); however, the shape of the luminosity function is different for galaxies with different colors. Low luminosity, blue galaxies have a much larger number density than low luminosity, red galaxies. Furthermore, the low luminosity end of the blue galaxy luminosity function is not well fit by a Schechter function. These two factors have been included in a very simple, no-evolution, model for the galaxy population. This model uses the luminosity functions from Shanks (1990) and spectral energy distributions (SED's) from Bruzual (1988). W sub 3727 is predicted using

  16. Red Sea isolation history suggested by Plio-Pleistocene seismic reflection sequences

    NASA Astrophysics Data System (ADS)

    Mitchell, Neil C.; Ligi, Marco; Rohling, Eelco J.

    2015-11-01

    High evaporation rates in the desert climate of the Red Sea ensure that, during glacial sea level lowstands when water exchange with the Indian Ocean was more restricted, water salinity and δ18 O became unusually extreme. Modeling of the effect on Red Sea sedimentary δ18 O has been used previously to reconstruct relative sea level to 500 ka and now poses the question of whether that sea-level model could be extended if continuous core material of older sediment became available. We attempt to address this question here by examining seismic reflection data. The upper Pleistocene hemipelagic sediments in the Red Sea contain intervals of inorganic aragonite precipitated during supersaturated conditions of sea-level lowstands. Seismic impedance changes associated with boundaries to those aragonite-rich layers appear to explain seismic reflection sequences. A segment of Chirp sediment profiler data from the central Red Sea reveals prominent reflections at ∼1, ∼5, ∼23, ∼26 and ∼36 ms two-way travel time (TWT) from the seabed. Based on depths to the glacial marine isotope stages (MIS) in cores, we relate the upper three reflections to the tops of aragonite-rich layers and hence the sea level rises immediately following MIS 2, 6 and 12. The reflection at 26 ms is related to an unusually rapid fall into MIS 12 predicted by one sea level reconstruction, which may have created an abrupt lower boundary to the MIS 12 aragonite-rich layer. With the aid of seismogram modeling, we tentatively associate the ∼36 ms reflection with the top of an aragonite-rich layer formed during MIS 16. Furthermore, some segments of lower frequency (airgun and sparker) seismic data from the central and southern Red Sea show a lower (earlier) Plio-Pleistocene (PP) interval that is less reflective than the upper (late) PP interval. This implies less variability in sediment impedance and that extreme variability in water salinity did not develop; water exchange with the Indian Ocean

  17. Stratigraphic sequence of a transgressive barrier-bar system, Red Fork sandstone, Wakita trend, Grant County, Oklahoma

    SciTech Connect

    O'Reilly, K.L.

    1987-08-01

    The stratigraphic sequence of the Red Fork sandstone (Boggy Formation, Krebs Group) along the Wakita trend, north-central Oklahoma, is interpreted as a transgressive barrier-bar system. The Red Fork sands were deposited along the northern shelf of the Anadarko basin in an elongate belt about 1-7 km wide. Within the belt, the sandstone forms podlike bodies ranging from 1 to 16 km long. The Red Fork is positioned in a generally onlapping sequence of strata, from the Inola Limestone Member at the base to the Tiawah (Pink) Limestone Member at the top. Shales that are interpreted as lagoonal deposits underlie and have a sharp contact with the Red Fork. To the north, the underlying shale is variegated green and red, and contains abundant rootlets and woody detritus; shale to the south is dark-gray and contains abundant brachiopod fragments. Glauconitic siltstone and shale overlie and have a gradational contact with the Red Fork sandstone. Sedimentation of the Red Fork sand was apparently localized on an east-west-striking hinge formed by increasing dip on the surface of the Inola. Shale overlying the Inola thickens to the south, forming a relatively flat surface upon which Red Fork deposition occurred. No evidence exists of valleys or channels cutting into shale underlying the Red Fork sandstone. Sedimentary structures in the Red Fork sandstone support interpretation of the stratigraphic sequence as a barrier-bar complex. Sandstone geometry and the nature of the encasing rocks are distinctly characteristic of transgressive barrier-bar systems.

  18. Chandra Observations of Faint LMXB's

    NASA Technical Reports Server (NTRS)

    Wilson, Colleen A.; Patel, S. K.; Kouveliotou, C.; vanderKlis, M.; Belloni, T.; Lewin, W. H. G.; Six, N. Frank (Technical Monitor)

    2002-01-01

    There exists a group of persistently faint galactic X-ray sources that based on their location in the galaxy, high Lx/Lopt, association with X-ray bursts, and absence of X-ray pulsations are thought to be low-mass X-ray binaries (LMXBs). We present results from Chandra observations for 7 of these systems: 1708-409, 1711-339, 1735-269, 1736-297, 1746-331, 1746.7-3224, and 1812-12. Improved locations for all sources, excluding 1736-297 and 1746-331 (which were not detected) are presented. Our observations are consistent with previously reported transient behavior of 1736-297, 1746-331, and 1711-339 (which we detect in one of two observations). Energy and power spectra are presented for 1735-269, 1711-339, and 1746.7-3224. The energy spectra are hard, consistent with typical faint LMXB spectra. Further, we present a newly discovered source, a very faint, soft, source, separated by 2.7' from 1746.7-3224.

  19. First ancient DNA sequences from the Late Pleistocene red deer (Cervus elaphus) in the Crimea, Ukraine

    NASA Astrophysics Data System (ADS)

    Stanković, Ana; Nadachowski, Adam; Doan, Karolina; Stefaniak, Krzysztof; Baca, Mateusz; Socha, Paweł; Wegleński, Piotr; Ridush, Bogdan

    2010-05-01

    The Late Pleistocene has been a period of significant population and species turnover and extinctions among the large mammal fauna. Massive climatic and environmental changes during Pleistocene significantly influenced the distribution and also genetic diversity of plants and animals. The model of glacial refugia and habitat contraction to southern peninsulas in Europe as areas for the survival of temperate animal species during unfavourable Pleistocene glaciations is at present widely accepted. However, both molecular data and the fossil record indicate the presence of northern and perhaps north-eastern refugia in Europe. In recent years, much new palaeontological data have been obtained in the Crimean Peninsula, Ukraine, following extensive investigations. The red deer (Cervus elaphus) samples for aDNA studies were collected in Emine-Bair-Khosar Cave, situated on the north edge of Lower Plateau of the Chatyrdag Massif (Crimean Mountains). The cave is a vertical shaft, which functioned as a huge mega-trap over a long period of time (probably most of the Pleistocene). The bone assemblages provided about 5000 bones belonging to more than 40 species. The C. elaphus bones were collected from three different stratigraphical levels, radiocarbon dated by accelerator mass spectrometry (AMS) method. The bone fragments of four specimens of red deer were used for the DNA isolation and analysis. The mtDNA (Cytochome b) was successfully isolated from three bone fragments and the cytochrome b sequences were amplified by multiplex PCR. The sequences obtained so far allowed for the reconstruction of only preliminary phylogenetic trees. A fragment of metatarsus from level dated to ca. 48,500±2,000 years BP, yielded a sequence of 513 bp, allowing to locate the specimen on the phylogenetic tree within modern C. elaphus specimens from southern and middle Europe. The second bone fragment, a fragment of mandible, collected from level dated approximately to ca. 33,500±400 years BP

  20. The far infra-red SEDs of main sequence and starburst galaxies

    NASA Astrophysics Data System (ADS)

    Cowley, William I.; Béthermin, Matthieu; del P. Lagos, Claudia; Lacey, Cedric G.; Baugh, Carlton M.; Cole, Shaun

    2017-01-01

    We compare observed far infra-red/sub-millimetre (FIR/sub-mm) galaxy spectral energy distributions (SEDs) of massive galaxies (M⋆ ≳ 1010 h-1 M⊙) derived through a stacking analysis with predictions from a new model of galaxy formation. The FIR SEDs of the model galaxies are calculated using a self-consistent model for the absorption and re-emission of radiation by interstellar dust based on radiative transfer calculations and global energy balance arguments. Galaxies are selected based on their position on the specific star formation rate (sSFR) - stellar mass (M⋆) plane. We identify a main sequence of star-forming galaxies in the model, i.e. a well defined relationship between sSFR and M⋆, up to redshift z ˜ 6. The scatter of this relationship evolves such that it is generally larger at higher stellar masses and higher redshifts. There is remarkable agreement between the predicted and observed average SEDs across a broad range of redshifts (0.5 ≲ z ≲ 4) for galaxies on the main sequence. However, the agreement is less good for starburst galaxies at z ≳ 2, selected here to have elevated sSFRs>10 × the main sequence value. We find that the predicted average SEDs are robust to changing the parameters of our dust model within physically plausible values. We also show that the dust temperature evolution of main sequence galaxies in the model is driven by star formation on the main sequence being more burst-dominated at higher redshifts.

  1. Comprehensive red blood cell and platelet antigen prediction from whole genome sequencing: proof of principle

    PubMed Central

    Westhoff, Connie M.; Uy, Jon Michael; Aguad, Maria; Smeland‐Wagman, Robin; Kaufman, Richard M.; Rehm, Heidi L.; Green, Robert C.; Silberstein, Leslie E.

    2015-01-01

    BACKGROUND There are 346 serologically defined red blood cell (RBC) antigens and 33 serologically defined platelet (PLT) antigens, most of which have known genetic changes in 45 RBC or six PLT genes that correlate with antigen expression. Polymorphic sites associated with antigen expression in the primary literature and reference databases are annotated according to nucleotide positions in cDNA. This makes antigen prediction from next‐generation sequencing data challenging, since it uses genomic coordinates. STUDY DESIGN AND METHODS The conventional cDNA reference sequences for all known RBC and PLT genes that correlate with antigen expression were aligned to the human reference genome. The alignments allowed conversion of conventional cDNA nucleotide positions to the corresponding genomic coordinates. RBC and PLT antigen prediction was then performed using the human reference genome and whole genome sequencing (WGS) data with serologic confirmation. RESULTS Some major differences and alignment issues were found when attempting to convert the conventional cDNA to human reference genome sequences for the following genes: ABO, A4GALT, RHD, RHCE, FUT3, ACKR1 (previously DARC), ACHE, FUT2, CR1, GCNT2, and RHAG. However, it was possible to create usable alignments, which facilitated the prediction of all RBC and PLT antigens with a known molecular basis from WGS data. Traditional serologic typing for 18 RBC antigens were in agreement with the WGS‐based antigen predictions, providing proof of principle for this approach. CONCLUSION Detailed mapping of conventional cDNA annotated RBC and PLT alleles can enable accurate prediction of RBC and PLT antigens from whole genomic sequencing data. PMID:26634332

  2. Fainting

    MedlinePlus

    ... usually because changes in the nervous system and circulatory system cause a temporary drop in the amount of ... a lot of changes, including changes in the circulatory system. This leads to low blood pressure that may ...

  3. Fainting

    MedlinePlus

    ... usually because changes in the nervous system and circulatory_system cause a temporary drop in the amount of ... a lot of changes, including changes in the circulatory system. This leads to low blood pressure that may ...

  4. Faintness

    MedlinePlus

    ... yourself? About Stephen J. Schueler, M.D News Advertising How It Works FAQ for Consumers FAQ for Physicians Testimonials Site Map Terms of Use Contact Us FreeMD is provided for information purposes only and should not be used as a ...

  5. HUBBLE'S SEARCH FOR FAINT FIELD STARS IN GALACTIC HALO

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Left A NASA Hubble Space Telescope image of a randomly selected area of sky taken to search for faint red stars that might constitute dark matter in our Milky Way Galaxy. (Dark matter is material of an unknown type that makes up most of the mass of our galaxy). If the dark matter in our Galaxy was made of faint red stars -- as many scientists have previously conjectured -- then about 38 such stars should have been visible in this HST image. The simulated stars (diamond-shaped symbols), based on theoretical calculations, illustrate what scientists would have seen if the dark matter were locked-up in faint red stars. These surprising results rule out dim stars as an explanation for dark matter in our Galaxy. Right The unmodified HST image shows the region is actually so devoid of stars that far more distant background galaxies can easily be seen. The field is in the constellation Eridanus, far outside the plane of our Milky Way Galaxy. This region was chosen to highlight stars in the galactic halo, where dark matter exists, and to avoid the contribution of faint stars in the plane of the Galaxy. Technical Information: The image was constructed from seven exposures totaling almost three hours of searching by HST. The field shown is about 1.5 arc-minutes across. The image was taken in near-infrared light (814 nm) with the Wide Field Planetary Camera 2, on Feb 8, 1994. This observation is part of the HST parallel observing program. Credit: J Bahcall, Institute for Advance Study, Princeton and NASA

  6. HUBBLE'S SEARCH FOR FAINT FIELD STARS IN GALACTIC HALO

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Left A NASA Hubble Space Telescope image of a randomly selected area of sky taken to search for faint red stars that might constitute dark matter in our Milky Way Galaxy. (Dark matter is material of an unknown type that makes up most of the mass of our galaxy). If the dark matter in our Galaxy was made of faint red stars -- as many scientists have previously conjectured -- then about 38 such stars should have been visible in this HST image. The simulated stars (diamond-shaped symbols), based on theoretical calculations, illustrate what scientists would have seen if the dark matter were locked-up in faint red stars. These surprising results rule out dim stars as an explanation for dark matter in our Galaxy. Right The unmodified HST image shows the region is actually so devoid of stars that far more distant background galaxies can easily be seen. The field is in the constellation Eridanus, far outside the plane of our Milky Way Galaxy. This region was chosen to highlight stars in the galactic halo, where dark matter exists, and to avoid the contribution of faint stars in the plane of the Galaxy. Technical Information: The image was constructed from seven exposures totaling almost three hours of searching by HST. The field shown is about 1.5 arc-minutes across. The image was taken in near-infrared light (814 nm) with the Wide Field Planetary Camera 2, on Feb 8, 1994. This observation is part of the HST parallel observing program. Credit: J Bahcall, Institute for Advance Study, Princeton and NASA

  7. Faint warm debris disks around nearby bright stars explored by AKARI and IRSF

    NASA Astrophysics Data System (ADS)

    Ishihara, Daisuke; Takeuchi, Nami; Kobayashi, Hiroshi; Nagayama, Takahiro; Kaneda, Hidehiro; Inutsuka, Shu-ichiro; Fujiwara, Hideaki; Onaka, Takashi

    2017-05-01

    Context. Debris disks are important observational clues for understanding planetary-system formation process. In particular, faint warm debris disks may be related to late planet formation near 1 au. A systematic search of faint warm debris disks is necessary to reveal terrestrial planet formation. Aims: Faint warm debris disks show excess emission that peaks at mid-IR wavelengths. Thus we explore debris disks using the AKARI mid-IR all-sky point source catalog (PSC), a product of the second generation unbiased IR all-sky survey. Methods: We investigate IR excess emission for 678 isolated main-sequence stars for which there are 18 μm detections in the AKARI mid-IR all-sky catalog by comparing their fluxes with the predicted fluxes of the photospheres based on optical to near-IR fluxes and model spectra. The near-IR fluxes are first taken from the 2MASS PSC. However, 286 stars with Ks < 4.5 in our sample have large flux errors in the 2MASS photometry due to saturation. Thus we have measured accurate J, H, and Ks band fluxes, applying neutral density (ND) filters for Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS) on IRSF, the φ1.4 m near-IR telescope in South Africa, and improved the flux accuracy from 14% to 1.8% on average. Results: We identified 53 debris-disk candidates including eight new detections from our sample of 678 main-sequence stars. The detection rate of debris disks for this work is 8%, which is comparable with those in previous works by Spitzer and Herschel. Conclusions: The importance of this study is the detection of faint warm debris disks around nearby field stars. At least nine objects have a large amount of dust for their ages, which cannot be explained by the conventional steady-state collisional cascade model. The full version of Table 2 is 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/601/A72

  8. A Photometric redshift galaxy catalog from the Red-Sequence Cluster Survey

    SciTech Connect

    Hsieh, Bau-Ching; Yee, H.K.C.; Lin, H.; Gladders, M.D.; /Carnegie Inst. Observ.

    2005-02-01

    The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the z' and R{sub c} bands for 90 square degrees of sky, and supplemental V and B data have been obtained for 33.6 deg{sup 2}. They compile a photometric redshift catalog from these 4-band data by utilizing the empirical quadratic polynomial photometric redshift fitting technique in combination with CNOC2 and GOODS/HDF-N redshift data. The training set includes 4924 spectral redshifts. The resulting catalog contains more than one million galaxies with photometric redshifts < 1.5 and R{sub c} < 24, giving an rms scatter {delta}({Delta}z) < 0.06 within the redshift range 0.2 < z < 0.5 and {sigma}({Delta}z) < 0.11 for galaxies at 0.0 < z < 1.5. They describe the empirical quadratic polynomial photometric redshift fitting technique which they use to determine the relation between red-shift and photometry. A kd-tree algorithm is used to divide up the sample to improve the accuracy of the catalog. They also present a method for estimating the photometric redshift error for individual galaxies. They show that the redshift distribution of the sample is in excellent agreement with smaller and much deeper photometric and spectroscopic redshift surveys.

  9. Determination of mitochondrial cytochrome B gene sequence for red deer (Cervus elaphus) and the differentiation of closely related deer meats.

    PubMed

    Matsunaga, T; Chikuni, K; Tanabe, R; Muroya, S; Nakai, H; Shibata, K; Yamada, J; Shinmura, Y

    1998-08-01

    The cytochrome b gene sequence for red deer was determined using the Dye Terminator Cycle Sequencing method and used for identification of deer meat in meat and meat products. Red deer showed a similarity of 94.1, 84.0, 81.1, 85.5 and 85.6% to sika deer (Cervus nippon), bovine, pigs, sheep and goats, respectively. To differentiate the deer meat, oligonucleotide primers RD-1(5'-TCATCGCAGCACTCGCTATAGTACACT-3'), RD-2(5'-ATCTCCAAGTAGGTCTGGTGCGAATAA-3') were designed for the region of the cytochrome b gene of red deer. The PCR amplified 194 bp fragments from red and sika deer, but no fragments from bovine, pig, chicken, sheep, goat, horse and rabbit DNA. Although cooking the meats reduced the PCR products, red deer could still be detected in meat heated at 120 °C. To discriminate between red and sika deer, these PCR products were digested by a restriction enzyme (EcoRI,BamHI,ScaI) and analyzed by 4% agorose gel electrophoresis. As a result, the red deer fragment was digested by EcoRI to 67/127 bp fragments but not by BamHI and ScaI. The sika deer fragment was digested to 48/146 bp and 49/145 bp fragments with the two other enzymes, and thus it is possible to differentiate between the two kinds of deer from the digestion pattern of restriction enzymes.

  10. Draft Genome Sequence of Colletotrichum falcatum - A Prelude on Screening of Red Rot Pathogen in Sugarcane.

    PubMed

    Viswanathan, Rasappa; Prasanth, Chandrasekaran Naveen; Malathi, Palaniyandi; Sundar, Amalraj Ramesh

    2016-01-01

    Colletotrichum falcatum, a concealed fungal ascomycete causes red rot, which is a serious disease in sugarcane. It infects economically important stalk tissues, considered as store house of sugar in sugarcane. The study is to find genetic complexities of C. falcatum in establishing this as a stalk infecting pathogen and to decipher the unique lifestyle of this pathogen using NGS technology. We report the draft genome of C. falcatum of about 48.16 Mb in size with 12,270 genes. The genome sequences were compared with other fungal species which revealed that C. falcatum is closely related to C. graminicola and C.sublineola the causal organisms of anthracnose in maize and sorghum. These results brought a new revelation to explore the lifestyle of this unique pathogen which is specialized to infect sugarcane stalk tissues in detail.

  11. The Binary Mass Transfer Origin of the Red Blue Straggler Sequence in M30

    NASA Astrophysics Data System (ADS)

    Xin, Y.; Ferraro, F. R.; Lu, P.; Deng, L.; Lanzoni, B.; Dalessandro, E.; Beccari, G.

    2015-03-01

    Two separated sequences of blue straggler stars (BSSs) have been revealed by Ferraro et al. in the color-magnitude diagram (CMD) of the Milky Way globular cluster M30. Their presence has been suggested to be related to the two BSS formation channels (namely, collisions and mass transfer in close binaries) operating within the same stellar system. The blue sequence was indeed found to be well reproduced by collisional BSS models. In contrast, no specific models for mass-transfer BSSs were available for an old stellar system like M30. Here we present binary evolution models, including case-B mass transfer and binary merging, specifically calculated for this cluster. We discuss in detail the evolutionary track of a 0.9 + 0.5 M ⊙ binary, which spends approximately 4 Gyr in the BSS region of the CMD of a 13 Gyr old cluster. We also run Monte Carlo simulations to study the distribution of mass-transfer BSSs in the CMD and to compare it with the observational data. Our results show that (1) the color and magnitude distribution of synthetic mass-transfer BSSs defines a strip in the CMD that nicely matches the observed red-BSS sequence, thus providing strong support to the mass-transfer origin for these stars; (2) the CMD distribution of synthetic BSSs never attains the observed location of the blue-BSS sequence, thus reinforcing the hypothesis that the latter formed through a different channel (likely collisions); (3) most (~60%) of the synthetic BSSs are produced by mass-transfer models, while the remaining <40% requires the contribution from merger models.

  12. rbcL sequences reveal multiple cryptic introductions of the Japanese red alga Polysiphonia harveyi.

    PubMed

    McIvor, L; Maggs, C A; Provan, J; Stanhope, M J

    2001-04-01

    In Europe, the last 20 years have seen a spectacular increase in accidental introductions of marine species, but it has recently been suggested that both the actual number of invaders and their impacts have been seriously underestimated because of the prevalence of sibling species in marine habitats. The red alga Polysiphonia harveyi is regarded as an alien in the British Isles and Atlantic Europe, having appeared in various locations there during the past 170 years. Similar or conspecific populations are known from Atlantic North America and Japan. To choose between three competing hypotheses concerning the origin of P. harveyi in Europe, we employed rbcL sequence analysis in conjunction with karyological and interbreeding data for samples and isolates of P. harveyi and various congeners from the Pacific and North Atlantic Oceans. All cultured isolates of P. harveyi were completely interfertile, and there was no evidence of polyploidy or aneuploidy. Thus, this biological species is both morphologically and genetically variable: intraspecific rbcL divergences of up to 2.1% are high even for red algae. Seven rbcL haplotypes were identified. The four most divergent haplotypes were observed in Japanese samples from Hokkaido and south-central Honshu, which are linked by hypothetical 'missing' haplotypes that may be located in northern Honshu. These data are consistent with Japan being the centre of diversity and origin for P. harveyi. Two non-Japanese lineages were linked to Hokkaido and Honshu, respectively. A single haplotype was found in all North Atlantic and Mediterranean accessions, except for North Carolina, where the haplotype found was the same as that invading in New Zealand and California. The introduction of P. harveyi into New Zealand has gone unnoticed because P. strictissima is a morphologically indistinguishable native sibling species. The sequence divergence between them is 4-5%, greater than between some morphologically distinct red algal species. Two

  13. The faint quasar luminosity function

    NASA Technical Reports Server (NTRS)

    Kron, Richard G.; Bershady, Matthew A.; Munn, Jeffrey A.; Smetanka, John J.; Majewski, Steven; Koo, David C.

    1991-01-01

    Preliminary results of an expanded program to determine the faint-quasar luminosity function are described. Quasars have been selected in four fields totaling 1.2 sq deg from four-band photometry. Out of a total of 130 quasars with good spectroscopy, 37 have J greater than 21.5 and 46 have F greater than 21.0. The spectroscopic sample is representative of all of the color-selected candidates. An estimate of the luminosity function as a function of redshift is derived.

  14. Novel mutations in patients with hereditary red blood cell membrane disorders using next-generation sequencing.

    PubMed

    He, Yunyan; Jia, Siyuan; Dewan, Roma Kajal; Liao, Ning

    2017-09-05

    To diagnose and investigate the genotype-phenotype relationship in intractable hereditary red blood cell (RBC) membrane cases, we have utilized next-generation sequencing (NGS) to develop a high-throughput, highly sensitive assay. Three unrelated families including 15 individuals were analysed with a panel interrogating 600 genes related to haematopathy disorders. Where possible, inheritance patterns of pathogenic mutations were determined by sequencing the relatives. We identified 2 novel mutations in ANK1 (Y216X and E142X) responsible for hereditary spherocytosis (HS) that were stop-gain single nucleotide variants (SNVs). Furthermore, a novel SPTA1 mutation (H54P) was identified; it is a nonsynonymous SNV and is associated with hereditary elliptocytosis (HE). In addition, patients who also carried erythropoiesis gene mutations showed more severe disease phenotype. The NGS panel provides a fast and accurate method for molecular diagnosis in patients with intractable hereditary RBC membrane disorders. An approach integrating medical history, clinical and molecular testing, and pedigree analysis is beneficial for these patients and families. Copyright © 2017. Published by Elsevier B.V.

  15. Extracellular DNA amplicon sequencing reveals high levels of benthic eukaryotic diversity in the central Red Sea.

    PubMed

    Pearman, John K; Irigoien, Xabier; Carvalho, Susana

    2016-04-01

    The present study aims to characterize the benthic eukaryotic biodiversity patterns at a coarse taxonomic level in three areas of the central Red Sea (a lagoon, an offshore area in Thuwal and a shallow coastal area near Jeddah) based on extracellular DNA. High-throughput amplicon sequencing targeting the V9 region of the 18S rRNA gene was undertaken for 32 sediment samples. High levels of alpha-diversity were detected with 16,089 operational taxonomic units (OTUs) being identified. The majority of the OTUs were assigned to Metazoa (29.2%), Alveolata (22.4%) and Stramenopiles (17.8%). Stramenopiles (Diatomea) and Alveolata (Ciliophora) were frequent in a lagoon and in shallower coastal stations, whereas metazoans (Arthropoda: Maxillopoda) were dominant in deeper offshore stations. Only 24.6% of total OTUs were shared among all areas. Beta-diversity was generally lower between the lagoon and Jeddah (nearshore) than between either of those and the offshore area, suggesting a nearshore-offshore biodiversity gradient. The current approach allowed for a broad-range of benthic eukaryotic biodiversity to be analysed with significantly less labour than would be required by other traditional taxonomic approaches. Our findings suggest that next generation sequencing techniques have the potential to provide a fast and standardised screening of benthic biodiversity at large spatial and temporal scales. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The Red Sequence at Birth in the Galaxy Cluster Cl J1449+0856 at z = 2

    NASA Astrophysics Data System (ADS)

    Strazzullo, V.; Daddi, E.; Gobat, R.; Valentino, F.; Pannella, M.; Dickinson, M.; Renzini, A.; Brammer, G.; Onodera, M.; Finoguenov, A.; Cimatti, A.; Carollo, C. M.; Arimoto, N.

    2016-12-01

    We use Hubble Space Telescope/WFC3 imaging to study the red population in the IR-selected, X-ray detected, low-mass cluster Cl J1449+0856 at z = 2, one of the few bona fide established clusters discovered at this redshift, and likely a typical progenitor of an average massive cluster today. This study explores the presence and significance of an early red sequence in the core of this structure, investigating the nature of red-sequence galaxies, highlighting environmental effects on cluster galaxy populations at high redshift, and at the same time underlining similarities and differences with other distant dense environments. Our results suggest that the red population in the core of Cl J1449+0856 is made of a mixture of quiescent and dusty star-forming galaxies, with a seedling of the future red sequence already growing in the very central cluster region, and already characterizing the inner cluster core with respect to lower-density environments. On the other hand, the color-magnitude diagram of this cluster is definitely different from that of lower-redshift z ≲ 1 clusters, as well as of some rare particularly evolved massive clusters at similar redshift, and it is suggestive of a transition phase between active star formation and passive evolution occurring in the protocluster and established lower-redshift cluster regimes.

  17. High-Throughput Sequencing and De Novo Assembly of Red and Green Forms of the Perilla frutescens var. crispa Transcriptome

    PubMed Central

    Fukushima, Atsushi; Nakamura, Michimi; Suzuki, Hideyuki; Saito, Kazuki; Yamazaki, Mami

    2015-01-01

    Perilla frutescens var. crispa (Labiatae) has two chemo-varietal forms, i.e. red and green forms of perilla, that differ in the production of anthocyanins. To facilitate molecular biological and biochemical studies in perilla-specialized metabolism we used Illumina RNA-sequencing technology in our comprehensive comparison of the transcriptome map of the leaves of red and green forms of perilla. Sequencing generated over 1.2 billion short reads with an average length of 101 nt. De novo transcriptome assembly yielded 47,788 and 47,840 unigenes in the red and green forms of perilla plants, respectively. Comparison of the assembled unigenes and existing perilla cDNA sequences showed highly reliable alignment. All unigenes were annotated with gene ontology (GO) and Enzyme Commission numbers and entered into the Kyoto Encyclopedia of Genes and Genomes. We identified 68 differentially expressed genes (DEGs) in red and green forms of perilla. GO enrichment analysis of the DEGs showed that genes involved in the anthocyanin metabolic process were enriched. Differential expression analysis revealed that the transcript level of anthocyanin biosynthetic unigenes encoding flavonoid 3’-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase was significantly higher in red perilla, while the transcript level of unigenes encoding limonene synthase was significantly higher in green perilla. Our data serve as a basis for future research on perilla bio-engineering and provide a shortcut for the characterization of new functional genes in P. frutescens. PMID:26070213

  18. High-Throughput Sequencing and De Novo Assembly of Red and Green Forms of the Perilla frutescens var. crispa Transcriptome.

    PubMed

    Fukushima, Atsushi; Nakamura, Michimi; Suzuki, Hideyuki; Saito, Kazuki; Yamazaki, Mami

    2015-01-01

    Perilla frutescens var. crispa (Labiatae) has two chemo-varietal forms, i.e. red and green forms of perilla, that differ in the production of anthocyanins. To facilitate molecular biological and biochemical studies in perilla-specialized metabolism we used Illumina RNA-sequencing technology in our comprehensive comparison of the transcriptome map of the leaves of red and green forms of perilla. Sequencing generated over 1.2 billion short reads with an average length of 101 nt. De novo transcriptome assembly yielded 47,788 and 47,840 unigenes in the red and green forms of perilla plants, respectively. Comparison of the assembled unigenes and existing perilla cDNA sequences showed highly reliable alignment. All unigenes were annotated with gene ontology (GO) and Enzyme Commission numbers and entered into the Kyoto Encyclopedia of Genes and Genomes. We identified 68 differentially expressed genes (DEGs) in red and green forms of perilla. GO enrichment analysis of the DEGs showed that genes involved in the anthocyanin metabolic process were enriched. Differential expression analysis revealed that the transcript level of anthocyanin biosynthetic unigenes encoding flavonoid 3'-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase was significantly higher in red perilla, while the transcript level of unigenes encoding limonene synthase was significantly higher in green perilla. Our data serve as a basis for future research on perilla bio-engineering and provide a shortcut for the characterization of new functional genes in P. frutescens.

  19. The Faint Young Sun and Faint Young Stars Paradox

    NASA Astrophysics Data System (ADS)

    Martens, Petrus C.

    2017-10-01

    The purpose of this paper is to explore a resolution for the Faint Young Sun Paradox that has been mostly rejected by the community, namely the possibility of a somewhat more massive young Sun with a large mass loss rate sustained for two to three billion years. This would make the young Sun bright enough to keep both the terrestrial and Martian oceans from freezing, and thus resolve the paradox. It is found that a large and sustained mass loss is consistent with the well observed spin-down rate of Sun-like stars, and indeed may be required for it. It is concluded that a more massive young Sun must be considered a plausible hypothesis.

  20. Temporal sequence of major biochemical events during Blood Bank storage of packed red blood cells

    PubMed Central

    Karon, Brad S.; van Buskirk, Camille M.; Jaben, Elizabeth A.; Hoyer, James D.; Thomas, David D.

    2012-01-01

    Background. We used sensitive spectroscopic techniques to measure changes in Band 3 oligomeric state during storage of packed red blood cells (RBC); these changes were compared to metabolic changes, RBC morphology, cholesterol and membrane protein loss, phospholipid reorganisation of the RBC membrane, and peroxidation of membrane lipid. The aim of the study was to temporally sequence major biochemical events occurring during cold storage, in order to determine which changes may underlie the structural defects in stored RBC. Materials and methods. Fifteen RBC units were collected from normal volunteers and stored under standard blood bank conditions; both metabolic changes and lipid parameters were measured by multiple novel assays including a new mass spectrometric measurement of isoprostane (lipid peroxidation) and flow cytometric assessment of CD47 expression. Band 3 oligomeric state was assessed by time-resolved phosphorescence anisotropy, and RBC morphology by microscopy of glutaraldehyde-fixed RBC. Results. Extracellular pH decreased and extracellular potassium increased rapidly during cold storage. Band 3 on the RBC membrane aggregated into large oligomers early in the storage period and coincident with changes in RBC morphology. Membrane lipid changes, including loss of unesterified cholesterol, lipid peroxidation and expression of CD47, also changed early during the storage period. In contrast loss of acetylcholinesterase activity and haemolysis of RBC occurred late during storage. Discussion. Our results demonstrate that changes in the macromolecular organisation of membrane proteins on the RBC occur early in storage and suggest that lipid peroxidation and/or oxidative damage to the membrane are responsible for irreversible morphological changes and loss of function during red cell storage. PMID:22507860

  1. Freeze, flight, fight, fright, faint: adaptationist perspectives on the acute stress response spectrum.

    PubMed

    Bracha, H Stefan

    2004-09-01

    This article reviews the existing evolutionary perspectives on the acute stress response habitual faintness and blood-injection-injury type-specific phobia (BIITS phobia). In this article, an alternative evolutionary perspective, based on recent advances in evolutionary psychology, is proposed. Specifically, that fear-induced faintness (eg, fainting following the sight of a syringe, blood, or following a trivial skin injury) is a distinct Homo sapiens-specific extreme-stress survival response to an inescapable threat. The article suggests that faintness evolved in response to middle paleolithic intra-group and inter-group violence (of con-specifics) rather than as a pan-mammalian defense response, as is presently assumed. Based on recent literature, freeze, flight, fight, fright, faint provides a more complete description of the human acute stress response sequence than current descriptions. Faintness, one of three primary physiological reactions involved in BIITS phobia, is extremely rare in other phobias. Since heritability estimates are higher for faintness than for fears or phobias, the author suggests that trait-faintness may be a useful complement to trait-anxiety as an endophenotype in research on the human fear circuitry. Some implications for the forthcoming Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition as well as for clinical, health services, and transcriptomic research are briefly discussed.

  2. Draft Genome Sequences of Semiconstitutive Red, Dry, and Rough Biofilm-Forming Commensal and Uropathogenic Escherichia coli Isolates

    PubMed Central

    Cimdins, Annika; Lüthje, Petra; Li, Fengyang; Ahmad, Irfan; Brauner, Annelie

    2017-01-01

    ABSTRACT Strains of Escherichia coli exhibit diverse biofilm formation capabilities. E. coli K-12 expresses the red, dry, and rough (rdar) morphotype below 30°C, whereas clinical isolates frequently display the rdar morphotype semiconstitutively. We sequenced the genomes of eight E. coli strains to subsequently investigate the molecular basis of semiconstitutive rdar morphotype expression. PMID:28126929

  3. Genome Sequences of Polyomaviruses from the Wild-Living Red Colobus (Piliocolobus badius) and Western Chimpanzee (Pan troglodytes verus).

    PubMed

    Ben Salem, Nicole; Leendertz, Fabian H; Ehlers, Bernhard

    2016-10-13

    We identified with PCR and sequencing the full genomes of the recently discovered Pan troglodytes verus polyomavirus 8 and Piliocolobus badius polyomavirus 2 in a western chimpanzee and a western red colobus free-ranging in Taï National Park of Côte d'Ivoire. Copyright © 2016 Ben Salem et al.

  4. Survey on viral pathogens in wild red foxes (Vulpes vulpes) in Germany with emphasis on parvoviruses and analysis of a DNA sequence from a red fox parvovirus.

    PubMed Central

    Truyen, U.; Müller, T.; Heidrich, R.; Tackmann, K.; Carmichael, L. E.

    1998-01-01

    The seroprevalence of canine parvovirus (CPV), canine distemper virus (CDV), canine adenovirus (CAV) and canine herpesvirus (CHV) infections in red foxes (Vulpes vulpes) was determined in fox sera collected between 1991 and 1995. A total of 500 sera were selected and the seroprevalences were estimated to be 13% (65 of 500 sera) for CPV, 4.4% (17 of 383 sera) for CDV, 35% (17 of 485 sera) for CAV, and 0.4% (2 of 485 sera) for CHV, respectively. No statistically significant differences were observed between the two (rural and suburban) areas under study. Parvovirus DNA sequences were amplified from tissues of free-ranging foxes and compared to those of prototype viruses from dogs and cats. We report here a parvovirus sequence indicative of a true intermediate between the feline panleukopenia virus-like viruses and the canine parvovirus-like viruses. The red fox parvoviral sequence, therefore, appears to represent a link between those viral groups. The DNA sequence together with a significant seroprevalence of parvovirus infections in foxes supports the hypothesis that the sudden emergence of canine parvovirus in the domestic dog population may have involved the interspecies transmission between wild and domestic carnivores. PMID:9825797

  5. Faint dwarfs in nearby groups

    SciTech Connect

    Speller, Ryan; Taylor, James E. E-mail: taylor@uwaterloo.ca

    2014-06-20

    The number and distribution of dwarf satellite galaxies remain a critical test of cold dark matter-dominated structure formation on small scales. Until recently, observational information about galaxy formation on these scales has been limited mainly to the Local Group. We have searched for faint analogues of Local Group dwarfs around nearby bright galaxies, using a spatial clustering analysis of the photometric catalog of the Sloan Digital Sky Survey (SDSS) Data Release 8. Several other recent searches of SDSS have detected clustered satellite populations down to Δm{sub r} ≡ (m{sub r,} {sub sat} – m{sub r,} {sub main}) ∼ 6-8, using photometric redshifts to reduce background contamination. SDSS photometric redshifts are relatively imprecise, however, for faint and nearby galaxies. Instead, we use angular size to select potential nearby dwarfs and consider only the nearest isolated bright galaxies as primaries. As a result, we are able to detect an excess clustering signal from companions down to Δm{sub r} = 12, 4 mag fainter than most recent studies. We detect an overdensity of objects at separations <400 kpc, corresponding to about 4.6 ± 0.5 satellites per central galaxy, consistent with the satellite abundance expected from the Local Group, given our selection function. Although the sample of satellites detected is incomplete by construction, since it excludes the least and most compact dwarfs, this detection provides a lower bound on the average satellite luminosity function, down to luminosities corresponding to the faintest ''classical'' dwarfs of the Local Group.

  6. Globular Clusters for Faint Galaxies

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-07-01

    The origin of ultra-diffuse galaxies (UDGs) has posed a long-standing mystery for astronomers. New observations of several of these faint giants with the Hubble Space Telescope are now lending support to one theory.Faint-Galaxy MysteryHubble images of Dragonfly 44 (top) and DFX1 (bottom). The right panels show the data with greater contrast and extended objects masked. [van Dokkum et al. 2017]UDGs large, extremely faint spheroidal objects were first discovered in the Virgo galaxy cluster roughly three decades ago. Modern telescope capabilities have resulted in many more discoveries of similar faint galaxies in recent years, suggesting that they are a much more common phenomenon than we originally thought.Despite the many observations, UDGs still pose a number of unanswered questions. Chief among them: what are UDGs? Why are these objects the size of normal galaxies, yet so dim? There are two primary models that explain UDGs:UDGs were originally small galaxies, hence their low luminosity. Tidal interactions then puffed them up to the large size we observe today.UDGs are effectively failed galaxies. They formed the same way as normal galaxies of their large size, but something truncated their star formation early, preventing them from gaining the brightness that we would expect for galaxies of their size.Now a team of scientists led by Pieter van Dokkum (Yale University) has made some intriguing observations with Hubble that lend weight to one of these models.Globulars observed in 16 Coma-cluster UDGs by Hubble. The top right panel shows the galaxy identifications. The top left panel shows the derived number of globular clusters in each galaxy. [van Dokkum et al. 2017]Globulars GaloreVan Dokkum and collaborators imaged two UDGs with Hubble: Dragonfly 44 and DFX1, both located in the Coma galaxy cluster. These faint galaxies are both smooth and elongated, with no obvious irregular features, spiral arms, star-forming regions, or other indications of tidal interactions

  7. Characterization of 32 microsatellite loci for the Pacific red snapper, Lutjanus peru, through next generation sequencing.

    PubMed

    Paz-García, David A; Munguía-Vega, Adrián; Plomozo-Lugo, Tomas; Weaver, Amy Hudson

    2017-04-01

    We developed a set of hypervariable microsatellite markers for the Pacific red snapper (Lutjanus peru), an economically important marine fish for small-scale fisheries in the west coast of Mexico. We performed shotgun genome sequencing with the 454 XL titanium chemistry and used bioinformatic tools to search for perfect microsatellite loci. We selected 66 primer pairs that were synthesized and genotyped in an ABI PRISM 3730XL DNA sequencer in 32 individuals from the Gulf of California. We estimated levels of genetic diversity, deviations from linkage and Hardy-Weinberg equilibrium, estimated the frequency of null alleles and the probability of individual identity for the new markers. We reanalyzed 16 loci in 16 individuals to estimate genotyping error rates. Eighteen loci failed to amplify, 16 loci were discarded due to unspecific amplifications and 32 loci (14 tetranucleotide and 18 dinucleotide) were successfully scored. The average number of alleles per locus was 21 (±6.87, SD) and ranged from 8 to 34. The average observed and expected heterozygosities were 0.787 (±0.144 SD, range 0.250-0.935) and 0.909 (±0.122 SD, range 0.381-0.965), respectively. No significant linkage was detected. Eight loci showed deviations from Hardy-Weinberg equilibrium, and from these, four loci showed moderate null allele frequencies (0.104-0.220). The probability of individual identity for the new loci was 1.46(-62). Genotyping error rates averaged 9.58%. The new markers will be useful to investigate patterns of larval dispersal, metapopulation dynamics, fine-scale genetic structure and diversity aimed to inform the implementation of spatially explicit fisheries management strategies in the Gulf of California.

  8. Transgressive reef sequences of the Devonian Devils Gate Limestone, Red Hill, Nevada

    SciTech Connect

    Shapiro, R. . Dept. of Geological Sciences); Dehler, C. . Dept. of Geology); Flynn, J. . Dept. of Geology)

    1993-04-01

    The Devils Gate Limestone at Red Hill, Simpson Park Range, Eureka Co., Nevada is composed of several conformable transgressive sequences cropping out in a series of step-like cliffs 1--5 m high. The general sequence is as follows: (1) a 1--4 m thick in situ boundstone dominated by large, period rugosans, domical and stratiform stromatoporids and rare, 1--3 cm diameter oncolites. Most of the boundstone is composed of small, cylindrical fossils. Petrographic observation revealed them to be mostly Amphipora and Cladopora. The upper portions of these units are packstones composed of Amphipora/Cladopora and, to a lesser degree, small favositids, round stromatoporoids (3--4 cm diameter), and rip-up clasts. (2) These beds grade upward into a thinly laminated and/or cross-bedded unfossiliferous mudstone. (3) Stratigraphically above the mudstone or in contact with the packstone, is a cross-bedded and/or bioturbated wackestone containing fossils no greater than 2 mm. In thin section, the mottled reddish-grey wackestone is pelletal, with rare lenses of small crinoid columnals. Disarticulated brachiopod shells of low diversity are found near the tops of some of these layers. Community dominance in the reefal units alternates between Amphipora/Cladopora, colonial rugose, and stromatoporoids. Oncolite mounds are common in the uppermost unit. The typical reef succession consists of domical and digitate stromatoporoids growing on the upper surfaces of in place or disturbed, large rugosans, though the reverse has been noted. Tabulate corals encrusted by stromatoporoids are often found in the packstone. It is important to note that often these successions' can be attributed to juxtaposition along styolites.

  9. Chemical overprint on the natural remanent magnetization of a subtropical red soil sequence in the Bose Basin, southern China

    NASA Astrophysics Data System (ADS)

    Deng, Chenglong; Liu, Qingsong; Wang, Wei; Liu, Caicai

    2007-11-01

    We present a high-resolution paleomagnetic investigation of the subtropical red soil sequence at the Damei section, Bose Basin, southern China. Maghemite with low coercivities and fine-grained hematite with high coercivities but relatively low unblocking temperatures were identified as main carriers of the natural remanent magnetization (NRM). Strong chemical weathering occurring under subtropical climatic conditions in southern China led to a chemical remanent magnetization (CRM) overprint that is sufficiently strong to mask the primary NRM. Analysis of the Bose Basin soil sequence indicates that the CRM has a large lock-in depth (>4 m). This example shows that magnetostratigraphic studies on red soil sequences in subtropical-tropical southern China should be interpreted with caution.

  10. The Red Sequence of High-Redshift Clusters: A Comparison with Cosmological Galaxy Formation Models

    NASA Astrophysics Data System (ADS)

    Menci, N.

    2008-10-01

    We compare the results from a state-of-the-art semi-analytic model of galaxy formation with spectroscopic observations of the distant galaxy clusters observed in the range 1≲ z≲ 1.5. In our model we find that i) a well-defined, narrow red sequence (RS) is obtained already by z≈ 1.2; this is more populated than the field RS analogously to what observed and predicted at z=0; ii) the predicted RS colors and width have average values of 1 and 0.15, respectively, with a cluster-to-cluster variance. The width of the RS of cluster galaxy is 5-10 times lower than the corresponding field value; iii) The predicted distribution of stellar ages of RS galaxies at z=1.2 are peaked at the value τ=3.7 Gyr for both cluster and field; however, for the latter the distribution is significantly skewed toward lower ages. When compared with observations, the above findings show an overall consistency, although the average value ≈ 0.07 of the observed cluster RS width at z≈1.2 is smaller than the corresponding model central value. We discuss the physical origin and the significance of the above results in the framework of cosmological galaxy formation.

  11. Interpretation of colors of faint galaxies

    SciTech Connect

    Kron, R.G.

    1980-10-01

    We present new calculations for evolving light in galaxies which allow the color distribution expected for faint field galaxies to be computed. We normalize the expected counts to data in catalogs of bright galaxies, and find that an excellent fit to Kron's faint photometry can be achieved with a Friedmann model and no other special assumptions.

  12. Complete Sequence and Analysis of Plastid Genomes of Two Economically Important Red Algae: Pyropia haitanensis and Pyropia yezoensis

    PubMed Central

    Wang, Li; Mao, Yunxiang; Kong, Fanna; Li, Guiyang; Ma, Fei; Zhang, Baolong; Sun, Peipei; Bi, Guiqi; Zhang, Fangfang; Xue, Hongfan; Cao, Min

    2013-01-01

    Background Pyropia haitanensis and P. yezoensis are two economically important marine crops that are also considered to be research models to study the physiological ecology of intertidal seaweed communities, evolutionary biology of plastids, and the origins of sexual reproduction. This plastid genome information will facilitate study of breeding, population genetics and phylogenetics. Principal Findings We have fully sequenced using next-generation sequencing the circular plastid genomes of P. hatanensis (195,597 bp) and P. yezoensis (191,975 bp), the largest of all the plastid genomes of the red lineage sequenced to date. Organization and gene contents of the two plastids were similar, with 211–213 protein-coding genes (including 29–31 unknown-function ORFs), 37 tRNA genes, and 6 ribosomal RNA genes, suggesting a largest coding capacity in the red lineage. In each genome, 14 protein genes overlapped and no interrupted genes were found, indicating a high degree of genomic condensation. Pyropia maintain an ancient gene content and conserved gene clusters in their plastid genomes, containing nearly complete repertoires of the plastid genes known in photosynthetic eukaryotes. Similarity analysis based on the whole plastid genome sequences showed the distance between P. haitanensis and P. yezoensis (0.146) was much smaller than that of Porphyra purpurea and P. haitanensis (0.250), and P. yezoensis (0.251); this supports re-grouping the two species in a resurrected genus Pyropia while maintaining P. purpurea in genus Porphyra. Phylogenetic analysis supports a sister relationship between Bangiophyceae and Florideophyceae, though precise phylogenetic relationships between multicellular red alage and chromists were not fully resolved. Conclusions These results indicate that Pyropia have compact plastid genomes. Large coding capacity and long intergenic regions contribute to the size of the largest plastid genomes reported for the red lineage. Possessing the largest

  13. Complete sequence and analysis of plastid genomes of two economically important red algae: Pyropia haitanensis and Pyropia yezoensis.

    PubMed

    Wang, Li; Mao, Yunxiang; Kong, Fanna; Li, Guiyang; Ma, Fei; Zhang, Baolong; Sun, Peipei; Bi, Guiqi; Zhang, Fangfang; Xue, Hongfan; Cao, Min

    2013-01-01

    Pyropia haitanensis and P. yezoensis are two economically important marine crops that are also considered to be research models to study the physiological ecology of intertidal seaweed communities, evolutionary biology of plastids, and the origins of sexual reproduction. This plastid genome information will facilitate study of breeding, population genetics and phylogenetics. We have fully sequenced using next-generation sequencing the circular plastid genomes of P. hatanensis (195,597 bp) and P. yezoensis (191,975 bp), the largest of all the plastid genomes of the red lineage sequenced to date. Organization and gene contents of the two plastids were similar, with 211-213 protein-coding genes (including 29-31 unknown-function ORFs), 37 tRNA genes, and 6 ribosomal RNA genes, suggesting a largest coding capacity in the red lineage. In each genome, 14 protein genes overlapped and no interrupted genes were found, indicating a high degree of genomic condensation. Pyropia maintain an ancient gene content and conserved gene clusters in their plastid genomes, containing nearly complete repertoires of the plastid genes known in photosynthetic eukaryotes. Similarity analysis based on the whole plastid genome sequences showed the distance between P. haitanensis and P. yezoensis (0.146) was much smaller than that of Porphyra purpurea and P. haitanensis (0.250), and P. yezoensis (0.251); this supports re-grouping the two species in a resurrected genus Pyropia while maintaining P. purpurea in genus Porphyra. Phylogenetic analysis supports a sister relationship between Bangiophyceae and Florideophyceae, though precise phylogenetic relationships between multicellular red alage and chromists were not fully resolved. These results indicate that Pyropia have compact plastid genomes. Large coding capacity and long intergenic regions contribute to the size of the largest plastid genomes reported for the red lineage. Possessing the largest coding capacity and ancient gene content yet

  14. Complete mitochondrial genome sequence of a Hungarian red deer (Cervus elaphus hippelaphus) from high-throughput sequencing data and its phylogenetic position within the family Cervidae.

    PubMed

    Frank, Krisztián; Barta, Endre; Bana, Nóra Á; Nagy, János; Horn, Péter; Orosz, László; Stéger, Viktor

    2016-06-01

    Recently, there has been considerable interest in genetic differentiation in the Cervidae family. A common tool used to determine genetic variation in different species, breeds and populations is mitochondrial DNA analysis, which can be used to estimate phylogenetic relationships among animal taxa and for molecular phylogenetic evolution analysis. With the development of sequencing technology, more and more mitochondrial sequences have been made available in public databases, including whole mitochondrial DNA sequences. These data have been used for phylogenetic analysis of animal species, and for studies of evolutionary processes. We determined the complete mitochondrial genome of a Central European red deer, Cervus elaphus hippelaphus, from Hungary by a next generation sequencing technology. The mitochondrial genome is 16 354 bp in length and contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region, all of which are arranged similar as in other vertebrates. We made phylogenetic analyses with the new sequence and 76 available mitochondrial sequences of Cervidae, using Bos taurus mitochondrial sequence as outgroup. We used 'neighbor joining' and 'maximum likelihood' methods on whole mitochondrial genome sequences; the consensus phylogenetic trees supported monophyly of the family Cervidae; it was divided into two subfamilies, Cervinae and Capreolinae, and five tribes, Cervini, Muntiacini, Alceini, Odocoileini, and Capreolini. The evolutionary structure of the family Cervidae can be reconstructed by phylogenetic analysis based on whole mitochondrial genomes; which method could be used broadly in phylogenetic evolutionary analysis of animal taxa.

  15. Classification, Naming and Evolutionary History of Glycosyltransferases from Sequenced Green and Red Algal Genomes

    PubMed Central

    Ulvskov, Peter; Paiva, Dionisio Soares; Domozych, David; Harholt, Jesper

    2013-01-01

    The Archaeplastida consists of three lineages, Rhodophyta, Virideplantae and Glaucophyta. The extracellular matrix of most members of the Rhodophyta and Viridiplantae consists of carbohydrate-based or a highly glycosylated protein-based cell wall while the Glaucophyte covering is poorly resolved. In order to elucidate possible evolutionary links between the three advanced lineages in Archaeplastida, a genomic analysis was initiated. Fully sequenced genomes from the Rhodophyta and Virideplantae and the well-defined CAZy database on glycosyltransferases were included in the analysis. The number of glycosyltransferases found in the Rhodophyta and Chlorophyta are generally much lower then in land plants (Embryophyta). Three specific features exhibited by land plants increase the number of glycosyltransferases in their genomes: (1) cell wall biosynthesis, the more complex land plant cell walls require a larger number of glycosyltransferases for biosynthesis, (2) a richer set of protein glycosylation, and (3) glycosylation of secondary metabolites, demonstrated by a large proportion of family GT1 being involved in secondary metabolite biosynthesis. In a comparative analysis of polysaccharide biosynthesis amongst the taxa of this study, clear distinctions or similarities were observed in (1) N-linked protein glycosylation, i.e., Chlorophyta has different mannosylation and glucosylation patterns, (2) GPI anchor biosynthesis, which is apparently missing in the Rhodophyta and truncated in the Chlorophyta, (3) cell wall biosynthesis, where the land plants have unique cell wall related polymers not found in green and red algae, and (4) O-linked glycosylation where comprehensive orthology was observed in glycosylation between the Chlorophyta and land plants but not between the target proteins. PMID:24146880

  16. The Red Sequence of High-Redshift Clusters: A Comparison with Cosmological Galaxy Formation Models

    NASA Astrophysics Data System (ADS)

    Menci, N.; Rosati, P.; Gobat, R.; Strazzullo, V.; Rettura, A.; Mei, S.; Demarco, R.

    2008-10-01

    We compare the results from a state-of-the-art semianalytic model of galaxy formation with spectrophotometric observations of distant galaxy clusters observed in the range 0.8 <= z<= 1.3. We investigate the properties of their red sequence (RS) galaxies and compare them with those of the field at the same redshift. In our model we find that (1) a well-defined, narrow RS is obtained already by z ≈ 1.2; this is found to be more populated than the field RS, analogously to what is observed and predicted at z = 0; (2) the predicted U-V rest-frame colors and scatter of the cluster RS at z = 1.2 have average values of 1 and 0.15, respectively, with a cluster-to-cluster variance of ≈0.2 and ≈0.06, respectively. The scatter of the RS of cluster galaxies is ≈5 times smaller than the corresponding field value; (3) when the RS galaxies are considered, the mass growth histories of field and cluster galaxies at z ≈ 1.2 are similar, with 90% of the stellar mass of RS galaxies at z = 1.2 already formed at cosmic times t = 2.5 Gyr, and 50% at t = 1 Gyr; and (4) the predicted distribution of stellar ages of RS galaxies at z = 1.2 peaks at 3.7 Gyr for both cluster and field populations; however, for the latter the distribution is significantly skewed toward lower ages. When compared with observations, the above findings show an overall consistency, although the average value ΔU - V ≈ 0.07 of the observed cluster RS scatter at z ≈ 1.2 is smaller than the corresponding model central value. We discuss the physical origin and the significance of the above results in the framework of cosmological galaxy formation.

  17. Classification, naming and evolutionary history of glycosyltransferases from sequenced green and red algal genomes.

    PubMed

    Ulvskov, Peter; Paiva, Dionisio Soares; Domozych, David; Harholt, Jesper

    2013-01-01

    The Archaeplastida consists of three lineages, Rhodophyta, Virideplantae and Glaucophyta. The extracellular matrix of most members of the Rhodophyta and Viridiplantae consists of carbohydrate-based or a highly glycosylated protein-based cell wall while the Glaucophyte covering is poorly resolved. In order to elucidate possible evolutionary links between the three advanced lineages in Archaeplastida, a genomic analysis was initiated. Fully sequenced genomes from the Rhodophyta and Virideplantae and the well-defined CAZy database on glycosyltransferases were included in the analysis. The number of glycosyltransferases found in the Rhodophyta and Chlorophyta are generally much lower then in land plants (Embryophyta). Three specific features exhibited by land plants increase the number of glycosyltransferases in their genomes: (1) cell wall biosynthesis, the more complex land plant cell walls require a larger number of glycosyltransferases for biosynthesis, (2) a richer set of protein glycosylation, and (3) glycosylation of secondary metabolites, demonstrated by a large proportion of family GT1 being involved in secondary metabolite biosynthesis. In a comparative analysis of polysaccharide biosynthesis amongst the taxa of this study, clear distinctions or similarities were observed in (1) N-linked protein glycosylation, i.e., Chlorophyta has different mannosylation and glucosylation patterns, (2) GPI anchor biosynthesis, which is apparently missing in the Rhodophyta and truncated in the Chlorophyta, (3) cell wall biosynthesis, where the land plants have unique cell wall related polymers not found in green and red algae, and (4) O-linked glycosylation where comprehensive orthology was observed in glycosylation between the Chlorophyta and land plants but not between the target proteins.

  18. MULTIPLE HYDROXYCINNAMOYL TRANSFERASES FROM RED CLOVER DIFFER IN SEQUENCE, EXPRESSION PATTERN, AND ENZYMATIC ACTIVITY

    USDA-ARS?s Scientific Manuscript database

    Phenylpropanoid o-diphenols accumulate in tissues of many plants, functioning as defensive molecules and antioxidants. Red clover leaves accumulate high levels of two o-diphenols, phasalic acid [2-O-(caffeoyl)-L-malate, see Fig. 1] and clovamide [N-(caffeoyl)-L-DOPA]. In red clover, post-harvest oxi...

  19. Deep sequencing and proteomic analysis of the microRNA-induced silencing complex in human red blood cells.

    PubMed

    Azzouzi, Imane; Moest, Hansjoerg; Wollscheid, Bernd; Schmugge, Markus; Eekels, Julia J M; Speer, Oliver

    2015-05-01

    During maturation, erythropoietic cells extrude their nuclei but retain their ability to respond to oxidant stress by tightly regulating protein translation. Several studies have reported microRNA-mediated regulation of translation during terminal stages of erythropoiesis, even after enucleation. In the present study, we performed a detailed examination of the endogenous microRNA machinery in human red blood cells using a combination of deep sequencing analysis of microRNAs and proteomic analysis of the microRNA-induced silencing complex. Among the 197 different microRNAs detected, miR-451a was the most abundant, representing more than 60% of all read sequences. In addition, miR-451a and its known target, 14-3-3ζ mRNA, were bound to the microRNA-induced silencing complex, implying their direct interaction in red blood cells. The proteomic characterization of endogenous Argonaute 2-associated microRNA-induced silencing complex revealed 26 cofactor candidates. Among these cofactors, we identified several RNA-binding proteins, as well as motor proteins and vesicular trafficking proteins. Our results demonstrate that red blood cells contain complex microRNA machinery, which might enable immature red blood cells to control protein translation independent of de novo nuclei information. Copyright © 2015 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  20. Genome Sequence of Acidovorax avenae Strain T10_61 Associated with Sugarcane Red Stripe in Argentina

    PubMed Central

    Fontana, Cecilia A.; Bassi, Daniela; Puglisi, Edoardo; Salazar, Sergio M.; Vignolo, Graciela M.; Coccocelli, Pier S.

    2016-01-01

    Red stripe of sugarcane in Argentina is a bacterial disease caused by Acidovorax avenae. The genome sequence from the first isolate of this bacterium in Argentina is presented here. The draft genome of the A. avenae T10_61 strain contains 5,646,552 bp and has a G+C content of 68.6 mol%. PMID:26847889

  1. Genetic Linkage Maps of the Red Flour Beetle, Tribolium castaneum, Based on Bacterial Artificial Chromosomes and Expressed Sequence Tags

    PubMed Central

    Lorenzen, Marcé D.; Doyungan, Zaldy; Savard, Joel; Snow, Kathy; Crumly, Lindsey R.; Shippy, Teresa D.; Stuart, Jeffrey J.; Brown, Susan J.; Beeman, Richard W.

    2005-01-01

    A genetic linkage map was constructed in a backcross family of the red flour beetle, Tribolium castaneum, based largely on sequences from bacterial artificial chromosome (BAC) ends and untranslated regions from random cDNA's. In most cases, dimorphisms were detected using heteroduplex or single-strand conformational polymorphism analysis after specific PCR amplification. The map incorporates a total of 424 markers, including 190 BACs and 165 cDNA's, as well as 69 genes, transposon insertion sites, sequence-tagged sites, microsatellites, and amplified fragment-length polymorphisms. Mapped loci are distributed along 571 cM, spanning all 10 linkage groups at an average marker separation of 1.3 cM. This genetic map provides a framework for positional cloning and a scaffold for integration of the emerging physical map and genome sequence assembly. The map and corresponding sequences can be accessed through BeetleBase (http://www.bioinformatics.ksu.edu/BeetleBase/). PMID:15834150

  2. Faint CV Monitoring at CBA Pretoria

    NASA Astrophysics Data System (ADS)

    Monard, L. A. G. B.

    2006-05-01

    The regular monitoring of faint cataclysmic variables (CV) is one of five observing programs that are run at CBA Pretoria. It started off in 2002 with about 120 CVs and related objects in the program. The intention was to observe those targets as often as possible with unfiltered CCD. There were continuous additions of more CVs by digging deeper in the CV atlas, new finds, and reclassified stars while some were taken off the list. At the end of 2004 the number of CVs in the observing program exceeded 200. With only one telescope and one observer and so many other things to observe, the actual number of snapshot CV observations have been much less than hoped. Despite this, the program has shown to be very successful. Publications have been referring to reported findings from this program while even more publications resulted from observing campaigns (time resolved photometry) dedicated to CVs that were found in outburst by observations at CBA Pretoria. In most cases they were the first real-time outburst detection of that CV. The present paper will not deal with those published or alerted finds but will show observing results of other CVs from the list just to give an indication of the broader meaningfulness of such a program. A selection of fifteen light curves obtained after three years of monitoring will be shown and discussed. The choice of the 15 stars was based on their possible interest and the fact that they have been positively observed on most occasions, since they were mostly brighter than magnitude 18 CR (unfiltered with red zero-point).

  3. The UV-Optical Galaxy Color-Magnitude Diagram. III. Constraints on Evolution from the Blue to the Red Sequence

    NASA Astrophysics Data System (ADS)

    Martin, D. Christopher; Wyder, Ted K.; Schiminovich, David; Barlow, Tom A.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Neff, Susan G.; Seibert, Mark; Small, Todd; Welsh, Barry Y.; Bianchi, Luciana; Donas, José; Heckman, Timothy M.; Lee, Young-Wook; Madore, Barry F.; Milliard, Bruno; Rich, R. Michael; Szalay, Alex S.; Yi, Sukyoung K.

    2007-12-01

    We introduce a new quantity, the mass flux density of galaxies evolving from the blue sequence to the red sequence. We propose a simple technique for constraining this mass flux using the volume-corrected number density in the extinction-corrected UV-optical color-magnitude distribution, the stellar age indexes HδA and Dn(4000), and a simple prescription for spectral evolution using a quenched star formation history. We exploit the excellent separation of red and blue sequences in the NUV-r band Hess function. The final value we measure, ρT˙=0.033 Msolar yr-1 Mpc-3, is strictly speaking an upper limit due to the possible contributions of bursting, composite, and extincted galaxies. However, it compares favorably with estimates of the average mass flux that we make based on the red luminosity function evolution derived from the DEEP2 and COMBO-17 surveys, ρ˙R=+0.034 Msolar yr-1 Mpc-3. We find that the blue sequence mass has remained roughly constant since z=1 (ρB˙~=0.01 Msolar yr-1 Mpc-3, but the average on-going star formation of ρ˙SF~=0.037 Msolar yr-1 Mpc-3 over 0sequence. We explore the nature of the galaxies in the transition zone with particular attention to the frequency and impact of active galactic nuclei (AGNs). The AGN fraction peaks in the transition zone. We find circumstantial, albeit weak evidence that the quench rates are higher in higher luminosity AGNs.

  4. Food for the photometrists - Faint galaxies revealed

    NASA Astrophysics Data System (ADS)

    Malin, D. F.

    The advantages of photographic plates over CCD detectors for some types of astronomical photometry (uniformity over large areas and information-storage capacity) are discussed, and illustrated using images of faint galaxies and faint galactic structures. It is pointed out that the photographic amplification technique (Malin, 1978), although at present only qualitative, is much more time-efficient than digital scanning. Consideration is also given to the production of full-color images by superimposition of B, V, and R plates.

  5. THE RED-SEQUENCE CLUSTER SURVEY-2 (RCS-2): SURVEY DETAILS AND PHOTOMETRIC CATALOG CONSTRUCTION

    SciTech Connect

    Gilbank, David G.; Gladders, M. D.; Yee, H. K. C.; Hsieh, B. C.

    2011-03-15

    The second Red-sequence Cluster Survey (RCS-2) is a {approx}1000 deg{sup 2}, multi-color imaging survey using the square-degree imager, MegaCam, on the Canada-France-Hawaii Telescope. It is designed to detect clusters of galaxies over the redshift range 0.1 {approx}< z {approx}< 1. The primary aim is to build a statistically complete, large ({approx}10{sup 4}) sample of clusters, covering a sufficiently long redshift baseline to be able to place constraints on cosmological parameters via the evolution of the cluster mass function. Other main science goals include building a large sample of high surface brightness, strongly gravitationally lensed arcs associated with these clusters, and an unprecedented sample of several tens of thousands of galaxy clusters and groups, spanning a large range of halo mass, with which to study the properties and evolution of their member galaxies. This paper describes the design of the survey and the methodology for acquiring, reducing, and calibrating the data for the production of high-precision photometric catalogs. We describe the method for calibrating our griz imaging data using the colors of the stellar locus and overlapping Two Micron All Sky Survey photometry. This yields an absolute accuracy of <0.03 mag on any color and {approx}0.05 mag in the r-band magnitude, verified with respect to the Sloan Digital Sky Survey (SDSS). Our astrometric calibration is accurate to <<0.''3 from comparison with SDSS positions. RCS-2 reaches average 5{sigma} point-source limiting magnitudes of griz = [24.4, 24.3, 23.7, 22.8], approximately 1-2 mag deeper than the SDSS. Due to the queue-scheduled nature of the observations, the data are highly uniform and taken in excellent seeing, mostly FWHM {approx}< 0.''7 in the r band. In addition to the main science goals just described, these data form the basis for a number of other planned and ongoing projects (including the WiggleZ survey), making RCS-2 an important next-generation imaging survey.

  6. Testing Scaling Relations for Solar-like Oscillations from the Main Sequence to Red Giants Using Kepler Data

    NASA Astrophysics Data System (ADS)

    Huber, D.; Bedding, T. R.; Stello, D.; Hekker, S.; Mathur, S.; Mosser, B.; Verner, G. A.; Bonanno, A.; Buzasi, D. L.; Campante, T. L.; Elsworth, Y. P.; Hale, S. J.; Kallinger, T.; Silva Aguirre, V.; Chaplin, W. J.; De Ridder, J.; García, R. A.; Appourchaux, T.; Frandsen, S.; Houdek, G.; Molenda-Żakowicz, J.; Monteiro, M. J. P. F. G.; Christensen-Dalsgaard, J.; Gilliland, R. L.; Kawaler, S. D.; Kjeldsen, H.; Broomhall, A. M.; Corsaro, E.; Salabert, D.; Sanderfer, D. T.; Seader, S. E.; Smith, J. C.

    2011-12-01

    We have analyzed solar-like oscillations in ~1700 stars observed by the Kepler Mission, spanning from the main sequence to the red clump. Using evolutionary models, we test asteroseismic scaling relations for the frequency of maximum power (νmax), the large frequency separation (Δν), and oscillation amplitudes. We show that the difference of the Δν-νmax relation for unevolved and evolved stars can be explained by different distributions in effective temperature and stellar mass, in agreement with what is expected from scaling relations. For oscillation amplitudes, we show that neither (L/M) s scaling nor the revised scaling relation by Kjeldsen & Bedding is accurate for red-giant stars, and demonstrate that a revised scaling relation with a separate luminosity-mass dependence can be used to calculate amplitudes from the main sequence to red giants to a precision of ~25%. The residuals show an offset particularly for unevolved stars, suggesting that an additional physical dependency is necessary to fully reproduce the observed amplitudes. We investigate correlations between amplitudes and stellar activity, and find evidence that the effect of amplitude suppression is most pronounced for subgiant stars. Finally, we test the location of the cool edge of the instability strip in the Hertzsprung-Russell diagram using solar-like oscillations and find the detections in the hottest stars compatible with a domain of hybrid stochastically excited and opacity driven pulsation.

  7. The evolutionary paths among galaxy types on the Red Sequence at 0.3

    NASA Astrophysics Data System (ADS)

    Eliche-Moral, M. C.; Prieto, M.; Balcells, M.; Abreu, D.; Barro, G.; Cristóbal-Hornillos, D.; Domínguez Palmero, L.; Erwin, P.; Gallego, J.; Guzmán, R.; Hempel, A.; López-Sanjuan, C.; Pérez-González, P. G.; Zamorano, J.

    2013-05-01

    We have studied the main evolutionary paths among the galaxy types residing on the massive end of the Red Sequence and nearby locations on the Green Valley during the last ~9 Gyr. The morphological and star formation properties of a sample of these galaxies at 0.35×10^10 M_⊙ have been analysed. We present direct observational evidence for the first time of the existence of two main evolutionary paths among the different red galaxy types since z~1.5, which provide some clues on the nature of the processes that have governed the assembly of present-day massive quiescent galaxies. The results are in excellent agreement with the hierarchical evolutionary framework proposed in the Eliche-Moral et al. (2010) model. Data from SHARDS (one of the ESO/GTC Large Programmes approved in 2009A) will complement and improve the present findings, shedding some light into many of the still unsettled questions concerning the migration of galaxies from the Blue Cloud to the Red Sequence at z<1.5.

  8. Development and transferability of black and red raspberry microsatellite markers from short-read sequences

    USDA-ARS?s Scientific Manuscript database

    The advent of next-generation sequencing technologies has been a boon to the cost-effective development of molecular markers, particularly in non-model species. Here, we demonstrate the efficiency of microsatellite or simple sequence repeat (SSR) marker development from short-read sequences using th...

  9. SNP discovery and High Resolution Melting Analysis from massive transcriptome sequencing in the California red abalone Haliotis rufescens.

    PubMed

    Valenzuela-Muñoz, Valentina; Araya-Garay, José Miguel; Gallardo-Escárate, Cristian

    2013-06-01

    The California red abalone, Haliotis rufescens that belongs to the Haliotidae family, is the largest species of abalone in the world that has sustained the major fishery and aquaculture production in the USA and Mexico. This native mollusk has not been evaluated or assigned a conservation category even though in the last few decades it was heavily exploited until it disappeared in some areas along the California coast. In Chile, the red abalone was introduced in the 1970s from California wild abalone stocks for the purposes of aquaculture. Considering the number of years that the red abalone has been cultivated in Chile crucial genetic information is scarce and critical issues remain unresolved. This study reports and validates novel single nucleotide polymorphisms (SNP) markers for the red abalone H. rufescens using cDNA pyrosequencing. A total of 622 high quality SNPs were identified in 146 sequences with an estimated frequency of 1 SNP each 1000bp. Forty-five SNPs markers with functional information for gene ontology were selected. Of these, 8 were polymorphic among the individuals screened: Heat shock protein 70 (HSP70), vitellogenin (VTG), lysin, alginate lyase enzyme (AL), Glucose-regulated protein 94 (GRP94), fructose-bisphosphate aldolase (FBA), sulfatase 1A precursor (S1AP) and ornithine decarboxylase antizyme (ODC). Two additional sequences were also identified with polymorphisms but no similarities with known proteins were achieved. To validate the putative SNP markers, High Resolution Melting Analysis (HRMA) was conducted in a wild and hatchery-bred population. Additionally, SNP cross-amplifications were tested in two further native abalone species, Haliotis fulgens and Haliotis corrugata. This study provides novel candidate genes that could be used to evaluate loss of genetic diversity due to hatchery selection or inbreeding effects. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Mitochondrial DNA sequence analyses and phylogenetic relationships among two Nigerian goat breeds and the South African Kalahari Red.

    PubMed

    Awotunde, Esther O; Bemji, Martha N; Olowofeso, Olajide; James, Ikechukwu J; Ajayi, O O; Adebambo, Ayotunde O

    2015-01-01

    The first hypervariable (HV1) region of mitochondrial DNA (mtDNA) of two popular Nigerian goat breeds: West African Dwarf (WAD) (n=35) and Red Sokoto (RS) (n=37) and one exotic breed: Kalahari Red (KR) (n=38) imported from South Africa were sequenced to investigate sequence diversity, genetic structure, origin, and demographic history of the populations. A total of 68 polymorphic sites were found in 110 sequences that grouped into 68 haplotypes. Average haplotype and nucleotide diversities for all breeds were 0.982±0.005 and 0.02350±0.00213, respectively. Phylogenetic analysis revealed two mtDNA lineages (A and B). Lineage A was predominant and included all haplotypes from WAD and RS and 5 out of 11 haplotypes of KR goats. The remaining haplotypes (6) of KR belong to lineage B. The analysis of molecular variance revealed a high-within breed genetic variance of 82.4% and a low-between breed genetic variance of 17.6%. The three breeds clustered with Capra aegagrus as their wild ancestor. Mismatch distribution analysis showed that WAD, RS and haplogroup A have experienced population expansion events. The study has revealed very high diversity within the three breeds which are not strongly separated from each other based on mtDNA analysis. The information obtained on the genetic structure of the breeds will be useful in planning improvement and conservation programs for the local populations.

  11. Deep COI sequencing of standardized benthic samples unveils overlooked diversity of Jordanian coral reefs in the northern Red Sea.

    PubMed

    Al-Rshaidat, Mamoon M D; Snider, Allison; Rosebraugh, Sydney; Devine, Amanda M; Devine, Thomas D; Plaisance, Laetitia; Knowlton, Nancy; Leray, Matthieu

    2016-09-01

    High-throughput sequencing (HTS) of DNA barcodes (metabarcoding), particularly when combined with standardized sampling protocols, is one of the most promising approaches for censusing overlooked cryptic invertebrate communities. We present biodiversity estimates based on sequencing of the cytochrome c oxidase subunit 1 (COI) gene for coral reefs of the Gulf of Aqaba, a semi-enclosed system in the northern Red Sea. Samples were obtained from standardized sampling devices (Autonomous Reef Monitoring Structures (ARMS)) deployed for 18 months. DNA barcoding of non-sessile specimens >2 mm revealed 83 OTUs in six phyla, of which only 25% matched a reference sequence in public databases. Metabarcoding of the 2 mm - 500 μm and sessile bulk fractions revealed 1197 OTUs in 15 animal phyla, of which only 4.9% matched reference barcodes. These results highlight the scarcity of COI data for cryptobenthic organisms of the Red Sea. Compared with data obtained using similar methods, our results suggest that Gulf of Aqaba reefs are less diverse than two Pacific coral reefs but much more diverse than an Atlantic oyster reef at a similar latitude. The standardized approaches used here show promise for establishing baseline data on biodiversity, monitoring the impacts of environmental change, and quantifying patterns of diversity at regional and global scales.

  12. Mass fainting in garment factories in Cambodia.

    PubMed

    Eisenbruch, Maurice

    2017-04-01

    This paper reports an ethnographic study of mass fainting among garment factory workers in Cambodia. Research was undertaken in 2010-2015 in 48 factories in Phnom Penh and 8 provinces. Data were collected in Khmer using nonprobability sampling. In participant observation with monks, factory managers, health workers, and affected women, cultural understandings were explored. One or more episodes of mass fainting occurred at 34 factories, of which 9 were triggered by spirit possession. Informants viewed the causes in the domains of ill-health/toxins and supernatural activities. These included "haunting" ghosts at factory sites in the wake of Khmer Rouge atrocities or recent fatal accidents and retaliating guardian spirits at sites violated by foreign owners. Prefigurative dreams, industrial accidents, or possession of a coworker heralded the episodes. Workers witnessing a coworker fainting felt afraid and fainted. When taken to clinics, some showed signs of continued spirit influence. Afterwards, monks performed ritual ceremonies to appease spirits, extinguish bonds with ghosts, and prevent recurrence. Decoded through its cultural motifs of fear and protest, contagion, forebodings, the bloody Khmer Rouge legacy, and trespass, mass fainting in Cambodia becomes less enigmatic.

  13. Going Faint and Variable: The Faint Sky Variability Survey

    NASA Astrophysics Data System (ADS)

    Groot, P.; Everett, M.; Howell, S.; Vreeswijk, P.; Huber, M.; van Paradijs, J.

    1999-12-01

    Using the Wide Field Camera on the 2.5m Isaac Newton Telescope on the island of La Palma, we are conducting a survey, covering a total of 50 sq. deg., specifically designed to search for photometrically and astrometrically variables stars. We can identify variability time-scales between tens of minutes and one year and we obtain color information (B,V,I) for all fields. The design and sensitivity of the WFC allows us to obtain light-curves at unprecedented limits and precisions ranging from 5 mmag errors at V=17 to 0.1 mag at V=24.5. Main targets of the survey include interacting close binary systems (CV, LMXBs, SXTs, AM CVn systems), RR Lyrae stars in the galactic halo, optical counterparts to Gamma-Ray Bursts, Kuiper Belt Objects and high proper motion stars in the Solar Neighborhood. We also have identified numerous very red sources likely to be very low-mass stars and brown dwarfs. We will present the results of our first year of observations which cover a total of 9 square degrees.

  14. A 100%-complete sequence reveals unusually simple genomic features in the hot-spring red alga Cyanidioschyzon merolae

    PubMed Central

    Nozaki, Hisayoshi; Takano, Hiroyoshi; Misumi, Osami; Terasawa, Kimihiro; Matsuzaki, Motomichi; Maruyama, Shinichiro; Nishida, Keiji; Yagisawa, Fumi; Yoshida, Yamato; Fujiwara, Takayuki; Takio, Susumu; Tamura, Katsunori; Chung, Sung Jin; Nakamura, Soichi; Kuroiwa, Haruko; Tanaka, Kan; Sato, Naoki; Kuroiwa, Tsuneyoshi

    2007-01-01

    Background All previously reported eukaryotic nuclear genome sequences have been incomplete, especially in highly repeated units and chromosomal ends. Because repetitive DNA is important for many aspects of biology, complete chromosomal structures are fundamental for understanding eukaryotic cells. Our earlier, nearly complete genome sequence of the hot-spring red alga Cyanidioschyzon merolae revealed several unique features, including just three ribosomal DNA copies, very few introns, and a small total number of genes. However, because the exact structures of certain functionally important repeated elements remained ambiguous, that sequence was not complete. Obviously, those ambiguities needed to be resolved before the unique features of the C. merolae genome could be summarized, and the ambiguities could only be resolved by completing the sequence. Therefore, we aimed to complete all previous gaps and sequence all remaining chromosomal ends, and now report the first nuclear-genome sequence for any eukaryote that is 100% complete. Results Our present complete sequence consists of 16546747 nucleotides covering 100% of the 20 linear chromosomes from telomere to telomere, representing the simple and unique chromosomal structures of the eukaryotic cell. We have unambiguously established that the C. merolae genome contains the smallest known histone-gene cluster, a unique telomeric repeat for all chromosomal ends, and an extremely low number of transposons. Conclusion By virtue of these attributes and others that we had discovered previously, C. merolae appears to have the simplest nuclear genome of the non-symbiotic eukaryotes. These unusually simple genomic features in the 100% complete genome sequence of C. merolae are extremely useful for further studies of eukaryotic cells. PMID:17623057

  15. Genetic diversity and population history of the red panda (Ailurus fulgens) as inferred from mitochondrial DNA sequence variations.

    PubMed

    Su, B; Fu, Y; Wang, Y; Jin, L; Chakraborty, R

    2001-06-01

    The red panda (Ailurus fulgens) is one of the flagship species in worldwide conservation and is of special interest in evolutionary studies due to its taxonomic uniqueness. We sequenced a 236-bp fragment of the mitochondrial D-loop region in a sample of 53 red pandas from two populations in southwestern China. Seventeen polymorphic sites were found, together with a total of 25 haplotypes, indicating a high level of genetic diversity in the red panda. However, no obvious genetic divergence was detected between the Sichuan and Yunnan populations. The consensus phylogenetic tree of the 25 haplotypes was starlike. The pairwise mismatch distribution fitted into a pattern of populations undergoing expansion. Furthermore, Fu's F(S) test of neutrality was significant for the total population (F(S) = -7.573), which also suggests a recent population expansion. Interestingly, the effective population size in the Sichuan population was both larger and more stable than that in the Yunnan population, implying a southward expansion from Sichuan to Yunnan.

  16. NIFTE: The Near Infrared Faint-Object Telescope Experiment

    NASA Technical Reports Server (NTRS)

    Bock, James J.; Lange, Andrew E.; Matsumoto, T.; Eisenhardt, Peter B.; Hacking, Perry B.; Schember, Helene R.

    1994-01-01

    The high sensitivity of large format InSb arrays can be used to obtain deep images of the sky at 3-5 micrometers. In this spectral range cool or highly redshifted objects (e.g. brown dwarfs and protogalaxies) which are not visible at shorter wavelengths may be observed. Sensitivity at these wavelengths in ground-based observations is severly limited by the thermal flux from the telescope and from the earth's atmosphere. The Near Infrared Faint-Object Telescope Experiment (NIFTE), a 50 cm cooled rocket-borne telescope combined with large format, high performance InSb arrays, can reach a limiting flux less than 1 micro-Jy(1-sigma) over a large field-of-view in a single flight. In comparison, the Infrared Space Observatory (ISO) will require days of observation to reach a sensitivity more than one order of magnitude worse over a similar area of the sky. The deep 3-5 micrometer images obtained by the rocket-borne telescope will assist in determining the nature of faint red objects detected by ground-based telescopes at 2 micrometers, and by ISO at wavelengths longer than 5 micrometers.

  17. Transient and stable GFP expression in germ cells by the vasa regulatory sequences from the red seabream (Pagrus major).

    PubMed

    Lin, Fan; Liu, Qinghua; Li, Mingyou; Li, Zhendong; Hong, Ni; Li, Jun; Hong, Yunhan

    2012-01-01

    Primordial germ cells (PGCs) are the precursors of gametes responsible for genetic transmission to the next generation. They provide an ideal system for cryopreservation and restoration of biodiversity. Recently, considerable attention has been raised to visualize, isolate and transplant PGCs within and between species. In fish, stable PGC visualization in live embryo and individual has been limited to laboratory fish models such as medaka and zebrafish. One exception is the rainbow trout, which represents the only species with aquaculture importance and has GFP-labeled germ cells throughout development. PGCs can be transiently labeled by embryonic injection of mRNA containing green fluorescence protein gene (GFP) and 3'-untranslated region (3'-UTR) of a maternal germ gene such as vasa, nos1, etc. Stable PGC labeling can be achieved through production of transgenic animals by some transcriptional regulatory sequences from germ genes, such as the vasa promoter and 3'-UTR. In this study, we reported the functional analyses of the red seabream vasa (Pmvas) regulatory sequences, using medaka as a model system. It was showed that injection of GFP-Pmvas3'UTR mRNA was able to label medaka PGCs during embryogenesis. Besides, we have constructed pPmvasGFP transgenic vector, and established a stable transgenic medaka line exhibiting GFP expression in germ cells including PGCs, mitotic and meiotic germ cells of both sexes, under control of the Pmvas transcriptional regulatory sequences. It is concluded that the Pmvas regulatory sequences examined in this study are sufficient for germ cell expression and labeling.

  18. A Study of Planetary Nebulae using the Faint Object Infrared Camera for the SOFIA Telescope

    NASA Technical Reports Server (NTRS)

    Davis, Jessica

    2012-01-01

    A planetary nebula is formed following an intermediate-mass (1-8 solar M) star's evolution off of the main sequence; it undergoes a phase of mass loss whereby the stellar envelope is ejected and the core is converted into a white dwarf. Planetary nebulae often display complex morphologies such as waists or torii, rings, collimated jet-like outflows, and bipolar symmetry, but exactly how these features form is unclear. To study how the distribution of dust in the interstellar medium affects their morphology, we utilize the Faint Object InfraRed CAmera for the SOFIA Telescope (FORCAST) to obtain well-resolved images of four planetary nebulae--NGC 7027, NGC 6543, M2-9, and the Frosty Leo Nebula--at wavelengths where they radiate most of their energy. We retrieve mid infrared images at wavelengths ranging from 6.3 to 37.1 micron for each of our targets. IDL (Interactive Data Language) is used to perform basic analysis. We select M2-9 to investigate further; analyzing cross sections of the southern lobe reveals a slight limb brightening effect. Modeling the dust distribution within the lobes reveals that the thickness of the lobe walls is higher than anticipated, or rather than surrounding a vacuum surrounds a low density region of tenuous dust. Further analysis of this and other planetary nebulae is needed before drawing more specific conclusions.

  19. A Study of Planetary Nebulae using the Faint Object Infrared Camera for the SOFIA Telescope

    NASA Technical Reports Server (NTRS)

    Davis, Jessica

    2012-01-01

    A planetary nebula is formed following an intermediate-mass (1-8 solar M) star's evolution off of the main sequence; it undergoes a phase of mass loss whereby the stellar envelope is ejected and the core is converted into a white dwarf. Planetary nebulae often display complex morphologies such as waists or torii, rings, collimated jet-like outflows, and bipolar symmetry, but exactly how these features form is unclear. To study how the distribution of dust in the interstellar medium affects their morphology, we utilize the Faint Object InfraRed CAmera for the SOFIA Telescope (FORCAST) to obtain well-resolved images of four planetary nebulae--NGC 7027, NGC 6543, M2-9, and the Frosty Leo Nebula--at wavelengths where they radiate most of their energy. We retrieve mid infrared images at wavelengths ranging from 6.3 to 37.1 micron for each of our targets. IDL (Interactive Data Language) is used to perform basic analysis. We select M2-9 to investigate further; analyzing cross sections of the southern lobe reveals a slight limb brightening effect. Modeling the dust distribution within the lobes reveals that the thickness of the lobe walls is higher than anticipated, or rather than surrounding a vacuum surrounds a low density region of tenuous dust. Further analysis of this and other planetary nebulae is needed before drawing more specific conclusions.

  20. Faint detection of exoplanets in microlensing surveys

    SciTech Connect

    Brown, Robert A.

    2014-06-20

    We propose a new approach to discovering faint microlensing signals below traditional thresholds, and for estimating the binary-lens mass ratio and the apparent separation from such signals. The events found will be helpful in accurately estimating the true distribution of planetary semimajor axes, which is an important goal of space microlensing surveys.

  1. Paleokarstic phenomena of the Lower Ordovician red bed sequences of the Arbuckle group, southern Oklahoma

    SciTech Connect

    Musselman, J.L. )

    1991-06-01

    Oil and gas production has been reported recently from paleokarstic Arbuckle reservoirs in the Ardmore and Arkoma basin. The West Spring Creek and the Kindblade formations apparently exhibit karstic features. The most extensive surface exposure of these formations is on the southern flank of the Arbuckle anticline along Interstate 35 north of Ardmore, Oklahoma. The lithology is predominantly limestone, ranging from argillaceous mudstone to oolitic and/or bioclastic grainstones. However, minor amounts of sandstone were also observed.These lithologies are characteristic of various peritidal facies. Of particular interest in this outcrop are three distinct red bed zones. Although the zones are part of the repetitive shallowing-upward cycles that characterize the West Spring Creek Formation, ample evidence suggests the red beds represent subaerial exposure surfaces where karstification took place. Many of the thin bedded, rubbly mudstones and wackestones actually represent varieties of breccia commonly associated with karst. Collapse and crackle breccia are most commonly observed. Small solution channels and other vugs are usually completely occluded by calcite cement. However, solution cavities or vugs with diameters larger than 10 cm (3.9 in.) are lined with drusy calcite. Hematite-impregnated sediment occurs as thinly laminated infilling of solution vugs and cavities and also acts as a cementing agent of collapse breccias. Preliminary evidence suggests that karstification processes were active during Arbuckle deposition.

  2. The far infra-red SEDs of main sequence and starburst galaxies

    NASA Astrophysics Data System (ADS)

    Cowley, William I.; Béthermin, Matthieu; Lagos, Claudia del P.; Lacey, Cedric G.; Baugh, Carlton M.; Cole, Shaun

    2017-05-01

    We compare observed far infrared/sub-millimetre (FIR/sub-mm) galaxy spectral energy distributions (SEDs) of massive galaxies (M⋆ ≳ 1010 h-1 M⊙) derived through a stacking analysis with predictions from a new model of galaxy formation. The FIR SEDs of the model galaxies are calculated using a self-consistent model for the absorption and re-emission of radiation by interstellar dust based on radiative transfer calculations and global energy balance arguments. Galaxies are selected based on their position on the specific star formation rate (sSFR)-stellar mass (M⋆) plane. We identify a main sequence of star-forming galaxies in the model, i.e. a well-defined relationship between sSFR and M⋆, up to redshift z ˜ 6. The scatter of this relationship evolves such that it is generally larger at higher stellar masses and higher redshifts. There is a remarkable agreement between the predicted and observed average SEDs across a broad range of redshifts (0.5 ≲ z ≲ 4) for galaxies on the main sequence. However, the agreement is less good for starburst galaxies at z ≳ 2, selected here to have elevated sSFRs>10× the main-sequence value. We find that the predicted average SEDs are robust to changing the parameters of our dust model within physically plausible values. We also show that the dust temperature evolution of the main-sequence galaxies in the model is driven by star formation on the main sequence being more burst-dominated at higher redshifts.

  3. Pedogenic slickensides, indicators of strain and deformation processes in red bed sequences of the Appalachian foreland

    SciTech Connect

    Gray, M.B. ); Nickelsen, R.P. )

    1989-01-01

    Pedogenic slickensides are convex-concave slip surfaces that form during expansion/contraction in expansive clay soils such as Vertisols. In the central Appalachians, they occur near the tops of fining-upward cycles in Paleozoic red beds such as the Bloomsburg, Catskill, and Mauch Chunk Formations. Pedogenic slickensides are found in association with other pedogenic (or paleosol) features such as clay-skinned peds, in situ calcareous nodules, and root impressions. Repeated movements along these shear planes during pedogenesis produce strongly aligned clay particles adjacent to pedogenic slickensides; as a result, they are preserved as discrete fractures throughout diagenesis, compaction, and superimposed tectonic deformation. During whole-rock deformation, pedogenic slickensides segregate penetratively deformed rocks into independent, foliate packets and serve as discontinuities that are followed by later structural features. Because the original morphology of pedogenic slickensides is known, they can be used as crude strain markers.

  4. Generation of 10,154 expressed sequence tags from a leafy gametophyte of a marine red alga, Porphyra yezoensis.

    PubMed

    Nikaido, I; Asamizu, E; Nakajima, M; Nakamura, Y; Saga, N; Tabata, S

    2000-06-30

    A total of 10,154 5'-end expressed sequence tags (EST) were established from the normalized and size-selected cDNA libraries of a marine red alga, Porphyra yezoensis. Among the ESTs, 2140 were unique species, and the remaining 8014 were grouped into 1127 species. Database search of the 3267 non-redundant ESTs by BLAST algorithm showed that the sequences of 1080 species (33.1%) have similarity to those of registered genes from various organisms including higher plants, mammals, yeasts, and cyanobacteria, while 2187 (66.9%) are novel. Codon usage analysis in the coding regions of 101 non-redundant EST groups showing significant similarity to known genes indicated the higher GC contents at the third position of codons (79.4%) than the first (62.2%) and the second position (45.0%), suggesting that the genome has been exposed to high GC pressure during evolution. The sequence data of individual ESTs are available at the web site http://www.kazusa.or.jp/en/plant/porphyra/EST/.

  5. A comparison of heavy mineral assemblage between the loess and the Red Clay sequences on the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Peng, Wenbin; Wang, Zhao; Song, Yougui; Pfaff, Katharina; Luo, Zeng; Nie, Junsheng; Chen, Wenhan

    2016-06-01

    QEMSCAN-based (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) heavy mineral analysis has recently been demonstrated an efficient way to allow a rapid extraction of provenance information from sediments. However, one key issue to correctly obtain a provenance signal using this technique is to clearly separate effects of diagenetic alteration on heavy minerals in sediments, especially in fine-grained loess. Here we compare heavy mineral assemblages of bottom Quaternary loess (L33) and upper Pliocene Red Clay of three sites on the Chinese Loess Plateau (CLP). Two sites (Chaona and Luochuan) with similar modern climate conditions show similar heavy mineral assemblages but contain much less of the unstable heavy mineral amphibole than the drier Xifeng site. This result provides strong evidence supporting that climate-caused diagenesis is an important factor controlling heavy mineral assemblages of fine-grained loess. However, heavy mineral assemblages are similar for loess and paleosol layers deposited after 0.5 Ma on the Chinese Loess Plateau regardless of climate differences, suggesting that time is also a factor controlling heavy mineral assemblages of loess and Red Clay. Our high resolution sampling of the upper Miocene-Pliocene Chaona Red Clay sequence reveals similar heavy mineral compositions with a minor amphibole content, different from the drier Xifeng site results of the same age. This result indicates that the monsoonal climate pattern might have been maintained since the late Miocene. Furthermore, it indicates that the heavy mineral method is promising in tracing provenance for sites northwest of the Xifeng site on the Loess Plateau.

  6. Galaxy Zoo: building the low-mass end of the red sequence with local post-starburst galaxies

    NASA Astrophysics Data System (ADS)

    Wong, O. I.; Schawinski, K.; Kaviraj, S.; Masters, K. L.; Nichol, R. C.; Lintott, C.; Keel, W. C.; Darg, D.; Bamford, S. P.; Andreescu, D.; Murray, P.; Raddick, M. J.; Szalay, A.; Thomas, D.; Vandenberg, J.

    2012-02-01

    We present a study of local post-starburst galaxies (PSGs) using the photometric and spectroscopic observations from the Sloan Digital Sky Survey and the results from the Galaxy Zoo project. We find that the majority of our local PSG population have neither early- nor late-type morphologies but occupy a well-defined space within the colour-stellar mass diagram, most notably, the low-mass end of the 'green valley' below the transition mass thought to be the mass division between low-mass star-forming galaxies and high-mass passively evolving bulge-dominated galaxies. Our analysis suggests that it is likely that local PSGs will quickly transform into 'red', low-mass early-type galaxies as the stellar morphologies of the 'green' PSGs largely resemble that of the early-type galaxies within the same mass range. We propose that the current population of PSGs represents a population of galaxies which is rapidly transitioning between the star-forming and the passively evolving phases. Subsequently, these PSGs will contribute towards the build-up of the low-mass end of the 'red sequence' once the current population of young stars fade and stars are no longer being formed. These results are consistent with the idea of 'downsizing' where the build-up of smaller galaxies occurs at later epochs. This publication has been made possible by the participation of more than 250 000 volunteers in the Galaxy Zoo project. Their contributions are individually acknowledged at .

  7. DNA sequence variation in the mitochondrial control region of red-backed voles (Clethrionomys).

    PubMed

    Matson, C W; Baker, R J

    2001-08-01

    The complete mitochondrial DNA (mtDNA) control region was sequenced for 71 individuals from five species of the rodent genus Clethrionomys both to understand patterns of variation and to explore the existence of previously described domains and other elements. Among species, the control region ranged from 942 to 971 bp in length. Our data were compatible with the proposal of three domains (extended terminal associated sequences [ETAS], central, conserved sequence blocks [CSB]) within the control region. The most conserved region in the control region was the central domain (12% of nucleotide positions variable), whereas in the ETAS and CSB domains, 22% and 40% of nucleotide positions were variable, respectively. Tandem repeats were encountered only in the ETAS domain of Clethrionomys rufocanus. This tandem repeat found in C. rufocanus was 24 bp in length and was located at the 5' end of the control region. Only two of the proposed CSB and ETAS elements appeared to be supported by our data; however, a "CSB1-like" element was also documented in the ETAS domain.

  8. The formation and build-up of the red-sequence over the past 9 Gyr in VIPERS

    NASA Astrophysics Data System (ADS)

    Fritz, Alexander; Abbas, U.; Adami, C.; Arnouts, S.; Bel, J.; Bolzonella, M.; Bottini, D.; Branchini, E.; Burden, A.; Cappi, A.; Coupon, J.; Cucciati, O.; Davidzon, I.; De Lucia, G.; de la Torre, S.; Di Porto, C.; Franzetti, P.; Fumana, M.; Garilli, B.; Granett, B. R.; Guzzo, L.; Ilbert, O.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marchetti, A.; Marinoni, C.; Marulli, F.; McCracken, H. J.; Mellier, Y.; Moscardini, L.; Nichol, R. C.; Paioro, L.; Peacock, J. A.; Percival, W. J.; Polletta, M.; Pollo, A.; Scodeggio, M.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zamorani, G.; Zanichelli, A.; VIPERS Team

    2015-02-01

    We present the Luminosity Function (LF) and Colour-Magnitude Relation (CMR) using ~45000 galaxies drawn from the VIMOS Public Extragalactic Redshift Survey (VIPERS). Using different selection criteria, we define several samples of early-type galaxies and explore their impact on the evolution of the red-sequence (RS) and the effects of dust. Our results suggest a rapid build-up of the RS within a short time scale. We find a rise in the number density of early-type galaxies and a strong evolution in LF and CMR. Massive galaxies exist already 9 Gyr ago and experience an efficient quenching of their star formation at z = 1, followed by a passive evolution with only limited merging activity. In contrast, low-mass galaxies indicate a different mass assembly history and cause a slow build-up of the CMR over cosmic time.

  9. A comparison of zircon U-Pb age results of the Red Clay sequence on the central Chinese Loess Plateau.

    PubMed

    Gong, Hujun; Nie, Junsheng; Wang, Zhao; Peng, Wenbin; Zhang, Rui; Zhang, Yunxiang

    2016-08-19

    Single grain zircon U-Pb geochronology has demonstrated great potentials in extracting tectonic and atmospheric circulation signal carried by aeolian, fluvial, and fluviolacustrine sediments. A routine in this sort of studies is analyzing 100-150 grains and then compares zircon U-Pb age spectra between the measured sample and the potential sources. Here we compared the zircon U-Pb age results of the late Miocene-Pliocene Red Clay sequence of two neighboring sites from the Chinese Loess Plateau where similar provenance signal is expected. Although the results from the 5.5 Ma sediment support this prediction, the results from the 3 Ma sediment at these two sites differ from each other significantly. These results emphasize the importance of increasing analysis number per sample and combining the zircon U-Pb geochronology with other provenance tools in order to get reliable provenance information.

  10. A comparison of zircon U-Pb age results of the Red Clay sequence on the central Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Gong, Hujun; Nie, Junsheng; Wang, Zhao; Peng, Wenbin; Zhang, Rui; Zhang, Yunxiang

    2016-08-01

    Single grain zircon U-Pb geochronology has demonstrated great potentials in extracting tectonic and atmospheric circulation signal carried by aeolian, fluvial, and fluviolacustrine sediments. A routine in this sort of studies is analyzing 100–150 grains and then compares zircon U-Pb age spectra between the measured sample and the potential sources. Here we compared the zircon U-Pb age results of the late Miocene-Pliocene Red Clay sequence of two neighboring sites from the Chinese Loess Plateau where similar provenance signal is expected. Although the results from the 5.5 Ma sediment support this prediction, the results from the 3 Ma sediment at these two sites differ from each other significantly. These results emphasize the importance of increasing analysis number per sample and combining the zircon U-Pb geochronology with other provenance tools in order to get reliable provenance information.

  11. A comparison of zircon U-Pb age results of the Red Clay sequence on the central Chinese Loess Plateau

    PubMed Central

    Gong, Hujun; Nie, Junsheng; Wang, Zhao; Peng, Wenbin; Zhang, Rui; Zhang, Yunxiang

    2016-01-01

    Single grain zircon U-Pb geochronology has demonstrated great potentials in extracting tectonic and atmospheric circulation signal carried by aeolian, fluvial, and fluviolacustrine sediments. A routine in this sort of studies is analyzing 100–150 grains and then compares zircon U-Pb age spectra between the measured sample and the potential sources. Here we compared the zircon U-Pb age results of the late Miocene-Pliocene Red Clay sequence of two neighboring sites from the Chinese Loess Plateau where similar provenance signal is expected. Although the results from the 5.5 Ma sediment support this prediction, the results from the 3 Ma sediment at these two sites differ from each other significantly. These results emphasize the importance of increasing analysis number per sample and combining the zircon U-Pb geochronology with other provenance tools in order to get reliable provenance information. PMID:27538343

  12. Comprehensive analysis of expressed sequence tags from the pulp of the red mutant 'Cara Cara' navel orange (Citrus sinensis Osbeck).

    PubMed

    Ye, Jun-Li; Zhu, An-Dan; Tao, Neng-Guo; Xu, Qiang; Xu, Juan; Deng, Xiu-Xin

    2010-10-01

    Expressed sequence tag (EST) analysis of the pulp of the red-fleshed mutant 'Cara Cara' navel orange provided a starting point for gene discovery and transcriptome survey during citrus fruit maturation. Interpretation of the EST datasets revealed that the mutant pulp transcriptome held a high section of stress responses related genes, such as the type III metallothionein-like gene (6.0%), heat shock protein (2.8%), Cu/Zn superoxide dismutase (0.8%), late embryogenesis abundant protein 5 (0.8%), etc. 133 transcripts were detected to be differentially expressed between the red mutant and its orange-color wild genotype 'Washington' via digital expression analysis. Among them, genes involved in metabolism, defense/stress and signal transduction were statistical overrepresented. Fifteen transcription factors, composed of NAM, ATAF, and CUC transcription factor (NAC); myeloblastosis (MYB); myelocytomatosis (MYC); basic helix-loop-helix (bHLH); basic leucine zipper (bZIP) domain members, were also included. The data reflected the distinct expression profile and the unique regulatory module associated with these two genotypes. Eight differently expressed genes analyzed in digital were validated by quantitative real-time polymerase chain reaction. For structural polymorphism, both simple sequence repeats and single nucleotide polymorphisms (SNP) loci were surveyed; dinucleotide presentation revealed a bias toward AG/GA/TC/CT repeats (52.5%), against GC/CG repeats (0%). SNPs analysis found that transitions (73%) outnumbered transversions (27%). Seventeen potential cultivar-specific and 387 heterozygous SNP loci were detected from 'Cara Cara' and 'Washington' EST pool. © 2010 Institute of Botany, Chinese Academy of Sciences.

  13. THE STAR FORMATION HISTORIES OF RED-SEQUENCE GALAXIES, MASS-TO-LIGHT RATIOS AND THE FUNDAMENTAL PLANE

    SciTech Connect

    Allanson, Steven P.; Hudson, Michael J.; Smith, Russell J.; Lucey, John R.

    2009-09-10

    This paper addresses the challenge of understanding the typical star formation histories of red-sequence galaxies, using linestrength indices and mass-to-light ratios as complementary constraints on their stellar age distribution. We first construct simple parametric models of the star formation history that bracket a range of scenarios, and fit these models to the linestrength indices of low-redshift cluster red-sequence galaxies. For giant galaxies, we confirm the downsizing trend, i.e., the stellar populations are younger, on average, for lower {sigma} galaxies. We find, however, that this trend flattens or reverses at {sigma} {approx}< 70 km s{sup -1}. We then compare predicted stellar mass-to-light ratios with dynamical mass-to-light ratios derived from the fundamental plane (FP), or by the SAURON group. For galaxies with {sigma} {approx} 70 km s{sup -1}, models with a late 'frosting' of young stars and models with exponential star formation histories have stellar mass-to-light ratios that are larger than observed dynamical mass-to-light ratios by factors of 1.7 and 1.4, respectively, and so are rejected. The single stellar population (SSP) model is consistent with the FP, and requires a modest amount of dark matter (between 20% and 30%) to account for the difference between stellar and dynamical mass-to-light ratios. A model in which star formation was 'quenched' at intermediate ages is also consistent with the observations, although in this case less dark matter is required for low mass galaxies. We also find that the contribution of stellar populations to the 'tilt' of the fundamental plane is highly dependent on the assumed star formation history: for the SSP model, the tilt of the FP is driven primarily by stellar-population effects. For a quenched model, two-thirds of the tilt is due to stellar populations and only one-third is due to dark matter or non-homology.

  14. The SAURON project - XV. Modes of star formation in early-type galaxies and the evolution of the red sequence

    NASA Astrophysics Data System (ADS)

    Shapiro, Kristen L.; Falcón-Barroso, Jesús; van de Ven, Glenn; de Zeeuw, P. Tim; Sarzi, Marc; Bacon, Roland; Bolatto, Alberto; Cappellari, Michele; Croton, Darren; Davies, Roger L.; Emsellem, Eric; Fakhouri, Onsi; Krajnović, Davor; Kuntschner, Harald; McDermid, Richard M.; Peletier, Reynier F.; van den Bosch, Remco C. E.; van der Wolk, Guido

    2010-03-01

    We combine SAURON integral field data of a representative sample of local early-type, red sequence galaxies with Spitzer/Infrared Array Camera imaging in order to investigate the presence of trace star formation in these systems. With the Spitzer data, we identify galaxies hosting low-level star formation, as traced by polycyclic aromatic hydrocarbon emission, with measured star formation rates that compare well to those estimated from other tracers. This star formation proceeds according to established scaling relations with molecular gas content, in surface density regimes characteristic of disc galaxies and circumnuclear starbursts. We find that star formation in early-type galaxies happens exclusively in fast-rotating systems and occurs in two distinct modes. In the first, star formation is a diffuse process, corresponding to widespread young stellar populations and high molecular gas content. The equal presence of co- and counter-rotating components in these systems strongly implies an external origin for the star-forming gas, and we argue that these star formation events may be the final stages of (mostly minor) mergers that build up the bulges of red sequence lenticulars. In the second mode of star formation, the process is concentrated into well-defined disc or ring morphologies, outside of which the host galaxies exhibit uniformly evolved stellar populations. This implies that these star formation events represent rejuvenations within previously quiescent stellar systems. Evidence for earlier star formation events similar to these in all fast-rotating early-type galaxies suggests that this mode of star formation may be common to all such galaxies, with a duty cycle of roughly 1/10, and likely contributes to the embedded, corotating inner stellar discs ubiquitous in this population.

  15. Extreme Faint Flux Imaging with an EMCCD

    NASA Astrophysics Data System (ADS)

    Daigle, Olivier; Carignan, Claude; Gach, Jean-Luc; Guillaume, Christian; Lessard, Simon; Fortin, Charles-Anthony; Blais-Ouellette, Sébastien

    2009-08-01

    An EMCCD camera, designed from the ground up for extreme faint flux imaging, is presented. CCCP, the CCD Controller for Counting Photons, has been integrated with a CCD97 EMCCD from e2v technologies into a scientific camera at the Laboratoire d’Astrophysique Expérimentale (LAE), Université de Montréal. This new camera achieves subelectron readout noise and very low clock-induced charge (CIC) levels, which are mandatory for extreme faint flux imaging. It has been characterized in laboratory and used on the Observatoire du Mont Mégantic 1.6 m telescope. The performance of the camera is discussed and experimental data with the first scientific data are presented.

  16. Faint-object spectrograph for Space Telescope

    NASA Technical Reports Server (NTRS)

    Harms, r. J.; Beaver, E.; Burbidge, E. M.; Angel, R.; Bartko, F.; Bloomquist, W.; Flemming, J. C.; Bohlin, R.; Davidsen, A. F.; Ford, H.

    1979-01-01

    The paper presents the Faint Object Spectrograph (FOS) for the Space Telescope to provide a digitized spectra of faint astronomical objects over the 115 to 700 nm wavelength range at resolving powers of 1000 and 100. A variety of concave gratings and prisms is employed to form nearly stigmatic spectra on one of the two Digicon photon counting detectors which are optimized for two different but overlapping ranges. The scientific goals associated with quasars, active galaxies, and objects within our solar system are discussed, and the FOS optical design features, including detectors, electronics, signal processing, power supplies, and data handling are examined. The FOS structural system, mechanism, and controls are described, along with the predicted performance capabilities in the spectral and spectropolarimetry modes. Finally, system performance parameters, including spatial resolution, time resolution, noise, and efficiency are discussed.

  17. [Next generation sequencing and stable isotope probing of active microorganisms responsible for aerobic methane oxidation in red paddy soils].

    PubMed

    Zheng, Yan; Jia, Zhongjun

    2013-02-04

    This study is aimed to establish an unbiased profiling strategy for investigating the microorganisms responsible for aerobic methane oxidation by pyrosequencing the total soil microbial communities at DNA and RNA levels, and to link aerobic methane oxidation activity with taxonomic identity of active microorganisms by DNA/RNA SIP in red paddy soils. Three red paddy soils derived from quaternary red clay were collected from Gushi and Taoyuan cities of Hunan province and Leizhou city of Guangdong province, were incubated with the labeled 13CH4 or 12CH4 for determination of aerobic methane oxidation kinetics. Pyrosequencing of the 16S rRNA andl6S rRNA gene at the whole microbial community levels were performed over the course of aerobic methane oxidation in soil microcosms. 13C-DNA and 13C-RNA were obtained through ultracentrifugation of the total soil DNA and RNA extracts, respectively. Clone library of pmoA genes in 13C-DNA and 16S rRNA genes in 13C-RNA were constructed. Pyrosequencing of the total microbial communities revealed significant increase in the relative abundance of aerobic methanotrophs in soil microcosms upon the completion of aerobic methane consumption. The proportional increase of aerobic methanotrophs was significantly higher at RNA than DNA levels. Type I and II aerobic methanotrophs significantly increased in Gushi soil, while the significant increase of type II aerobic methanotrophs was observed in Taoyuan soil. In the meantime, type I aerobic methanotrophs appeared to be stimulated exclusively in Leizhou soil. Sequencing analysis of the 13C-labeled pmoA genes and 16S rRNA further demonstrate that phylogenetically distinct methanotrophs dominated aerobic methane oxidation activity in paddy soils of Gushi (Type I and II), Taoyuan (Type II) and Leizhou (Type I). High-throughput pyrosequencing at the whole community level of 16S rRNA genes provides an almost unbiased profiling stragety for measuring characteristic changes in relative proportions of

  18. Does faint galaxy clustering contradict gravitational instability?

    NASA Technical Reports Server (NTRS)

    Melott, Adrian L.

    1992-01-01

    It has been argued, based on the weakness of clustering of faint galaxies, that these objects cannot be the precursors of present galaxies in a simple Einstein-de Sitter model universe with clustering driven by gravitational instability. It is shown that the assumptions made about the growth of clustering were too restrictive. In such a universe, the growth of clustering can easily be fast enough to match the data.

  19. Faint Submillimeter Galaxies Behind Lensing Clusters

    NASA Astrophysics Data System (ADS)

    Hsu, Li-Yen; Lauchlan Cowie, Lennox; Barger, Amy J.; Desai, Vandana; Murphy, Eric J.

    2017-01-01

    Faint submillimeter galaxies are the major contributors to the submillimeter extragalactic background light and hence the dominant star-forming population in the dusty universe. Determining how much these galaxies overlap the optically selected samples is critical to fully account for the cosmic star formation history. Observations of massive cluster fields are the best way to explore this faint submillimeter population, thanks to gravitational lensing effects. We have been undertaking a lensing cluster survey with the SCUBA-2 camera on the James Clerk Maxwell Telescope to map nine galaxy clusters, including the northern five clusters in the HST Frontier Fields program. We have also been using the Submillimeter Array and the Very Large Array to determine the accurate positions of our detected sources. Our observations have discovered high-redshift dusty galaxies with far-infrared luminosities similar to that of the Milky Way or luminous infrared galaxies. Some of these galaxies are still undetected in deep optical and near-infrared images. These results suggest that a substantial amount of star formation in even the faint submillimeter population may be hidden from rest-frame optical surveys.

  20. Complete genome sequence of the orange-red pigmented, radioresistant Deinococcus proteolyticus type strain (MRPT)

    SciTech Connect

    Copeland, A; Zeytun, Ahmet; Yasawong, Montri; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; Goodwin, Lynne A.; Pitluck, Sam; Mavromatis, K; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Hauser, Loren John; Jeffries, Cynthia; Brambilla, Evelyne-Marie; Rohde, Manfred; Sikorski, Johannes; Pukall, Rudiger; Goker, Markus; Detter, J. Chris; Woyke, Tanja; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Lapidus, Alla L.

    2012-01-01

    Deinococcus proteolyticus (ex Kobatake et al. 1973) Brook and Murray 1981 is one of currently 47 species in the genus Deinococcus within the family Deinococcaceae. Strain MRPTT was isolated from faeces of Lama glama; it shares with various other species of the genus the extreme radiation resistance, with D. proteolyticus being resistant up to 1.5 Mrad of gamma radiation. Strain MRPT{sup T} is of further interest for its carotenoid pigment. The genome presented here is only the fifth completed genome sequence of a member of the genus Deinococcus (and the forth type strain) to be published, and will hopefully contribute to a better understanding of how members of this genus adapted to high gamma- or UV ionizing-radiation. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,886,836 bp long genome with its four large plasmids of 97 kbp, 132 kbp, 196 kbp and 315 kbp harbours 2,741 protein-coding and 58 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  1. THE ASSEMBLY OF THE RED SEQUENCE AT z {approx} 1: THE COLOR AND SPECTRAL PROPERTIES OF GALAXIES IN THE Cl1604 SUPERCLUSTER

    SciTech Connect

    Lemaux, B. C.; Gal, R. R.; Lubin, L. M.; Fassnacht, C. D.; and others

    2012-02-01

    We investigate the properties of the 525 spectroscopically confirmed members of the Cl1604 supercluster at z {approx} 0.9 as part of the Observations of Redshift Evolution in Large Scale Environments survey. In particular, we focus on the photometric, stellar mass, morphological, and spectral properties of the 305 member galaxies of the eight clusters and groups that comprise the Cl1604 supercluster. Using an extensive Keck Low-Resolution Imaging Spectrometer (LRIS)/DEep Imaging Multi-Object Spectrograph (DEIMOS) spectroscopic database in conjunction with ten-band ground-based, Spitzer, and Hubble Space Telescope imaging, we investigate the buildup of the red sequence in groups and clusters at high redshift. Nearly all of the brightest and most massive red-sequence galaxies present in the supercluster environment are found to lie within the bounds of the cluster and group systems, with a surprisingly large number of such galaxies present in low-mass group systems. Despite the prevalence of these red-sequence galaxies, we find that the average cluster galaxy has a spectrum indicative of a star-forming galaxy, with a star formation rate between those of z {approx} 1 field galaxies and moderate-redshift cluster galaxies. The average group galaxy is even more active, exhibiting spectral properties indicative of a starburst. The presence of massive, red galaxies and the high fraction of starbursting galaxies present in the group environment suggest that significant processing is occurring in group environments at z {approx} 1 and earlier. There is a deficit of low-luminosity red-sequence galaxies in all Cl1604 clusters and groups, suggesting that such galaxies transition to the red sequence at later times. Extremely massive ({approx}10{sup 12} M{sub sun}) red-sequence galaxies routinely observed in rich clusters at z {approx} 0 are also absent from the Cl1604 clusters and groups. We suggest that such galaxies form at later times through merging processes. There are

  2. STELLAR POPULATIONS AND STRUCTURAL PROPERTIES OF ULTRA FAINT DWARF GALAXIES, CANES VENATICI I, BOOeTES I, CANES VENATICI II, AND LEO IV

    SciTech Connect

    Okamoto, Sakurako; Arimoto, Nobuo; Yamada, Yoshihiko; Onodera, Masato

    2012-01-10

    We take deep images of four ultra faint dwarf (UFD) galaxies, Canes Venatici I (CVn I), Booetes I (Booe I), Canes Venatici II (CVn II), and Leo IV, using the Suprime-Cam on the Subaru Telescope. Color-magnitude diagrams (CMDs) extend below main-sequence turnoffs (MSTOs) and yield measurements of the ages of stellar populations. The stellar populations of three faint galaxies, the Booe I, CVn II, and Leo IV dwarf spheroidal galaxies (dSphs), are estimated to be as old as the Galactic globular cluster M92. We confirm that Booe I dSph has no intrinsic color spread in the MSTO and no spatial difference in the CMD morphology, which indicates that Booe I dSph is composed of an old single stellar population. One of the brightest UFDs, CVn I dSph, shows a relatively younger age ({approx}12.6 Gyr) with respect to Booe I, CVn II, and Leo IV dSphs, and the distribution of red horizontal branch (HB) stars is more concentrated toward the center than that of blue HB stars, suggesting that the galaxy contains complex stellar populations. Booe I and CVn I dSphs show the elongated and distorted shapes. CVn II dSph has the smallest tidal radius of a Milky Way satellite and has a distorted shape, while Leo IV dSph shows a less concentrated spherical shape. The simple stellar population of faint UFDs indicates that the gases in their progenitors were removed more effectively than those of brighter dSphs at the occurrence of their initial star formation. This is reasonable if the progenitors of UFDs belong to less massive halos than those of brighter dSphs.

  3. Transcriptomic analysis of the venom gland of the red-headed krait (Bungarus flaviceps) using expressed sequence tags

    PubMed Central

    2010-01-01

    Background The Red-headed krait (Bungarus flaviceps, Squamata: Serpentes: Elapidae) is a medically important venomous snake that inhabits South-East Asia. Although the venoms of most species of the snake genus Bungarus have been well characterized, a detailed compositional analysis of B. flaviceps is currently lacking. Results Here, we have sequenced 845 expressed sequence tags (ESTs) from the venom gland of a B. flaviceps. Of the transcripts, 74.8% were putative toxins; 20.6% were cellular; and 4.6% were unknown. The main venom protein families identified were three-finger toxins (3FTxs), Kunitz-type serine protease inhibitors (including chain B of β-bungarotoxin), phospholipase A2 (including chain A of β-bungarotoxin), natriuretic peptide (NP), CRISPs, and C-type lectin. Conclusion The 3FTxs were found to be the major component of the venom (39%). We found eight groups of unique 3FTxs and most of them were different from the well-characterized 3FTxs. We found three groups of Kunitz-type serine protease inhibitors (SPIs); one group was comparable to the classical SPIs and the other two groups to chain B of β-bungarotoxins (with or without the extra cysteine) based on sequence identity. The latter group may be functional equivalents of dendrotoxins in Bungarus venoms. The natriuretic peptide (NP) found is the first NP for any Asian elapid, and distantly related to Australian elapid NPs. Our study identifies several unique toxins in B. flaviceps venom, which may help in understanding the evolution of venom toxins and the pathophysiological symptoms induced after envenomation. PMID:20350308

  4. Genetic characterization of red-colored heartwood genotypes of Chinese fir using simple sequence repeat (SSR) markers.

    PubMed

    Duan, H J; Hu, R Y; Wu, B; Chen, D X; Huang, K Y; Dai, J; Chen, Q; Wei, Z C; Cao, S; Sun, Y H; Li, Y

    2015-12-29

    The present study investigated the genetic characterization of red-colored heartwood Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.] in Guangxi using 21 simple sequence repeat (SSR) markers and analyzes of the genetic variation (N = 149) in samples obtained from five sites in Guangxi Province, China. The number of different alleles and the Shannon's information index per locus ranged from 3 to 12 and from 0.398 to 2.258 with average values of 6 and 1.211, respectively, indicating moderate levels of genetic diversity within this germplasm collection. The observed and expected heterozygosity ranged from 0.199 to 0.827 and from 0.198 to 0.878 with an average of 0.562 and 0.584, respectively. Although, the mean fixation index was 0.044, indicative of a low level of genetic differentiation among germplasms, analysis of molecular variance revealed considerable differentiation (99%) within the samples. The neighbor-joining dendrogram revealed that the majority of red-colored Chinese fir genotypes were apparently not associated with their geographic origins. Further analysis by STRUCTURE showed that this Guangxi germplasm collection could be divided into three genetic groups comprising 76, 37, and 36 members, respectively; these were classified into mixed groups with no obvious population structure. These results were consistent with those of the cluster analysis. On the whole, our data provide a starting point for the management and conservation of the current Guangxi germplasm collection as well as for their efficient use in Chinese fir-breeding programs.

  5. ASSEMBLY OF THE RED SEQUENCE IN INFRARED-SELECTED GALAXY CLUSTERS FROM THE IRAC SHALLOW CLUSTER SURVEY

    SciTech Connect

    Snyder, Gregory F.; Brodwin, Mark; Mancone, Conor M.; Gonzalez, Anthony H.; Zeimann, Gregory R.; Stanford, S. A.; Stern, Daniel; Eisenhardt, Peter R. M.; Brown, Michael J. I.; Dey, Arjun; Jannuzi, Buell; Perlmutter, Saul

    2012-09-10

    We present results for the assembly and star formation histories (SFHs) of massive ({approx}L*) red sequence galaxies (RSGs) in 11 spectroscopically confirmed, infrared-selected galaxy clusters at 1.0 < z < 1.5, the precursors to present-day massive clusters with M {approx} 10{sup 15} M{sub Sun }. Using rest-frame optical photometry, we investigate evolution in the color and scatter of the RSG population, comparing with models of possible SFHs. In contrast to studies of central cluster galaxies at lower redshift (z < 1), these data are clearly inconsistent with the continued evolution of stars formed and assembled primarily at a single, much earlier time. Specifically, we find that the colors of massive cluster galaxies at z Almost-Equal-To 1.5 imply that the bulk of star formation occurred at z {approx} 3, whereas by z Almost-Equal-To 1 their colors imply formation at z {approx} 2; therefore these galaxies exhibit approximately the same luminosity-weighted stellar age at 1 < z < 1.5. This likely reflects star formation that occurs over an extended period, the effects of significant progenitor bias, or both. Our results generally indicate that massive cluster galaxy populations began forming a significant mass of stars at z {approx}> 4, contained some red spheroids by z Almost-Equal-To 1.5, and were actively assembling much of their final mass during 1 < z < 2 in the form of younger stars. Qualitatively, the slopes of the cluster color-magnitude relations are consistent with no significant evolution relative to local clusters.

  6. Draft Genome Sequence of Francisella noatunensis subsp. orientalis STIR-GUS-F2f7, a Highly Virulent Strain Recovered from Diseased Red Nile Tilapia Farmed in Europe

    PubMed Central

    Larsson, Pär; Wehner, Stefanie; Bekaert, Michaël; Öhrman, Caroline; Metselaar, Matthijs; Thompson, Kimberly Dawn; Richards, Randolph Harvey; Penman, David James; Adams, Alexandra

    2017-01-01

    ABSTRACT A highly virulent strain of Francisella noatunensis subsp. orientalis, STIR-GUS-F2f7, was isolated from moribund red Nile tilapia (Oreochromis niloticus) farmed in Europe. In this communication, the complete genome sequencing of this bacterium is reported. PMID:28302784

  7. Size growth of red-sequence early-type galaxies in clusters in the last 10 Gyr

    NASA Astrophysics Data System (ADS)

    Andreon, S.; Dong, Hui; Raichoor, A.

    2016-08-01

    We carried out a photometric and structural analysis in the rest-frame V band of a mass-selected (log M/M⊙> 10.7) sample of red-sequence galaxies in 14 galaxy clusters, 6 of which are at z> 1.45, namely JKCS041, IDCS J1426.5+3508, SpARCS104922.6+564032.5, SpARCSJ021524-034331, XDCPJ0044.0-2033, and SPT-CLJ2040-4451. To this end, we reduced/analyzed about 300 orbits of multicolor images taken with the Advanced Camera for Survey and the Wide Field Camera 3 on the Hubble Space Telescope. We uniformly morphologically classified galaxies from z = 0.023 to z = 1.803, and we homogeneously derived sizes (effective radii) for the entire sample. Furthermore, our size derivation allows, and therefore is not biased by, the presence of the usual variety of morphological structures seen in early-type galaxies, such as bulges, bars, disks, isophote twists, and ellipiticy gradients. By using such a mass-selected sample, composed of 244 red-sequence early-type galaxies, we find that the log of the galaxy size at a fixed stellar mass, log M/M⊙ = 11, has increased with time at a rate of 0.023 ± 0.002 dex per Gyr over the last 10 Gyr, in marked contrast with the threefold increase found in the literature for galaxies in the general field over the same period. This suggests, at face value, that secular processes should be excluded as the primary drivers of size evolution because we observed an environmental dependent size growth. Using spectroscopic ages of Coma early-type galaxies we also find that recently quenched early-type galaxies are a numerically minor population not different enough in size to alter the mean size at a given mass, which implies that the progenitor bias is minor, i.e., that the size evolution measured by selecting galaxies at the redshift of observation is indistinguishable from the one that compares ancestors and descendents. Full Table 3 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  8. The Population of Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Gomez, Juan; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.

    2016-01-01

    The 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile has been used for spot surveys of the GEO orbital regime to study the population of optically faint GEO debris. The goal is to estimate the size of the population of GEO debris at sizes much smaller than can be studied with 1-meter class telescopes. Despite the small size of the field of view of the Magellan instrument (diameter 0.5-degree), a significant population of objects fainter than R = 19th magnitude have been found with angular rates consistent with circular orbits at GEO. We compare the size of this population with the numbers of GEO objects found at brighter magnitudes by smaller telescopes. The observed detections have a wide range in characteristics starting with those appearing as short uniform streaks. But there are a substantial number of detections with variations in brightness, flashers, during the 5-second exposure. The duration of each of these flashes can be extremely brief: sometimes less than half a second. This is characteristic of a rapidly tumbling object with a quite variable projected size times albedo. If the albedo is of the order of 0.2, then the largest projected size of these objects is around 10-cm. The data in this paper was collected over the last several years using Magellan's IMACS camera in f/2 mode. The analysis shows the brightness bins for the observed GEO population as well as the periodicity of the flashers. All objects presented are correlated with the catalog: the focus of the paper will be on the uncorrelated, optically faint, objects. The goal of this project is to better characterize the faint debris population in GEO that access to a 6.5-m optical telescope in a superb site can provide.

  9. The formation of Jupiter's faint rings

    PubMed

    Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

    1999-05-14

    Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets.

  10. Faint variable stars observed with Kepler

    NASA Astrophysics Data System (ADS)

    Lovekin, Catherine; Tompkins, Jasmin

    2017-09-01

    We present preliminary analysis of approximately 10 variable stars observed with Kepler. The sample stars are faint, and have temperatures greater than 8000 K. The stars were observed for up to three quarters (Q14-Q16) in long cadence mode. Frequencies were extracted with Period04, and 1-21 frequencies were detected in each quarter, with an average of 8 frequencies per quarter. Some variability is detected from quarter to quarter, while the dominant frequencies remain unchanged. We fit the frequencies using MESA models between 1.5 and 3 solar masses, and varied the core overshoot. Best fitting properties of each of these stars will be discussed.

  11. The road to the red sequence via secular and environmental processes: insights from the local Universe

    NASA Astrophysics Data System (ADS)

    Consolandi, Guido

    2017-04-01

    The evolution of galaxies can be thought as the result of the cumulative effects of two broad classes of processes: (i) secular (internal) processes determined by the very nature of the galaxy, and (ii) external processes that are determined by the environment in which the object is embedded. In this thesis I face both aspects of galaxy evolution. Among secular processes, I investigated the effects of stellar bars on the gaseous components of galaxies and their consequences on their evolution. In particular I show how bars affect both the ionized and cold gas in two different samples: the sample of the Halpha3 survey, an Halpha imaging survey of galaxies selected from ALFALFA in the Local and Coma superclusters; the Herschel Reference Sample, a representative sample of 323 local galaxies observed with the space-based Herschel observatory sensitive to the far-infrared emission of dust, a good tracer of cold gas. Owing to the Halpha3 data I demonstrate that main sequence barred galaxies have specific star formation rate suppressed with respect to pure disks. Here I propose a simple model in which bars drive the evolution of disk galaxies. Hydrodynamical simulations indeed show that a barred potential funnels the gas inside the corotation radius toward the center of the galaxy where it reaches high densities, cools and can be consumed by a burst of star formation. At the same time the dynamical torque of the bar keeps the gas outside the corotation radius in place, cutting the gas supply to the central region that consequently stops its star formation activity. Taking advantage of the images of the HRS sample, we show the evidences of such quenching. The aforementioned model is further tested by studying the stellar population properties of galaxies belonging to a sample of 6000 galaxies extracted from SDSS. To this aim, I designed in-house IDL codes that automatically perform aperture photometry and isophotal fitting recovering reliable magnitudes, colors

  12. Sequence polymorphism in the human melanocortin 1 receptor gene as an indicator of the red hair phenotype.

    PubMed

    Grimes, E A; Noake, P J; Dixon, L; Urquhart, A

    2001-11-01

    We describe a minisequencing protocol for screening DNA samples for the presence of 12 mutations in the human melanocortin 1 receptor gene (MC1R), eight of which are associated with the red hair phenotype. A minisequencing profile which shows homozygosity for one of these mutations or the presence of two different mutations would strongly indicate that the sample donor is red haired. The absence of any red hair causing mutations would indicate that the sample donor does not have red hair. We report the frequencies of MC1R variants in the British red haired population.

  13. Identification of sequence-related amplified polymorphism markers linked to the red leaf trait in ornamental kale (Brassica oleracea L. var. acephala).

    PubMed

    Wang, Y S; Liu, Z Y; Li, Y F; Zhang, Y; Yang, X F; Feng, H

    2013-04-02

    Artistic diversiform leaf color is an important agronomic trait that affects the market value of ornamental kale. In the present study, genetic analysis showed that a single-dominant gene, Re (red leaf), determines the red leaf trait in ornamental kale. An F2 population consisting of 500 individuals from the cross of a red leaf double-haploid line 'D05' with a white leaf double-haploid line 'D10' was analyzed for the red leaf trait. By combining bulked segregant analysis and sequence-related amplified polymorphism technology, we identified 3 markers linked to the Re/re locus. A genetic map of the Re locus was constructed using these sequence-related amplified polymorphism markers. Two of the markers, Me8Em4 and Me8Em17, were located on one side of Re/re at distances of 2.2 and 6.4 cM, whereas the other marker, Me9Em11, was located on the other side of Re/re at a distance of 3.7 cM. These markers could be helpful for the subsequent cloning of the red trait gene and marker-assisted selection in ornamental kale breeding programs.

  14. Development and characterization of novel microsatellite markers by Next Generation Sequencing for the blue and red shrimp Aristeus antennatus

    PubMed Central

    Heras, Sandra; Planella, Laia; Caldarazzo, Ilaria; Vera, Manuel; García-Marín, José-Luis

    2016-01-01

    The blue and red shrimp, Aristeus antennatus, is a commercially important crustacean, in the Mediterranean Sea, which has been listed as a priority species for fishery management. Hypervariable microsatellite markers could be a useful tool to identify genetic stocks among geographically close fishing grounds. Potential microsatellite markers (97) identified from next-generation sequencing of an individual shrimp using a 454 GS Junior Pyrosequencer were tested on a preliminary panel of 15 individuals representing the four worldwide genetic stocks of the species from which 35 polymorphic loci were identified and used to characterize an additional 20 individuals from the Western Mediterranean Sea. In the Western Mediterranean sample, 32 out of 35 were polymorphic loci and the number of alleles per locus ranged from 2 to 14 and expected heterozygosity ranged from 0.050 to 0.968. No linkage disequilibrium was detected, indicating the independence of the loci. These novel microsatellites provide additional tools to address questions relating to genetic diversity, parentage studies and connectivity patterns of A. antennatus populations and help develop effective strategies to ensure long-term sustainability of this resource. PMID:27547526

  15. Inferring Invasion History of Red Swamp Crayfish (Procambarus clarkii) in China from Mitochondrial Control Region and Nuclear Intron Sequences.

    PubMed

    Li, Yanhe; Guo, Xianwu; Chen, Liping; Bai, Xiaohui; Wei, Xinlan; Zhou, Xiaoyun; Huang, Songqian; Wang, Weimin

    2015-06-29

    Identifying the dispersal pathways of an invasive species is useful for adopting the appropriate strategies to prevent and control its spread. However, these processes are exceedingly complex. So, it is necessary to apply new technology and collect representative samples for analysis. This study used Approximate Bayesian Computation (ABC) in combination with traditional genetic tools to examine extensive sample data and historical records to infer the invasion history of the red swamp crayfish, Procambarus clarkii, in China. The sequences of the mitochondrial control region and the proPOx intron in the nuclear genome of samples from 37 sites (35 in China and one each in Japan and the USA) were analyzed. The results of combined scenarios testing and historical records revealed a much more complex invasion history in China than previously believed. P. clarkii was most likely originally introduced into China from Japan from an unsampled source, and the species then expanded its range primarily into the middle and lower reaches and, to a lesser extent, into the upper reaches of the Changjiang River in China. No transfer was observed from the upper reaches to the middle and lower reaches of the Changjiang River. Human-mediated jump dispersal was an important dispersal pathway for P. clarkii. The results provide a better understanding of the evolutionary scenarios involved in the rapid invasion of P. clarkii in China.

  16. Inferring Invasion History of Red Swamp Crayfish (Procambarus clarkii) in China from Mitochondrial Control Region and Nuclear Intron Sequences

    PubMed Central

    Li, Yanhe; Guo, Xianwu; Chen, Liping; Bai, Xiaohui; Wei, Xinlan; Zhou, Xiaoyun; Huang, Songqian; Wang, Weimin

    2015-01-01

    Identifying the dispersal pathways of an invasive species is useful for adopting the appropriate strategies to prevent and control its spread. However, these processes are exceedingly complex. So, it is necessary to apply new technology and collect representative samples for analysis. This study used Approximate Bayesian Computation (ABC) in combination with traditional genetic tools to examine extensive sample data and historical records to infer the invasion history of the red swamp crayfish, Procambarus clarkii, in China. The sequences of the mitochondrial control region and the proPOx intron in the nuclear genome of samples from 37 sites (35 in China and one each in Japan and the USA) were analyzed. The results of combined scenarios testing and historical records revealed a much more complex invasion history in China than previously believed. P. clarkii was most likely originally introduced into China from Japan from an unsampled source, and the species then expanded its range primarily into the middle and lower reaches and, to a lesser extent, into the upper reaches of the Changjiang River in China. No transfer was observed from the upper reaches to the middle and lower reaches of the Changjiang River. Human-mediated jump dispersal was an important dispersal pathway for P. clarkii. The results provide a better understanding of the evolutionary scenarios involved in the rapid invasion of P. clarkii in China. PMID:26132567

  17. Crowded Field Photometry in the CLASH Clusters: Measuring the Red Sequence of Cluster Galaxies with Robust Photometry

    NASA Astrophysics Data System (ADS)

    Connor, Thomas; Donahue, Megan; Moustakas, John; Kelson, Daniel; Coe, Dan A.; Postman, Marc; CLASH Team

    2016-01-01

    The Cluster Lensing And Supernova survey with Hubble (CLASH) is an HST multi-cycle treasury program investigating 25 massive clusters of galaxies with X-ray gas Tx > 5 keV, spanning ~5 to ~30 x 10^14 solar masses, and a redshift range of 0.15 < z < 0.9. With 500 orbits of HST time and 16-filter, ultraviolet to infrared photometry of each cluster, this survey offers an unprecedented dataset for cluster galaxy photometry across a span of age and mass, but obtaining robust photometry for the cluster members has been hampered by the crowded field. We have developed a new technique to detect and define objects despite the presence of overlapping light profiles and to measure photometry of galaxies overlapping the extended haloes of massive galaxies. Utilizing spectral energy distribution fitting, we infer the properties of the detected galaxies, including their abundances and the time since their first star formation. Here we will discuss our technique and results, including the role metallicity and age play in shaping the red sequence of cluster galaxies.

  18. Microsatellite markers and cytoplasmic sequences reveal contrasting pattern of spatial genetic structure in the red algae species complex Mazzaella laminarioides.

    PubMed

    Guillemin, Marie-Laure; Valero, Myriam; Morales Collio, Kennia; Pinochet Sanchez, Ramona; Henríquez Espinosa, Miguel; Silva, Andrea X

    2016-10-01

    Mazzaella laminarioides is a common haploid-diploid red alga that forms dense beds. This alga has a wide distributional range, covering 3,500 km of the Chilean coast, but is restricted to high rocky intertidal zones. Recently, the existence of three highly divergent genetic lineages was demonstrated for this taxon, and two cytoplasmic markers were used to determine that these lineages are distributed in strict parapatry. Here, using 454 next-generation sequencing, we developed polymorphic microsatellite loci that cross amplify in all three cytoplasmic lineages. Six sites (i.e., two sites within each lineage) were analyzed using nine microsatellite loci. Our work shows that, although substantial cytoplasmic differentiation occurs within M. laminarioides, the microsatellite loci did not retrieve three nuclear genetic clusters as expected. Indeed, while the northernmost and southernmost cytoplasmic lineages form two strongly divergent nuclear groups characterized by diagnostic alleles, the third cytoplasmic lineage did not form a third nuclear independent group. It is possible that inter-lineage gene exchange has occurred, particularly at sites along the contact zone between the different cytoplasmic lineages. This nuclear-cytoplasmic incongruence in M. laminarioides could be explained by incomplete lineage sorting of the nuclear genes or asymmetric introgressive hybridization between the lineages. Finally, highly significant heterozygote deficiencies (suggesting occurrence of intergametophytic selfing) were observed in the three small northernmost sites while the large southernmost sites generally approached panmixia. © 2016 Phycological Society of America.

  19. Cold H I in faint dwarf galaxies

    NASA Astrophysics Data System (ADS)

    Patra, Narendra Nath; Chengalur, Jayaram N.; Karachentsev, Igor D.; Kaisin, Serafim S.; Begum, Ayesha

    2016-03-01

    We present the results of a study of the amount and distribution of cold atomic gas, as well its correlation with recent star formation in a sample of extremely faint dwarf irregular galaxies. Our sample is drawn from the Faint Irregular Galaxy GMRT Survey (FIGGS) and its extension, FIGGS2. We use two different methods to identify cold atomic gas. In the first method, line-of-sight H I spectra were decomposed into multiple Gaussian components and narrow Gaussian components were identified as cold H I. In the second method, the brightness temperature (TB ) is used as a tracer of cold H I. We find that the amount of cold gas identified using the TB method is significantly larger than the amount of gas identified using Gaussian decomposition. We also find that a large fraction of the cold gas identified using the TB method is spatially coincident with regions of recent star formation, although the converse is not true. That is only a small fraction of the regions with recent star formation are also covered by cold gas. For regions where the star formation and the cold gas overlap, we study the relationship between the star formation rate density and the cold H I column density. We find that the star formation rate density has a power-law dependence on the H I column density, but that the slope of this power law is significantly flatter than that of the canonical Kennicutt-Schmidt relation.

  20. SMASH 1: A Very Faint Globular Cluster Disrupting in the Outer Reaches of the LMC?

    NASA Astrophysics Data System (ADS)

    Martin, Nicolas F.; Jungbluth, Valentin; Nidever, David L.; Bell, Eric F.; Besla, Gurtina; Blum, Robert D.; Cioni, Maria-Rosa L.; Conn, Blair C.; Kaleida, Catherine C.; Gallart, Carme; Jin, Shoko; Majewski, Steven R.; Martinez-Delgado, David; Monachesi, Antonela; Muñoz, Ricardo R.; Noël, Noelia E. D.; Olsen, Knut; Stringfellow, Guy S.; van der Marel, Roeland P.; Vivas, A. Katherina; Walker, Alistair R.; Zaritsky, Dennis

    2016-10-01

    We present the discovery of a very faint stellar system, SMASH 1, that is potentially a satellite of the Large Magellanic Cloud. Found within the Survey of the Magellanic Stellar History (SMASH), SMASH 1 is a compact ({r}h={9.1}-3.4+5.9 {pc}) and very low luminosity ({M}V=-1.0+/- 0.9, {L}V={10}2.3+/- 0.4 {L}⊙ ) stellar system that is revealed by its sparsely populated main sequence and a handful of red giant branch candidate member stars. The photometric properties of these stars are compatible with a metal-poor ([{Fe}/{{H}}]=-2.2) and old (13 Gyr) isochrone located at a distance modulus of ˜18.8, i.e., a distance of ˜ 57 {kpc}. Situated at 11.°3 from the LMC in projection, its three-dimensional distance from the Cloud is ˜ 13 {kpc}, consistent with a connection to the LMC, whose tidal radius is at least 16 {kpc}. Although the nature of SMASH 1 remains uncertain, its compactness favors it being a stellar cluster and hence dark-matter free. If this is the case, its dynamical tidal radius is only ≲ 19 {pc} at this distance from the LMC, and smaller than the system’s extent on the sky. Its low luminosity and apparent high ellipticity (ɛ ={0.62}-0.21+0.17) with its major axis pointing toward the LMC may well be the tell-tale sign of its imminent tidal demise.

  1. Lucky imaging and speckle discrimination for the detection of faint companions with adaptive optics

    NASA Astrophysics Data System (ADS)

    Gladysz, Szymon; Christou, Julian; Law, Nicholas; Dekany, Richard; Redfern, Michael; Mackay, Craig

    2008-07-01

    We have analyzed the application of frame selection ("lucky imaging") to adaptive optics (AO), short-exposure observations of faint companions. We have used the instantaneous Strehl ratio as an image quality metric. The probability density function (PDF) of this quantity can be used to determine the outcome of frame selection in terms of optimizing the Strehl ratio and the peak-signal-to-noise-ratio of the shift-and-add image. In the presence of static speckles, frame selection can lead to both: improvement in resolution--as quantified by the Strehl ratio, as well as faint signal detectability--given by the peak-signal-to-noise-ratio. This theoretical prediction is confirmed with real data from AO observations using Lick Observatory's 3m Shane telescope, and the Palomar Observatory's 5m Hale telescope. In addition, we propose a novel statistics-based technique for the detection of faint companions from a sequence of AO-corrected exposures. The algorithm, which we call stochastic speckle discrimination, utilizes the "statistical signature" of the centre of the point spread function (PSF) to discriminate between faint companions and static speckles. The technique yields excellent results even for signals invisible in the shift-and-add images.

  2. A Search for Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Lederer, Susan M.; Barker, Edwin S.; Cowardin, Heather; Abercromby, Kira J.; ilha, Jiri

    2011-01-01

    Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan 1 telescope Walter Baade at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r filter. The limiting magnitude for 5 second exposures is estimated to be fainter than 22. With this small field of view and the limited observing time, our objective was to search for optically faint objects from the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris (SSN # 25001 and 33519) with the 6.5-m telescope, followed by a survey for objects on similar orbits but with a spread in mean anomaly. To detect bright objects over a wider field of view (1.6x1.6 degrees), we observed the same field centers at the same time through a similar filter with the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will describe our experiences using Magellan, a telescope never used previously for orbital debris research, and our initial results.

  3. A Search For Optically Faint GEO Debris

    NASA Astrophysics Data System (ADS)

    Seitzer, P.; Lederer, S.; Barker, E.; Cowardin, H.; Abercromby, K.; Silha, J.; Burkhardt, A.

    2011-09-01

    Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan telescope ‘Walter Baade’ at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe preliminary results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r’ filter. The limiting magnitude for 5 second exposures is measured to be fainter tan R = 21. With this small field of view and the limited observing time, our objective was to search for optically faint objects from the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris (SSN # 25001 and 33519) with the 6.5-m telescope, followed by a survey for objects on similar orbits but with a spread in mean anomaly. To detect bright objects over a wider field of view (1.6x1.6 degrees), we observed the same field centers at the same time through a similar filter with the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will describe our experiences using Magellan, a telescope never used previously for orbital debris research, and our initial results.

  4. The Faint Object Infrared Camera for the SOFIA Telescope

    NASA Astrophysics Data System (ADS)

    Keller, L. D.; Herter, T. L.; Stacey, G.; Gull, G. E.; Schoenwald, J.; Pirger, B.; Nikola, Tomas

    2002-06-01

    The Faint Object infraRed CAmera for the Sofia Telescope (FORCAST) is a facility-class, mid/far-infrared camera for the Stratospheric Observatory for Infrared Astronomy (SOFIA). FORCAST is a two-channel design with selectable filters for narrowband and broadband imaging in the 5-8, 17-25 micron, and/or 25-40 micron regions. Simultaneous imaging in the two-channels (lambda < 25 microns and lambda > 25 microns) is possible. FORCAST will sample images at 0.75 arcsec/pixel and have a 3.2?x3.2? instantaneous field-of-view. Imaging is diffraction limited for lambda > 15 microns. Since FORCAST operates in the wavelength range where the seeing from SOFIA is best, it will provide the highest spatial resolution possible with SOFIA. FORCAST may eventually support a spectroscopy mode (resolving power, R ~ 300 and R ~ 1000-2000) using silicon grisms mounted in the filter wheels. The science projects planned by the investigator team include multicolor imaging of the galactic center, Vega-like dust clouds, and star formation regions in normal spiral galaxies and active galaxies. This instrument will be of great value to the SOFIA community for imaging of protostellar environments, young star clusters, molecular clouds, and galaxies. We present details of the FORCAST instrument, including filter lists and sensitivity estimates, that will be useful to astronomers intending to use SOFIA for mid-infrared imaging.

  5. SUPERNOVA 2003ie WAS LIKELY A FAINT TYPE IIP EVENT

    SciTech Connect

    Arcavi, Iair; Gal-Yam, Avishay; Sergeev, Sergey G.

    2013-04-15

    We present new photometric observations of supernova (SN) 2003ie starting one month before discovery, obtained serendipitously while observing its host galaxy. With only a weak upper limit derived on the mass of its progenitor (<25 M{sub Sun }) from previous pre-explosion studies, this event could be a potential exception to the ''red supergiant (RSG) problem'' (the lack of high-mass RSGs exploding as Type IIP SNe). However, this is true only if SN2003ie was a Type IIP event, something which has never been determined. Using recently derived core-collapse SN light-curve templates, as well as by comparison to other known SNe, we find that SN2003ie was indeed a likely Type IIP event. However, with a plateau magnitude of {approx} - 15.5 mag, it is found to be a member of the faint Type IIP class. Previous members of this class have been shown to arise from relatively low-mass progenitors (<12 M{sub Sun }). It therefore seems unlikely that this SN had a massive RSG progenitor. The use of core-collapse SN light-curve templates is shown to be helpful in classifying SNe with sparse coverage. These templates are likely to become more robust as large homogeneous samples of core-collapse events are collected.

  6. Faint radio sources and gravitational lensing

    SciTech Connect

    Langston, G.I.; Conner, S.R.; Heflin, M.B.; Lehar, J.; Burke, B.F. MIT, Cambridge, MA )

    1990-04-01

    Measurements of the surface density of radio sources resulting from a deep VLA integration at 5 GHz and the MIT-Green Bank (MG) II 5 GHz survey are summarized. The faint source counts are combined with previous observations and fitted to a power-law function of surface density vs. limiting flux density. The surface density of radio sources brighter than 1 mJy is k = 0.019 + or - 0.004/arcmin. The power-law exponent is best fit by -0.93 + or - 0.14. Between 15 and 100 mJy, the surface density of radio sources varies nearly as predicted by Euclidian models of the universe. Estimates are given for the number of chance alignments of radio sources in the VLA snapshot observations of the MIT-Princeton-Caltech gravitational lens search. The probability of lens candidate configurations occurring by chance alignment is calculated. 28 refs.

  7. Spectroscopy of faint asteroids, satellites, and comets

    NASA Technical Reports Server (NTRS)

    Degewij, J.

    1980-01-01

    Nineteen asteroids with orbital elements comparable to those of short-period comets and the outer Jovian satellites J6 Himalia and J7 Elara have been observed with the 228-cm telescope and image-tube spectrograph of Steward Observatory. No activity indicating cometary outgassing was detected. If comets are being perturbed into asteroidal orbits, then this lack of activity can be explained by an apparently short transition time between active and extinct phase. In addition, spectra of the faint comets Sanguin 1977p, Chernykh 1977l, Arend-Rigaux 1950 VII, West 1978a, and van Biesbroeck 1954 IV were obtained, showing CN(0,0) and in some cases C2(1,0) and C3 emission. Comet Arend-Rigaux was active again in the fall of 1977 and Comet West showed on May 31, 1978 a weak tail at a distance from the sun of 6.0 AU.

  8. Employment of bromophenol red and bovine serum albumin as luminol signal co-enhancer in chemiluminescent detection of sequence-specific DNA.

    PubMed

    Yu, Xiaoqian; Sheng, Yingying; Zhao, Yanjun; Fan, Aiping

    2016-01-01

    Bromophenol red, known as chemical indicator, was found to act as a novel potent signal enhancer of the peroxidase-catalyzed luminol-H2O2 chemiluminescent (CL) reaction. It was found interestingly that bovine serum albumin (BSA) played a role in the enhanced chemiluminescent reaction (ECR). The addition of 2.5 mg mL(-1) BSA into bromophenol red-enhance CL system showed 36 times stronger CL signal than that without addition of BSA. Mechanism study showed that the luminophors in the ECR were still 3-aminophthalate ion in an excited state (3-APA*). In addition, singlet oxygen ((1)O2) and hydroxyl radical ((∙)OH) played a role in the ECR. The possible mechanism was discussed in the present study. The effect of pH, reaction time, and concentration of bromophenol red, BSA, luminol, and H2O2 on CL intensity of the peroxidase-catalyzed CL reaction was studied. The detection limit value (LOD) of HRP and streptavidin-modified HRP in the proposed ECR with bromophenol red and BSA was 0.20 ng mL(-1) and 0.05 ng mL(-1), respectively. This novel luminol-H2O2-HRP-bromophenol red-BSA CL system was applied to the CL detection of sequence-specific DNA based on a magnetic separation process. As low as 0.4 fmol of target DNA could be sensitively detected using the proposed CL system without any amplification process. The obtained results demonstrate very promising perspectives for using bromophenol red and BSA to improve the sensitivity of CL detection of sequence-specific DNA. In addition, this novel ECR system can also be generalized for CL immunoassay, CL western blotting, and so on. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Searching for Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Lederer, Susan M.; Abercromby, Kira J.; Barker, Edwin S.; Burkhardt, Andrew; Cowardin, Heather; Krisko, Paula; Silha, Jiri

    2012-01-01

    We report on results from a search for optically faint debris (defined as R > 20th magnitude, or smaller than 10 cm assuming an albedo of 0.175)) at geosynchronous orbit (GEO) using the 6.5-m Magellan telescope "Walter Baade" at Las Campanas Observatory in Chile. Our goal is to characterize the brightness distribution of debris to the faintest limiting magnitude possible. Our data was obtained during 6 hours of observing time during the photometric nights of 26 and 27 March 2011 with the IMACS f/2 instrument, which has a field of view (fov) of 0.5 degrees in diameter. All observations were obtained through a Sloan r filter, and calibrated by observations of Landolt standard stars. Our primary objective was to search for optically faint objects from one of the few known fragmentations at GEO: the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris with the 6.5-m telescope, followed by a survey for unknown objects on similar orbits but with different mean anomalies. To establish the bright end of the debris population, calibrated observations were acquired on the same field centers, telescope rates, and time period with a similar filter on the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will show the calibrated brightness distributions from both telescopes, and compare the observed brightness distributions with that predicted for various population models of debris of different sizes.

  10. LoCuSS: exploring the selection of faint blue background galaxies for cluster weak-lensing

    NASA Astrophysics Data System (ADS)

    Ziparo, Felicia; Smith, Graham P.; Okabe, Nobuhiro; Haines, Chris P.; Pereira, Maria J.; Egami, Eiichi

    2016-12-01

    Cosmological constraints from galaxy clusters rely on accurate measurements of the mass and internal structure of clusters. An important source of systematic uncertainty in cluster mass and structure measurements is the secure selection of background galaxies that are gravitationally lensed by clusters. This issue has been shown to be particular severe for faint blue galaxies. We therefore explore the selection of faint blue background galaxies, by reference to photometric redshift catalogues derived from the Cosmological Evolution Survey (COSMOS) and our own observations of massive galaxy clusters at z ≃ 0.2. We show that methods relying on photometric redshifts of galaxies in/behind clusters based on observations through five filters, and on deep 30-band COSMOS photometric redshifts are both inadequate to identify safely faint blue background galaxies with the same 1 per cent contamination level that we have achieved with red galaxies. This is due to the small number of filters used by the former, and absence of massive galaxy clusters at redshifts of interest in the latter. Nevertheless, our least contaminated blue galaxy sample yields stacked weak-lensing results consistent with our previously published results based on red galaxies, and we show that the stacked clustercentric number density profile of these faint blue galaxies is consistent with expectations from consideration of the lens magnification signal of the clusters. Indeed, the observed number density of blue background galaxies changes by ˜10-30 per cent across the radial range over which other surveys assume it to be flat.

  11. Polarizer mechanism for the space telescope faint object spectrograph

    NASA Technical Reports Server (NTRS)

    Thulson, M. D.

    1983-01-01

    The polarizer mechanism for the Space Telescope Faint Object Spectrograph is described. This device will allow spectropolarimetric measurements of faint astronomical objects. The mechanism employs a unique arrangement to meet functional requirements in a compact package and with only one actuator. Detailed tolerance analysis and a variety of tests indicate that the polarizer is capable of accurate and reliable performance.

  12. First Results from the ISO-IRAS Faint Galaxy Survey

    NASA Technical Reports Server (NTRS)

    Wolstencroft, R. D.; Wehrle, A. E.; Levine, D. A.

    1997-01-01

    We present the first result from the ISO-IRAS Faint Galaxy Survey (IIFGS), a program designed to obtain ISO observations of the most distant and luminous galaxies in the IRAS Faint Source Survey by filling short gaps in the ISO observing schedule with pairs of 12um ISOCAM AND 90um ISOPHOT observation.

  13. First Results from the ISO-IRAS Faint Galaxy Survey

    NASA Technical Reports Server (NTRS)

    Wolstencroft, R. D.; Wehrle, A. E.; Levine, D. A.

    1997-01-01

    We present the first result from the ISO-IRAS Faint Galaxy Survey (IIFGS), a program designed to obtain ISO observations of the most distant and luminous galaxies in the IRAS Faint Source Survey by filling short gaps in the ISO observing schedule with pairs of 12um ISOCAM AND 90um ISOPHOT observation.

  14. Complete genome sequence of Coriobacterium glomerans type strain (PW2T) from the midgut of Pyrrhocoris apterus L. (red soldier bug)

    SciTech Connect

    Stackebrandt, Erko; Zeytun, Ahmet; Lapidus, Alla L.; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Mavromatis, K; Mikhailova, Natalia; Huntemann, Marcel; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Chang, Yun-Juan; Land, Miriam L; Hauser, Loren John; Rohde, Manfred; Pukall, Rudiger; Goker, Markus; Detter, J. Chris; Woyke, Tanja; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter

    2013-01-01

    Coriobacterium glomerans Haas and Ko nig 1988, is the only species of the genus Coriobacterium, family Coriobacteriaceae, order Coriobacteriales, phylum Actinobacteria. The bacterium thrives as an endosymbiont of pyrrhocorid bugs, i.e. the red fire bug Pyrrhocoris apterus L. The rationale for sequencing the genome of strain PW2T is its endosymbiotic life style which is rare among members of Actinobacteria. Here we describe the features of this symbiont, together with the complete genome sequence and its annotation. This is the first complete genome sequence of a member of the genus Coriobacterium and the sixth member of the order Coriobacteriales for which complete genome sequences are now available. The 2,115,681 bp long single replicon genome with its 1,804 protein-coding and 54 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  15. Complete genome sequence of Coriobacterium glomerans type strain (PW2(T)) from the midgut of Pyrrhocoris apterus L. (red soldier bug).

    PubMed

    Stackebrandt, Erko; Zeytun, Ahmet; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Goodwin, Lynne A; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, Natalia; Mavromatis, Konstantinos; Mikhailova, Natalia; Huntemann, Marcel; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Chang, Yun-Juan; Land, Miriam; Hauser, Loren; Rohde, Manfred; Pukall, Rüdiger; Göker, Markus; Detter, John C; Woyke, Tanja; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter

    2013-04-15

    Coriobacterium glomerans Haas and König 1988, is the only species of the genus Coriobacterium, family Coriobacteriaceae, order Coriobacteriales, phylum Actinobacteria. The bacterium thrives as an endosymbiont of pyrrhocorid bugs, i.e. the red fire bug Pyrrhocoris apterus L. The rationale for sequencing the genome of strain PW2(T) is its endosymbiotic life style which is rare among members of Actinobacteria. Here we describe the features of this symbiont, together with the complete genome sequence and its annotation. This is the first complete genome sequence of a member of the genus Coriobacterium and the sixth member of the order Coriobacteriales for which complete genome sequences are now available. The 2,115,681 bp long single replicon genome with its 1,804 protein-coding and 54 RNA genes is part of the G enomic E ncyclopedia of Bacteria and Archaea project.

  16. The mitochondrial genome of the red alga Kappaphycus striatus ("Green Sacol" variety): complete nucleotide sequence, genome structure and organization, and comparative analysis.

    PubMed

    Tablizo, Francis A; Lluisma, Arturo O

    2014-12-01

    The complete mitochondrial (mt) DNA sequence of the rhodophyte Kappaphycus striatus ("Green Sacol" variety) was determined. The mtDNA is circular, 25,242 bases long (A+T content: 69.94%), and contains 50 densely packed genes comprising 93.22% of the mitochondrial genome, with genes encoded on both strands. Through comparative analysis, the overall sequence, genome structure, and organization of K. striatus mtDNA were seen to be highly similar with other fully sequenced mitochondrial genomes of the class Florideophyceae. On the other hand, certain degrees of genome rearrangements and greater sequence dissimilarities were observed for the mtDNAs of other evolutionarily distant red algae, such as those from the class Bangiophyceae and Cyanidiophyceae, compared to that of K. striatus. Furthermore, a trend was observed wherein the red algal mtDNAs tend to encode lesser number of protein-coding genes, albeit not necessarily shorter, as the organism becomes more morphologically complex. This trend is supported by the phylogenetic tree inferred from the concatenated amino acid sequences of the deduced protein products of cytochrome c oxidase subunit genes (cox1, 2, and 3).

  17. Novel sequence types of Chlamydia pecorum infect free-ranging Alpine ibex (Capra ibex) and red deer (Cervus elaphus) in Switzerland.

    PubMed

    Jelocnik, Martina; Self, Rachel; Timms, Peter; Borel, Nicole; Polkinghorne, Adam

    2015-04-01

    Chlamydia pecorum, a recognized pathogen of domesticated ruminants and koalas (Phascolarctos cinereus), has been recently reported in a broad range of other wildlife species including water buffalo (Bubalus bubalis), ibex (Capra ibex), chamois (Rupicapra rupicapra), red deer (Cervus elaphus), and birds. This identification raises questions as to whether cross-host transmission may be a factor in the epidemiology of infections in these species. To begin to address this question, we employed a C. pecorum species-specific multi-locus sequence typing (MLST) scheme to characterize a small collection of C. pecorum-positive samples from wild, free-range ibex, a chamois, and a red deer from Grison, Switzerland, a canton where domesticated and wild ruminants graze in close proximity during the summer. Screening by PCR confirmed low to moderate levels of Chlamydia pecorum DNA in the eyes of healthy ibex (n = 4) and in the deer fecal sample (n = 1). The MLST analysis revealed three novel sequence types (STs; 88, 90, and 89) in these samples. On phylogenetic analysis, the ibex and deer sequences clustered by host species in their own well-supported clades and away from C. pecorum STs found in other hosts. Even though the analyzed sample size was small, the identification of unique C. pecorum STs infecting free-ranging Alpine ibex and red deer provides useful information for further C. pecorum epidemiologic studies.

  18. Revealing a comet-like shape of the faint periphery of the nearby galaxy M 32

    NASA Astrophysics Data System (ADS)

    Georgiev, Ts. B.

    2016-02-01

    We performed BVRI photometry of the galaxy M 32 building images and isophote maps in magnitudes and in color indexes. While searching for the faint thick disk of M 32 we apply median filtering with aperture of 7.3 arcmin to detach the residual image of M 32 and its periphery above the surrounding magnitude or color background. The residual images in all photometric systems show that the periphery of M 32 possesses a comet-like shape with a tail oriented to SSE, in a direction opposite to the direction of M 110. The images calibrated in color indexes (b - v) and (b - v)+(r - i) show that the tail is redder than the local median background. The residual images in color indexes show that the red tail broadens and curves in direction towards S and SW. Simultaneously, the brightest part of M 32 occurs bounded from NW-NE-SE sides by a sickle-like formation with a significantly lower red color index. Generally, we do not find a faint thick disk of M 32. However, the comet-like shape on the periphery of M 32, especially as a formation with an increased red color index, provokes involuntarily the impression that the satellite M 32 overtakes the Andromeda galaxy. The redshifts show that the intimacy velocity of M 32 and Andromeda galaxy is about 100 km/s.

  19. Organization, expression and nucleotide sequence of the operon encoding R-phycoerythrin alpha and beta subunits from the red alga Polysiphonia boldii.

    PubMed

    Roell, M K; Morse, D E

    1993-01-01

    The characterization of the operon encoding the alpha and beta subunits of rhodophytan (R)-phycoerythrin (PE) from the macrophytic red alga Polysiphonia boldii is reported. This plastid-encoded operon was cloned, its nucleotide sequence determined, and its expression characterized by northern and primer extension analyses. The arrangement and expression of the PE alpha and beta genes, named rpeA and rpeB, are similar to those of the cyanobacterial (C)-PE genes: rpeB is located 5' of rpeA, with an intergenic region of 64 nucleotides. The two genes are transcribed on a 1.25 kb dicistronic transcript, and each coding region is preceded by a prokaryotic ribosome binding site consensus sequence. Transcription is initiated 95 nucleotides upstream of the initiating methionine codon of rpeB. The promoter region resembles that of prokaryotic genes, with an AT-rich -10 sequence. A direct pentanucleotide repeat (5'-TGTTA-3') was found in the -35 region. This pentanucleotide is present upstream of all PE operons that have been characterized thus far. An extensive inverted repeat is present 3' of rpeA; inverted repeats are found downstream of all PE operons sequenced to date, although the sequence is not conserved. The deduced amino acid sequences from these genes provide complete sequences for an R-PE. Of the amino acid residues 85% are identical to those of bangeophycean (B)-PE from the unicellular red alga Porphyridium cruentum. Conserved residues include cysteines at the bilin attachment sites of C- and B-PEs, aspartates at positions postulated to interact with bilin chromophores, and an apparent consensus sequence for N-methylation of an asparagine residue in C-PEs.

  20. Hot Young Solution to Faint Sun Paradox

    NASA Astrophysics Data System (ADS)

    Riofrio, L.

    2006-12-01

    The "Faint Young Sun" has been a paradox of astrophysics. The standard solar model predicts that 4 billion years ago Earth was too cold to support life. Geology and the fossil record contradict this prediction. The paradox and possible solution are a fascinating combination of astrophysics, relativity and the Earth sciences. Models predict that 4 billion years ago the Sun shone with only 70 % of its present luminosity. Since power P is related to temperature T by the Stefan-Boltzmann Law P ∝ T4, Earth temperature would have been only 91 % of its present value. That temperature is approximately 283K, so temperature in the past would have been only 258K. Earth's surface would have frozen solid, making evolution of life very unlikely. Geology shows evidence of extensive sedimentation 4 billion years ago. Other geological markers corroborate the presence of liquid water on Earth during this period. Paleontology dates the earliest organisms at least 3.4 to 4 billion years old. Clearly liquid water and life both existed when the model predicts Earth was frozen solid. This conflict with observations is the Faint Young Sun paradox. Fortunately, Relativity and Space/Time can help save the standard solar model. The Sun converts its fuel to energy according to E=mc2. Unified Space/Time predicts that c is given by: GM=tc3. Where t is age of the Universe, GM combines its mass and gravitational constant. Solving, we have c(t)=(GM)^{1/3} t^{-1/3}. Billions of years ago, solar output and temperature were therefore higher than originally calculated. Earth is estimated to be 4.6 billion years and the Universe 13.7 billion years old, 1.5 times its age at the time of Earth's formation. Energy e=mc2 is adjusted by (1.5)^{2/3} = 1.31 times the initial estimate. Multiplying by that estimate of 70 %, the Sun's actual output was 0.917 of the present value. Temperature was then (0.917)^{1/4} = 98 % of today's value. If we start with an estimate of 76 %, the Sun's true output was exactly

  1. Is the faint young Sun paradox solved?

    NASA Astrophysics Data System (ADS)

    Wolf, E. T.; Toon, O. B.

    2013-12-01

    How did the early Earth remain warm despite weak solar luminosity? The faint young Sun paradox has stubbornly resisted a self-consistent solution since it was first introduced by Sagan and Mullen [1] over four decades ago. However, recent revisions to expected paleo-ocean temperatures [2, 3] along with new results from three-dimensional climate models [4] may allow this long standing problem to be finally put to rest. Here we use a modified version of the Community Atmosphere Model version 3 from the National Center for Atmospheric Research to study early climate. We find that resolving the faint young Sun paradox becomes less problematic when viewing a full representation of the climate system. For the late Archean climate (80% solar constant), relatively modest amounts of CO2 (≤0.02 bar) and CH4 (0.001 bar) yield surface temperatures equal to the present day with no other alterations to climate. Cooler climates with large ice caps but with temperate tropical regions can be supported with considerably smaller greenhouse gas burdens. The incorporation of systematic climate system elements expected for the Archean such as fewer cloud condensation nuclei (CCN) [5], reduced land albedos [5], and an increased atmospheric inventory of N2 [6], can provide a combined 10 to 20 K of additional surface warming given reasonable assumptions. With the inclusion of 0.001 bar of CH4, 2 PAL of N2, reduced land albedos, and reduced CCN, present day mean surface temperatures can be maintained for the earliest Archean (75% solar constant) with only ~0.01 bar of CO2. However, lower requirements for atmospheric CO2 may imply that photochemical hazes were frequent during the Archean. [1] Sagan, C., & Mullen, G. Science 177, 52 (1972) [2] Hren, M.T., Tice, M.M., & Chamberlin, C.P. Nature 462, 205 (2009) [3] Blake. R.E., Chang, S.J., & Lepland, A. Nature 464, 1029 (2010) [4] Wolf, E.T., & Toon, O.B. Astrobiology 13(7), 1 (2013) [5] Rosing, M.T., Bird, D.K., Sleep, N.H., & Bjerrum, C

  2. Faint high-latitude carbon stars

    NASA Astrophysics Data System (ADS)

    Green, Paul Jonathan

    We have undertaken a wide area survey to search for faint high latitude carbon (FHLC) stars. Carbon giants are ideal for study of the structure and kinematics of the outer galactic halo. We use two color photometric selection with large format charge-coupled devices (CCD's) to cover 52 deg2 of sky to a depth of about V = 18. Below this limit, we find good (approximately less than 20 percent) agreement between our object counts as a function of magnitude and the galactic models of Bahcall and Soneira at a variety of latitudes and longitudes. Our spectroscopic followup began with low-resolution spectra of 19 unconfirmed C star candidates from the Case objective-prism photographic survey of Sanduleak and Pesch. Four of these we find to be M stars. The 15 C stars we classify on the two-parameter Keenan-Morgan system as warm (color class less than 3). Of 94 faint C star candidates from our own CCD survey, one highly ranked V = 17 candidate was found to have strong carbon and CN bands. We estimate that to a depth of V = 18, the surface density FHLC stars is 0.019+0.044-.016 deg-2. We identify two FHLC stars with previously catalogued high proper motion objects. These objects are thus inferred to be dwarf carbon (dC) stars, supplementing the one previously known case, G77-61. Not all dC stars will have detectable proper motions, so other luminosity/distance indicators are needed: we find that C dwarfs all have similar JHK colors, and possibly an unusually strong lambda-6191 bandhead of carbon. By comparing positions in the HST Guide Star Catalog and the original Palomar Observatory Sky Survey, we detect proper motions in two additional FHLC stars. Our proper motion survey, spanning a 30 year baseline, thus identifies two new dC's, and provides proper motion upper limits for another 44 FHLC stars. Kinematic simulations suggest that virtually all Population 2 dC's will have detectable proper motions in a survey as sensitive as our own, and that to a limit of V approximately

  3. Faint High-Latitude Carbon Stars

    NASA Astrophysics Data System (ADS)

    Green, Paul J.

    1992-10-01

    Since carbon giants are ideal for study of the structure and kinematics of the outer galactic halo, we have undertaken a wide-area survey to search for faint high-latitude carbon (FHLC) stars. We use two-color photometric selection with large format CCDs to cover 52 deg^2 of sky to a depth of about V=18. Below this limit, we find good (< 20%) agreement between our object counts as a function of magnitude and the galactic models of Bahcall and Coneira (1984) at a variety of latitudes and longitudes. Our spectroscopic followup began with low-resolution spectra of 19 unconfirmed C-star candidates from the Case objective-prism photographic survey of Sanduleak and Pesch (1988). Four of these we find to be M stars. The 15 C stars we classify on the two-parameter Keenan-Morgan (1941) system as warm (color class < 4), with moderate to weak carbon band strengths (C class < 3). Of 94 faint C-star candidates from our own CCD survey, one highly ranked V=17 candidate was found to have strong carbon and CN bands. We estimate that to a depth of V=18, the surface density of FHLC stars is 0.019^0.044_-0.016 deg^-2. We identify two FHLC stars with previously cataloged high-proper-motion objects. These objects are thus inferred to be dwarf carbon (dC) stars, supplementing the one previously known case, G 77-61. Not all dC stars will have detectable proper motions, so other luminosity/distance indicators are needed: we find that C dwarfs all have similar JHK colors, and possibly an unusually strong lambda-6191 bandhead of carbon. By comparing positions of the HST Guide Star Catalog and the original Palomar Observatory Sky Survey, we detect proper motions in two additional FHLC stars. Our proper-motion survey, spanning a 30-yr base line, thus identifies four new dC's, and provides proper-motion upper limits for another 44 FHLC stars. Kinematic simulations suggest that virtually all Population II dCs will have detectable proper motions in a survey as sensitive as our own, and that to a

  4. A Peculiar Faint Satellite in the Remote Outer Halo of M31

    NASA Astrophysics Data System (ADS)

    Mackey, A. D.; Huxor, A. P.; Martin, N. F.; Ferguson, A. M. N.; Dotter, A.; McConnachie, A. W.; Ibata, R. A.; Irwin, M. J.; Lewis, G. F.; Sakari, C. M.; Tanvir, N. R.; Venn, K. A.

    2013-06-01

    We present Hubble Space Telescope imaging of a newly discovered faint stellar system, PAndAS-48, in the outskirts of the M31 halo. Our photometry reveals this object to be comprised of an ancient and very metal-poor stellar population with age >~ 10 Gyr and [Fe/H] lsim -2.3. Our inferred distance modulus (m - M)0 = 24.57 ± 0.11 confirms that PAndAS-48 is most likely a remote M31 satellite with a three-dimensional galactocentric radius of 149^{+19}_{-8} kpc. We observe an apparent spread in color on the upper red giant branch that is larger than the photometric uncertainties should allow, and briefly explore the implications of this. Structurally, PAndAS-48 is diffuse, faint, and moderately flattened, with a half-light radius r_h=26^{+4}_{-3} pc, integrated luminosity MV = -4.8 ± 0.5, and ellipticity \\epsilon =0.30^{+0.08}_{-0.15}. On the size-luminosity plane it falls between the extended globular clusters seen in several nearby galaxies and the recently discovered faint dwarf satellites of the Milky Way; however, its characteristics do not allow us to unambiguously classify it as either type of system. If PAndAS-48 is a globular cluster then it is among the most elliptical, isolated, and metal-poor of any seen in the Local Group, extended or otherwise. Conversely, while its properties are generally consistent with those observed for the faint Milky Way dwarfs, it would be a factor of ~2-3 smaller in spatial extent than any known counterpart of comparable luminosity. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO 12515.

  5. A PECULIAR FAINT SATELLITE IN THE REMOTE OUTER HALO OF M31

    SciTech Connect

    Mackey, A. D.; Dotter, A.; Huxor, A. P.; Martin, N. F.; Ibata, R. A.; Ferguson, A. M. N.; McConnachie, A. W.; Irwin, M. J.; Lewis, G. F.; Sakari, C. M.; Venn, K. A.; Tanvir, N. R.

    2013-06-20

    We present Hubble Space Telescope imaging of a newly discovered faint stellar system, PAndAS-48, in the outskirts of the M31 halo. Our photometry reveals this object to be comprised of an ancient and very metal-poor stellar population with age {approx}> 10 Gyr and [Fe/H] {approx}< -2.3. Our inferred distance modulus (m - M){sub 0} = 24.57 {+-} 0.11 confirms that PAndAS-48 is most likely a remote M31 satellite with a three-dimensional galactocentric radius of 149{sup +19}{sub -8} kpc. We observe an apparent spread in color on the upper red giant branch that is larger than the photometric uncertainties should allow, and briefly explore the implications of this. Structurally, PAndAS-48 is diffuse, faint, and moderately flattened, with a half-light radius r{sub h}=26{sup +4}{sub -3} pc, integrated luminosity M{sub V} = -4.8 {+-} 0.5, and ellipticity {epsilon}=0.30{sup +0.08}{sub -0.15}. On the size-luminosity plane it falls between the extended globular clusters seen in several nearby galaxies and the recently discovered faint dwarf satellites of the Milky Way; however, its characteristics do not allow us to unambiguously classify it as either type of system. If PAndAS-48 is a globular cluster then it is among the most elliptical, isolated, and metal-poor of any seen in the Local Group, extended or otherwise. Conversely, while its properties are generally consistent with those observed for the faint Milky Way dwarfs, it would be a factor of {approx}2-3 smaller in spatial extent than any known counterpart of comparable luminosity.

  6. Melanocortin 1 receptor (MC1R) gene sequence variation and melanism in the gray (Sciurus carolinensis), fox (Sciurus niger), and red (Sciurus vulgaris) squirrel.

    PubMed

    McRobie, Helen R; King, Linda M; Fanutti, Cristina; Coussons, Peter J; Moncrief, Nancy D; Thomas, Alison P M

    2014-01-01

    Sequence variations in the melanocortin 1 receptor (MC1R) gene are associated with melanism in many different species of mammals, birds, and reptiles. The gray squirrel (Sciurus carolinensis), found in the British Isles, was introduced from North America in the late 19th century. Melanism in the British gray squirrel is associated with a 24-bp deletion in the MC1R. To investigate the origin of this mutation, we sequenced the MC1R of 95 individuals including 44 melanic gray squirrels from both the British Isles and North America. Melanic gray squirrels of both populations had the same 24-bp deletion associated with melanism. Given the significant deletion associated with melanism in the gray squirrel, we sequenced the MC1R of both wild-type and melanic fox squirrels (Sciurus niger) (9 individuals) and red squirrels (Sciurus vulgaris) (39 individuals). Unlike the gray squirrel, no association between sequence variation in the MC1R and melanism was found in these 2 species. We conclude that the melanic gray squirrel found in the British Isles originated from one or more introductions of melanic gray squirrels from North America. We also conclude that variations in the MC1R are not associated with melanism in the fox and red squirrels.

  7. Red, green, blue equals 1, 2, 3: Digit-color synesthetes can use structured digit information to boost recall of color sequences.

    PubMed

    Teichmann, A Lina; Nieuwenstein, Mark R; Rich, Anina N

    2015-01-01

    Digit-color synesthetes report experiencing colors when perceiving letters and digits. The conscious experience is typically unidirectional (e.g., digits elicit colors but not vice versa) but recent evidence shows subtle bidirectional effects. We examined whether short-term memory for colors could be affected by the order of presentation reflecting more or less structure in the associated digits. We presented a stream of colored squares and asked participants to report the colors in order. The colors matched each synesthete's colors for digits 1-9 and the order of the colors corresponded either to a sequence of numbers (e.g., [red, green, blue] if 1 = red, 2 = green, 3 = blue) or no systematic sequence. The results showed that synesthetes recalled sequential color sequences more accurately than pseudo-randomized colors, whereas no such effect was found for the non-synesthetic controls. Synesthetes did not differ from non-synesthetic controls in recall of color sequences overall, providing no evidence of a general advantage in memory for serial recall of colors.

  8. Faint Compact Galaxy in the Early Universe

    NASA Image and Video Library

    2015-12-03

    This is a Hubble Space Telescope view of a very massive cluster of galaxies, MACS J0416.1-2403, located roughly 4 billion light-years away and weighing as much as a million billion suns. The cluster's immense gravitational field magnifies the image of galaxies far behind it, in a phenomenon called gravitational lensing. The inset is an image of an extremely faint and distant galaxy that existed only 400 million years after the big bang. It was discovered by Hubble and NASA's Spitzer Space Telescope. The gravitational lens makes the galaxy appear 20 times brighter than normal. The galaxy is comparable in size to the Large Magellanic Cloud (LMC), a diminutive satellite galaxy of our Milky Way. It is rapidly making stars at a rate ten times faster than the LMC. This might be the growing core of what was to eventually evolve into a full-sized galaxy. The research team has nicknamed the object Tayna, which means "first-born" in Aymara, a language spoken in the Andes and Altiplano regions of South America. http://photojournal.jpl.nasa.gov/catalog/PIA20054

  9. Detection of Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, P.; Lederer, S.; Barker, E.; Cowardin, H.; Abercromby, K.; Silha, J.; Burkhardt, A.

    2014-01-01

    There have been extensive optical surveys for debris at geosynchronous orbit (GEO) conducted with meter-class telescopes, such as those conducted with MODEST (the Michigan Orbital DEbris Survey Telescope, a 0.6-m telescope located at Cerro Tololo in Chile), and the European Space Agency's 1.0-m space debris telescope (SDT) in the Canary Islands. These surveys have detection limits in the range of 18th or 19th magnitude, which corresponds to sizes larger than 10 cm assuming an albedo of 0.175. All of these surveys reveal a substantial population of objects fainter than R = 15th magnitude that are not in the public U.S. Satellite Catalog. To detect objects fainter than 20th magnitude (and presumably smaller than 10 cm) in the visible requires a larger telescope and excellent imaging conditions. This combination is available in Chile. NASA's Orbital Debris Program Office has begun collecting orbital debris observations with the 6.5-m (21.3-ft diameter) "Walter Baade" Magellan telescope at Las Campanas Observatory. The goal is to detect objects as faint as possible from a ground-based observatory and begin to understand the brightness distribution of GEO debris fainter than R = 20th magnitude.

  10. The Population of Optically Faint GEO Debris

    NASA Astrophysics Data System (ADS)

    Seitzer, P.; Barker, E.; Buckalew, B.; Burkhardt, A.; Cowardin, H.; Frith, J.; Kaleida, C.; Lederer, S.; Lee, C.

    2016-09-01

    The 6.5-m Magellan telescope, 'Walter Baade', at the Las Campanas Observatory in Chile has been used for spot surveys of the geosynchronous Earth orbit (GEO) regime to study the population of optically faint GEO debris. The goal is to estimate the population of GEO debris at sizes much smaller than can be studied with 1-meter class telescopes. Despite the small field of view of the Magellan instrument (diameter 0.5-degree), a significant population of objects fainter than R = 19th magnitude has been found with angular rates consistent with circular orbits at GEO. We compare the size of this population with the numbers of GEO objects found at brighter magnitudes by smaller telescopes. The detections have a wide range of characteristics starting with those appearing as short uniform streaks. But there are a substantial number of detections that vary in brightness ("flashers") during the 5-second exposure. The duration of each of these flashes can be extremely brief: sometimes less than half a second. This is characteristic of a rapidly tumbling object with a quite variable projected product of size * albedo. If the albedo is of the order of 0.2, then the largest projected size of these objects is around 10-cm.

  11. Optically faint radio sources: reborn AGN?

    NASA Astrophysics Data System (ADS)

    Filho, M. E.; Brinchmann, J.; Lobo, C.; Antón, S.

    2011-12-01

    We present our discovery of several relatively strong radio sources in the field-of-view of SDSS galaxy clusters that have no optical counterparts down to the magnitude limits of the SDSS. The optically faint radio sources appear as double-lobed or core-jet objects in the FIRST radio images and have projected angular sizes ranging from 0.5 to 1.0 arcmin. We followed-up these sources with near-infrared imaging using the wide-field imager HAWK-I on the VLT. We detected Ks-band emitting regions, about 1.5 arcsec in size and coincident with the centers of the radio structures, in all sources, with magnitudes in the range 17-20 mag. We used spectral modelling to characterize the sample sources. In general, the radio properties are similar to those observed in 3CRR sources but the optical-radio slopes are consistent with those of moderate to high redshift (z < 4) gigahertz-peaked spectrum sources. Our results suggest that these unusual objects are galaxies whose black hole has been recently re-ignited but that retain large-scale radio structures, which are signatures of previous AGN activity.

  12. Accurate shear measurement with faint sources

    SciTech Connect

    Zhang, Jun; Foucaud, Sebastien; Luo, Wentao E-mail: walt@shao.ac.cn

    2015-01-01

    For cosmic shear to become an accurate cosmological probe, systematic errors in the shear measurement method must be unambiguously identified and corrected for. Previous work of this series has demonstrated that cosmic shears can be measured accurately in Fourier space in the presence of background noise and finite pixel size, without assumptions on the morphologies of galaxy and PSF. The remaining major source of error is source Poisson noise, due to the finiteness of source photon number. This problem is particularly important for faint galaxies in space-based weak lensing measurements, and for ground-based images of short exposure times. In this work, we propose a simple and rigorous way of removing the shear bias from the source Poisson noise. Our noise treatment can be generalized for images made of multiple exposures through MultiDrizzle. This is demonstrated with the SDSS and COSMOS/ACS data. With a large ensemble of mock galaxy images of unrestricted morphologies, we show that our shear measurement method can achieve sub-percent level accuracy even for images of signal-to-noise ratio less than 5 in general, making it the most promising technique for cosmic shear measurement in the ongoing and upcoming large scale galaxy surveys.

  13. Spectral Indices of Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Gim, Hansung B.; Hales, Christopher A.; Momjian, Emmanuel; Yun, Min Su

    2015-01-01

    The significant improvement in bandwidth and the resultant sensitivity offered by the Karl G. Jansky Very Large Array (VLA) allows us to explore the faint radio source population. Through the study of the radio continuum we can explore the spectral indices of these radio sources. Robust radio spectral indices are needed for accurate k-corrections, for example in the study of the radio - far-infrared (FIR) correlation. We present an analysis of measuring spectral indices using two different approaches. In the first, we use the standard wideband imaging algorithm in the data reduction package CASA. In the second, we use a traditional approach of imaging narrower bandwidths to derive the spectral indices. For these, we simulated data to match the observing parameter space of the CHILES Con Pol survey (Hales et al. 2014). We investigate the accuracy and precision of spectral index measurements as a function of signal-to noise, and explore the requirements to reliably probe possible evolution of the radio-FIR correlation in CHILES Con Pol.

  14. Carbon Dioxide Cycling, Climate, Impacts, and the Faint Young Sun

    NASA Technical Reports Server (NTRS)

    Zahnle, K. J.; Sleep, H. H.

    1999-01-01

    Evidence for relatively mild climates on ancient Earth and Mars has been a puzzle in light of the faint early sun. The geologic evidence, although far from conclusive, would appear to indicate that the surfaces of both planets were, if anything, warmer ca. 3-4 Ga than they are now. The astrophysical argument that the sun ought to have brightened approx. 30% since it reached the main sequence is hard to refute. There results a paradox between the icehouse we expect and the greenhouse we think we see. The usual fix has been to posit massive CO2 atmospheres, although reduced gases (e.g., NH3 or CH4 ) have had their partisans. Evidence against siderite in paleosols dated 2.2-2.75 Ga sets a rough upper limit of 30 PAL (present atmospheric levels) on pCO2 at that time. This is an order of magnitude short of what is needed to defeat the fainter sun. We present here an independent argument against high pCO2 on early Earth that applies not only to the Archean but yet more forcefully to the Hadean era. Additional information is contained in the original extended abstract.

  15. Carbon Dioxide Cycling, Climate, Impacts, and the Faint Young Sun

    NASA Technical Reports Server (NTRS)

    Zahnle, K. J.; Sleep, H. H.

    1999-01-01

    Evidence for relatively mild climates on ancient Earth and Mars has been a puzzle in light of the faint early sun. The geologic evidence, although far from conclusive, would appear to indicate that the surfaces of both planets were, if anything, warmer ca. 3-4 Ga than they are now. The astrophysical argument that the sun ought to have brightened approx. 30% since it reached the main sequence is hard to refute. There results a paradox between the icehouse we expect and the greenhouse we think we see. The usual fix has been to posit massive CO2 atmospheres, although reduced gases (e.g., NH3 or CH4 ) have had their partisans. Evidence against siderite in paleosols dated 2.2-2.75 Ga sets a rough upper limit of 30 PAL (present atmospheric levels) on pCO2 at that time. This is an order of magnitude short of what is needed to defeat the fainter sun. We present here an independent argument against high pCO2 on early Earth that applies not only to the Archean but yet more forcefully to the Hadean era. Additional information is contained in the original extended abstract.

  16. Galaxy population properties of the massive X-ray luminous galaxy cluster XDCP J0044.0-2033 at z = 1.58. Red-sequence formation, massive galaxy assembly, and central star formation activity

    NASA Astrophysics Data System (ADS)

    Fassbender, R.; Nastasi, A.; Santos, J. S.; Lidman, C.; Verdugo, M.; Koyama, Y.; Rosati, P.; Pierini, D.; Padilla, N.; Romeo, A. D.; Menci, N.; Bongiorno, A.; Castellano, M.; Cerulo, P.; Fontana, A.; Galametz, A.; Grazian, A.; Lamastra, A.; Pentericci, L.; Sommariva, V.; Strazzullo, V.; Šuhada, R.; Tozzi, P.

    2014-08-01

    cluster-core population comprises post-quenched galaxies transitioning toward the red sequence at intermediate magnitudes, while additionally a significant blue-cloud population of faint star-forming galaxies is present even in the densest central regions. Based on a color-color selection performed to separate different cluster galaxy types, we find that the blue star-forming population is concentrated in clumpy structures and dominates in particular at and beyond the R500 radius. On the other hand, the fraction of post-starburst galaxies steadily increases toward the center, while the red-locus population and red-sequence transition galaxies seem to reach their peak fractions already at intermediate cluster-centric radii of about r ~ 200 kpc. Conclusions: Our observations support the scenario in which the dominant effect of the dense z ≃ 1.6 cluster environment is an accelerated mass-assembly timescale (~1 Gyr or shorter) through merging activity that is responsible for driving core galaxies across the mass-quenching threshold of log (M∗/M⊙) ≃ 10.4. Beyond this mass limit, star formation is suppressed on timescales of ~1 Gyr, while the direct environmental quenching process seems to be subdominant and is acting on significantly longer timescales (~2-3 Gyr). Based on observations under programme ID 084.A-0844, 087.A-0351, and 089.A-0419 collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile.J- and Ks-band FITS files are 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/568/A5

  17. Faint spatial object classifier construction based on data mining technology

    NASA Astrophysics Data System (ADS)

    Lou, Xin; Zhao, Yang; Liao, Yurong; Nie, Yong-ming

    2016-11-01

    Data mining can effectively obtain the faint spatial object's patterns and characteristics, the universal relations and other implicated data characteristics, the key of which is classifier construction. Faint spatial object classifier construction with spatial data mining technology for faint spatial target detection is proposed based on theoretical analysis of design procedures and guidelines in detail. For the one-sidedness weakness during dealing with the fuzziness and randomness using this method, cloud modal classifier is proposed. Simulating analyzing results indicate that this method can realize classification quickly through feature combination and effectively resolve the one-sidedness weakness problem.

  18. DISCOVERY OF A NEW FAINT DWARF GALAXY ASSOCIATED WITH NGC 253

    SciTech Connect

    Sand, D. J.; Crnojević, D.; Strader, J.; Toloba, E.; Guhathakurta, P.; Caldwell, N.; McLeod, B.; Seth, A. C.

    2014-09-20

    We report the discovery of a new faint dwarf galaxy, which we dub Scl-MM-Dw1, at a projected distance of ∼65 kpc from the spiral galaxy NGC 253. The discovery results from the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS), a program with the Magellan/Megacam imager to study faint substructure in resolved stellar light around massive galaxies outside of the Local Group. We measure a tip of the red giant branch distance to Scl-MM-Dw1 of D = 3.9 ± 0.5 Mpc, consistent with that of NGC 253, making their association likely. The new dwarf's stellar population is complex, with an old, metal-poor red giant branch (≳10 Gyr, [Fe/H] ∼ –2), and an asymptotic giant branch with an age of ∼500 Myr. Scl-MM-Dw1 has a half-light radius of r{sub h} = 340 ± 50 pc and an absolute magnitude of M{sub V}  = –10.3 ± 0.6 mag, comparable to the Milky Way's satellites at the same luminosity. Once complete, our imaging survey of NGC 253 and other nearby massive galaxies will provide a census of faint substructure in halos beyond the Local Group, both to put our own environment into context and to confront models of hierarchical structure formation.

  19. The ISO-IRAS Faint Galaxy Survey

    NASA Technical Reports Server (NTRS)

    Smith, Harding E.

    1999-01-01

    As part of the ISO-IRAS Faint Galaxy Survey ISO Satellite observations of over 600 IRAS sources have been obtained with the ISOCAM instrument. Because our survey strategy involved relatively short integrations, great care was required in developing analysis software including cosmic-ray and transient removal and calibration. These observations have now been through final pipeline processing at IPAC and ground-based follow-up is ongoing. The observations are for sources from two samples: a " Filler' sample selected to be at z greater than 0.1 and a fainter sample which selected for the highest redshift galaxies in the IRAS survey, with redshifts 0.2 less than z less than 1.0. I now have obtained ground-based follow-up spectrophotometry at Lick and Palomar observatories for 100 LFIRGs with 0.1 less than z less than 0.7. Our observations have confirmed that these systems are comparable to nearby LFIRGs such as Arp 220, with L (sub -)(fir) greater than 10(exp 11) L(sub -) sun and typically HII/Liner optical excitation. About 10% of the galaxies show true AGN (Sy2) excitation. Based on our work on a nearby complete sample of LFIRGS, we believe that the majority of these systems are luminous Starbursts, thus this project is tracing the luminous end of the galaxy star-forming luminosity function - the (infrared) star-formation history of the Universe to z approx. 1, a topic of some considerable recent interest. A by-product of these ISOCAM observations is approximately 1 square degree of deep 2 microns pointings outside the IRAS error boxes, allowing us an independent estimate of the mid-infrared log N - log S relation. Ground-based observations of this sample are continuing.

  20. Faint solar radio structures from decametric observations

    NASA Astrophysics Data System (ADS)

    Briand, C.; Zaslavsky, A.; Maksimovic, M.; Zarka, P.; Lecacheux, A.; Rucker, H. O.; Konovalenko, A. A.; Abranin, E. P.; Dorovsky, V. V.; Stanislavsky, A. A.; Melnik, V. N.

    2008-10-01

    Aims: Decameter radio observations of the solar corona reveal the presence of numerous faint frequency drifting emissions, similar to “solar S bursts” which are reported in the literature. We present a statistical analysis of the characteristics of these emissions and propose a mechanism to excite the Langmuir waves thought to be at the origin of these emissions. Methods: The observations were performed between 1998 and 2002 with the Digital Spectro Polarimeter (DSP) receivers operated at the UTR-2 and Nançay decameter radio telescopes in the frequency range 15-30 MHz. Our theoretical explanation is based on Vlasov-Ampère simulations. Results: Based on the frequency drift rate, three populations of structures can be identified. The largest population presents an average negative frequency drift of -0.9 MHz s-1 and a lifetime up to 11 s (median value of 2.72 s). A second population shows a very small frequency drift of -0.1 MHz s-1 and a short lifetime of about 1 s. The third population presents an average positive frequency drift of +0.95 MHz s-1 and a lifetime of up to 3 s. Also, the frequency drift as a function of frequency is consistent with the former results, which present results in higher frequency range. No specific relationship was found between the occurrence of these emissions and the solar cycle or presence of flares. Assuming that these emissions are produced by “electron clouds” propagating the solar corona, we deduce electron velocities of about 3-5 times the electron thermal velocity. As previously shown, a localized, time-dependent modulation of the electron distribution function (heating) leads to low velocity electron clouds (consistent with observations), which, in turn, can generate Langmuir waves and electromagnetic signals by nonlinear processes.

  1. The ISO-IRAS Faint Galaxy Survey

    NASA Technical Reports Server (NTRS)

    Smith, Harding E.

    1999-01-01

    As part of the ISO-IRAS Faint Galaxy Survey ISO Satellite observations of over 600 IRAS sources have been obtained with the ISOCAM instrument. Because our survey strategy involved relatively short integrations, great care was required in developing analysis software including cosmic-ray and transient removal and calibration. These observations have now been through final pipeline processing at IPAC and ground-based follow-up is ongoing. The observations are for sources from two samples: a " Filler' sample selected to be at z greater than 0.1 and a fainter sample which selected for the highest redshift galaxies in the IRAS survey, with redshifts 0.2 less than z less than 1.0. I now have obtained ground-based follow-up spectrophotometry at Lick and Palomar observatories for 100 LFIRGs with 0.1 less than z less than 0.7. Our observations have confirmed that these systems are comparable to nearby LFIRGs such as Arp 220, with L (sub -)(fir) greater than 10(exp 11) L(sub -) sun and typically HII/Liner optical excitation. About 10% of the galaxies show true AGN (Sy2) excitation. Based on our work on a nearby complete sample of LFIRGS, we believe that the majority of these systems are luminous Starbursts, thus this project is tracing the luminous end of the galaxy star-forming luminosity function - the (infrared) star-formation history of the Universe to z approx. 1, a topic of some considerable recent interest. A by-product of these ISOCAM observations is approximately 1 square degree of deep 2 microns pointings outside the IRAS error boxes, allowing us an independent estimate of the mid-infrared log N - log S relation. Ground-based observations of this sample are continuing.

  2. Microbial Diversity of the Brine-Seawater Interface of the Kebrit Deep, Red Sea, Studied via 16S rRNA Gene Sequences and Cultivation Methods

    PubMed Central

    Eder, Wolfgang; Jahnke, Linda L.; Schmidt, Mark; Huber, Robert

    2001-01-01

    The brine-seawater interface of the Kebrit Deep, northern Red Sea, was investigated for the presence of microorganisms using phylogenetic analysis combined with cultivation methods. Under strictly anaerobic culture conditions, novel halophiles were isolated. The new rod-shaped isolates belong to the halophilic genus Halanaerobium and are the first representatives of the genus obtained from deep-sea, anaerobic brine pools. Within the genus Halanaerobium, they represent new species which grow chemoorganotrophically at NaCl concentrations ranging from 5 to 34%. The cellular fatty acid compositions are consistent with those of other Halanaerobium representatives, showing unusually large amounts of Δ7 and Δ11 16:1 fatty acids. Phylogenetic analysis of the brine-seawater interface sample revealed the presence of various bacterial 16S rRNA gene sequences dominated by cultivated members of the bacterial domain, with the majority affiliated with the genus Halanaerobium. The new Halanaerobium 16S rRNA clone sequences showed the highest similarity (99.9%) to the sequence of isolate KT-8-13 from the Kebrit Deep brine. In this initial survey, our polyphasic approach demonstrates that novel halophiles thrive in the anaerobic, deep-sea brine pool of the Kebrit Deep, Red Sea. They may contribute significantly to the anaerobic degradation of organic matter enriched at the brine-seawater interface. PMID:11425725

  3. NASA Researches the 'FaINT' Side of Sonic Booms

    NASA Image and Video Library

    As the latest in a continuing progression of NASA supersonics research projects aimed at reducing or mitigating the effect of sonic booms, the Farfield Investigation of No Boom Threshold, or FaINT,...

  4. a Faint and Lonely Brown Dwarf in the Solar Vicinity

    NASA Astrophysics Data System (ADS)

    1997-04-01

    Discovery of KELU-1 Promises New Insights into Strange Objects Brown Dwarfs are star-like objects which are too small to become real stars, yet too large to be real planets. Their mass is too small to ignite those nuclear processes which are responsible for the large energies and high temperatures of stars, but it is much larger than that of the planets we know in our solar system. Until now, very few Brown Dwarfs have been securely identified as such. Two are members of double-star systems, and a few more are located deep within the Pleiades star cluster. Now, however, Maria Teresa Ruiz of the Astronomy Department at Universidad de Chile (Santiago de Chile), using telescopes at the ESO La Silla observatory, has just discovered one that is all alone and apparently quite near to us. Contrary to the others which are influenced by other objects in their immediate surroundings, this new Brown Dwarf is unaffected and will thus be a perfect object for further investigations that may finally allow us to better understand these very interesting celestial bodies. It has been suggested that Brown Dwarfs may constitute a substantial part of the unseen dark matter in our Galaxy. This discovery may therefore also have important implications for this highly relevant research area. Searching for nearby faint stars The story of this discovery goes back to 1987 when Maria Teresa Ruiz decided to embark upon a long-term search (known as the Calan-ESO proper-motion survey ) for another type of unusual object, the so-called White Dwarfs , i.e. highly evolved, small and rather faint stars. Although they have masses similar to that of the Sun, such stars are no larger than the Earth and are therefore extremely compact. They are particularly interesting, because they most probably represent the future end point of evolution of our Sun, some billions of years from now. For this project, the Chilean astronomer obtained large-field photographic exposures with the 1-m ESO Schmidt telescope at

  5. Spectroscopic Confirmation of a Massive Red-sequence Selected Galaxy Cluster at Z=1.34 in the SpARCS-South Cluster Survey

    NASA Technical Reports Server (NTRS)

    Wilson, Gillian; Demarco, Ricardo; Muzzin, Adam; Yee, H.K.C.; Lacy, Mark; Surace, Jason; Gilbank, David; Blindert, Kris; Hoekstra, Henk; Majumdar, Subhabrata; hide

    2008-01-01

    The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a z'-passband imaging survey, consisting of deep (z' approx. 24 AB) observations made from both hemispheres using the CFHT 3.6m and CTIO 4m telescopes. The survey was designed with the primary aim of detecting galaxy clusters at z > 1. In tandem with pre-existing 3.6 micron observations from the Spitzer Space Telescope SWIRE Legacy Survey, SpARCS detects clusters using an infrared adaptation of the two-filter red-sequence cluster technique. The total effective area of the SpARCS cluster survey is 41.9 sq deg. In this paper, we provide an overview of the 13.6 sq deg Southern CTIO/MOSAICII observations. The 28.3 sq deg Northern CFHT/MegaCam observations are summarized in a companion paper by Muzzin et al. (2008a). In this paper, we also report spectroscopic confirmation of SpARCS J003550-431224, a very rich galaxy cluster at z = 1.335, discovered in the ELAIS-S1 field. To date, this is the highest spectroscopically confirmed redshift for a galaxy cluster discovered using the red-sequence technique. Based on nine confirmed members, SpARCS J003550-431224 has a preliminary velocity dispersion of 1050+/-230 km/s. With its proven capability for efficient cluster detection, SpARCS is a demonstration that we have entered an era of large, homogeneously-selected z > 1 cluster surveys.

  6. De Novo Transcriptome Sequencing Analysis of cDNA Library and Large-Scale Unigene Assembly in Japanese Red Pine (Pinus densiflora).

    PubMed

    Liu, Le; Zhang, Shijie; Lian, Chunlan

    2015-12-04

    Japanese red pine (Pinus densiflora) is extensively cultivated in Japan, Korea, China, and Russia and is harvested for timber, pulpwood, garden, and paper markets. However, genetic information and molecular markers were very scarce for this species. In this study, over 51 million sequencing clean reads from P. densiflora mRNA were produced using Illumina paired-end sequencing technology. It yielded 83,913 unigenes with a mean length of 751 bp, of which 54,530 (64.98%) unigenes showed similarity to sequences in the NCBI database. Among which the best matches in the NCBI Nr database were Picea sitchensis (41.60%), Amborella trichopoda (9.83%), and Pinus taeda (4.15%). A total of 1953 putative microsatellites were identified in 1784 unigenes using MISA (MicroSAtellite) software, of which the tri-nucleotide repeats were most abundant (50.18%) and 629 EST-SSR (expressed sequence tag- simple sequence repeats) primer pairs were successfully designed. Among 20 EST-SSR primer pairs randomly chosen, 17 markers yielded amplification products of the expected size in P. densiflora. Our results will provide a valuable resource for gene-function analysis, germplasm identification, molecular marker-assisted breeding and resistance-related gene(s) mapping for pine for P. densiflora.

  7. De Novo Transcriptome Sequencing Analysis of cDNA Library and Large-Scale Unigene Assembly in Japanese Red Pine (Pinus densiflora)

    PubMed Central

    Liu, Le; Zhang, Shijie; Lian, Chunlan

    2015-01-01

    Japanese red pine (Pinus densiflora) is extensively cultivated in Japan, Korea, China, and Russia and is harvested for timber, pulpwood, garden, and paper markets. However, genetic information and molecular markers were very scarce for this species. In this study, over 51 million sequencing clean reads from P. densiflora mRNA were produced using Illumina paired-end sequencing technology. It yielded 83,913 unigenes with a mean length of 751 bp, of which 54,530 (64.98%) unigenes showed similarity to sequences in the NCBI database. Among which the best matches in the NCBI Nr database were Picea sitchensis (41.60%), Amborella trichopoda (9.83%), and Pinus taeda (4.15%). A total of 1953 putative microsatellites were identified in 1784 unigenes using MISA (MicroSAtellite) software, of which the tri-nucleotide repeats were most abundant (50.18%) and 629 EST-SSR (expressed sequence tag- simple sequence repeats) primer pairs were successfully designed. Among 20 EST-SSR primer pairs randomly chosen, 17 markers yielded amplification products of the expected size in P. densiflora. Our results will provide a valuable resource for gene-function analysis, germplasm identification, molecular marker-assisted breeding and resistance-related gene(s) mapping for pine for P. densiflora. PMID:26690126

  8. The morphology of faint galaxies in Medium Deep Survey images using WFPC2

    NASA Technical Reports Server (NTRS)

    Griffiths, R. E.; Casertano, S.; Ratnatunga, K. U.; Neuschaefer, L. W.; Ellis, R. S.; Gilmore, G. F.; Glazebrook, K.; Santiago, B.; Huchra, J. P.; Windhorst, R. A.

    1994-01-01

    First results from Hubble Space Telescope (HST) Medium Deep Survey images taken with Wide Field/Planetary Camera-2 (WFPC2) demonstrate that galaxy classifications can be reliably performed to magnitudes I814 approximately less than 22.0 in the F815W band. Published spectroscopic surveys to this depth indicate a mean redshift of bar-z approximately 0.5. We have classified over 200 galaxies in nine WFPC2 fields according to a basic morphological scheme. The majority of these faint galaxies appear to be similar to regular Hubble-sequence examples observed at low redshift. To the precision of our classification scheme, the relative proportion of spheroidal and disk systems of normal appearance is as expected from nearby samples, indicating that the bulk of the local galaxy population was in place at half the Hubble time. However, the most intriguing result is the relatively high proportion (approximately 40%) of objects which are in some way anomalous, and which may be of relevance in understanding the origin of the familiar excess population of faint galaxies established by others. These diverse objects include apparently interacting pairs whose multiple structure is only revealed with HST's angular resolution, galaxies with superluminous star-forming regions, diffuse low surface brightness galaxies of various forms, and compact galaxies. These anomalous galaxies contribute a substantial fraction of the excess counts at our limiting magnitude, and may provide insights into the 'faint blue galaxy' problem.

  9. HST observations of faint Cold Classical KBOs

    NASA Astrophysics Data System (ADS)

    Penteado, Paulo F.; Trilling, David E.; Grundy, Will

    2016-10-01

    The size distribution of the known Kuiper Belt Objects has been described by a double power law, with a break at R magnitude 25. There are two leading interpretations to this break: 1) It is the result of the collisional evolution, with the objects smaller than the break being the population most affected by collisional erosion. 2) The size distribution break is primordial, set during the Kuiper Belt formation.The low inclination KBOs, the Cold Classical population, is thought to have been dynamically isolated since the formation of the Solar System, and thus only collisions between Cold Classicals would have affected their size distribution. If the distribution is collisional, it probes parameters of the Kuiper Belt history: strengths of the bodies, impact energies and frequency, and the the number of objects. If the distribution is primordial, it reveals parameters of the Kuiper Belt accretion, as well as limits on its subsequent collisional history.We obtained HST observations of 16 faint Cold Classicals, which we combine with archival HST observations of 20 others, to examine the distribution of two properties of the smallest KBOs: colors and binary fraction. These properties can differentiate between a primordial and a collisional origin of the size distribution break. If the smaller bodies have been through extensive collisional evolution, they will have exposed materials from their interiors, which has not been exposed to weathering, and thus should be bluer than the old surfaces of the larger bodies. Another constraint can be derived from the fraction of binary objects: the angular momentum of the observed binaries is typically too high to result from collisions, thus a collisionally-evolved population would have a lower binary fraction, due to the easier separation of binaries, compared to the disruption of similar-sized bodies, and the easier disruption of the binary components, due to the smaller size.We present the constraints to the color and binary

  10. Sarcocystis species in red deer revisited: with a re-description of two known species as Sarcocystis elongata n. sp. and Sarcocystis truncata n. sp. based on mitochondrial cox1 sequences.

    PubMed

    Gjerde, Bjørn

    2014-03-01

    In a previous investigation, five Sarcocystis species were described from Norwegian red deer and believed to be conspecific with species occurring in either reindeer or moose based on sarcocyst morphology and nucleotide sequences of the nuclear ribosomal DNA unit. The aim of the present study was to characterize numerous isolates of these sarcocyst types at the mitochondrial cytochrome c oxidase subunit I gene (cox1) in order to corroborate or refute previous species designations of Sarcocystis in red deer. The Sarcocystis tarandi- and Sarcocystis rangiferi-like taxa in red deer and reindeer, respectively, were thoroughly compared by sequencing 14-27 isolates of each type. Sequence comparisons revealed four distinct sequence types, which by phylogenetic analyses were placed in four monophyletic groups according to host origin, and they were therefore considered to represent four separate species. The two taxa of this type in red deer were named Sarcocystis elongata and Sarcocystis truncata, respectively. Sequencing of many isolates of Sarcocystis hjorti and Sarcocystis ovalis from red deer and moose confirmed that these species occur in both hosts. A revised description of the two new species is given and the current knowledge concerning all six Sarcocystis species in red deer is reviewed.

  11. Use of simple sequence repeat markers for DNA fingerprinting and diversity analysis of sugarcane (Saccharum spp) cultivars resistant and susceptible to red rot.

    PubMed

    Hameed, U; Pan, Y-B; Muhammad, K; Afghan, S; Iqbal, J

    2012-05-08

    Red rod is an economically important disease of sugarcane caused by the fungus Colletotrichum falcatum. We used a simple sequence repeat (SSR)-based marker system to identify and analyze genetic relationships of red rot resistant and susceptible sugarcane cultivars grown in Pakistan. Twenty-one highly polymorphic SSR markers were used for DNA fingerprinting and genetic diversity analysis of 20 sugarcane cultivars. These SSR markers were found to be highly robust; we identified 144 alleles, with 3-11 alleles per marker and a mean of 6.8. Three SSR markers were able to identify all 20 cultivars. DNAMAN(®)-generated homology tree was used to analyze genetic diversity among these cultivars; all cultivars shared 58% or more similarity. We correlated polymorphism information content and resolving power values with marker effectiveness in the process of sugarcane cultivar identification. We concluded that a small number of SSR-derived DNA markers will allow breeders to identify red rot resistant and susceptible cultivars.

  12. Predicting the fate of binary red giants using the observed sequence E star population: binary planetary nebula nuclei and post-RGB stars

    NASA Astrophysics Data System (ADS)

    Nie, J. D.; Wood, P. R.; Nicholls, C. P.

    2012-07-01

    Sequence E variables are close binary red giants that show ellipsoidal light variations. They are likely the immediate precursors of planetary nebulae (PNe) with close binary central stars as well as other binary post-asymptotic giant branch (post-AGB) and binary post-red giant branch (post-RGB) stars. We have made a Monte Carlo simulation to determine the fraction of red giant binaries that go through a common envelope event leading to the production of a close binary system or a merged star. The novel aspect of this simulation is that we use the observed frequency of sequence E binaries in the Large Magellanic Cloud (LMC) to normalize our calculations. This normalization allows us to produce predictions that are relatively independent of model assumptions. In our standard model, and assuming that the relative numbers of PNe of various types are proportional to their birth rates, we find that in the LMC today the fraction of PNe with close binary central stars is 7-9 per cent, the fraction of PNe with intermediate period binary central stars having separations capable of influencing the nebula shape (orbital periods less than 500 yr) is 23-27 per cent, the fraction of PNe containing wide binaries that are unable to influence the nebula shape (orbital period greater than 500 yr) is 46-55 per cent, the fraction of PNe derived from single stars is 3-19 per cent, and 5-6 per cent of PNe are produced by previously merged stars. We also predict that the birth rate of post-RGB stars is ˜4 per cent of the total PN birth rate, equivalent to ˜50 per cent of the production rate of PNe with close binary central stars. These post-RGB stars most likely appear initially as luminous low-mass helium white dwarf binaries. The average lifetime of sequence E ellipsoidal variability with amplitude more than 0.02 mag is predicted to be ˜0.95 Myr. We use our model and the observed number of red giant stars in the top one magnitude of the RGB in the LMC to predict the number of PNe in

  13. Uncloned expanded CAG/CTG repeat sequences in autosomal dominant cerebellar ataxia (ADCA) detected by the repeat expansion detection (RED) method.

    PubMed Central

    Pujana, M A; Volpini, V; Gratacós, M; Corral, J; Banchs, I; Sánchez, A; Genís, D; Cervera, C; Estivill, X

    1998-01-01

    In some neurodegenerative diseases, genetic anticipation correlates with expansions of the CAG/CTG repeat sequence above the normal range through the generations of a pedigree. Among these neurodegenerative diseases are late onset autosomal dominant cerebellar ataxias (ADCA). ADCA are genetically heterogeneous disorders with different cloned genes for spinocerebellar ataxia type 1 (SCA1), type 2 (SCA2), type 3 or Machado-Joseph disease (SCA3/MJD), and type 6 (SCA6). Another related dominant ataxia, dentatorubral-pallidoluysian atrophy (DRPLA), also shows CAG/CTG repeat expansions. Genetic anticipation has been reported for all of them except for the recently cloned SCA6 gene. Other, as yet undetected SCA genes may show the same features. We have used the repeat expansion detection (RED) method to detect repeat expansions directly in DNA samples from ADCA patients not resulting from known genes. Our sample consists of 19 affected index cases, corresponding to 52.8% of our ADCA families without CAG/CTG repeat expansions in the SCA1, SCA2, SCA3/MJD, SCA6, or DRPLA genes. Eighty-nine percent of the index cases had expansions of a CAG/CTG sequence greater than 40 repeats by RED, while these were observed in only 26.9% of 78 healthy subjects from the general population (p < 0.0001). The distribution of RED fragments in controls and ADCA patients also shows significant differences with the Mann-Whitney U test (U = 376.5, p = 0.0007). Moreover, there was a significant inverse correlation between the size of expansion and the age of onset (r = -0.54, p = 0.018). These results show CAG/CTG repeat expansions of over 40 repeats in our sample of ADCA families not resulting from known SCA genes. Images PMID:9507387

  14. Kinematics and chemistry of faint high latitude dwarf carbon stars

    NASA Astrophysics Data System (ADS)

    Yoon, Jinmi; Beers, Timothy C.; Dietz, Sarah; Lee, Young Sun; Placco, Vinicius M.

    2017-01-01

    The diffuse halo system of the Milky Way is complex, and has been shown to comprise at least two main components: a near-zero net rotation inner-halo and a more rapidly rotating outer-halo component. Studies of the ancient, very metal-poor stars in the Galactic halo system are crucial for understanding its early formation history. The so-called carbon-enhanced metal-poor (CEMP) stars are an important subset of the stars in the halo system, which exhibit distinctive kinematic and chemical signatures that can be used to constrain the star-formation histories and assembly of the various Galactic components.We have examined the sample of main-sequence dwarf and other faint high Galactic latitude carbon-enhanced stars from the Sloan Digital Sky Survey studied by Green (2013). As noted by Green, many of these starsexhibit high proper motions, which have been later claimed to be related to possible binary ejection models Plant et al. (2016). By use of the CEMP sub-classification approach of Yoon et al. (2016), we investigate whether the kinematics of these stars might instead result from their membership in the inner/outer halo populations of the Galaxy.ReferencesGreen, P. 2013, ApJ, 765, 12Plant, K. et al. 2016, AAS 227.34115Yoon, J. et al. 2016, ApJ, in pressAcknowledgementThis work was supported in part by the National Science Foundation under Grant No. PHY-1430152 (JINA Center for the Evolution of the Elements).

  15. Characterizing elusive, faint dusty star-forming galaxies: a lensed, optically undetected ALMA galaxy at z 3.3

    NASA Astrophysics Data System (ADS)

    Santini, P.; Castellano, M.; Fontana, A.; Merlin, E.; Maiolino, R.; Mason, C.; Mignano, A.; Pilo, S.; Amorin, R.; Berta, S.; Bourne, N.; Calura, F.; Daddi, E.; Elbaz, D.; Grazian, A.; Magliocchetti, M.; Michałowski, M. J.; Pentericci, L.; Pozzi, F.; Rodighiero, G.; Schreiber, C.; Valiante, R.

    2016-12-01

    We present the serendipitous ALMA detection of a faint submillimeter galaxy (SMG) lensed by a foreground z 1 galaxy. By optimizing the source detection to deblend the system, we accurately build the full spectral energy distribution of the distant galaxy from the I814 band to radio wavelengths. It is extremely red, with a I-K colour larger than 2.5. We estimate a photometric redshift of 3.28 and determine the physical parameters. The distant galaxy turns out to be magnified by the foreground lens by a factor of 1.5, which implies an intrinsic Ks-band magnitude of 24.5, a submillimeter flux at 870 μm of 2.5 mJy and a SFR of 150-300 M⊙/ yr, depending on the adopted tracer. These values place our source towards the faint end of the distribution of observed SMGs, and in particular among the still few faint SMGs with a fully characterized spectral energy distribution, which allows us not only to accurately estimate its redshift, but also to measure its stellar mass and other physical properties. The galaxy studied in this work is a representative of the population of faint SMGs, of which only few objects are known to date, that are undetected in optical and therefore are not typically accounted for when measuring the cosmic star formation history (SFH). This faint galaxy population thus likely represents an important and missing piece in our understanding of the cosmic SFH. Its observation and characterization is of major importance to achieve a solid picture of galaxy evolution.

  16. Phenolic compositions of 50 and 30 year sequences of Australian red wines: the impact of wine age.

    PubMed

    McRae, Jacqui M; Dambergs, Robert G; Kassara, Stella; Parker, Mango; Jeffery, David W; Herderich, Markus J; Smith, Paul A

    2012-10-10

    The phenolic composition of red wine impacts upon the color and mouthfeel and thus quality of the wine. Both of these characteristics differ depending on the age of a wine, with the purple of young wines changing to brick red and the puckering or aggressive astringency softening in older wines. This study investigated the color parameters, tannin concentrations and tannin composition of a 50 year series of Cabernet Sauvignon wines from a commercial label as well as 30 year series of Cabernet Sauvignon and Shiraz wines from a separate commercial label to assess the impact of wine age on phenolic composition and concentration. The wine color density in wines of 40 to 50 years old was around 5 AU compared with 16 AU of wine less than 12 months old, which correlated well with the concentration of non-bleachable pigments and pigmented polymers. Conversely, the anthocyanin concentrations in 10 year old wines were substantially lower than that of recently bottled wines (around 100 mg/L compared with 627 mg/L, respectively), adding further evidence that non-bleachable pigments including pigmented polymers play a much larger role in long-term wine color than anthocyanins. No age-related trend was observed for tannin concentration, indicating that the widely noted softer astringency of older red wines cannot necessarily be directly related to lower concentrations of soluble wine tannin and is potentially a consequence of changes in tannin structure. Wine tannins from older wines were generally larger than tannins from younger wines and showed structural changes consistent with oxidation.

  17. The faint galaxy contribution to the diffuse extragalactic background light

    NASA Technical Reports Server (NTRS)

    Cole, Shaun; Treyer, Marie-Agnes; Silk, Joseph

    1992-01-01

    Models of the faint galaxy contribution to the diffuse extragalactic background light are presented, which are consistent with current data on faint galaxy number counts and redshifts. The autocorrelation function of surface brightness fluctuations in the extragalactic diffuse light is predicted, and the way in which these predictions depend on the cosmological model and assumptions of biasing is determined. It is confirmed that the recent deep infrared number counts are most compatible with a high density universe (Omega-0 is approximately equal to 1) and that the steep blue counts then require an extra population of rapidly evolving blue galaxies. The faintest presently detectable galaxies produce an interesting contribution to the extragalactic diffuse light, and still fainter galaxies may also produce a significant contribution. These faint galaxies still only produce a small fraction of the total optical diffuse background light, but on scales of a few arcminutes to a few degrees, they produce a substantial fraction of the fluctuations in the diffuse light.

  18. Enhanced faint companion photometry and astrometry using wavelength diversity.

    PubMed

    Burke, Daniel; Devaney, Nicholas

    2010-11-01

    In this paper we examine approaches to faint companion detection and estimation in multi-spectral images. We will employ the Hotelling observer, which is the optimal linear algorithm for signal detection. We have shown how to use this observer to estimate faint object position and brightness in the presence of residual speckle, which usually limits astrometric and photometric techniques. These speckles can be reduced by differential imaging techniques such as Angular Differential Imaging and Spectral Differential Imaging. Here we present results based on simulations of adaptive-optics-corrected images from an Extremely Large Telescope (ELT) that contain quasi-static speckle noise. The simulation includes Angular Differential Imaging and Spectral Differential Imaging to reduce the residual speckle and subsequent multi-wavelength processing. We examine the feasibility of this approach on simulated ELT observations of faint companions.

  19. Draft Genome Sequence of Oenococcus oeni Strain X2L (CRL1947), Isolated from Red Wine of Northwest Argentina

    PubMed Central

    Saavedra, Lucila

    2015-01-01

    We report the draft genome sequence of Oenococcus oeni strain X2L, a potential starter culture of malolactic fermentation, isolated from Malbec wine of Argentina. Genes encoding for enzymes involved in the metabolism of malate, citrate, and nitrogen compounds, as well as aroma compounds, were found in this genome, showing its ability to improve the sensorial characteristics of wines. PMID:25555740

  20. Genome Sequence of the Red Pigment-Forming Meiothermus taiwanensis Strain RP Isolated from Paniphala Hot Spring, India

    PubMed Central

    Mukherjee, Trinetra; Bose, Sucharita; Sen, Urmimala; Roy, Chayan; Rameez, Moidu Jameela; Ghosh, Wriddhiman

    2016-01-01

    Here we report the draft genome sequence of Meiothermus taiwanensis strain RP (MCC 2966), isolated from the Paniphala hot spring of India, which contains genes encoding for enzymes of the methyl erythritol 4-phosphate (MEP) pathway of isoprenoid biosynthesis and carotenoid backbone synthesis. PMID:27365353

  1. Complete mitogenome sequences of the pacific red snapper (Lutjanus peru) and the spotted rose snapper (Lutjanus gutattus).

    PubMed

    Bayona-Vásquez, Natalia Juliana; Hernández-Álvarez, Cristóbal Alejandro; Glenn, Travis; Domínguez-Domínguez, Omar; Uribe-Alcocer, Manuel; Díaz-Jaimes, Píndaro

    2017-03-01

    The structure of the mitochondrial genome for the Pacific red snapper, Lutjanus peru, and the spotted rose snapper, Lutjanus gutattus, of specimens collected in the eastern Pacific is similar to the reported for other teleosts and shares the same configuration with other members of the family Lutjanidae. It has a total length of 16 502 and 16 508 base pairs (bp) for Lutjanus peru and L. gutattus, respectively; on average the base composition was A (27.9%), T (24.8%) C (30.9%), and G (16.4%), containing 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes; and the leucine (Leu) tRNA is duplicated.

  2. The Origin of the Heaviest Metals in Most Ultra-faint Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Roederer, Ian U.

    2017-01-01

    The heaviest metals found in stars in most ultra-faint dwarf (UFD) galaxies in the Milky Way halo are generally underabundant by an order of magnitude or more when compared with stars in the halo field. Among the heavy elements produced by n-capture reactions, only Sr and Ba can be detected in red giant stars in most UFD galaxies. This limited chemical information is unable to identify the nucleosynthesis process(es) responsible for producing the heavy elements in UFD galaxies. Similar [Sr/Ba] and [Ba/Fe] ratios are found in three bright halo field stars, BD‑18°5550, CS 22185–007, and CS 22891–200. Previous studies of high-quality spectra of these stars report detections of additional n-capture elements, including Eu. The [Eu/Ba] ratios in these stars span +0.41 to +0.86. These ratios and others among elements in the rare Earth domain indicate an r-process origin. These stars have some of the lowest levels of r-process enhancement known, with [Eu/H] spanning ‑3.95 to ‑3.32, and they may be considered nearby proxies for faint stars in UFD galaxies. Direct confirmation, however, must await future observations of additional heavy elements in stars in the UFD galaxies themselves.

  3. Seismic strain tensor in the area to the South of Ras Mohamed region during the November-December, 2012 seismic sequence, Northern Red Sea, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Gad-Elkareem A.; Abd Allah, Saud A.

    2014-06-01

    We calculated the strain tensor for a sequence of earthquakes that occurred in front of Ras Mohamed, Northern Red Sea within the period from 19th November up to 31st of December 2011. The value and the direction of the strain are evaluated based on a reliable number of focal mechanism solutions. Most of the solutions indicate the dominance of normal faulting. The principal strain axis shows that the deformation is taken up mainly as an extension in the NE-SW direction with a very small crustal thinning rate. The orientation of the principal strain axes deduced from the eigenvectors is in good agreement with the main trend of the focal mechanisms of the selected events (normal type faulting).

  4. Seismic strain tensor in the area to the South of Ras Mohamed region during the November-December, 2011 seismic sequence, Northern Red Sea, Egypt.

    NASA Astrophysics Data System (ADS)

    Mohamed, Gad-Elkareem; Abdallah, Saud

    2016-04-01

    We calculated the strain tensor for a sequence of earthquakes that occurred in front of Ras Mohamed, Northern Red Sea within the period from 19th November up to 31st of December 2011. The value and the direction of the strain are evaluated based on a reliable number of focal mechanism solutions. Most of the solutions indicate the dominance of normal faulting. The principal strain axis shows that the deformation is taken up mainly as an extension in the NE-SW direction with a very small crustal thinning rate. The orientation of the principal strain axes deduced from the eigenvectors is in good agreement with the main trend of the focal mechanisms of the selected events (normal type faulting).

  5. Spectroscopic Confirmation of Two Massive Red-sequence-selected Galaxy Clusters at Z Approximately Equal to 1.2 in the Sparcs-North Cluster Survey

    NASA Technical Reports Server (NTRS)

    Muzzin, Adam; Wilson, Gillian; Yee, H.K.C.; Hoekstra, Henk; Gilbank, David; Surace, Jason; Lacy, Mark; Blindert, Kris; Majumdar, Subhabrata; Demarco, Ricardo; hide

    2008-01-01

    The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a deep z -band imaging survey covering the Spitzer SWIRE Legacy fields designed to create the first large homogeneously-selected sample of massive clusters at z > 1 using an infrared adaptation of the cluster red-sequence method. We present an overview of the northern component of the survey which has been observed with CFHT/MegaCam and covers 28.3 deg(sup 2). The southern component of the survey was observed with CTIO/MOSAICII, covers 13.6 deg(sup 2), and is summarized in a companion paper by Wilson et al. (2008). We also present spectroscopic confirmation of two rich cluster candidates at z approx. 1.2. Based on Nod-and- Shuffle spectroscopy from GMOS-N on Gemini there are 17 and 28 confirmed cluster members in SpARCS J163435+402151 and SpARCS J163852+403843 which have spectroscopic redshifts of 1.1798 and 1.1963, respectively. The clusters have velocity dispersions of 490 +/- 140 km/s and 650 +/- 160 km/s, respectively which imply masses (M(sub 200)) of (1.0 +/- 0.9) x 10(exp 14) Stellar Mass and (2.4 +/- 1.8) x 10(exp 14) Stellar Mass. Confirmation of these candidates as bonafide massive clusters demonstrates that two-filter imaging is an effective, yet observationally efficient, method for selecting clusters at z > 1.

  6. Galaxy Populations in Massive Galaxy Clusters to z = 1.1: Color Distribution, Concentration, Halo Occupation Number and Red Sequence Fraction

    NASA Astrophysics Data System (ADS)

    Hennig, C.; Mohr, J. J.; Zenteno, A.; Desai, S.; Dietrich, J. P.; Bocquet, S.; Strazzullo, V.; Saro, A.; Abbott, T. M. C.; Abdalla, F. B.; Bayliss, M.; Benoit-Lévy, A.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Capasso, R.; Capozzi, D.; Carnero, A.; Kind, M. Carrasco; Carretero, J.; Chiu, I.; D'Andrea, C. B.; daCosta, L. N.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti-Neto, A.; Fosalba, P.; Frieman, J.; Gangkofner, C.; Gonzalez, A.; Gruen, D.; Gruendl, R. A.; Gupta, N.; Gutierrez, G.; Honscheid, K.; Hlavacek-Larrondo, J.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; March, M.; Marshall, J. L.; Martini, P.; McDonald, M.; Melchior, P.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nord, B.; Ogando, R.; Plazas, A. A.; Reichardt, C.; Romer, A. K.; Rozo, E.; Rykoff, E. S.; Sanchez, E.; Santiago, B.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Stalder, B.; Stanford, S. A.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Vikram, V.; Walker, A. R.; Zhang, Y.

    2017-01-01

    We study the galaxy populations in 74 Sunyaev Zeldovich Effect (SZE) selected clusters from the South Pole Telescope (SPT) survey that have been imaged in the science verification phase of the Dark Energy Survey (DES). The sample extends up to z ˜ 1.1 with 4 × 1014M⊙ ≤ M200 ≤ 3 × 1015M⊙. Using the band containing the 4000 Å break and its redward neighbor, we study the color-magnitude distributions of cluster galaxies to ˜m★ + 2, finding: (1) the intrinsic rest frame g - r color width of the red sequence (RS) population is ˜0.03 out to z ˜ 0.85 with a preference for an increase to ˜0.07 at z = 1 and (2) the prominence of the RS declines beyond z ˜ 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R200 with a concentration of cg = 3.59^{+0.20}_{-0.18}, 5.37^{+0.27}_{-0.24} and 1.38^{+0.21}_{-0.19} for the full, the RS and the blue non-RS populations, respectively, but with ˜40% to 55% cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The red sequence (RS) fraction within R200 is (68 ± 3)% at z = 0.46, varies from ˜55% at z = 1 to ˜80% at z = 0.1, and exhibits intrinsic variation among clusters of ˜14%. We discuss a model that suggests the observed redshift trend in RS fraction favors a transformation timescale for infalling field galaxies to become RS galaxies of 2 to 3 Gyr.

  7. SPECTROSCOPIC CONFIRMATION OF THREE RED-SEQUENCE SELECTED GALAXY CLUSTERS AT z = 0.87, 1.16, AND 1.21 FROM THE SPARCS SURVEY

    SciTech Connect

    Demarco, Ricardo; Wilson, Gillian; Muzzin, Adam; Lacy, Mark; Surace, Jason; Yee, H. K. C.; Hoekstra, Henk; Blindert, Kris; Gilbank, David

    2010-03-10

    The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a z'-passband imaging survey of the 50 deg{sup 2} Spitzer SWIRE Legacy fields, designed with the primary aim of creating the first large, homogeneously selected sample of massive clusters at z > 1. SpARCS uses an infrared adaptation of the two-filter cluster red-sequence technique. In this paper, we report Keck/LRIS spectroscopic confirmation of two new exceptionally rich galaxy clusters, SpARCS J161315+564930 at z = 0.871 +- 0.002, with 14 high-confidence members and a rest-frame velocity dispersion of sigma{sub v} = 1230 +- 320 km s{sup -1}, and SpARCS J161641+554513 at z = 1.161 +- 0.003, with seven high-confidence members (including one active galactic nucleus) and a rest-frame velocity dispersion of sigma{sub v} = 950 +- 330 km s{sup -1}. We also report confirmation of a third new system, SpARCS J161037+552417 at z = 1.210 +- 0.002, with seven high-confidence members and a rest-frame velocity dispersion of sigma{sub v} = 410 +- 300 km s{sup -1}. These three new spectroscopically confirmed clusters further demonstrate the efficiency and effectiveness of two-filter imaging for detecting bona fide galaxy clusters at high redshift. We conclude by demonstrating that prospects are good for the current generation of surveys aiming to estimate cluster redshifts and masses at z {approx}> 1 directly from optical-infrared imaging.

  8. Cloning, sequencing and functional analysis of a truncated cDNA encoding red deer prolactin receptor: an alternative tyrosine residue mediates beta-casein promoter activation.

    PubMed

    Jabbour, H N; Clarke, L A; Boddy, S; Pezet, A; Edery, M; Kelly, P A

    1996-10-14

    This study reports the isolation and in vitro characterisation of a truncated cDNA encoding the red deer long form prolactin receptor. The cDNA sequence predicts a protein of 557 amino acids which differs from the rat sequence by a 3' truncation of the cytoplasmic domain located 34 residues before the stop codon. The deer sequence shares the regions of homology which are important for maintenance of structural and functional integrity, high affinity binding and signal transduction. However, the truncated deer receptor lacks the most C-terminal tyrosine residue in the intracellular domain which is believed to be essential for activation of the beta-casein promoter. Transfection studies of the cervine cDNA into human 293 fibroblast cells confirmed the expression of a receptor that has high affinity binding to ovine prolactin (Ka = 0.65 x 10(9)M(-1) and Bmax = 548.6 fmol/mg protein). Co-transfection of CHO cells with expression vector encoding the cervine prolactin receptor cDNA along with a fusion gene containing the promoter region of beta-casein followed by beta-luciferase coding sequence led to 8.13 +/- 0.13-fold induction of luciferase enzyme activity in the presence of 400 ng/ml ovine prolactin. This was comparable to fold induction observed with the wild type long form rat prolactin receptor (6.37 +/- 0.48); macaque growth hormone receptor was without effect. Western blot analysis demonstrated tyrosine phosphorylation of the cervine receptor and the associated kinase Jak2 following stimulation with prolactin. This confirms that the cervine cDNA although truncated is fully functional and that Jak2 and an alternative tyrosine residue in the intracellular domain are involved in the signalling pathway leading to activation of the beta-casein promoter. Northern blot analysis provides evidence that the prolactin receptor in the liver is encoded by transcripts of approximately 2.5 and 3.5 kb. Comparison of Northern blots of different deer species suggests that the

  9. 1. Dyea Dock looking south. Note faint evenly spaced circular ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Dyea Dock looking south. Note faint evenly spaced circular dark pieces of grass up through the middle of the picture indicating posts making up the pier. Photograph made from park service cherry picker. - Dyea Dock & Association (Ruins), Skagway, Skagway, AK

  10. The CFHT (MOS/PUMA) faint quasar survey

    NASA Astrophysics Data System (ADS)

    Schade, David

    A multi-aperture spectroscopic survey for faint quasars has been carried out at Canada-France-Hawaii telescope. The survey is capable of reaching two magnitudes deeper into the luminosity function at redshifts greater than 3 than the deepest existing surveys. The technique is discussed and preliminary results are presented.

  11. CONFIRMATION OF FAINT DWARF GALAXIES IN THE M81 GROUP

    SciTech Connect

    Chiboucas, Kristin; Jacobs, Bradley A.; Tully, R. Brent; Karachentsev, Igor D. E-mail: bjacobs@ifa.hawaii.edu E-mail: ikar@luna.sao.ru

    2013-11-01

    We have followed up on the results of a 65 deg{sup 2} CFHT/MegaCam imaging survey of the nearby M81 Group searching for faint and ultra-faint dwarf galaxies. The original survey turned up 22 faint candidate dwarf members. Based on two-color HST ACS/WFC and WFPC2 photometry, we now confirm 14 of these as dwarf galaxy members of the group. Distances and stellar population characteristics are discussed for each. To a completeness limit of M{sub r{sup '}}= -10, we find a galaxy luminosity function slope of –1.27 ± 0.04 for the M81 Group. In this region, there are now 36 M81 Group members known, including 4 blue compact dwarfs; 8 other late types including the interacting giants M81, NGC 3077, and M82; 19 early type dwarfs; and at least 5 potential tidal dwarf galaxies. We find that the dSph galaxies in M81 appear to lie in a flattened distribution, similar to that found for the Milky Way and M31. One of the newly discovered dSph galaxies has properties similar to the ultra-faint dwarfs being found in the Local Group with a size R{sub e} ∼ 100 pc and total magnitude estimates M{sub r{sup '}}= -6.8 and M{sub I} ∼ –9.1.

  12. Cortical responses elicited by luminance and compound stimuli modulated by pseudo-random sequences: comparison between normal trichromats and congenital red-green color blinds.

    PubMed

    Risuenho, Bárbara B O; Miquilini, Letícia; Lacerda, Eliza Maria C B; Silveira, Luiz Carlos L; Souza, Givago S

    2015-01-01

    Conventional pattern-reversal visual evoked cortical potential (VECP) shows positivity for luminance and chromatic equiluminant stimuli while conventional pattern-onset VECP shows positivity for luminance pattern-onset and negativity for chromatic pattern-onset. We evaluated how the presentation mode affects VECPs elicited by luminance and compound (luminance plus chromatic) pseudo-random stimulation. Eleven normal trichromats and 17 red-green color-blinds were studied. Pattern-reversal and pattern-onset luminance and compound (luminance plus red-green) gratings were temporally modulated by m-sequence. We used a cross-correlation routine to extract the first order kernel (K1) and the first and second slices of the second order kernel (K2.1 and K2.2, respectively) from the VECP response. We integrated the amplitude of VECP components as a function of time in order to estimate its magnitude for each stimulus condition. We also used a normalized cross-correlation method in order to test the similarity of the VECP components. The VECP components varied with the presentation mode and the presence of red-green contrast in the stimuli. In trichromats, for compound conditions, pattern-onset K1, K2.1, and K2.2, and pattern-reversal K2.1 and K2.2 had negative-dominated waveforms at 100 ms. Small negativity or small positivity were observed in dichromats. Trichromats had larger VECP magnitude than color-blinds for compound pattern-onset K1 (with large variability across subjects), compound pattern-onset and pattern-reversal K2.1, and compound pattern-reversal K2.2. Trichromats and color-blinds had similar VECP amplitude for compound pattern-reversal K1 and compound pattern-onset K2.2, as well as for all luminance conditions. The cross-correlation analysis showed high similarity between waveforms of compound pattern-onset K2.1 and pattern-reversal K2.2 as well as pattern-reversal K2.1 and K2.2. We suggest that compound pattern-reversal K2.1 is an appropriate response to study

  13. GALAXY-SCALE STAR FORMATION ON THE RED SEQUENCE: THE CONTINUED GROWTH OF S0s AND THE QUIESCENCE OF ELLIPTICALS

    SciTech Connect

    Salim, Samir; Fang, Jerome J.; Faber, S. M.; Thilker, David A.

    2012-08-20

    This paper examines star formation (SF) in relatively massive, primarily early-type galaxies (ETGs) at z {approx} 0.1. A sample is drawn from bulge-dominated Galaxy Evolution Explorer/Sloan Digital Sky Survey (GALEX/SDSS) galaxies on the optical red sequence with strong UV excess and yet quiescent SDSS spectra. High-resolution far-UV imaging of 27 such ETGs using Hubble Space Telescope Advanced Camera for Surveys/Solar Blind Channel (ACS/SBC) reveals structured UV morphology in 93% of the sample, consistent with low-level ongoing SF ({approx}0.5 M{sub Sun} yr{sup -1}). In 3/4 of the sample the SF is extended on galaxy scales (25-75 kpc), while the rest contains smaller (5-15 kpc) SF patches in the vicinity of an ETG-presumably gas-rich satellites being disrupted. Optical imaging reveals that all ETGs with galaxy-scale SF in our sample have old stellar disks (mostly S0 type). None is classified as a true elliptical. In our sample, galaxy-scale SF takes the form of UV rings of varying sizes and morphologies. For the majority of such objects we conclude that the gas needed to fuel current SF has been accreted from the intergalactic medium, probably in a prolonged, quasi-static manner, leading in some cases to additional disk buildup. The remaining ETGs with galaxy-scale SF have UV and optical morphologies consistent with minor merger-driven SF or with the final stages of SF in fading spirals. Our analysis excludes that all recent SF on the red sequence resulted from gas-rich mergers. We find further evidence that galaxy-scale SF is almost exclusively an S0 phenomenon ({approx}20% S0s have SF) by examining the overall optically red SDSS ETGs. Conclusion is that significant number of field S0s maintain or resume low-level SF because the preventive feedback is not in place or is intermittent. True ellipticals, on the other hand, stay entirely quiescent even in the field.

  14. PESSTO monitoring of SN 2012hn: further heterogeneity among faint Type I supernovae

    NASA Astrophysics Data System (ADS)

    Valenti, S.; Yuan, F.; Taubenberger, S.; Maguire, K.; Pastorello, A.; Benetti, S.; Smartt, S. J.; Cappellaro, E.; Howell, D. A.; Bildsten, L.; Moore, K.; Stritzinger, M.; Anderson, J. P.; Benitez-Herrera, S.; Bufano, F.; Gonzalez-Gaitan, S.; McCrum, M. G.; Pignata, G.; Fraser, M.; Gal-Yam, A.; Le Guillou, L.; Inserra, C.; Reichart, D. E.; Scalzo, R.; Sullivan, M.; Yaron, O.; Young, D. R.

    2014-01-01

    We present optical and infrared monitoring data of SN 2012hn collected by the Public European Southern Observatory Spectroscopic Survey for Transient Objects. We show that SN 2012hn has a faint peak magnitude (MR ˜ -15.65) and shows no hydrogen and no clear evidence for helium in its spectral evolution. Instead, we detect prominent Ca II lines at all epochs, which relates this transient to previously described `Ca-rich' or `gap' transients. However, the photospheric spectra (from -3 to +32 d with respect to peak) of SN 2012hn show a series of absorption lines which are unique and a red continuum that is likely intrinsic rather than due to extinction. Lines of Ti II and Cr II are visible. This may be a temperature effect, which could also explain the red photospheric colour. A nebular spectrum at +150 d shows prominent Ca II, O I, C I and possibly Mg I lines which appear similar in strength to those displayed by core-collapse supernovae (SNe). To add to the puzzle, SN 2012hn is located at a projected distance of 6 kpc from an E/S0 host and is not close to any obvious star-forming region. Overall SN 2012hn resembles a group of faint H-poor SNe that have been discovered recently and for which a convincing and consistent physical explanation is still missing. They all appear to explode preferentially in remote locations offset from a massive host galaxy with deep limits on any dwarf host galaxies, favouring old progenitor systems. SN 2012hn adds heterogeneity to this sample of objects. We discuss potential explosion channels including He-shell detonations and double detonations of white dwarfs as well as peculiar core-collapse SNe.

  15. Antlia B: A Faint Dwarf Galaxy Member of the NGC 3109 Association

    NASA Astrophysics Data System (ADS)

    Sand, D. J.; Spekkens, K.; Crnojević, D.; Hargis, J. R.; Willman, B.; Strader, J.; Grillmair, C. J.

    2015-10-01

    We report the discovery of Antlia B, a faint dwarf galaxy at a projected distance of ˜72 kpc from NGC 3109 ({M}V ˜ -15 {mag}), the primary galaxy of the NGC 3109 dwarf association at the edge of the Local Group. The tip of the red giant branch distance to Antlia B is D = 1.29 ± 0.10 Mpc, which is consistent with the distance to NGC 3109. A qualitative analysis indicates the new dwarf's stellar population has both an old, metal-poor red giant branch (≳ 10 {{Gyr}}, [Fe/H] ˜ -2), and a younger blue population with an age of ˜200-400 Myr, analogous to the original Antlia dwarf, another likely satellite of NGC 3109. Antlia B has H i gas at a velocity of {v}{helio,{{H}} {{I}}} = 376 km s-1, confirming the association with NGC 3109 (vhelio = 403 km s-1). The H i gas mass (MH i = 2.8 ± 0.2 × 105 {M}⊙ ), stellar luminosity (MV = -9.7 ± 0.6 mag) and half light radius (rh = 273 ± 29 pc) are all consistent with the properties of dwarf irregular and dwarf spheroidal galaxies in the Local Volume, and is most similar to the Leo P dwarf galaxy. The discovery of Antlia B is the initial result from a Dark Energy Camera survey for halo substructure and faint dwarf companions to NGC 3109 with the goal of comparing observed substructure with expectations from the Λ+Cold Dark Matter model in the sub-Milky Way regime.

  16. Complete genome sequence of the orange-red pigmented, radioresistant Deinococcus proteolyticus type strain (MRP(T)).

    PubMed

    Copeland, Alex; Zeytun, Ahmet; Yassawong, Montri; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; Goodwin, Lynne A; Pitluck, Sam; Mavromatis, Konstantinos; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, Natalia; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Jeffries, Cynthia D; Brambilla, Evelyne-Marie; Rohde, Manfred; Sikorski, Johannes; Pukall, Rüdiger; Göker, Markus; Detter, John C; Woyke, Tanja; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Lapidus, Alla

    2012-05-25

    Deinococcus proteolyticus (ex Kobatake et al. 1973) Brook and Murray 1981 is one of currently 47 species in the genus Deinococcus within the family Deinococcaceae. Strain MRP(T) was isolated from feces of Lama glama and possesses extreme radiation resistance, a trait is shares with various other species of the genus Deinococcus, with D. proteolyticus being resistant up to 1.5 Mrad of gamma radiation. Strain MRP(T) is of further interest for its carotenoid pigment. The genome presented here is only the fifth completed genome sequence of a member of the genus Deinococcus (and the forth type strain) to be published, and will hopefully contribute to a better understanding of how members of this genus adapted to high gamma- or UV ionizing-radiation. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,886,836 bp long genome with its four large plasmids of lengths 97 kbp, 132 kbp, 196 kbp and 315 kbp harbors 2,741 protein-coding and 58 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  17. Post-main-sequence and POST red giant branch variables with pulsation periods less than one day

    NASA Astrophysics Data System (ADS)

    Eggen, Olin J.

    1994-06-01

    Post-main-sequence (mass 1 to 3 solar masses) and post-giant branch (0.5 to 1 solar mass) pulsators are discussed on the basis of four color and H beta light curves published elsewhere. The post-main-sequence variables, called ultrashort period cepheid (USPC) (delta Sct), pulsate in the fundamental and first harmonic modes of radial pulsation and, in many cases, in nonradial modes. The variables for which photometry allows accurate, luminosity estimates and are known to pulsate simultaneously in the fundamental and first harmonic or in the fundamental mode alone, define a PL relation (MV = -2.80 log P - 0.60, fundamental). It is notable that the slope of this relation is in the range of slopes found for classical cepheids. Accurate V photometry is lacking for many of the variables known as 'anomalous cepheids', but the available data divide them into low mass, pseudocepheids (BL Her and W Vir stars) and post-main-sequence USPC (delta Sct) variables. Four USPC in NGC 5053 and six in NGC 6466, for which accurate photometry is available, give remarkably consistent moduli of 16.06 +/- 0.05 and 15.98 +/- 0.08 mag, respectively, for the clusters, in which they are blue stragglers similar to SX Phe in Kapteyn's star group. The assumption that the four post-giant branch variables, called VSPC (RR Lyr), S Ari, SU Dra, and ST Leo in Kapteyn's star group and RR Lyr in the Groombridge 1830 group, are physical members of these groups and share their V-velocities, leads to a calibration of the photometry for the derivation of reddening, luminosity, and heavy element abundance of 45 field variables. The resulting reddenings are consistent with values obtained by other methods and the metallicities are consistent with the most accurately available spectroscopic determinations of delta S and of Ca II K. The luminosities of the bulk of the variables confirm Sandage's (1993) relation between MV and (Fe/H). Four or five of the field variables are probably binary, including BB Vir

  18. THE ORIGIN OF [O II] IN POST-STARBURST AND RED-SEQUENCE GALAXIES IN HIGH-REDSHIFT CLUSTERS

    SciTech Connect

    Lemaux, B. C.; Lubin, L. M.; Kocevski, D.; Shapley, A.; Gal, R. R.; Squires, G. K.

    2010-06-20

    We present the first results from a near-IR spectroscopic campaign of the Cl1604 supercluster at z {approx} 0.9 and the cluster RX J1821.6+6827 at z {approx} 0.82 to investigate the nature of [O II] {lambda}3727 emission in cluster galaxies at high redshift. Of the 401 members in Cl1604 and RX J1821+6827 confirmed using the Keck II/DEIMOS spectrograph, 131 galaxies have detectable [O II] emission with no other signs of current star formation activity, as well as strong absorption features indicative of a well-established older stellar population. The combination of these features suggests that the primary source of [O II] emission in these galaxies is not a result of star formation processes, but rather due to the presence of a low-ionization nuclear emission-line region (LINER) or Seyfert component. Using the NIRSPEC spectrograph on the Keck II 10 m telescope, 19 such galaxies were targeted, as well as 6 additional [O II]-emitting cluster members that exhibited signs of ongoing star formation activity. Nearly half ({approx}47%) of the 19 [O II]-emitting, absorption-line-dominated galaxies exhibit [O II] to H{alpha} equivalent width (EW) ratios higher than unity, the typical observed value for star-forming galaxies, with an EW distribution similar to that observed for LINERs at low redshift. A majority ({approx}68%) of these 19 galaxies are classified as LINER/Seyfert based primarily on the emission-line ratio of [N II] {lambda}6584 and H{alpha}. The fraction of LINER/Seyferts increases to {approx}85% for red [O II]-emitting, absorption-line-dominated galaxies. The LINER/Seyfert galaxies in our Cl1604 sample exhibit average L([O II])/L(H{alpha}) ratios that are significantly higher than that observed in populations of star-forming galaxies, suggesting that [O II] is a poor indicator of star formation in a significant fraction of high-redshift cluster members. From the prevalence of [O II]-emitting, absorption-line-dominated galaxies in both systems and the fraction

  19. The VIMOS Public Extragalactic Redshift Survey (VIPERS):. A quiescent formation of massive red-sequence galaxies over the past 9 Gyr

    NASA Astrophysics Data System (ADS)

    Fritz, A.; Scodeggio, M.; Ilbert, O.; Bolzonella, M.; Davidzon, I.; Coupon, J.; Garilli, B.; Guzzo, L.; Zamorani, G.; Abbas, U.; Adami, C.; Arnouts, S.; Bel, J.; Bottini, D.; Branchini, E.; Cappi, A.; Cucciati, O.; De Lucia, G.; de la Torre, S.; Franzetti, P.; Fumana, M.; Granett, B. R.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; McCracken, H. J.; Paioro, L.; Polletta, M.; Pollo, A.; Schlagenhaufer, H.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Burden, A.; Di Porto, C.; Marchetti, A.; Marinoni, C.; Mellier, Y.; Moscardini, L.; Nichol, R. C.; Peacock, J. A.; Percival, W. J.; Phleps, S.; Wolk, M.

    2014-03-01

    We explore the evolution of the colour-magnitude relation (CMR) and luminosity function (LF) at 0.4 < z < 1.3 from the VIMOS Public Extragalactic Redshift Survey (VIPERS) using ~45 000 galaxies with precise spectroscopic redshifts down to i'AB < 22.5 over ~10.32 deg2 in two fields. From z = 0.5 to z = 1.3 the LF and CMR are well defined for different galaxy populations and M*B evolves by ~1.04(1.09) ± 0.06(0.10) mag for the total (red) galaxy sample. We compare different criteria for selecting early-type galaxies: (1) a fixed cut in rest-frame (U - V) colours, (2) an evolving cut in (U - V) colours, (3) a rest-frame (NUV - r') - (r' - K) colour selection, and (4) a spectral-energy-distribution classification. The completeness and contamination varies for the different methods and with redshift, but regardless of the method we measure a consistent evolution of the red-sequence (RS). Between 0.4 < z < 1.3 we find a moderate evolution of the RS intercept of Δ(U - V) = 0.28 ± 0.14 mag, favouring exponentially declining star formation (SF) histories with SF truncation at 1.7 ≤ z ≤ 2.3. Together with the rise in the number density of red galaxies by 0.64 dex since z = 1, this suggests a rapid build-up of massive galaxies (M⋆ > 1011 M⊙) and expeditious RS formation over a short period of ~1.5 Gyr starting before z = 1. This is supported by the detection of ongoing SF in early-type galaxies at 0.9 < z < 1.0, in contrast with the quiescent red stellar populations of early-type galaxies at 0.5 < z < 0.6. There is an increase in the observed CMR scatter with redshift, which is two times larger than observed in galaxy clusters and at variance with theoretical model predictions. We discuss possible physical mechanisms that support the observed evolution of the red galaxy population. Our findings point out that massive galaxies have experienced a sharp SF quenching at z ~ 1 with only limited additional merging. In contrast, less-massive galaxies experience a mix of SF

  20. KIM 3: An Ultra-faint Star Cluster in the Constellation of Centaurus

    NASA Astrophysics Data System (ADS)

    Kim, Dongwon; Jerjen, Helmut; Mackey, Dougal; Da Costa, Gary S.; Milone, Antonino P.

    2016-04-01

    We report the discovery of an ultra-faint star cluster in the constellation of Centaurus. This new stellar system, Kim 3, features a half-light radius of {r}h={2.29}-0.52+1.28 pc and a total luminosity of MV = +0.7 ± 0.3. Approximately 26 stars are identified as candidate member stars down to four magnitudes below the main-sequence turn-off, which makes Kim 3 the least luminous star cluster known to date. The compact physical size and extreme low luminosity place it close to faint star clusters in the size-luminosity plane. The stellar population of Kim 3 appears to be relatively young ({9.5}-1.7+3.0 Gyr) and metal-poor ([Fe/H]\\quad =\\quad -{1.6}-0.30+0.45) at a heliocentric distance of {15.14}-0.28+1.00 kpc. The cluster lacks a well-defined center, and a small but prominent group of stars consistent with the Kim 3 isochrone is present approximately 9.7 pc in projection south of the cluster center. Both are signs of the cluster being in the final stage of tidal disruption.

  1. X-ray Counterparts of Infrared Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Schartel, Norbert

    2011-10-01

    Infrared Faint Radio Sources (IFRS) are radio sources with extremely faint or even absent infrared emission in deep Spitzer Surveys. Models of their spectral energy distributions, the ratios of radio to infrared flux densities and their steep radio spectra strongly suggest that IFRS are AGN at high redshifts (2

  2. Faint High Orbit Debris Observations with ISON Optical Network

    NASA Astrophysics Data System (ADS)

    Molotov, I.; Agapov, V.

    New cooperation for global monitoring of space objects at high orbits, International Scientific Optical Network (ISON), is appeared under auspices of the Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences. ISON provides the observations of faint deep space debris in cooperation with team of the Astronomical Institute of the University of Bern (AIUB) since 2004. It is jointly discovered already about 500 faint space debris fragments at high orbits and almost 200 of them are continuously tracked with ISON. Presence of space debris clouds created in earlier suspected fragmentations of GEO objects is proved by long deterministic observations of individual members of the clouds. For the first time, a large amount of data on long time intervals is obtained for objects with high area-to-mass ratio (AMR). Till present, the uncatalogued faint deep debris are discovering mainly with Teide ESA OGS telescope and Crimean observatory in Nauchny, while object tracking is providing by cooperation of the 0.5-2.6-m class telescopes including Zimmerwald, Gissar, Mondy, Abastumany, Arkhyz, Mayaki, Andrushivka and Terskol. During 2009 it is planned to join several telescopes with large field of view (1.3 - 2.3 degree) in Ussuriysk, Krasnojarsk, Mondy, Nauchniy, Andrushivka, Abastumani, Mayaki and Kitab into semi-automatic network in order to try to establish the faint debris quasi continuous orbit maintenance. It is planned to use survey mode for this purpose as it is adjusted now for brighter GEO objects with ISON survey subsystem of 22-cm telescopes. Along with sensors development, it is elaborated and tested a few survey modes and algorithm permitting to find correlation between short arc tracks of non-correlated objects in order to discovery of new objects and to establish their orbits.

  3. The Faint Globular Cluster in the Dwarf Galaxy Andromeda I

    NASA Astrophysics Data System (ADS)

    Caldwell, Nelson; Strader, Jay; Sand, David J.; Willman, Beth; Seth, Anil C.

    2017-09-01

    Observations of globular clusters in dwarf galaxies can be used to study a variety of topics, including the structure of dark matter halos and the history of vigorous star formation in low-mass galaxies. We report on the properties of the faint globular cluster (M V -3.4) in the M31 dwarf galaxy Andromeda I. This object adds to the growing population of low-luminosity Local Group galaxies that host single globular clusters.

  4. Faint Submillimeter Galaxies Behind the Frontier Field Clusters

    NASA Astrophysics Data System (ADS)

    Hsu, Li-Yen; Cowie, Lennox; Barger, Amy; Wang, Wei-Hao; Chen, Chian-Chou

    2015-08-01

    Faint submillimeter galaxies are the major contributors to the submillimeter extragalactic background light and hence the dominant star-forming population in the dusty universe. Determining how much these galaxies overlap the optically selected samples is critical to fully account for the cosmic star formation history. To explore this faint submillimeter population, we have been observing nine galaxy clusters with the SCUBA-2 camera on the James Clerk Maxwell Telescope, including five of the clusters in the HST Frontier Fields program. We have also been using the Submillimeter Array to determine the positions of our detected sources precisely. Our recent observations have discovered several high-redshift dusty galaxies with far-infrared luminosities similar to that of the Milky Way or luminous infrared galaxies but which are undetected in current deep radio, optical and near-infrared images. These remarkable results suggest that a substantial amount of star formation in even the faint submillimeter population may be hidden from rest-frame optical surveys.

  5. Spectrophotometric Redshifts in the Faint Infrared Grism Survey

    NASA Astrophysics Data System (ADS)

    Pharo, John; Malhotra, Sangeeta; Rhoads, James E.

    2016-06-01

    We have combined HST grism spectroscopy and deep broadband imaging to measure spectro-photometric redshifts (SPZs) of faint galaxies. Using a technique pioneered by Ryan et al. 2007, one can combine spectra and photometry to yield an SPZ that is more accurate than pure photometric redshifts, and can probe more deeply than ground-based spectroscopic redshifts. By taking mid-resolution spectra from the HST Faint Infrared Grism Survey (FIGS), SPZs can be found for measurements potentially down to 27th magnitude (the typical brightness of a dwarf galaxy at redshift ˜1.5). A galaxy’s redshift is vital for understanding its place in the growth and evolution of the universe. The measurement of high-accuracy SPZs for FIGS sources will improve the faint-end and high-redshift portions of the luminosity function, and make possible a robust analysis of the FIGS fields for signs of Large Scale Structure (LSS). The improved redshift and distance measurements allowed for the identification of a structure at z=0.83 in one of the FIGS fields.

  6. The faint end of the galaxy luminosity function

    NASA Technical Reports Server (NTRS)

    Treyer, Marie A.; Silk, Joseph

    1994-01-01

    The evolution of the B- and K-band luminosity functions of galaxies is inferred in a relatively model-independent way from deep spectroscopic and photometric surveys. We confirm earlier evidence by Eales for an increase in the amplitude of the B-band galaxy luminosity function at modest redshift (z less than or approx. 0.2). We find in addition that the slope of the faint end of the luminosity function must systematically steepen and progress toward more luminous galaxies with increasing lookback time, assuming that the galaxy redshift distribution may be smoothly extrapolated 2 mag fainter than observed, as suggested by recent gravitational lensing studies. This evolution is shown to be color-dependent, and we predict the near-infrared color distribution of faint galaxies. The luminosity function of blue (B - K less than or approx. 4) galaxies in the range 0.2 less than or approx. z less than or approx. 1 can be represented by a Schechter function with characteristic light density phi(sup *) L(sup *) comparable to that of present-day late-type galaxies, but with a steeper faint end slope alpha approx. 1.4.

  7. Seeing Red

    NASA Technical Reports Server (NTRS)

    2008-01-01

    volcanos. Though the plume deposits are red, the plume itself is blue, because it is composed of very tiny particles that preferentially scatter blue light, like smoke. Also faintly visible in the left image is the pale-colored Prometheus plume, almost on the edge of the disk on the equator at the 9 o'clock position.

    Io was 2.4 million kilometers from the spacecraft when the picture was taken, and the center of Io's disk is at 77 degrees West longitude, 5 degrees South latitude. The solar phase angle was 107 degrees.

  8. Seeing Red

    NASA Technical Reports Server (NTRS)

    2008-01-01

    volcanos. Though the plume deposits are red, the plume itself is blue, because it is composed of very tiny particles that preferentially scatter blue light, like smoke. Also faintly visible in the left image is the pale-colored Prometheus plume, almost on the edge of the disk on the equator at the 9 o'clock position.

    Io was 2.4 million kilometers from the spacecraft when the picture was taken, and the center of Io's disk is at 77 degrees West longitude, 5 degrees South latitude. The solar phase angle was 107 degrees.

  9. The Role of Major Gas-rich Mergers on the Evolution of Galaxies from the Blue Cloud to the Red Sequence

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Hao, Cai-Na; Xia, X. Y.; Mao, Shude; Shi, Yong

    2016-07-01

    With the aim of exploring the fast evolutionary path from the blue cloud of star-forming galaxies to the red sequence of quiescent galaxies in the local universe, we select a local advanced merging infrared luminous and ultraluminous galaxy (adv-merger (U)LIRGs) sample and perform careful dust extinction corrections to investigate their positions in the star formation rate-M *, u - r, and NUV - r color-mass diagrams. The sample consists of 89 (U)LIRGs at the late merger stage, obtained from cross-correlating the Infrared Astronomical Satellite Point Source Catalog Redshift Survey and 1 Jy ULIRGs samples with the Sloan Digital Sky Survey DR7 database. Our results show that 74 % +/- 5 % of adv-merger (U)LIRGs are localized above the 1σ line of the local star-forming galaxy main sequence. We also find that all adv-merger (U)LIRGs are more massive than and as blue as the blue cloud galaxies after corrections for Galactic and internal dust extinctions, with 95 % +/- 2 % and 81 % +/- 4 % of them outside the blue cloud on the u - r and NUV - r color-mass diagrams, respectively. These results, combined with the short timescale for exhausting the molecular gas reservoir in adv-merger (U)LIRGs (3× {10}7 to 3× {10}8 years), imply that the adv-merger (U)LIRGs are likely at the starting point of the fast evolutionary track previously proposed by several groups. While the number density of adv-merger (U)LIRGs is only ˜ 0.1 % of the blue cloud star-forming galaxies in the local universe, this evolutionary track may play a more important role at high redshift.

  10. Characterization of microRNAs by deep sequencing in red claw crayfish Cherax quadricarinatus haematopoietic tissue cells after white spot syndrome virus infection.

    PubMed

    Zhao, Meng-Ru; Meng, Chuang; Xie, Xiao-Lu; Li, Cheng-Hua; Liu, Hai-Peng

    2016-12-01

    White spot syndrome virus (WSSV) is one of the most prevalent and widespread viruses in both shrimp and crayfish aquaculture. MicroRNAs (miRNAs) are crucial post-transcriptional regulators and play critical roles in cell differentiation and proliferation, apoptosis, signal transduction and immunity. In this study, miRNA expression profiles were identified via deep sequencing in red claw crayfish Cherax quadricarinatus haematopoietic tissue (Hpt) cell cultures infected with WSSV at both early (i.e., 1 hpi) and late (i.e., 12 hpi) infection stages. The results showed that 2 known miRNAs, namely, miR-7 and miR-184 play key roles in immunity. Meanwhile, 106 novel miRNA candidates were predicted by software in these combined miRNA transcriptomes. Compared with two control groups, 36 miRNAs showed significantly different expression levels after WSSV challenge. Furthermore, 10 differentially expressed miRNAs in WSSV-exposed Hpt cells were randomly selected for expression analysis by quantitative real-time RT-PCR. Consistent with the expression profiles identified by deep sequencing, RT-PCR showed a significant increase or decrease in miRNA expression in Hpt cells after WSSV infection. Prediction of targets of miRNAs such as miR-7, cqu-miR-52, cqu-miR-126 and cqu-miR-141 revealed that their target genes have diverse biological roles, including not only immunity but also transcriptional regulation, energy metabolism, cell communication, cell differentiation, cell death, autophagy, endocytosis and apoptosis. These results provide insight into the molecular mechanism of WSSV infection and highlight the function of miRNAs in the regulation of the immune response against WSSV infection in crustaceans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Particle-based ablation model for faint meteors

    NASA Astrophysics Data System (ADS)

    Stokan, E.; Campbell-Brown, M.

    2014-07-01

    Modeling the ablation of meteoroids as they enter the atmosphere is a way of determining their physical structure and elemental composition. This can provide insight into the structure of parent bodies when combined with an orbit computed from observations. The Canadian Automated Meteor Observatory (CAMO) is a source of new, high-resolution observations of faint meteors [1]. These faint objects tend to have pre-atmospheric masses around 10^{-5} kg, corresponding to a radius of 1 mm. A wide-field camera with a 28° field of view provides guidance to a high-resolution camera that tracks meteors in flight with 1.5° field of view. Meteors are recorded with a scale of 4 m per pixel at a range of 135 km, at 110 frames per second, allowing us to investigate detailed meteor morphology. This serves as an important new constraint for ablation models, in addition to meteor brightness (lightcurves) and meteoroid deceleration. High-resolution observations of faint meteors have revealed that contemporary ablation models are not able to predict meteor morphology, even while matching the observed lightcurve and meteoroid deceleration [2]. This implies that other physical processes, in addition to fragmentation, must be considered for faint meteor ablation. We present a new, particle-based approach to modeling the ablation of small meteoroids. In this model, we simulate the collisions between atmospheric particles and the meteoroid to determine the rate of evaporation and deceleration. Subsequent collisions simulated between evaporated meteoroid particles and ambient atmospheric particles then produce light that would be observed by high-resolution cameras. Preliminary results show simultaneous agreement with meteor morphology, lightcurves, and decelerations recorded with CAMO. A sample comparison of simulated and observed meteor morphology is given in the attached figure. Several meteoroids are well-represented as solid, stony bodies, but some require modeling as a dustball [3

  12. Chemical Diversity in the Ultra-faint Dwarf Galaxy Tucana II

    NASA Astrophysics Data System (ADS)

    Ji, Alexander P.; Frebel, Anna; Ezzeddine, Rana; Casey, Andrew R.

    2016-11-01

    We present the first detailed chemical abundance study of the ultra-faint dwarf galaxy Tucana II, based on high-resolution Magellan/MIKE spectra of four red giant stars. The metallicities of these stars range from [Fe/H] = -3.2 to -2.6, and all stars are low in neutron-capture abundances ([Sr/Fe] and [Ba/Fe] < -1). However, a number of anomalous chemical signatures are present. One star is relatively metal-rich ([Fe/H] = -2.6) and shows [Na, α, Sc/Fe] < 0, suggesting an extended star formation history with contributions from AGB stars and SNe Ia. Two stars with [Fe/H] < -3 are mildly carbon-enhanced ([C/Fe] ˜ 0.7) and may be consistent with enrichment by faint supernovae, if such supernovae can produce neutron-capture elements. A fourth star with [Fe/H] = -3 is carbon-normal, and exhibits distinct light element abundance ratios from the carbon-enhanced stars. This carbon-normal star implies that at least two distinct nucleosynthesis sources, both possibly associated with Population III stars, contributed to the early chemical enrichment of this galaxy. Despite its very low luminosity, Tucana II shows a diversity of chemical signatures that preclude it from being a simple “one-shot” first galaxy yet still provide a window into star and galaxy formation in the early universe. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  13. Identification of meats from red deer (Cervus elaphus), fallow deer (Dama dama), and roe deer (Capreolus capreolus) using polymerase chain reaction targeting specific sequences from the mitochondrial 12S rRNA gene.

    PubMed

    Fajardo, V; González, I; López-Calleja, I; Martín, I; Rojas, M; Hernández, P E; García, T; Martín, Rosario

    2007-06-01

    Polymerase chain reaction (PCR) based on oligonucleotide primers targeting the mitochondrial 12S rRNA gene was applied to the specific identification of meats from red deer (Cervus elaphus), fallow deer (Dama dama), and roe deer (Capreolus capreolus). The use of a common reverse primer, together with forward specific primers for red deer, fallow deer, and roe deer, allowed the selective amplification of the desired cervid sequences. The specificity of each primer pair was verified by PCR analysis of DNA from various game and domestic meats. The assay can be useful for the accurate identification of meats from cervid species, avoiding mislabeling or fraudulent species substitution in meat products.

  14. Long-Term Continuous Double Station Observation of Faint Meteor Showers.

    PubMed

    Vítek, Stanislav; Páta, Petr; Koten, Pavel; Fliegel, Karel

    2016-09-14

    Meteor detection and analysis is an essential topic in the field of astronomy. In this paper, a high-sensitivity and high-time-resolution imaging device for the detection of faint meteoric events is presented. The instrument is based on a fast CCD camera and an image intensifier. Two such instruments form a double-station observation network. The MAIA (Meteor Automatic Imager and Analyzer) system has been in continuous operation since 2013 and has successfully captured hundreds of meteors belonging to different meteor showers, as well as sporadic meteors. A data processing pipeline for the efficient processing and evaluation of the massive amount of video sequences is also introduced in this paper.

  15. The Faint Hot Component of Debris Disks Revealed by Infrared Interferometry

    NASA Astrophysics Data System (ADS)

    di Folco, E.; Absil, O.; Augereau, J.-C.; Du Foresto, C.

    2007-06-01

    Very few main-sequence stars exhibit warm dust in their 5-10AU close environment, where terrestrial planets are expected to have formed. Near-infrared interferometry is a powerful means, combining high dynamic range and high spatial resolution, to directly detect faint emission from hot grains in exozodiacal clouds. We will review the results of our search for 2 micron excesses around Vega-like stars, including the nearby Sun-like stars Tau Ceti and Epsilon Eridani, with the FLUOR interferometric instrument and the CHARA Array of telescopes. Our recent detections, combined with Spitzer observations around 10 micron, put strong constrains on the properties and distribution of hot grains in these inner planetary systems. We will present the conclusions of our preliminary modeling for the detected hot grains as well as their implication for the selection of targets for future planet finding missions like DARWIN or TPF.

  16. Long-Term Continuous Double Station Observation of Faint Meteor Showers

    PubMed Central

    Vítek, Stanislav; Páta, Petr; Koten, Pavel; Fliegel, Karel

    2016-01-01

    Meteor detection and analysis is an essential topic in the field of astronomy. In this paper, a high-sensitivity and high-time-resolution imaging device for the detection of faint meteoric events is presented. The instrument is based on a fast CCD camera and an image intensifier. Two such instruments form a double-station observation network. The MAIA (Meteor Automatic Imager and Analyzer) system has been in continuous operation since 2013 and has successfully captured hundreds of meteors belonging to different meteor showers, as well as sporadic meteors. A data processing pipeline for the efficient processing and evaluation of the massive amount of video sequences is also introduced in this paper. PMID:27649179

  17. OPTICAL–INFRARED PROPERTIES OF FAINT 1.3 mm SOURCES DETECTED WITH ALMA

    SciTech Connect

    Hatsukade, Bunyo; Yabe, Kiyoto; Ohta, Kouji; Seko, Akifumi; Makiya, Ryu; Akiyama, Masayuki

    2015-09-10

    We report optical-infrared (IR) properties of faint 1.3 mm sources (S{sub 1.3mm} = 0.2–1.0 mJy) detected with the Atacama Large Millimeter/submillimeter Array (ALMA) in the Subaru/XMM-Newton Deep Survey field. We searched for optical/IR counterparts of eight ALMA-detected sources (≥4.0σ, the sum of the probability of spurious source contamination is ∼1) in a K-band source catalog. Four ALMA sources have K-band counterpart candidates within a 0.″4 radius. Comparison between ALMA-detected and undetected K-band sources in the same observing fields shows that ALMA-detected sources tend to be brighter, more massive, and more actively forming stars. While many of the ALMA-identified submillimeter-bright galaxies (SMGs) in previous studies lie above the sequence of star-forming galaxies in the stellar mass–star formation rate plane, our ALMA sources are located in the sequence, suggesting that the ALMA-detected faint sources are more like “normal” star-forming galaxies rather than “classical” SMGs. We found a region where multiple ALMA sources and K-band sources reside in a narrow photometric redshift range (z ∼ 1.3–1.6) within a radius of 5″ (42 kpc if we assume z = 1.45). This is possibly a pre-merging system and we may be witnessing the early phase of formation of a massive elliptical galaxy.

  18. Full-length genome sequence of a simian immunodeficiency virus (SIV) infecting a captive agile mangabey (Cercocebus agilis) is closely related to SIVrcm infecting wild red-capped mangabeys (Cercocebus torquatus) in Cameroon.

    PubMed

    Ahuka-Mundeke, Steve; Liegeois, Florian; Ayouba, Ahidjo; Foupouapouognini, Yacouba; Nerrienet, Eric; Delaporte, Eric; Peeters, Martine

    2010-12-01

    Simian immunodeficiency viruses (SIVs) are lentiviruses that infect an extensive number of wild African primate species. Here we describe for the first time SIV infection in a captive agile mangabey (Cercocebus agilis) from Cameroon. Phylogenetic analysis of the full-length genome sequence of SIVagi-00CM312 showed that this novel virus fell into the SIVrcm lineage and was most closely related to a newly characterized SIVrcm strain (SIVrcm-02CM8081) from a wild-caught red-capped mangabey (Cercocebus torquatus) from Cameroon. In contrast to red-capped mangabeys, no 24 bp deletion in CCR5 has been observed in the agile mangabey. Further studies on wild agile mangabeys are needed to determine whether agile and red-capped mangabeys are naturally infected with the same SIV lineage, or whether this agile mangabey became infected with an SIVrcm strain in captivity. However, our study shows that agile mangabeys are susceptible to SIV infection.

  19. Full-length genome sequence of a simian immunodeficiency virus (SIV) infecting a captive agile mangabey (Cercocebus agilis) is closely related to SIVrcm infecting wild red-capped mangabeys (Cercocebus torquatus) in Cameroon

    PubMed Central

    Ahuka-Mundeke, Steve; Liegeois, Florian; Ayouba, Ahidjo; Foupouapouognini, Yacouba; Nerrienet, Eric; Delaporte, Eric; Peeters, Martine

    2010-01-01

    Simian immunodeficiency viruses (SIVs) are lentiviruses that infect an extensive number of wild African primate species. Here we describe for the first time SIV infection in a captive agile mangabey (Cercocebus agilis) from Cameroon. Phylogenetic analysis of the full-length genome sequence of SIVagi-00CM312 showed that this novel virus fell into the SIVrcm lineage and was most closely related to a newly characterized SIVrcm strain (SIVrcm-02CM8081) from a wild-caught red-capped mangabey (Cercocebus torquatus) from Cameroon. In contrast to red-capped mangabeys, no 24 bp deletion in CCR5 has been observed in the agile mangabey. Further studies on wild agile mangabeys are needed to determine whether agile and red-capped mangabeys are naturally infected with the same SIV lineage, or whether this agile mangabey became infected with an SIVrcm strain in captivity. However, our study shows that agile mangabeys are susceptible to SIV infection. PMID:20797968

  20. Distribution of Faint Atomic Gas in Hickson Compact Groups

    NASA Astrophysics Data System (ADS)

    Borthakur, Sanchayeeta; Yun, Min Su; Verdes-Montenegro, Lourdes; Heckman, Timothy M.; Zhu, Guangtun; Braatz, James A.

    2015-10-01

    We present 21 cm H i observations of four Hickson Compact Groups (HCGs) with evidence for a substantial intragroup medium using the Robert C. Byrd Green Bank Telescope (GBT). By mapping H i emission in a region of 25‧ × 25‧ (140-650 kpc) surrounding each HCG, these observations provide better estimates of H i masses. In particular, we detected 65% more H i than that detected in the Karl G. Jansky Very Large Array (VLA) imaging of HCG 92. We also identify whether the diffuse gas has the same spatial distribution as the high surface brightness (HSB) H i features detected in the VLA maps of these groups by comparing the H i strengths between the observed and modeled masses based on VLA maps. We found that the H i observed with the GBT has a similar spatial distribution to the HSB structures in HCG 31 and HCG 68. Conversely, the observed H i distributions in HCG 44 and HCG 92 were extended and showed significant offsets from the modeled masses. Most of the faint gas in HCG 44 lies to the northeast-southwest region and in HCG 92 lies in the northwest region of their respective groups. The spatial and dynamical similarities between the total (faint+HSB) and the HSB H i indicate that the faint gas is of tidal origin. We found that the gas will survive ionization by the cosmic UV background and the escaping ionizing photons from the star-forming regions and stay primarily neutral for at least 500 Myr.

  1. DISTRIBUTION OF FAINT ATOMIC GAS IN HICKSON COMPACT GROUPS

    SciTech Connect

    Borthakur, Sanchayeeta; Heckman, Timothy M.; Zhu, Guangtun; Yun, Min Su; Verdes-Montenegro, Lourdes; Braatz, James A.

    2015-10-10

    We present 21 cm H i observations of four Hickson Compact Groups (HCGs) with evidence for a substantial intragroup medium using the Robert C. Byrd Green Bank Telescope (GBT). By mapping H i emission in a region of 25′ × 25′ (140–650 kpc) surrounding each HCG, these observations provide better estimates of H i masses. In particular, we detected 65% more H i than that detected in the Karl G. Jansky Very Large Array (VLA) imaging of HCG 92. We also identify whether the diffuse gas has the same spatial distribution as the high surface brightness (HSB) H i features detected in the VLA maps of these groups by comparing the H i strengths between the observed and modeled masses based on VLA maps. We found that the H i observed with the GBT has a similar spatial distribution to the HSB structures in HCG 31 and HCG 68. Conversely, the observed H i distributions in HCG 44 and HCG 92 were extended and showed significant offsets from the modeled masses. Most of the faint gas in HCG 44 lies to the northeast–southwest region and in HCG 92 lies in the northwest region of their respective groups. The spatial and dynamical similarities between the total (faint+HSB) and the HSB H i indicate that the faint gas is of tidal origin. We found that the gas will survive ionization by the cosmic UV background and the escaping ionizing photons from the star-forming regions and stay primarily neutral for at least 500 Myr.

  2. Intermediate-band photometry of faint standard stars

    NASA Technical Reports Server (NTRS)

    Dawson, D. W.

    1976-01-01

    The David Dunlap Observatory system uses six intermediate-band filters whose central wavelengths were chosen to cover important features in the spectrum of a late-type star. Calibrations of the color indices with physical parameters, allow one to estimate T sub eff, log g, Fe/H, M sub v and reddening directly from the photometry. Although a number of standards lists exist, only a small fraction of the stars is fainter than V=6. It is desirable to add to the numbers of faint standards. Results are presented of photometry of sixteen stars obtained during a program of variable-star photometry at Blue Mesa Observatory.

  3. A survey for faint variable objects in SA 57

    SciTech Connect

    Trevese, D.; Pittella, G.; Kron, R.G.; Koo, D.C.; Bershady, M.; Roma, Osservatorio Astronomico; ESA, European Space Research Institute, Frascati; Yerkes Observatory, Williams Bay, WI; Space Telescope Science Institute, Baltimore, MD; Lick Observatory, Santa Cruz, CA; Chicago Univ., IL )

    1989-07-01

    Nine Mayall 4 m prime-focus Kodak IIIa-J plates spanning an 11-yr baseline are analyzed in a uniform manner for the detection of variable objects to B = 22.6 at the level of Sigma of about 0.1 mag. Techniques are developed that succeed in independently finding objects already known to be variable, namely a sample of QSOs. Few additional objects were identified as variables with high certainty. The principal result, therefore, is an upper limit both to variable QSOs not previously identified by other techniques, and an upper limit at faint magnitudes on other classes of variable objects. 21 refs.

  4. Are the infrared-faint radio sources pulsars?

    NASA Astrophysics Data System (ADS)

    Cameron, A. D.; Keith, M.; Hobbs, G.; Norris, R. P.; Mao, M. Y.; Middelberg, E.

    2011-07-01

    Infrared-faint radio sources (IFRS) are objects which are strong at radio wavelengths but undetected in sensitive Spitzer observations at infrared wavelengths. Their nature is uncertain and most have not yet been associated with any known astrophysical object. One possibility is that they are radio pulsars. To test this hypothesis we undertook observations of 16 of these sources with the Parkes Radio Telescope. Our results limit the radio emission to a pulsed flux density of less than 0.21 mJy (assuming a 50 per cent duty cycle). This is well below the flux density of the IFRS. We therefore conclude that these IFRS are not radio pulsars.

  5. Fine mapping of Plasmodium falciparum ribosomal phosphoprotein PfP0 revealed sequences with highly specific binding activity to human red blood cells.

    PubMed

    Arevalo-Pinzon, Gabriela; Curtidor, Hernando; Reyes, Claudia; Pinto, Martha; Vizcaíno, Carolina; Patarroyo, Manuel A; Patarroyo, Manuel E

    2010-01-01

    The Plasmodium falciparum P0 ribosomal phosphoprotein (PfP0) was identified for the first time by screening a cDNA expression library of P. falciparum parasites with sera from malaria-immune individuals. Due to its localization on the surface of different parasite life-cycle stages (merozoites and gametocytes) and its recognition by invasion-blocking antibodies, PfP0 has been considered a potential malaria-vaccine component. In this study, 16 20-mer-long synthetic peptides spanning the entire PfP0 sequence were evaluated by means of receptor-ligand assays with human red blood cells (RBCs) in order to determine the role played by these peptides in the invasion process. Four RBC high-activity binding peptides (HABPs), located mostly toward the N-terminal region, were identified: HABP 33898 ((1)MAKLSKQQKKQMYIEKLSSL(20)), HABP 33900 ((41)ASVRKSLRGKATILMGKNTRY(60)), HABP 33901 ((61)IRTALKKNLQAVPQIEKLLPY (80)), and HABP 33906 ((161)LIKQGEKVTASSATLLRKFNY(180)). The binding pattern of HABPs 33898 and 33906 to enzyme-treated RBCs suggests receptors of protein nature for these two HABPs, one of which could correspond to a common 58-kDa RBC membrane protein, as indicated by results of cross-linking assays. Both HABPs exhibited high content of alpha-helical features and prevented P. falciparum merozoite invasion to RBCs in vitro by up to 91%. The invasion-blocking ability reported here for these PfP0 HABPs supports their inclusion in immunological studies with the aim of assessing their potential as candidates for a vaccine against P. falciparum malaria.

  6. The Historical Demography and Genetic Variation of the Endangered Cycas multipinnata (Cycadaceae) in the Red River Region, Examined by Chloroplast DNA Sequences and Microsatellite Markers

    PubMed Central

    Gong, Yi-Qing; Zhan, Qing-Qing; Nguyen, Khang Sinh; Nguyen, Hiep Tien; Wang, Yue-Hua; Gong, Xun

    2015-01-01

    Cycas multipinnata C.J. Chen & S.Y. Yang is a cycad endemic to the Red River drainage region that occurs under evergreen forest on steep limestone slopes in Southwest China and northern Vietnam. It is listed as endangered due to habitat loss and over-collecting for the ornamental plant trade, and only several populations remain. In this study, we assess the genetic variation, population structure, and phylogeography of C. multipinnata populations to help develop strategies for the conservation of the species. 60 individuals from six populations were used for chloroplast DNA (cpDNA) sequencing and 100 individuals from five populations were genotyped using 17 nuclear microsatellites. High genetic differentiation among populations was detected, suggesting that pollen or seed dispersal was restricted within populations. Two main genetic clusters were observed in both the cpDNA and microsatellite loci, corresponding to Yunnan China and northern Vietnam. These clusters indicated low levels of gene flow between the regions since their divergence in the late Pleistocene, which was inferred from both Bayesian and coalescent analysis. In addition, the result of a Bayesian skyline plot based on cpDNA portrayed a long history of constant population size followed by a decline in the last 50,000 years of C. multipinnata that was perhaps affected by the Quaternary glaciations, a finding that was also supported by the Garza-Williamson index calculated from the microsatellite data. The genetic consequences produced by climatic oscillations and anthropogenic disturbances are considered key pressures on C. multipinnata. To establish a conservation management plan, each population of C. multipinnata should be recognized as a Management Unit (MU). In situ and ex situ actions, such as controlling overexploitation and creating a germplasm bank with high genetic diversity, should be urgently implemented to preserve this species. PMID:25689828

  7. The high-mass end of the red sequence at z ˜ 0.55 from SDSS-III/BOSS: completeness, bimodality and luminosity function

    NASA Astrophysics Data System (ADS)

    Montero-Dorta, Antonio D.; Bolton, Adam S.; Brownstein, Joel R.; Swanson, Molly; Dawson, Kyle; Prada, Francisco; Eisenstein, Daniel; Maraston, Claudia; Thomas, Daniel; Comparat, Johan; Chuang, Chia-Hsun; McBride, Cameron K.; Favole, Ginevra; Guo, Hong; Rodríguez-Torres, Sergio; Schneider, Donald P.

    2016-09-01

    We have developed an analytical method based on forward-modelling techniques to characterize the high-mass end of the red sequence (RS) galaxy population at redshift z ˜ 0.55, from the DR10 BOSS (Baryon Oscillation Spectroscopic Survey) CMASS spectroscopic sample, which comprises ˜600 000 galaxies. The method, which follows an unbinned maximum likelihood approach, allows the deconvolution of the intrinsic CMASS colour-colour-magnitude distributions from photometric errors and selection effects. This procedure requires modelling the covariance matrix for the i-band magnitude, g - r colour and r - i colour using Stripe 82 multi-epoch data. Our results indicate that the error-deconvolved intrinsic RS distribution is consistent, within the photometric uncertainties, with a single point (<0.05 mag) in the colour-colour plane at fixed magnitude, for a narrow redshift slice. We have computed the high-mass end (0.55Mi ≲ -22) of the 0.55i-band RS luminosity function (RS LF) in several redshift slices within the redshift range 0.52 < z < 0.63. In this narrow redshift range, the evolution of the RS LF is consistent, within the uncertainties in the modelling, with a passively evolving model with Φ* = (7.248 ± 0.204) × 10- 4 Mpc-3 mag-1, fading at a rate of 1.5 ± 0.4 mag per unit redshift. We report RS completeness as a function of magnitude and redshift in the CMASS sample, which will facilitate a variety of galaxy-evolution and clustering studies using BOSS. Our forward-modelling method lays the foundations for future studies using other dark-energy surveys like the Extended Baryon Oscillation Spectroscopic Survey or the Dark Energy Spectroscopic Instrument, which are affected by the same type of photometric blurring/selection effects.

  8. Abundances in Stars from the Red Giant Branch Tip to Near the Main-Sequence Turnoff in M71. III. Abundance Ratios

    NASA Astrophysics Data System (ADS)

    Ramírez, Solange V.; Cohen, Judith G.

    2002-06-01

    We present abundance ratios for 23 elements with respect to Fe in a sample of stars with a wide range in luminosity, from luminous giants to stars near the turnoff in a globular cluster. Our sample of 25 stars in M71 includes 10 giant stars more luminous than the red horizontal branch (RHB), three HB stars, nine giant stars less luminous than the RHB, and three stars near the turnoff. The analyzed spectra, obtained with HIRES at the Keck Observatory, are of high dispersion (R=λ/Δλ=35,000). We find that the neutron capture, the iron peak, and the α-element abundance ratios show no trend with Teff and low scatter around the mean between the top of the RGB and near the main-sequence turnoff. The α-elements Mg, Ca, Si, and Ti are overabundant relative to Fe. The anticorrelation between O and Na abundances observed in other metal-poor globular clusters is detected in our sample and extends to the main sequence. A statistically significant correlation between Al and Na abundances is observed among the M71 stars in our sample, extending to MV=+1.8, fainter than the luminosity of the RGB bump in M5. Lithium is varying, as expected, and Zr may be varying from star to star as well. M71 appears to have abundance ratios very similar to M5, whose bright giants were studied by Ivans et al., but seems to have a smaller amplitude of star-to-star variations at a given luminosity, as might be expected from its higher metallicity. Neither extremely O-poor, Na-rich stars nor extremely O-rich, Na-poor, stars such as are observed in M5 and in M13, are present in our sample of M71 stars. The results of our abundance analysis of 25 stars in M71 provide sufficient evidence of abundance variations at unexpectedly low luminosities to rule out the mixing scenario. Either alone or, even more powerfully, combined with other recent studies of C and N abundances in M71 stars, the existence of such abundance variations cannot be reproduced within the context of our current understanding of

  9. Phylogeny of geminivirus coat protein sequences and digital PCR aid in identifying Spissistilus festinus (Say) as a vector of Grapevine red blotch-associated virus

    USDA-ARS?s Scientific Manuscript database

    Grapevine red blotch-associated virus (GRBaV) is a newly identified virus of grapevines, and a putative member of a new genus within the family Geminiviridae. This virus is associated with red blotch disease that was first reported in California in 2008. It affects the profitability of vineyards by ...

  10. DISCOVERY OF A CLOSE PAIR OF FAINT DWARF GALAXIES IN THE HALO OF CENTAURUS A

    SciTech Connect

    Crnojević, D.; Sand, D. J.; Caldwell, N.; McLeod, B.; Guhathakurta, P.; Toloba, E.; Simon, J. D.; Strader, J.

    2014-11-10

    As part of the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS), we report the discovery of a pair of faint dwarf galaxies (CenA-MM-Dw1 and CenA-MM-Dw2) at a projected distance of ∼90 kpc from the nearby elliptical galaxy NGC 5128 (CenA). We measure a tip of the red giant branch distance to each dwarf, finding D = 3.63 ± 0.41 Mpc for CenA-MM-Dw1 and D = 3.60 ± 0.41 Mpc for CenA-MM-Dw2, both of which are consistent with the distance to NGC 5128. A qualitative analysis of the color-magnitude diagrams indicates stellar populations consisting of an old, metal-poor red giant branch (≳12 Gyr, [Fe/H] ∼ –1.7 to –1.9). In addition, CenA-MM-Dw1 seems to host an intermediate-age population as indicated by its candidate asymptotic giant branch stars. The derived luminosities (M{sub V} = –10.9 ± 0.3 for CenA-MM-Dw1 and –8.4 ± 0.6 for CenA-MM-Dw2) and half-light radii (r{sub h} = 1.4 ± 0.04 kpc for CenA-MM-Dw1 and 0.36 ± 0.08 kpc for CenA-MM-Dw2) are consistent with those of Local Group dwarfs. CenA-MM-Dw1's low central surface brightness (μ {sub V,} {sub 0} = 27.3 ± 0.1 mag arcsec{sup –2}) places it among the faintest and most extended M31 satellites. Most intriguingly, CenA-MM-Dw1 and CenA-MM-Dw2 have a projected separation of only 3 arcmin (∼3 kpc): we are possibly observing the first, faint satellite of a satellite in an external group of galaxies.

  11. Detectability of Ultra Faint Dwarf Galaxies with Gaia

    NASA Astrophysics Data System (ADS)

    Mateu, C.; Antoja, T.; Aguilar, L.; Figueras, F.; Brown, A.; Antiche, E.; Hernández-Pérez, F.; Valenzuela, O.; Aparicio, A.; Hidalgo, S.; Velázquez, H.

    2014-07-01

    We present a technique to detect Ultra-Faint Dwarf Galaxies (UFDs) in the Galactic Halo, using sky and proper motion information.The method uses wavelet transforms to detect peaks in the sky and proper motion planes, and to evaluate the probability of these being stochastic fluctuations. We aim to map thoroughly the detection limits of this technique. For this, we have produced a library of 15,000 synthetic UFDs, embedded in the Gaia Universe Model Snapshot (GUMS) background (Robin et al. 2012), each at a different distance, different luminosity, half-light radius, velocity dispersion and center-of-mass velocity, varying in ranges that extend well beyond those spanned by known classical and ultra-faint dSphs. We use these synthetic UFDs as a benchmark to characterize the completeness and detection limits of our technique, and present our results as a function of different physical and observable parameters of the UFDs (see full poster for more details at https://gaia.ub.edu/Twiki/pub/GREATITNFC/ProgramFinalconference/Poster_UFGX_Bcn_C_Mateu.pdf).

  12. A Tool for Optimizing Observation Planning for Faint Moving Objects

    NASA Astrophysics Data System (ADS)

    Arredondo, Anicia; Bosh, Amanda S.; Levine, Stephen

    2016-10-01

    Observations of small solar system bodies such as trans-Neptunian objects and Centaurs are vital for understanding the basic properties of these small members of our solar system. Because these objects are often very faint, large telescopes and long exposures may be necessary, which can result in crowded fields in which the target of interest may be blended with a field star. For accurate photometry and astrometry, observations must be planned to occur when the target is free of background stars; this restriction results in limited observing windows. We have created a tool that can be used to plan observations of faint moving objects. Features of the tool include estimates of best times to observe (when the object is not too near another object), a finder chart output, a list of possible astrometric and photometric reference stars, and an exposure time calculator. This work makes use of the USNOFS Image and Catalogue Archive operated by the United States Naval Observatory, Flagstaff Station (S.E. Levine and D.G. Monet 2000), the JPL Horizons online ephemeris service (Giorgini et al. 1996), the Minor Planet Center's MPChecker (http://cgi.minorplanetcenter.net/cgi-bin/checkmp.cgi), and source extraction software SExtractor (Bertin & Arnouts 1996). Support for this work was provided by NASA SSO grant NNX15AJ82G.

  13. The faint radio AGN population in the spotlight

    NASA Astrophysics Data System (ADS)

    Herrera Ruiz, Noelia; Middelberg, Enno

    2016-08-01

    To determine the AGN component in the faint radio population is fundamental in galaxy evolution studies. A relatively easy and direct way to determine which galaxies do have a radio-active AGN is a detection using the Very Long Baseline Interferometry (VLBI) technique. The goal of this project is to study with statistically relevant numbers the faint radio source population using VLBI observations. To achieve this goal, the project is divided into two parts. In the first part, we have observed ~3000 radio sources in the COSMOS extragalactic field with the Very Long Baseline Array (VLBA) at 1.4GHz. We have detected 468 sources. In the second part, we have observed ~200 radio sources in the COSMOS field with extremely high sensitivity using the VLBA together with the Green Bank Telescope (GBT) at 1.4GHz, to explore an even fainter population in the flux density regime of tens of uJy. We are currently calibrating this data. In this overview I will present the survey design, observations, and calibration, along with some first results.

  14. Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey

    SciTech Connect

    Huber, M E; Everett, M E; Howell, S B

    2005-03-07

    The authors present an analysis of the color and variability characteristics for point sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged {approx} 23 square degrees in BVI filters from {approx} 16-24 mag to investigate variability in faint sources at moderate to high Galactic latitudes. Point source completeness is found to be >83% for a selected representative sample (V - 17.5-22.0 mag, B-V = 0.0-1.5) containing both photometric B, V detections and 80% of the time-sampled V data available compared to a basic internal source completeness of 99%. Multi-epoch (10-30) observations in V spanning minutes to years modeled by light curve simulations reveal amplitude sensitivities to {approx} 0.015-0.075 mag over a representative V = 18-22 mag range. Periodicity determinations appear viable to time-scales of an order 1 day or less using the most sampled fields ({approx} 30 epochs). The fraction of point sources is found to be generally variable at 5-8% over V = 17.5-22.0 mag. For V brighter than 19 mag, the variable population is dominated by low amplitude (< 0.05 mag) and blue (B-V < 0.35) sources, possibly representing a population of {gamma} Doradus stars. Overall, the dominant population of variable sources are bluer than B-V = 0.65 and have Main Sequence colors, likely reflecting larger populations of RR Lyrae, SX Phe, {gamma} Doradus, and W UMa variables.

  15. Galaxy populations in massive galaxy clusters to z = 1.1: colour distribution, concentration, halo occupation number and red sequence fraction

    NASA Astrophysics Data System (ADS)

    Hennig, C.; Mohr, J. J.; Zenteno, A.; Desai, S.; Dietrich, J. P.; Bocquet, S.; Strazzullo, V.; Saro, A.; Abbott, T. M. C.; Abdalla, F. B.; Bayliss, M.; Benoit-Lévy, A.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Capasso, R.; Capozzi, D.; Carnero, A.; Carrasco Kind, M.; Carretero, J.; Chiu, I.; D'Andrea, C. B.; daCosta, L. N.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti-Neto, A.; Fosalba, P.; Frieman, J.; Gangkofner, C.; Gonzalez, A.; Gruen, D.; Gruendl, R. A.; Gupta, N.; Gutierrez, G.; Honscheid, K.; Hlavacek-Larrondo, J.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; March, M.; Marshall, J. L.; Martini, P.; McDonald, M.; Melchior, P.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nord, B.; Ogando, R.; Plazas, A. A.; Reichardt, C.; Romer, A. K.; Rozo, E.; Rykoff, E. S.; Sanchez, E.; Santiago, B.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Stalder, B.; Stanford, S. A.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Vikram, V.; Walker, A. R.; Zhang, Y.

    2017-06-01

    We study the galaxy populations in 74 Sunyaev-Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z ˜ 1.1 with 4 × 1014 M⊙ ≤ M200 ≤ 3 × 1015M⊙. Using the band containing the 4000 Å break and its redward neighbour, we study the colour-magnitude distributions of cluster galaxies to ˜m* + 2, finding that: (1)The intrinsic rest frame g - r colour width of the red sequence (RS) population is ˜0.03 out to z ˜ 0.85 with a preference for an increase to ˜0.07 at z = 1, and (2) the prominence of the RS declines beyond z ˜ 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R200 with a concentration of cg = 3.59^{+0.20}_{-0.18}, 5.37^{+0.27}_{-0.24} and 1.38^{+0.21}_{-0.19} for the full, the RS and the blue non-RS populations, respectively, but with ˜40 per cent to 55 per cent cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The RS fraction within R200 is (68 ± 3) per cent at z = 0.46, varies from ˜55 per cent at z = 1 to ˜80 per cent at z = 0.1 and exhibits intrinsic variation among clusters of ˜14 per cent. We discuss a model that suggests that the observed redshift trend in RS fraction favours a transformation time-scale for infalling field galaxies to become RS galaxies of 2-3 Gyr.

  16. SOLiD SAGE sequencing shows differential gene expression in jejunal lymph node samples of resistant and susceptible red deer (Cervus elaphus) challenged with Mycobacterium avium subsp. paratuberculosis.

    PubMed

    Mackintosh, C G; Griffin, J F T; Scott, I C; O'Brien, R; Stanton, J L; MacLean, P; Brauning, R

    2016-01-01

    This study compared in vivo lymph node gene expression levels between six young red deer that were either relatively resistant (R) or susceptible (S) to paratuberculosis following experimental challenge with Mycobacterium avium subsp. paratuberculosis. Intestinal lymph nodes were biopsied at 4, 12 and 50 weeks post challenge (pc) and parallel changes in histopathology, immunology and bacterial load monitored. SOLiD SAGE (serial analysis of gene expression) next generation sequencing of biopsied lymph node samples generated a total of 373 million transcript tags 26-28bp in length after filtering. A total of 36,632 unique transcripts were identified and 14,325 of these were able to be annotated. The copy number of each transcript was counted, averaged and compared for R and S animals (R-S). P values and False Discovery Rates (FDR) were calculated for each transcript. Genes differentially upregulated ≥2 fold (FDR<0.5) totalled 9, 40 and 32 in R animals (+ values) and 23, 164 and 47 in S animals (- values) at weeks 4, 12, and 50pc, respectively. Transcripts displaying greatest differential expression between R and S animals at each time point were IFIT2 (189 fold) and S100A8 (-32.7 fold) at week 4, LRR1 (52.7 fold), SERPINF2 (-214.6 fold) at week 12 and CEACAM8 (84.6 fold), and STK31 (-129.5 fold) at week 50, respectively. All 9 genes significantly upregulated at week 4 in R animals relate specifically to host defence and all involve Type I interferon stimulated genes. By contrast genes upregulated in S animals at week 4, relate predominantly to inflammation, but also involve adaptive immune responses, mitochondrial function and apoptosis regulation. At week 12, the genes differentially upregulated in R animals are linked predominantly to regulation of adaptive immunity and mucosal immunity, while many of the genes in S animals are associated with pro-inflammatory interleukins involved with innate and adaptive immunity. These correlated with greater lesion severity

  17. Galaxy populations in massive galaxy clusters to $z$ = 1.1: Color distribution, concentration, halo occupation number and red sequence fraction

    DOE PAGES

    Hennig, C.; Mohr, Joseph J.; Zenteno, A.; ...

    2017-01-23

    We study the galaxy populations in 74 Sunyaev–Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z ~ 1.1 with 4 × 1014 M⊙ ≤ M200 ≤ 3 × 1015M⊙. Using the band containing the 4000 Å break and its redward neighbour, we study the colour–magnitude distributions of cluster galaxies to ~m* + 2, finding that: (1)The intrinsic rest frame g – r colour width of the red sequence (RS) population is ~0.03 out to z ~ 0.85 with a preference for an increase to ~0.07 at z = 1, and (2) the prominence of the RS declines beyond z ~ 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R200 with a concentration of cg = 3.59more » $$+0.20\\atop{–0.18}$$, 5.37$$+0.27\\atop{-0.24}$$ and 1.38$$+0.21\\atop{-0.19}$$ for the full, the RS and the blue non-RS populations, respectively, but with ~40 per cent to 55 per cent cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The RS fraction within R200 is (68 ± 3) per cent at z = 0.46, varies from ~55 per cent at z = 1 to ~80 per cent at z = 0.1 and exhibits intrinsic variation among clusters of ~14 per cent. Finally, we discuss a model that suggests that the observed redshift trend in RS fraction favours a transformation time-scale for infalling field galaxies to become RS galaxies of 2–3 Gyr.« less

  18. D1005+68: A New Faint Dwarf Galaxy in the M81 Group

    NASA Astrophysics Data System (ADS)

    Smercina, Adam; Bell, Eric F.; Slater, Colin T.; Price, Paul A.; Bailin, Jeremy; Monachesi, Antonela

    2017-07-01

    We present the discovery of d1005+68, a new faint dwarf galaxy in the M81 Group, using observations taken with the Subaru Hyper Suprime-Cam. d1005+68's color-magnitude diagram is consistent with a distance of {3.98}-0.43+0.39 Mpc, establishing group membership. We derive an absolute V-band magnitude, from stellar isochrone fitting, of {M}V=-{7.94}-0.50+0.38, with a half-light radius of {r}h={188}-41+39 pc. These place d1005+68 within the radius-luminosity locus of Local Group and M81 satellites and among the faintest confirmed satellites outside the Local Group. Assuming an age of 12 Gyr, d1005+68's red giant branch is best fit by an isochrone of [Fe/H] = -1.90 ± 0.24. It has a projected separation from nearby M81 satellite BK5N of only 5 kpc. As this is well within BK5N’s virial radius, we speculate that d1005+68 may be a satellite of BK5N. If confirmed, this would make d1005+68 one of the first detected satellites-of-a-satellite.

  19. HAWAII QUASAR AND T DWARF SURVEY. I. METHOD AND DISCOVERY OF FAINT FIELD ULTRACOOL DWARFS ,

    SciTech Connect

    Kakazu, Yuko; Capak, Peter L.; Hu, Esther M.; Liu, Michael C.; Wainscoat, Richard J.; Wang Weihao

    2010-11-01

    The Hawaii Quasar and T dwarf survey (HQT Survey) is a wide-field, red optical survey carried out with the Suprime-Cam mosaic CCD camera on the 8.2 m Subaru telescope. The HQT survey is designed to search for low-luminosity (M{sub AB1450} < -23) quasars at high redshift (z>5.7) as well as T dwarfs, both of which are selected by their very red I - z' colors. We use an optical narrowband filter NB816 to break a well-known I - z' color degeneracy between high-z quasars and foreground M and L dwarfs, which are more numerous than quasars. This paper is the first in a series of papers from the HQT survey and we report on the discovery of six faint (19 {<=} J {<=} 20) ultracool dwarfs found over a {approx}9.3 deg{sup 2} area with a limiting magnitude of z'{sub AB} {<=} 23.3. These dwarfs were confirmed by near-IR imaging and/or spectroscopy conducted at various facilities on Mauna Kea. With estimated distances of 60-170 pc, these are among the most distant spectroscopically confirmed field brown dwarfs to date. Limits on the proper motions of these ultracool dwarfs suggest that they are old members of the Galactic disk, though future follow-up observations are necessary to minimize errors. Our finding rate of ultracool dwarfs is within model predictions of Liu et al. However, the large brightening amplitude ({approx}1 mag) previously reported for the L/T transition objects appears to overpredict the numbers. We also examine how the survey field latitude affects the survey sensitivity to the vertical scale height of ultracool dwarfs.

  20. Hubble Space Telescope: Faint object spectrograph instrument handbook. Version 1.1

    NASA Technical Reports Server (NTRS)

    Ford, Holland C. (Editor)

    1990-01-01

    The Faint Object Spectrograph (FOS) has undergone substantial rework since the 1985 FOS Instrument Handbook was published, and we are now more knowledgeable regarding the spacecraft and instrument operations requirements and constraints. The formal system for observation specification has also evolved considerably, as the GTO programs were defined in detail. This supplement to the FOS Instrument Handbook addresses the important aspects of these changes, to facilitate proper selection and specification of FOS observing programs. Since the Handbook was published, the FOS red detector has been replaced twice, first with the best available spare in 1985 (which proved to have a poor, and steadily degrading red response), and later with a newly developed Digicon, which exhibits a high, stable efficiency and a dark-count rate less than half that of its predecessors. Also, the FOS optical train was realigned in 1987-88 to eliminate considerable beam-vignetting losses, and the collimators were both removed and recoated for greater reflectivity. Following the optics and detector rework, the FOS was carefully recalibrated (although only ambient measurements were possible, so the far-UV characteristics could not be re-evaluated directly). The resulting efficiency curves, including improved estimates of the telescope throughput, are shown. A number of changes in the observing-mode specifications and addition of several optional parameters resulted as the Proposal Instructions were honed during the last year. Target-brightness limitations, which have only recently been formulated carefully, are described. Although these restrictions are very conservative, it is imperative that the detector safety be guarded closely, especially during the initial stages of flight operations. Restrictions on the use of the internal calibration lamps and aperture-illumination sources (TA LEDs), also resulting from detector safety considerations, are outlined. Finally, many changes have been made to

  1. A Comprehensive Survey of Neptune's Small Moons and Faint Rings

    NASA Astrophysics Data System (ADS)

    Showalter, Mark

    2009-07-01

    We will use a subarray of the WFC3/UVIS to study the inner rings, arcs and moons of Neptune with a sensitivity that exceeds that achieved by any previous observations, including Voyager 2 during its 1989 flyby. Our study will reveal any inner moons down to V magnitude 25, corresponding to a radius 20 km {assuming 9% albedo}, to address a peculiar, apparent truncation in the size distribution of inner moons and to look for the "shepherds" and source bodies for Neptune's dusty rings. {For comparison, the radius of Neptune's smallest known regular moon, Naiad, is 33 km.} Monitoring of the arcs at fine resolution and sensitivity will reveal their ongoing evolution more clearly and will enable us to assess the role of Galatea, whose resonant perturbations are widely believed to confine the arcs. Our study will also reveal any broad, faint rings with optical depth 10^-6, comparable to those now known to encircle all of the other giant planets.

  2. A sample of Swift/SDSS faint blazars

    NASA Astrophysics Data System (ADS)

    Fraga, Bernardo; Giommi, Paolo; Turriziani, Sara

    2015-12-01

    We aim here to provide a complete sample of faint (fr ≳ 1 mJy, fx ≳ 10-15 erg cm-2 s-1) blazars and blazar candidates serendipitously discovered in deep Swift images centered on Gamma-ray bursts (GRBs). By stacking all available images, we obtain exposures ranging from 104 to more than a million seconds. Since GRBs are thought to explode randomly across the sky, this set of deep fields can be considered as an unbiased survey of ≈ 12 square degrees of extragalactic sky, with sensitivities reaching a few 10-15 erg cm-2 s-1 in the 0.5-2 keV band. We then derive the x-ray Log N Log S and show that, considering that our sample may be contaminated by sources other than blazars, we are in agreement with previous estimations based on data and simulations.

  3. Faint Object Camera observations of a globular cluster nova field

    NASA Technical Reports Server (NTRS)

    Margon, Bruce; Anderson, Scott F.; Downes, Ronald A.; Bohlin, Ralph C.; Jakobsen, Peter

    1991-01-01

    The Faint Object Camera onboard Hubble Space Telescope has obtained U and B images of the field of Nova Ophiuchi 1938 in the globular cluster M14 (NGC 6402). The candidate for the quiescent nova suggested by Shara et al. (1986) is clearly resolved into at least six separate images, probably all stellar, in a region of 0.5 arcsec. Although two of these objects are intriguing as they are somewhat ultraviolet, the actual nova counterpart remains ambiguous, as none of the images in the field has a marked UV excess. Many stars within the 1.4 arcsec (2 sigma) uncertainty of the nova outburst position are viable counterparts if only astrometric criteria are used for selection. The 11 x 11 arcsec frames easily resolve several hundred stars in modest exposures, implying that HST even in its current optical configuration will be unique for studies of very crowded fields at moderate (B = 22) limiting magnitudes.

  4. First results from the Faint Object Camera - SN 1987A

    NASA Technical Reports Server (NTRS)

    Jakobsen, P.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

    1991-01-01

    The first images of SN 1987A taken on day 1278 after outburst with the Faint Object Camera on board the Hubble Space Telescope are presented. The supernova is well detected and resolved spatially in three broadband ultraviolet exposures spanning the 1500-3800 A range and in a narrow-band image centered on the forbidden O III 5007 line. Simple uniform disk fits to the profiles of SN 1987A yield an average angular diameter of 170 + or - 30 mas, corresponding to an average expansion velocity of 6000 km/s. The derived broadband ultraviolet fluxes, when corrected for interstellar absorption, indicate a blue ultraviolet spectrum corresponding to a color temperature near 13,000 K.

  5. Tomography of faint spinning objects: From molecules to viruses

    NASA Astrophysics Data System (ADS)

    Ourmazd, Abbas

    2010-03-01

    A new generation of powerful algorithms is poised to enable the determination of the three-dimensional structure of objects ranging from single molecules to beating hearts and breathing lungs. At one extreme, new algorithms are paving the way to atomic-level mapping of the conformations of biological molecules with femtosecond time resolution. At the other, they are driving ultra-low-dose tomography of non-stationary, faintly scattering macroscopic objects. These approaches combine concepts from information theory, graph theory, Riemannian geometry, and scattering physics to reconstruct objects at signal levels orders of magnitude below what was previously thought possible. We describe how data from a new generation of X-ray Free Electron Lasers or existing electron microscopes can be used to reconstruct the structure and conformational continuum of individual molecules, viruses, and potentially living cells.

  6. Clustering Effect on the Number Count of Faint Galaxies

    NASA Astrophysics Data System (ADS)

    Yamashita, K.

    1992-08-01

    We have tested the cosmological model of Ω0 = 1 and Λ = 0 against the faint galaxy number count taking the clustering effect of galaxies into account. The evolution of the large scale structure is simulated numerically by means of the particle mesh method in three dimensional space. We use 643 particles and the same number of mesh cells. We have found that the flat Friedmann-Robertson-Walker model without the cosmological constant does not explain the excess of the number count observed by Tyson even if the clustering effect is taken into account, provided the cluster size and the correlation length among clusters are less than the simulation box size of 128 h-1 Mpc. The clustering on scales larger than 128 h-1 Mpc is also considered.

  7. The faint young sun-climate paradox - Continental influences

    NASA Technical Reports Server (NTRS)

    Endal, A. S.; Schatten, K. H.

    1982-01-01

    We examine the various mechanisms which have been proposed to compensate for the climatic effects of a 30% increase in the solar luminosity over the past 4 1/2 billion years. Although atmospheric greenhouse effects have received most attention, other mechanisms may have played a role of comparable importance. In particular, we note that the development of continents during the past 2 1/2 billion years could have had a significant secular effect on the atmosphere-ocean heat transport system. As a result, past climates may have been less susceptible to complete freeze-over. A simple energy balance model is used to demonstrate the magnitude of this effect. Because the CO2 greenhouse effect is not the only means of compensating for solar evolution, the faint-young-sun problem should not be used to infer past levels of atmospheric CO2.

  8. Epidemic faintness and syncope in a school marching band.

    PubMed

    Levine, R J

    1977-11-28

    On Sept 21, 1973, during and following a football game at which they had participated, 57 members of an Alabama high school marching band (and one accompanying adult) experienced an illness characterized by headache, nausea, weakness, or dizziness. Six girls fainted. Thirty-six students were treated at a hospital emergency room. Those who had played wind instruments and had worn heavier uniforms including an impermeable plastic jacket overlay were affected earlier and more frequently than the others. Several organic causes were examined in an epidemiologic investigation and considered unlikely to explain the epidemic. Female preponderance, a bimodal epidemic curve, hyperventilation, relapses, and clinical features characterized by subjective complaints in the absence of physical findings suggested a syncopal reaction to heat exacerbated and propagated by mass hysteria.

  9. Faint UBVRI Standard Star Fields at +50° Declination

    NASA Astrophysics Data System (ADS)

    Clem, James L.; Landolt, Arlo U.

    2016-10-01

    Precise and accurate CCD-based UBVRI photometry is presented for ˜2000 stars distributed around the sky in a declination zone centered approximately at +50°. Their photometry has been calibrated to the standard Johnson UBV and Kron-Cousins RI systems through observations of the UBVRI standard stars presented in the various works of Landolt. The magnitude and color range for these stars are 12 ≲ V ≲ 22 and -0.3 ≲ (B - V) ≲ 1.8, respectively. Each star averages 13 measures in each UBVRI filter from data taken on 41 different photometric nights obtained over a 21 month period. Hence, there now exists a network of faint UBVRI photometric standard stars centered on the declination zones δ = -50°, 0°, and +50°.

  10. First results from the Faint Object Camera - SN 1987A

    SciTech Connect

    Jakobsen, P.; Albrecht, R.; Barbieri, C.; Blades, J.C.; Boksenberg, A. Space Telescope European Coordinating Facility, Garching Padova, Osservatorio Astronomico, Padua Space Telescope Science Institute, Baltimore, MD Royal Greenwich Observatory, Cambridge )

    1991-03-01

    The first images of SN 1987A taken on day 1278 after outburst with the Faint Object Camera on board the Hubble Space Telescope are presented. The supernova is well detected and resolved spatially in three broadband ultraviolet exposures spanning the 1500-3800 A range and in a narrow-band image centered on the forbidden O III 5007 line. Simple uniform disk fits to the profiles of SN 1987A yield an average angular diameter of 170 + or - 30 mas, corresponding to an average expansion velocity of 6000 km/s. The derived broadband ultraviolet fluxes, when corrected for interstellar absorption, indicate a blue ultraviolet spectrum corresponding to a color temperature near 13,000 K. 24 refs.

  11. Faint Object Camera observations of a globular cluster nova field

    NASA Technical Reports Server (NTRS)

    Margon, Bruce; Anderson, Scott F.; Downes, Ronald A.; Bohlin, Ralph C.; Jakobsen, Peter

    1991-01-01

    The Faint Object Camera onboard Hubble Space Telescope has obtained U and B images of the field of Nova Ophiuchi 1938 in the globular cluster M14 (NGC 6402). The candidate for the quiescent nova suggested by Shara et al. (1986) is clearly resolved into at least six separate images, probably all stellar, in a region of 0.5 arcsec. Although two of these objects are intriguing as they are somewhat ultraviolet, the actual nova counterpart remains ambiguous, as none of the images in the field has a marked UV excess. Many stars within the 1.4 arcsec (2 sigma) uncertainty of the nova outburst position are viable counterparts if only astrometric criteria are used for selection. The 11 x 11 arcsec frames easily resolve several hundred stars in modest exposures, implying that HST even in its current optical configuration will be unique for studies of very crowded fields at moderate (B = 22) limiting magnitudes.

  12. Do the enigmatic ``Infrared-Faint Radio Sources'' include pulsars?

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Middelberg, Enno; Norris, Ray; Keith, Michael; Mao, Minnie; Champion, David

    2009-04-01

    The Australia Telescope Large Area Survey (ATLAS) team have surveyed seven square degrees of sky at 1.4GHz. During processing some unexpected infrared-faint radio sources (IFRS sources) were discovered. The nature of these sources is not understood, but it is possible that some of these sources may be pulsars within our own galaxy. We propose to observe the IFRS sources with steep spectral indices using standard search techniques to determine whether or not they are pulsars. A pulsar detection would 1) remove a subset of the IFRS sources from the ATLAS sample so they would not need to be observed with large optical/IR telescopes to find their hosts and 2) be intrinsically interesting as the pulsar would be a millisecond pulsar and/or have an extreme spatial velocity.

  13. Morphology and astrometry of Infrared-Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Middelberg, Enno; Norris, Ray; Randall, Kate; Mao, Minnie; Hales, Christopher

    2008-10-01

    Infrared-Faint Radio Sources, or IFRS, are an unexpected class of object discovered in the Australia Telescope Large Area Survey, ATLAS. They are compact 1.4GHz radio sources with no visible counterparts in co-located (relatively shallow) Spitzer infrared and optical images. We have detected two of these objects with VLBI, indicating the presence of an AGN. These observations and our ATLAS data indicate that IFRS are extended on scales of arcseconds, and we wish to image their morphologies to obtain clues about their nature. These observations will also help us to select optical counterparts from very deep, and hence crowded, optical images which we have proposed. With these data in hand, we will be able to compare IFRS to known object types and to apply for spectroscopy to obtain their redshifts.

  14. MEASURING SIZES OF ULTRA-FAINT DWARF GALAXIES

    SciTech Connect

    Munoz, Ricardo R.; Padmanabhan, Nikhil; Geha, Marla

    2012-02-01

    The discovery of ultra-faint dwarf (UFD) galaxies in the halo of the Milky Way extends the faint end of the galaxy luminosity function to a few hundred solar luminosities. This extremely low luminosity regime poses a significant challenge for the photometric characterization of these systems. We present a suite of simulations aimed at understanding how different observational choices related to the properties of a low-luminosity system impact our ability to determine its true structural parameters such as half-light radius and central surface brightness. We focus on estimating half-light radii (on which mass estimates depend linearly) and find that these numbers can have up to 100% uncertainties when relatively shallow photometric surveys, such as the Sloan Digital Sky Survey, are used. Our simulations suggest that to recover structural parameters within 10% or better of their true values: (1) the ratio of the field of view to the half-light radius of the satellite must be greater than three, (2) the total number of stars, including background objects should be larger than 1000, and (3) the central to background stellar density ratio must be higher than 20. If one or more of these criteria are not met, the accuracy of the resulting structural parameters can be significantly compromised. In the context of future surveys such as Large Synoptic Survey Telescope, the latter condition will be closely tied to our ability to remove unresolved background galaxies. Assessing the reliability of measured structural parameters will become increasingly critical as the next generation of deep wide-field surveys detects UFDs beyond the reach of current spectroscopic limits.

  15. The morphology of nine radio-selected faint galaxies from deep Hubble Space Telescope imaging

    NASA Astrophysics Data System (ADS)

    Roche, Nathan D.; Lowenthal, James D.; Koo, David C.

    2002-12-01

    Using the Hubble Space Telescope (HST) WFPC2 we perform deep I-band imaging of nine radio-selected [F(8.5 GHz) >=14 μJy] faint galaxies from the Roche, Lowenthal & Koo (2002) sample. Two are also observed in V using HST STIS. Six of the galaxies have known redshifts, in the range 0.4 < z < 1.0. Radial intensity profiles indicate that seven are disc galaxies and two are bulge-dominated. Four of the six with redshifts have a high optical surface brightness in comparison with previous studies of disc galaxies at similar redshifts (e.g. Lilly et al. 1998). The HST imaging reveals that two of the nine galaxies are in close interacting pairs and another five show morphological evidence of recent interactions - two are very asymmetric (Aasym~ 0.4) and three have large, luminous rings resembling the collisional starburst rings in the Cartwheel galaxy. For the two ring galaxies with redshifts, we measure ring radii of 7.05 and 10.0 h-150 kpc, which suggest post-collision ages 0.1-0.2 Gyr. One has a fainter inner ring, like the original Cartwheel. The remaining two appear to be late-type barred galaxies and relatively undisturbed. Our HST imaging confirms the high incidence of interactions and dynamical disturbance in faint radio-selected galaxies, as reported by Windhorst et al. and Serjeant et al., for example. In the great majority of these galaxies the high radio luminosities are probably the result of interaction-triggered starbursts. However, one interacting galaxy is a very radio-luminous giant elliptical, with red V-I colours, a normal surface brightness and no evidence of star-forming regions, so its radio source is probably an obscured active galactic nucleus (AGN). The mixture of observed morphologies suggests that enhanced radio luminosities often persist to a late stage of interaction, i.e. at least ~0.2 Gyr after the perigalactic encounter.

  16. The Subaru/XMM-Newton Deep Survey (SXDS). V. Optically Faint Variable Object Survey

    NASA Astrophysics Data System (ADS)

    Morokuma, Tomoki; Doi, Mamoru; Yasuda, Naoki; Akiyama, Masayuki; Sekiguchi, Kazuhiro; Furusawa, Hisanori; Ueda, Yoshihiro; Totani, Tomonori; Oda, Takeshi; Nagao, Tohru; Kashikawa, Nobunari; Murayama, Takashi; Ouchi, Masami; Watson, Mike G.; Richmond, Michael W.; Lidman, Christopher; Perlmutter, Saul; Spadafora, Anthony L.; Aldering, Greg; Wang, Lifan; Hook, Isobel M.; Knop, Rob A.

    2008-03-01

    We present our survey for optically faint variable objects using multiepoch (8-10 epochs over 2-4 years) i'-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg2 in the Subaru/XMM-Newton Deep Field (SXDF). We found 1040 optically variable objects by image subtraction for all the combinations of images at different epochs. This is the first statistical sample of variable objects at depths achieved with 8-10 m class telescopes or the Hubble Space Telescope. The detection limit for variable components is i'vari ~ 25.5 mag. These variable objects were classified into variable stars, supernovae (SNe), and active galactic nuclei (AGNs), based on the optical morphologies, magnitudes, colors, and optical-mid-infrared colors of the host objects, spatial offsets of variable components from the host objects, and light curves. Detection completeness was examined by simulating light curves for periodic and irregular variability. We detected optical variability for 36% +/- 2% (51% +/- 3% for a bright sample with i' < 24.4 mag) of X-ray sources in the field. Number densities of variable objects as functions of time intervals Δ t and variable component magnitudes i'vari are obtained. Number densities of variable stars, SNe, and AGNs are 120, 489, and 579 objects deg-2, respectively. Bimodal distributions of variable stars in the color-magnitude diagrams indicate that the variable star sample consists of bright (V ~ 22 mag) blue variable stars of the halo population and faint (V ~ 23.5 mag) red variable stars of the disk population. There are a few candidates of RR Lyrae providing a possible number density of ~10-2 kpc-3 at a distance of >150 kpc from the Galactic center. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based on observations (program GN-2002B-Q-30) obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a

  17. Diet analysis by next-generation sequencing indicates the frequent consumption of introduced plants by the critically endangered red-headed wood pigeon (Columba janthina nitens) in oceanic island habitats

    PubMed Central

    Ando, Haruko; Setsuko, Suzuki; Horikoshi, Kazuo; Suzuki, Hajime; Umehara, Shoko; Inoue-Murayama, Miho; Isagi, Yuji

    2013-01-01

    Oceanic island ecosystems are vulnerable to the introduction of alien species, and they provide a habitat for many endangered species. Knowing the diet of an endangered animal is important for appropriate nature restoration efforts on oceanic islands because introduced species may be a major component of the diets of some endangered species. DNA barcoding techniques together with next-generation sequencing may provide more detailed information on animal diets than other traditional methods. We performed a diet analysis using 48 fecal samples from the critically endangered red-headed wood pigeon that is endemic to the Ogasawara Islands based on chloroplast trnL P6 loop sequences. The frequency of each detected plant taxa was compared with a microhistological analysis of the same sample set. The DNA barcoding approach detected a much larger number of plants than the microhistological analysis. Plants that were difficult to identify by microhistological analysis after being digested in the pigeon stomachs were frequently identified only by DNA barcoding. The results of the barcoding analysis indicated the frequent consumption of introduced species, in addition to several native species, by the red-headed wood pigeon. The rapid eradication of specific introduced species may reduce the food resources available to this endangered bird; thus, balancing eradication efforts with the restoration of native food plants should be considered. Although some technical problems still exist, the trnL approach to next-generation sequencing may contribute to a better understanding of oceanic island ecosystems and their conservation. PMID:24324859

  18. Diet analysis by next-generation sequencing indicates the frequent consumption of introduced plants by the critically endangered red-headed wood pigeon (Columba janthina nitens) in oceanic island habitats.

    PubMed

    Ando, Haruko; Setsuko, Suzuki; Horikoshi, Kazuo; Suzuki, Hajime; Umehara, Shoko; Inoue-Murayama, Miho; Isagi, Yuji

    2013-10-01

    Oceanic island ecosystems are vulnerable to the introduction of alien species, and they provide a habitat for many endangered species. Knowing the diet of an endangered animal is important for appropriate nature restoration efforts on oceanic islands because introduced species may be a major component of the diets of some endangered species. DNA barcoding techniques together with next-generation sequencing may provide more detailed information on animal diets than other traditional methods. We performed a diet analysis using 48 fecal samples from the critically endangered red-headed wood pigeon that is endemic to the Ogasawara Islands based on chloroplast trnL P6 loop sequences. The frequency of each detected plant taxa was compared with a microhistological analysis of the same sample set. The DNA barcoding approach detected a much larger number of plants than the microhistological analysis. Plants that were difficult to identify by microhistological analysis after being digested in the pigeon stomachs were frequently identified only by DNA barcoding. The results of the barcoding analysis indicated the frequent consumption of introduced species, in addition to several native species, by the red-headed wood pigeon. The rapid eradication of specific introduced species may reduce the food resources available to this endangered bird; thus, balancing eradication efforts with the restoration of native food plants should be considered. Although some technical problems still exist, the trnL approach to next-generation sequencing may contribute to a better understanding of oceanic island ecosystems and their conservation.

  19. THE EVOLUTION OF DUSTY STAR FORMATION IN GALAXY CLUSTERS TO z = 1: SPITZER INFRARED OBSERVATIONS OF THE FIRST RED-SEQUENCE CLUSTER SURVEY

    SciTech Connect

    Webb, T. M. A.; O'Donnell, D.; Coppin, Kristen; Faloon, Ashley; Geach, James E.; Noble, Allison; Yee, H. K. C.; Gilbank, David; Ellingson, Erica; Gladders, Mike; Muzzin, Adam; Wilson, Gillian; Yan, Renbin

    2013-10-01

    We present the results of an infrared (IR) study of high-redshift galaxy clusters with the MIPS camera on board the Spitzer Space Telescope. We have assembled a sample of 42 clusters from the Red-Sequence Cluster Survey-1 over the redshift range 0.3 < z < 1.0 and spanning an approximate range in mass of 10{sup 14-15} M {sub ☉}. We statistically measure the number of IR-luminous galaxies in clusters above a fixed inferred IR luminosity of 2 × 10{sup 11} M {sub ☉}, assuming a star forming galaxy template, per unit cluster mass and find it increases to higher redshift. Fitting a simple power-law we measure evolution of (1 + z){sup 5.1±1.9} over the range 0.3 < z < 1.0. These results are tied to the adoption of a single star forming galaxy template; the presence of active galactic nuclei, and an evolution in their relative contribution to the mid-IR galaxy emission, will alter the overall number counts per cluster and their rate of evolution. Under the star formation assumption we infer the approximate total star formation rate per unit cluster mass (ΣSFR/M {sub cluster}). The evolution is similar, with ΣSFR/M {sub cluster} ∼ (1 + z){sup 5.4±1.9}. We show that this can be accounted for by the evolution of the IR-bright field population over the same redshift range; that is, the evolution can be attributed entirely to the change in the in-falling field galaxy population. We show that the ΣSFR/M {sub cluster} (binned over all redshift) decreases with increasing cluster mass with a slope (ΣSFR/M{sub cluster}∼M{sub cluster}{sup -1.5±0.4}) consistent with the dependence of the stellar-to-total mass per unit cluster mass seen locally. The inferred star formation seen here could produce ∼5%-10% of the total stellar mass in massive clusters at z = 0, but we cannot constrain the descendant population, nor how rapidly the star-formation must shut-down once the galaxies have entered the cluster environment. Finally, we show a clear decrease in the number of IR

  20. Use of Simple Sequence Repeat (SSR) markers for DNA fingerprinting and diversity analysis of sugarcane (Saccharum spp.) cultivars resistant and susceptible to red rot

    USDA-ARS?s Scientific Manuscript database

    In recent years SSR markers have been used widely for the genetic analysis. The objective of present research was to use SSR markers to develop DNA-based genetic identification and analyze genetic relationship of sugarcane cultivars grown in Pakistan either resistant or susceptible to red rot. Twent...

  1. Red Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  The Red Sea     View Larger Image ... 2000. Located between the East African coast and the Saudi Arabian peninsula, the Red Sea got its name because the blooms of a type of ... 2000 - The Red Sea between the East Africa coast and Saudi Arabian peninsula. project:  MISR category:  ...

  2. Serendipitous discovery of the faint solar twin Inti 1

    NASA Astrophysics Data System (ADS)

    Galarza, Jhon Yana; Meléndez, Jorge; Cohen, Judith G.

    2016-05-01

    Context. Solar twins are increasingly the subject of many studies owing to their wide range of applications from testing stellar evolution models to the calibration of fundamental observables; these stars are also of interest because high precision abundances could be achieved that are key to investigating the chemical anomalies imprinted by planet formation. Furthermore, the advent of photometric surveys with large telescopes motivates the identification of faint solar twins in order to set the zero point of fundamental calibrations. Aims: We intend to perform a detailed line-by-line differential analysis to verify whether 2MASS J23263267-0239363 (designated here as Inti 1) is indeed a solar twin. Methods: We determine the atmospheric parameters and differential abundances using high-resolution (R ≈ 50 000), high signal-to-noise (S/N ≈ 110-240 per pixel) Keck/HIRES spectra for our solar twin candidate, the previously known solar twin HD 45184, and the Sun (using reflected light from the asteroid Vesta). Results: For the bright solar twin HD 45184, we found Teff = 5864 ± 9 K, log g = 4.45 ± 0.03 dex, vt = 1.11 ± 0.02 km s-1, and [Fe/H] = 0.04 ± 0.01 dex, which are in good agreement with previous works. Our abundances are in excellent agreement with a recent high-precision work, with an element-to-element scatter of only 0.01 dex. The star Inti 1 has atmospheric parameters Teff = 5837 ± 11 K, log g = 4.42 ± 0.03 dex, vt = 1.04 ± 0.02 km s-1, and [Fe/H] = 0.07 ± 0.01 dex that are higher than solar. The age and mass of the solar twin HD 45184 (3 Gyr and 1.05 M⊙) and the faint solar twin Inti 1 (4 Gyr and 1.04 M⊙) were estimated using isochrones. The differential analysis shows that HD 45184 presents an abundance pattern that is similar to typical nearby solar twins; this means this star has an enhanced refractory relative to volatile elements, while Inti 1 has an abundance pattern closer to solar, albeit somewhat enhanced in refractories. The abundance

  3. Surprising Rapid Collapse of Sirius B from Red Giant to White Dwarf Through Mass Transfer to Sirius a

    NASA Astrophysics Data System (ADS)

    Yousef, Shahinaz; Ali, Ola

    2013-03-01

    Sirius was observed in antiquity as a red star. In his famous astronomy textbook the Almagest written 140 AD, Ptolemy described the star Sirius as fiery red. He curiously depicted it as one of six red-colored stars. The other five are class M and K stars, such as Arcturus and Betelgeuse. Apparent confirmation in ancient Greek and Roman sources are found and Sirius was also reported red in Europe about 1400 years ago. Sirius must have changed to a white dwarf in the night of Ascension. The star chapter in the Quran started with "by the star as it collapsed (1) your companion have not gone astray nor being misled (2), and in verse 49 which is the rotation period of the companion Sirius B around Sirius A, it is said" He is the Lord of Sirius (49). If Sirius actually was red what could have caused it to change into the brilliant bluish-white star we see today? What the naked eye perceives as a single star is actually a binary star system, consisting of a white main sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B. The red color indicates that the star seen then was a red giant. It looks that what they have seen in antiquity was Sirius B which was then a red giant and it collapsed to form a white dwarf. Since there is no evidence of a planetary nebula, then the red Sirius paradox can be solved in terms of stellar evolution with mass transfer. Sirius B was the most massive star which evolved to a red giant and filled the Roche lobe. Mass transfer to Sirius A occurred through the Lagrangian point. Sirius A then became more massive while Sirius B lost mass and shrank. Sirius B then collapsed abruptly into a white dwarf. In the case of Algol, Ptolmy observed it as white star but it was red at the time of El sufi. At present it is white. The rate of mass transfer from Sirius B to Sirius A, and from Algol B to A is estimated from observational data of colour change from red to bullish white to be 0

  4. HST NICMOS snapshot survey of faint galaxies at z < 1

    NASA Astrophysics Data System (ADS)

    Hinkley, S.; Im, M.; DEEP Team

    2000-12-01

    During Cycle 7 HST observations, we have obtained NICMOS H-band images of faint field galaxies for which both HST morphological information (in V and/or I) and spectroscopic redshifts are available. The purpose of the NICMOS observation is to provide their morphology in rest frame NIR wavelengths (8000 - 16000 Å), where the effect of dust extinction is less severe, and to obtain their near infrared (NIR) colors. The objects in our field are partly contained in the Groth Strip being studied in detail by the DEEP team. In addition, we have made use of a software package called GIM2D (Simard et al. 2001). This package is designed to perform detailed 2-dimensional decompositions for images of distant galaxies. Using this software, we have obtained structural parameters for the objects in the H-band to complement those parameters in V and I. We will present: i) color gradients inside elliptical galaxies to test models of their formation; ii) the effect of dust extinction on the properties of field galaxies at 0 < z < 1; iii) evolution of V-H, and V-I colors of bulges as well as the B/T ratio of spiral galaxies as a function of redshift; iv) morphological k-correction. The median redshift of our sample is z ~ 0.5 and this corresponds to about one half of the current age of the universe. This work is supported by the STScI grant GO-07895.02-96A.

  5. Helium shells and faint emission lines from slitless flash spectra

    PubMed Central

    Bazin, Cyril; Koutchmy, Serge

    2013-01-01

    At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence. PMID:25685435

  6. Helium shells and faint emission lines from slitless flash spectra.

    PubMed

    Bazin, Cyril; Koutchmy, Serge

    2013-05-01

    At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence.

  7. FIGS—Faint Infrared Grism Survey: Description and Data Reduction

    NASA Astrophysics Data System (ADS)

    Pirzkal, Norbert; Malhotra, Sangeeta; Ryan, Russell E.; Rothberg, Barry; Grogin, Norman; Finkelstein, Steven L.; Koekemoer, Anton M.; Rhoads, James; Larson, Rebecca L.; Christensen, Lise; Cimatti, Andrea; Ferreras, Ignacio; Gardner, Jonathan P.; Gronwall, Caryl; Hathi, Nimish P.; Hibon, Pascale; Joshi, Bhavin; Kuntschner, Harald; Meurer, Gerhardt R.; O’Connell, Robert W.; Oestlin, Goeran; Pasquali, Anna; Pharo, John; Straughn, Amber N.; Walsh, Jeremy R.; Watson, Darach; Windhorst, Rogier A.; Zakamska, Nadia L.; Zirm, Andrew

    2017-09-01

    The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8 μm–1.15 μm continuous coverage) with a total exposure time of 40 orbits (≈100 kilo-seconds) per field. This reaches a 3σ continuum depth of ≈ 26 AB magnitudes and probes emission lines to ∼ {10}-17 {erg} {{{s}}}-1 {{cm}}-2. This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10,000 spectra of over 2000 distinct sources brighter than {m}F105W=26.5 mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D spectra for each object in the survey.

  8. Detecting faint nearby companions to geostationary satellites with optical interferometry

    NASA Astrophysics Data System (ADS)

    Schmitt, Henrique R.; Restaino, Sergio R.; Armstrong, J. Thomas; Baines, Ellyn K.

    2017-05-01

    One of the main problems faced by the Space Situational Awareness community is the detection and characterization of faint objects around geosats. Independent of the origin of these objects, whether they are debris or controlled spacecraft, they can potentially harm these assets and contaminate the geobelt environment. The challenge of detecting these companion objects comes from their proximity and brightness ratio relative to geosats. Here we present a novel interferometric fringe nulling technique, aimed at solving these issues. This technique takes advantage of the fact that the presence of companions introduces large phase fluctuations in the fringe phase observed by an interferometer, when the interferometer is observing a target at spatial frequencies where the fringe amplitude is near zero. We describe the ongoing development of this technique at the Navy Precision Optical Interferometer, and the results of simulations of interferometric observations of satellites with companions. We also present the current state of the NPOI and related SSA work being done with this interferometer, as well as undergoing upgrades to the system.

  9. FORCAST: the faint object infared camera for the SOFIA telescope

    NASA Astrophysics Data System (ADS)

    Keller, Luke D.; Herter, Terry L.; Stacey, Gordon J.; Gull, George E.; Schoenwald, Justin; Pirger, Bruce; Nikola, Tomas

    2003-02-01

    We report final design details and development progress for the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST). FORCAST is a two-channel camera with selectable filters for continuum and line imaging in the 5-40 micron wavelength region. Simultaneous imaging will be possible in the two-channels--5-25 microns using a Si:As 256×256 blocked impurity band (BIB) detector array, and 25-40 microns using a Si:Sb BIB. FORCAST will sample 0.75 arcseconds per pixel allowing a 3.2'×3.2' instantaneous field-of-view in both channels simultaneously. Imaging will be diffraction limited for lambda > 15 microns. Since FORCAST operates in the wavelength range where the seeing is best from SOFIA, it will provide the highest spatial resolution possible from the airborne observatory. In addition to imaging, the FORCAST optical design provides for a simple upgrade to include spectroscopic observations using grisms mounted in the filter wheels. We report improvements to the optical system and progress in construction of this SOFIA facility instrument and its subsystems. FORCAST will be available for facility testing and astronomical observations at SOFIA first (f)light.

  10. Serendipitous ALMA detections of faint submm galaxies in SERVS

    NASA Astrophysics Data System (ADS)

    Patil, Pallavi; Lacy, Mark; Nyland, Kristina

    2017-01-01

    We present a preliminary ALMA study of faint (<1mJy) submm galaxies with counterparts in the Spitzer Extragalactic Representative Volume Survey (SERVS). SERVS provides post-cryogenic IRAC imaging at 3.6 and 4.5 microns over an 18 deg2 area of the sky over five famous deep fields. The depth of the survey is ~ 2 µJy, and it provides a complete census of galaxies up to z ~ 5. While it is known that bright submm galaxies are associated with dusty, ultra-luminous starforming galaxies at z ~ 2, the sub-mJy population is still not well understood. A key missing piece of information is their morphologies at rest-frame optical wavelengths, which for high-redshift submm galaxies is only accessible through ALMA observations. The high sensitivity, spatial resolution, and positional accuracy of ALMA have enabled us to probe the nature of the sub-mJy population by resolving their spatial extents and improving constraints on their SEDS and photometric redshifts. We are building a catalog of sources by searching the ALMA archive for moderate to deep observations in the area covered by SERVS. This study will help us begin to understand the contribution of obscured star formation to the total star formation rate at high redshift and guide future wide-area surveys of submm galaxies with ALMA.

  11. No climate paradox under the faint early Sun.

    PubMed

    Rosing, Minik T; Bird, Dennis K; Sleep, Norman H; Bjerrum, Christian J

    2010-04-01

    Environmental niches in which life first emerged and later evolved on the Earth have undergone dramatic changes in response to evolving tectonic/geochemical cycles and to biologic interventions, as well as increases in the Sun's luminosity of about 25 to 30 per cent over the Earth's history. It has been inferred that the greenhouse effect of atmospheric CO(2) and/or CH(4) compensated for the lower solar luminosity and dictated an Archaean climate in which liquid water was stable in the hydrosphere. Here we demonstrate, however, that the mineralogy of Archaean sediments, particularly the ubiquitous presence of mixed-valence Fe(II-III) oxides (magnetite) in banded iron formations is inconsistent with such high concentrations of greenhouse gases and the metabolic constraints of extant methanogens. Prompted by this, and the absence of geologic evidence for very high greenhouse-gas concentrations, we hypothesize that a lower albedo on the Earth, owing to considerably less continental area and to the lack of biologically induced cloud condensation nuclei, made an important contribution to moderating surface temperature in the Archaean eon. Our model calculations suggest that the lower albedo of the early Earth provided environmental conditions above the freezing point of water, thus alleviating the need for extreme greenhouse-gas concentrations to satisfy the faint early Sun paradox.

  12. THE PRIMEVAL POPULATIONS OF THE ULTRA-FAINT DWARF GALAXIES

    SciTech Connect

    Brown, Thomas M.; Tumlinson, Jason; Kalirai, Jason S.; Avila, Roberto J.; Ferguson, Henry C. E-mail: tumlinson@stsci.edu E-mail: avila@stsci.edu; and others

    2012-07-01

    We present new constraints on the star formation histories of the ultra-faint dwarf (UFD) galaxies, using deep photometry obtained with the Hubble Space Telescope (HST). A galaxy class recently discovered in the Sloan Digital Sky Survey, the UFDs appear to be an extension of the classical dwarf spheroidals to low luminosities, offering a new front in efforts to understand the missing satellite problem. They are the least luminous, most dark-matter-dominated, and least chemically evolved galaxies known. Our HST survey of six UFDs seeks to determine if these galaxies are true fossils from the early universe. We present here the preliminary analysis of three UFD galaxies: Hercules, Leo IV, and Ursa Major I. Classical dwarf spheroidals of the Local Group exhibit extended star formation histories, but these three Milky Way satellites are at least as old as the ancient globular cluster M92, with no evidence for intermediate-age populations. Their ages also appear to be synchronized to within {approx}1 Gyr of each other, as might be expected if their star formation was truncated by a global event, such as reionization.

  13. Observations and ephemerides of the faint satellites of Jupiter.

    NASA Astrophysics Data System (ADS)

    Rocher, P.; Chapront, J.

    1996-07-01

    The observations of the faint satellites of Jupiter JVI, JVII, JVIII and JIX, have been collected since their discoveries. Numerical integrations of their motions have been performed and fitted to all observations. The final standard deviations in right ascension and declination for the whole set of satellites lie between 0.9" and 1.4". Besides, a list of the individual observations and post-fit residuals is provided. Using the results from the numerical integrations, we have constructed ephemerides of the equatorial jovicentric rectangular coordinates of the satellites. Usually the results are represented in form of series of Chebychev polynomials; here instead, we have taken advantage of a new type of approximation in Poisson series, available on relatively long time intervals. The natural frequencies of the motion have been obtained by frequency analysis of the time series. This process of approximation economizes the amount of numbers necessary to evaluate the jovicentric or geocentric coordinates to a reasonable precision (below 0.01"), and allows one to produce compact and easily-handled ephemerides programs. The main practical result of this contribution is to provide to users numerical tools for the reconstruction of satellite ephemerides, covering 150 years starting from 1900. Tables and software are published in electronic form.

  14. Luminosity Function of Faint Globular Clusters in M87

    SciTech Connect

    Waters, Christopher Z.; Zepf, Stephen E.; Lauer, Tod R.; Baltz, Edward A.; Silk, Joseph; /Oxford U.

    2006-07-14

    We present the luminosity function to very faint magnitudes for the globular clusters in M87, based on a 30 orbit Hubble Space Telescope (HST) WFPC2 imaging program. The very deep images and corresponding improved false source rejection allow us to probe the mass function further beyond the turnover than has been done before. We compare our luminosity function to those that have been observed in the past, and confirm the similarity of the turnover luminosity between M87 and the Milky Way. We also find with high statistical significance that the M87 luminosity function is broader than that of the Milky Way. We discuss how determining the mass function of the cluster system to low masses can constrain theoretical models of the dynamical evolution of globular cluster systems. Our mass function is consistent with the dependence of mass loss on the initial cluster mass given by classical evaporation, and somewhat inconsistent with newer proposals that have a shallower mass dependence. In addition, the rate of mass loss is consistent with standard evaporation models, and not with the much higher rates proposed by some recent studies of very young cluster systems. We also find that the mass-size relation has very little slope, indicating that there is almost no increase in the size of a cluster with increasing mass.

  15. VLBI observations of Infrared-Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Middelberg, Enno; Phillips, Chris; Norris, Ray; Tingay, Steven

    2006-10-01

    We propose to observe a small sample of radio sources from the ATLAS project (ATLAS = Australia Telescope Large Area Survey) with the LBA, to determine their compactness and map their structures. The sample consists of three radio sources with no counterpart in the co-located SWIRE survey (3.6 um to 160 um), carried out with the Spitzer Space Telescope. This rare class of sources, dubbed Infrared-Faint Radio Sources, or IFRS, is inconsistent with current galaxy evolution models. VLBI observations are an essential way to obtain further clues on what these objects are and why they are hidden from infrared observations: we will map their structure to test whether they resemble core-jet or double-lobed morphologies, and we will measure the flux densities on long baselines, to determine their compactness. Previous snapshot-style LBA observations of two other IFRS yielded no detections, hence we propose to use disk-based recording with 512 Mbps where possible, for highest sensitivity. With the observations proposed here, we will increase the number of VLBI-observed IFRS from two to five, soon allowing us to draw general conclusions about this intriguing new class of objects.

  16. Whence the red panda?

    PubMed

    Flynn, J J; Nedbal, M A; Dragoo, J W; Honeycutt, R L

    2000-11-01

    The evolutionary history of the red panda (Ailurus fulgens) plays a pivotal role in the higher-level phylogeny of the "bear-like" arctoid carnivoran mammals. Characters from morphology and molecules have provided inconsistent evidence for placement of the red panda. Whereas it certainly is an arctoid, there has been major controversy about whether it should be placed with the bears (ursids), ursids plus pinnipeds (seals, sea lions, walrus), raccoons (procyonids), musteloids (raccoons plus weasels, skunks, otters, and badgers [mustelids]), or as a monotypic lineage of uncertain phylogenetic affinities. Nucleotide sequence data from three mitochondrial genes and one nuclear intron were analyzed, with more complete taxonomic sampling of relevant taxa (arctoids) than previously available in analyses of primary molecular data, to clarify the phylogenetic relationships of the red panda to other arctoid carnivorans. This study provides detailed phylogenetic analyses (both parsimony and maximum-likelihood) of primary character data for arctoid carnivorans, including bootstrap and decay indices for all arctoid nodes, and three statistical tests of alternative phylogenetic hypotheses for the placement of the red panda. Combined phylogenetic analyses reject the hypotheses that the red panda is most closely related to the bears (ursids) or to the raccoons (procyonids). Rather, evidence from nucleotide sequences strongly support placement of the red panda within a broad Musteloidea (sensu lato) clade, including three major lineages (the red panda, the skunks [mephitids], and a clearly monophyletic clade of procyonids plus mustelids [sensu stricto, excluding skunks]). Within the Musteloidea, interrelationships of the three major lineages are unclear and probably are best considered an unresolved trichotomy. These data provide compelling evidence for the relationships of the red panda and demonstrate that small taxonomic sample sizes can result in misleading or possibly erroneous

  17. A white dwarf companion to the main-sequence star 4 Omicron(1) Orionis and the binary hypothesis for the origin of peculiar red giants

    NASA Technical Reports Server (NTRS)

    Ake, Thomas B.; Johnson, Hollis R.

    1988-01-01

    Ultraviolet spectra of the peculiar red giants (PRGs) called MS stars are investigated, and the discovery of a white dwarf (WD) companion to the MS star 4 Omicron(1) Orionis is reported. The observations and data analysis are discussed and compared with those for field WDs in order to derive parameters for the WD and the luminosity of the primary. Detection limits for the other MS stars investigated are derived, and the binary hypothesis for PRGs is reviewed.

  18. The Distribution of Alpha Elements in Ultra-faint Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Vargas, Luis C.; Geha, Marla; Kirby, Evan N.; Simon, Joshua D.

    2013-04-01

    The Milky Way ultra-faint dwarf (UFD) galaxies contain some of the oldest, most metal-poor stars in the universe. We present [Mg/Fe], [Si/Fe], [Ca/Fe], [Ti/Fe], and mean [α/Fe] abundance ratios for 61 individual red giant branch stars across eight UFDs. This is the largest sample of alpha abundances published to date in galaxies with absolute magnitudes MV > -8, including the first measurements for Segue 1, Canes Venatici II, Ursa Major I, and Leo T. Abundances were determined via medium-resolution Keck/DEIMOS spectroscopy and spectral synthesis. The sample spans the metallicity range -3.4 <[Fe/H] < -1.1. With the possible exception of Segue 1 and Ursa Major II, the individual UFDs show on average lower [α/Fe] at higher metallicities, consistent with enrichment from Type Ia supernovae. Thus, even the faintest galaxies have undergone at least a limited level of chemical self-enrichment. Together with recent photometric studies, this suggests that star formation in the UFDs was not a single burst, but instead lasted at least as much as the minimum time delay of the onset of Type Ia supernovae (~100 Myr) and less than ~2 Gyr. We further show that the combined population of UFDs has an [α/Fe] abundance pattern that is inconsistent with a flat, Galactic halo-like alpha abundance trend, and is also qualitatively different from that of the more luminous CVn I dSph, which does show a hint of a plateau at very low [Fe/H].

  19. THE DISTRIBUTION OF ALPHA ELEMENTS IN ULTRA-FAINT DWARF GALAXIES

    SciTech Connect

    Vargas, Luis C.; Geha, Marla; Kirby, Evan N.; Simon, Joshua D.

    2013-04-20

    The Milky Way ultra-faint dwarf (UFD) galaxies contain some of the oldest, most metal-poor stars in the universe. We present [Mg/Fe], [Si/Fe], [Ca/Fe], [Ti/Fe], and mean [{alpha}/Fe] abundance ratios for 61 individual red giant branch stars across eight UFDs. This is the largest sample of alpha abundances published to date in galaxies with absolute magnitudes M{sub V} > -8, including the first measurements for Segue 1, Canes Venatici II, Ursa Major I, and Leo T. Abundances were determined via medium-resolution Keck/DEIMOS spectroscopy and spectral synthesis. The sample spans the metallicity range -3.4 <[Fe/H] < -1.1. With the possible exception of Segue 1 and Ursa Major II, the individual UFDs show on average lower [{alpha}/Fe] at higher metallicities, consistent with enrichment from Type Ia supernovae. Thus, even the faintest galaxies have undergone at least a limited level of chemical self-enrichment. Together with recent photometric studies, this suggests that star formation in the UFDs was not a single burst, but instead lasted at least as much as the minimum time delay of the onset of Type Ia supernovae ({approx}100 Myr) and less than {approx}2 Gyr. We further show that the combined population of UFDs has an [{alpha}/Fe] abundance pattern that is inconsistent with a flat, Galactic halo-like alpha abundance trend, and is also qualitatively different from that of the more luminous CVn I dSph, which does show a hint of a plateau at very low [Fe/H].

  20. Revealing a strongly reddened, faint active galactic nucleus population by stacking deep co-added images

    NASA Astrophysics Data System (ADS)

    Varga, József; Csabai, István.; Dobos, László

    2012-10-01

    More than half of the sources identified by recent radio sky surveys have not been detected by wide-field optical surveys. We present a study, based on our co-added image stacking technique, in which our aim is to detect the optical emission from unresolved, isolated radio sources of the Very Large Array (VLA) Faint Images of the Radio Sky at Twenty-cm (FIRST) survey that have no identified optical counterparts in the Sloan Digital Sky Survey (SDSS) Stripe 82 co-added data set. From the FIRST catalogue, 2116 such radio point sources were selected, and cut-out images, centred on the FIRST coordinates, were generated from the Stripe 82 images. The already co-added cut-outs were stacked once again to obtain images of high signal-to-noise ratio, in the hope that optical emission from the radio sources would become detectable. Multiple stacks were generated, based on the radio luminosity of the point sources. The resulting stacked images show central peaks similar to point sources. The peaks have very red colours with steep optical spectral energy distributions. We have found that the optical spectral index αν falls in the range -2.9 ≤ αν ≤ -2.2 (Sν∝ναν), depending only weakly on the radio flux. The total integration times of the stacks are between 270 and 300 h, and the corresponding 5σ detection limit is estimated to be about mr ≃ 26.6 mag. We argue that the detected light is mainly from the central regions of dust-reddened Type 1 active galactic nuclei. Dust-reddened quasars might represent an early phase of quasar evolution, and thus they can also give us an insight into the formation of massive galaxies. The data used in the paper are available on-line at http://www.vo.elte.hu/doublestacking.

  1. MEASURING X-RAY VARIABILITY IN FAINT/SPARSELY SAMPLED ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Allevato, V.; Paolillo, M.; Papadakis, I.; Pinto, C.

    2013-07-01

    We study the statistical properties of the normalized excess variance of variability process characterized by a ''red-noise'' power spectral density (PSD), as in the case of active galactic nuclei (AGNs). We perform Monte Carlo simulations of light curves, assuming both a continuous and a sparse sampling pattern and various signal-to-noise ratios (S/Ns). We show that the normalized excess variance is a biased estimate of the variance even in the case of continuously sampled light curves. The bias depends on the PSD slope and on the sampling pattern, but not on the S/N. We provide a simple formula to account for the bias, which yields unbiased estimates with an accuracy better than 15%. We show that the normalized excess variance estimates based on single light curves (especially for sparse sampling and S/N < 3) are highly uncertain (even if corrected for bias) and we propose instead the use of an ''ensemble estimate'', based on multiple light curves of the same object, or on the use of light curves of many objects. These estimates have symmetric distributions, known errors, and can also be corrected for biases. We use our results to estimate the ability to measure the intrinsic source variability in current data, and show that they could also be useful in the planning of the observing strategy of future surveys such as those provided by X-ray missions studying distant and/or faint AGN populations and, more in general, in the estimation of the variability amplitude of sources that will result from future surveys such as Pan-STARRS and LSST.

  2. SN 2009E: a faint clone of SN 1987A

    NASA Astrophysics Data System (ADS)

    Pastorello, A.; Pumo, M. L.; Navasardyan, H.; Zampieri, L.; Turatto, M.; Sollerman, J.; Taddia, F.; Kankare, E.; Mattila, S.; Nicolas, J.; Prosperi, E.; San Segundo Delgado, A.; Taubenberger, S.; Boles, T.; Bachini, M.; Benetti, S.; Bufano, F.; Cappellaro, E.; Cason, A. D.; Cetrulo, G.; Ergon, M.; Germany, L.; Harutyunyan, A.; Howerton, S.; Hurst, G. M.; Patat, F.; Stritzinger, M.; Strolger, L.-G.; Wells, W.

    2012-01-01

    H, Na I, [Ca II] and [O I], with the [O I] feature being relatively strong compared to the [Ca II] doublet. The overall spectroscopic evolution is reminiscent of that of the faint 56Ni-poor type II-plateau supernovae. This suggests that SN 2009E belongs to the low-luminosity, low 56Ni mass, low-energy tail in the distribution of the 1987A-like objects in the same manner as SN 1997D and similar events represent the faint tail in the distribution of physical properties for normal type II-plateau supernovae. Appendices A and B are available in electronic form at http://www.aanda.orgFull Table 2 is only available in electronic form 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/537/A141

  3. A new, faint population of X-ray transients

    NASA Astrophysics Data System (ADS)

    Bauer, Franz E.; Treister, Ezequiel; Schawinski, Kevin; Schulze, Steve; Luo, Bin; Alexander, David M.; Brandt, William N.; Comastri, Andrea; Forster, Francisco; Gilli, Roberto; Kann, David Alexander; Maeda, Keiichi; Nomoto, Ken'ichi; Paolillo, Maurizio; Ranalli, Piero; Schneider, Donald P.; Shemmer, Ohad; Tanaka, Masaomi; Tolstov, Alexey; Tominaga, Nozomu; Tozzi, Paolo; Vignali, Cristian; Wang, Junxian; Xue, Yongquan; Yang, Guang

    2017-06-01

    We report on the detection of a remarkable new fast high-energy transient found in the Chandra Deep Field-South, robustly associated with a faint (mR = 27.5 mag, zph ˜ 2.2) host in the CANDELS survey. The X-ray event is comprised of 115^{+12}_{-11} net 0.3-7.0 keV counts, with a light curve characterized by an ≈100 s rise time, a peak 0.3-10 keV flux of ≈5 × 10-12 erg s-1 cm-2 and a power-law decay time slope of -1.53 ± 0.27. The average spectral slope is Γ = 1.43^{+0.23}_{-0.13}, with no clear spectral variations. The X-ray and multiwavelength properties effectively rule out the vast majority of previously observed high-energy transients. A few theoretical possibilities remain: an 'orphan' X-ray afterglow from an off-axis short-duration gamma-ray burst (GRB) with weak optical emission, a low-luminosity GRB at high redshift with no prompt emission below ˜20 keV rest frame, or a highly beamed tidal disruption event (TDE) involving an intermediate-mass black hole and a white dwarf with little variability. However, none of the above scenarios can completely explain all observed properties. Although large uncertainties exist, the implied rate of such events is comparable to those of orphan and low-luminosity GRBs as well as rare TDEs, implying the discovery of an untapped regime for a known transient class, or a new type of variable phenomena whose nature remains to be determined.

  4. Faint Object Camera imaging and spectroscopy of NGC 4151

    NASA Technical Reports Server (NTRS)

    Boksenberg, A.; Catchpole, R. M.; Macchetto, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.

    1995-01-01

    We describe ultraviolet and optical imaging and spectroscopy within the central few arcseconds of the Seyfert galaxy NGC 4151, obtained with the Faint Object Camera on the Hubble Space Telescope. A narrowband image including (O III) lambda(5007) shows a bright nucleus centered on a complex biconical structure having apparent opening angle approximately 65 deg and axis at a position angle along 65 deg-245 deg; images in bands including Lyman-alpha and C IV lambda(1550) and in the optical continuum near 5500 A, show only the bright nucleus. In an off-nuclear optical long-slit spectrum we find a high and a low radial velocity component within the narrow emission lines. We identify the low-velocity component with the bright, extended, knotty structure within the cones, and the high-velocity component with more confined diffuse emission. Also present are strong continuum emission and broad Balmer emission line components, which we attribute to the extended point spread function arising from the intense nuclear emission. Adopting the geometry pointed out by Pedlar et al. (1993) to explain the observed misalignment of the radio jets and the main optical structure we model an ionizing radiation bicone, originating within a galactic disk, with apex at the active nucleus and axis centered on the extended radio jets. We confirm that through density bounding the gross spatial structure of the emission line region can be reproduced with a wide opening angle that includes the line of sight, consistent with the presence of a simple opaque torus allowing direct view of the nucleus. In particular, our modelling reproduces the observed decrease in position angle with distance from the nucleus, progressing initially from the direction of the extended radio jet, through our optical structure, and on to the extended narrow-line region. We explore the kinematics of the narrow-line low- and high-velocity components on the basis of our spectroscopy and adopted model structure.

  5. Faint Object Camera imaging and spectroscopy of NGC 4151

    NASA Technical Reports Server (NTRS)

    Boksenberg, A.; Catchpole, R. M.; Macchetto, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.

    1995-01-01

    We describe ultraviolet and optical imaging and spectroscopy within the central few arcseconds of the Seyfert galaxy NGC 4151, obtained with the Faint Object Camera on the Hubble Space Telescope. A narrowband image including (O III) lambda(5007) shows a bright nucleus centered on a complex biconical structure having apparent opening angle approximately 65 deg and axis at a position angle along 65 deg-245 deg; images in bands including Lyman-alpha and C IV lambda(1550) and in the optical continuum near 5500 A, show only the bright nucleus. In an off-nuclear optical long-slit spectrum we find a high and a low radial velocity component within the narrow emission lines. We identify the low-velocity component with the bright, extended, knotty structure within the cones, and the high-velocity component with more confined diffuse emission. Also present are strong continuum emission and broad Balmer emission line components, which we attribute to the extended point spread function arising from the intense nuclear emission. Adopting the geometry pointed out by Pedlar et al. (1993) to explain the observed misalignment of the radio jets and the main optical structure we model an ionizing radiation bicone, originating within a galactic disk, with apex at the active nucleus and axis centered on the extended radio jets. We confirm that through density bounding the gross spatial structure of the emission line region can be reproduced with a wide opening angle that includes the line of sight, consistent with the presence of a simple opaque torus allowing direct view of the nucleus. In particular, our modelling reproduces the observed decrease in position angle with distance from the nucleus, progressing initially from the direction of the extended radio jet, through our optical structure, and on to the extended narrow-line region. We explore the kinematics of the narrow-line low- and high-velocity components on the basis of our spectroscopy and adopted model structure.

  6. Chemical enrichment in Ultra-Faint Dwarf galaxies

    NASA Astrophysics Data System (ADS)

    Romano, Donatella

    2015-08-01

    The origin and evolution of galaxies is one of the great outstanding problems of astrophysics. The elusive, basic processes that govern galaxy formation can be advantageously studied in the simplest structures found orbiting the Milky Way, namely, the newly discovered Ultra-Faint Dwarf (UFD) galaxies. These low luminosity objects are the most dark matter-dominated galaxies known and likely the relics of the complex assembly processes that shaped the Galaxy over a Hubble time. They formed stars long (~12 Gyr) ago and have been quiescent ever since. Their present-day stellar masses are comparable to those of typical Milky Way globular clusters (GCs) but, at variance with GCs, they have large [Fe/H] spreads and average metallicities lower than those of the most metal-poor GCs, which clearly indicates they followed distinct evolutionary paths. The abundance ratios [α/Fe] measured in a few UFD giant stars closely resemble those of similarly metal-poor Galactic halo stars, suggesting that chemical evolution proceeded similarly in different systems at the earliest times. Despite their simplicity, a number of questions remain unanswered with regards to these systems: did they suffer 'one-shot' or extended star formation? what is the level and significance of chemical inhomogeneity inside these systems? was stellar feedback effective in removing all the gas left over from the star formation process, or did the interaction with the environment play a major role? In this contribution we discuss these issues basing on results we got from pure chemical evolution models, as well as three-dimensional hydrodynamical simulations run at subparsec resolution.

  7. On The Nature of Faint Galaxies with Strong UV Excess

    NASA Astrophysics Data System (ADS)

    Cruzen, S.; Weistrop, D.; Angione, R.

    1993-05-01

    Four faint galaxies identified in the Case Low-Dispersion Northern Sky Survey (Stephenson, Pesch, MacConnell 1992,ApJSS,82,471) show unusually strong UV excess in their objective prism spectra. We are currently investigating the nature of these galaxies (CG 1280, CG 1293, CG 1298, CG 1331). The preliminary results from the analysis of the spectra for galaxies CG 1293 (R.A.=15(h}22({m}00^{s)) .0, Decl.=+30deg 29(') .7 [1950]) and CG 1331 (R.A.=15(h}54({m}41^{s)) .9, Decl.=+29deg 57(') .4 [1950]) are presented. Stephenson, Pesch and MacConnell report that both galaxies have blue magnitudes of approximately 17. We obtained observations of these objects on 1992 July 2 and 3 with the CCD spectrograph on the 40-inch telescope at Mount Laguna Observatory. This CCD has an 800 x 800 format and covers an approximate wavelength range of 4000 Angstroms to 7000 Angstroms. Our analysis of the spectra reveals strong Hα emission with broad line profiles characteristic of Seyfert 1 galaxies. The spectrum of CG 1293 indicates a redshift of z = 0.1255 0.0003 and an Hα emission line width of 4180 km/sec (FWHM). The [SII] pair lambda 6717 and lambda 6731 have also been identified. We have determined a preliminary redshift for CG 1331 of z = 0.089 +/- 0.004. The Hα emission line width for CG 1331 is 7350 km/sec (FWHM). Lines corresponding to Hβ and Hγ have also been identified. This research has been supported in part by NASA through the Nevada Space Grant Consortium.

  8. The radio properties of infrared-faint radio sources

    NASA Astrophysics Data System (ADS)

    Middelberg, E.; Norris, R. P.; Hales, C. A.; Seymour, N.; Johnston-Hollitt, M.; Huynh, M. T.; Lenc, E.; Mao, M. Y.

    2011-02-01

    Context. Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4 GHz, but that are invisible at 3.6 μm when using sensitive Spitzer observations with μJy sensitivities. Their nature is unclear and difficult to investigate since they are only visible in the radio. Aims: High-resolution radio images and comprehensive spectral coverage can yield constraints on the emission mechanisms of IFRS and can give hints to similarities with known objects. Methods: We imaged a sample of 17 IFRS at 4.8 GHz and 8.6 GHz with the Australia Telescope Compact Array to determine the structures on arcsecond scales. We added radio data from other observing projects and from the literature to obtain broad-band radio spectra. Results: We find that the sources in our sample are either resolved out at the higher frequencies or are compact at resolutions of a few arcsec, which implies that they are smaller than a typical galaxy. The spectra of IFRS are remarkably steep, with a median spectral index of -1.4 and a prominent lack of spectral indices larger than -0.7. We also find that, given the IR non-detections, the ratio of 1.4 GHz flux density to 3.6 μm flux density is very high, and this puts them into the same regime as high-redshift radio galaxies. Conclusions: The evidence that IFRS are predominantly high-redshift sources driven by active galactic nuclei (AGN) is strong, even though not all IFRS may be caused by the same phenomenon. Compared to the rare and painstakingly collected high-redshift radio galaxies, IFRS appear to be much more abundant, but less luminous, AGN-driven galaxies at similar cosmological distances.

  9. Faint photoelectric photometric standard star sequences. Final report, 1 January 1982-30 June 1988

    SciTech Connect

    Landolt, A.

    1988-07-15

    The primary purpose of the research funded via AFOSR Grant No. 82-0192 was to establish highly accurate standard stars covering a wide range both in brightness and color around the celestial sphere. The availability of such standard stars would enable anyone to determine the brightness or color of any object projected against the sky from land, the air, or in space. Other secondary projects also were undertaken as circumstances warrented. This document outlines the overall program, including the data acquisition, analysis, and results.

  10. Astrometric observations of the faint outer satellites of Jupiter during the 1993 opposition

    NASA Technical Reports Server (NTRS)

    Shelus, Peter J.; Whipple, Arthur L.; Benedict, G. F.

    1993-01-01

    Astrometric positions for the faint outer Jovian satellites VI-XIII during the 1993 opposition have been obtained from the measurement of plates taken with the 2.1 m Otto Struve reflector at McDonald Observatory.

  11. The Origin of Dwarf Galaxies in Clusters: The Faint-End Slope of Abell 85 Galaxy Luminosity Function

    NASA Astrophysics Data System (ADS)

    Agulli, I.; Aguerri, J. A. L.; Barrena, R.; Diaferio, A.; Sánchez-Janssen, R.

    2016-10-01

    Dwarf galaxies (Mb>-18) are important because of their cosmological interest as tests of hierarchical theories. The formation of these galaxies is still an open question but red dwarf galaxies are preferentially located in high density environments, indicating that they are end-products of galaxy transformations in clusters. Deep spectroscopic studies of galaxy clusters are needed to put some constraints on dwarf galaxy formation and evolution. We have observed and analyzed Abell 85, a nearby (z = 0.055) and massive cluster down to M*+6, using the MOS instruments VIMOS@VLT and AF2@WHT. The first and powerful tool to study the characteristics of galaxies and compare with different density environments is the galaxy luminosity function. The comparison of the results for Abell 85 with literature outcomes for clusters and field, allows us to conclude that, at least for this cluster, the environment plays a major role in the nature of the faint-end galaxies, transforming blue dwarfs in the field into red ones in the cluster, but not in the formation of the luminosity function slope.

  12. Red Arcs on Tethys

    NASA Image and Video Library

    2015-07-29

    Unusual arc-shaped, reddish streaks cut across the surface of Saturn's ice-rich moon Tethys in this enhanced-color mosaic. The red streaks are narrow, curved lines on the moon's surface, only a few miles (or kilometers) wide but several hundred miles (or kilometers) long. The red streaks are among the most unusual color features on Saturn's moons to be revealed by Cassini's cameras. A few of the red arcs can be faintly seen in Cassini imaging observations made earlier in the mission, but the color images for this observation, which were obtained in April 2015, were the first to show large northern areas of Tethys under the illumination and viewing conditions necessary to see the features clearly. As the Saturn system moved into its northern hemisphere summer over the past few years, northern latitudes have become increasingly well illuminated. As a result, the red arc features have become clearly visible for the first time. The origin of the features and their reddish color is currently a mystery to Cassini scientists. Possibilities being studied include ideas that the reddish material is exposed ice with chemical impurities, or the result of outgassing from inside Tethys. The streaks could also be associated with features like fractures that are below the resolution of the available images. Except for a few small craters on Dione, reddish tinted features are rare on other moons of Saturn. However, many reddish features are observed on the geologically young surface of Jupiter's moon Europa. Images taken using clear, green, infrared and ultraviolet spectral filters were combined to create the view, which highlights subtle color differences across Tethys' surface at wavelengths not visible to human eyes. The moon's surface is fairly uniform in natural color. The yellowish tones on the left side of the view are a result of alteration of the moon's surface by high-energy particles from Saturn's magnetosphere. This particle radiation slams into the moon's trailing

  13. Witnessing the Birth of the Red Sequence: ALMA High-resolution Imaging of [C II] and Dust in Two Interacting Ultra-red Starbursts at z = 4.425

    NASA Astrophysics Data System (ADS)

    Oteo, I.; Ivison, R. J.; Dunne, L.; Smail, I.; Swinbank, A. M.; Zhang, Z.-Y.; Lewis, A.; Maddox, S.; Riechers, D.; Serjeant, S.; Van der Werf, P.; Biggs, A. D.; Bremer, M.; Cigan, P.; Clements, D. L.; Cooray, A.; Dannerbauer, H.; Eales, S.; Ibar, E.; Messias, H.; Michałowski, M. J.; Pérez-Fournon, I.; van Kampen, E.

    2016-08-01

    Exploiting the sensitivity and spatial resolution of the Atacama Large Millimeter/submillimeter Array, we have studied the morphology and the physical scale of the interstellar medium—both gas and dust—in SGP 38326, an unlensed pair of interacting starbursts at z = 4.425. SGP 38326 is the most luminous star bursting system known at z > 4, with a total IR luminosity of L IR ˜ 2.5 × 1013 L ⊙ and a star formation rate of ˜ 4500 M ⊙ yr-1. SGP 38326 also contains a molecular gas reservoir among the most massive yet found in the early universe, and it is the likely progenitor of a massive, red-and-dead elliptical galaxy at z ˜ 3. Probing scales of ˜0.″1 or ˜800 pc we find that the smooth distribution of the continuum emission from cool dust grains contrasts with the more irregular morphology of the gas, as traced by the [C ii] fine structure emission. The gas is also extended over larger physical scales than the dust. The velocity information provided by the resolved [C ii] emission reveals that the dynamics of the two interacting components of SGP 38326 are each compatible with disk-like, ordered rotation, but also reveals an ISM which is turbulent and unstable. Our observations support a scenario where at least a subset of the most distant extreme starbursts are highly dissipative mergers of gas-rich galaxies.

  14. Spitzer ultra faint survey program (surfs up). I. An overview

    SciTech Connect

    Bradač, Maruša; Huang, Kuang-Han; Cain, Benjamin; Hall, Nicholas; Lubin, Lori; Ryan, Russell; Casertano, Stefano; Lemaux, Brian C.; Schrabback, Tim; Hildebrandt, Hendrik; Gonzalez, Anthony H.; Allen, Steve; Von der Linden, Anja; Gladders, Mike; Hinz, Joannah; Zaritsky, Dennis; Treu, Tommaso

    2014-04-20

    Spitzer UltRa Faint SUrvey Program is a joint Spitzer and Hubble Space Telescope Exploration Science program using 10 galaxy clusters as cosmic telescopes to study z ≳ 7 galaxies at intrinsically lower luminosities, enabled by gravitational lensing, than blank field surveys of the same exposure time. Our main goal is to measure stellar masses and ages of these galaxies, which are the most likely sources of the ionizing photons that drive reionization. Accurate knowledge of the star formation density and star formation history at this epoch is necessary to determine whether these galaxies indeed reionized the universe. Determination of the stellar masses and ages requires measuring rest-frame optical light, which only Spitzer can probe for sources at z ≳ 7, for a large enough sample of typical galaxies. Our program consists of 550 hr of Spitzer/IRAC imaging covering 10 galaxy clusters with very well-known mass distributions, making them extremely precise cosmic telescopes. We combine our data with archival observations to obtain mosaics with ∼30 hr exposure time in both 3.6 μm and 4.5 μm in the central 4' × 4' field and ∼15 hr in the flanking fields. This results in 3σ sensitivity limits of ∼26.6 and ∼26.2 AB magnitudes for the central field in the IRAC 3.6 and 4.5 μm bands, respectively. To illustrate the survey strategy and characteristics we introduce the sample, present the details of the data reduction and demonstrate that these data are sufficient for in-depth studies of z ≳ 7 sources (using a z = 9.5 galaxy behind MACS J1149.5+2223 as an example). For the first cluster of the survey (the Bullet Cluster) we have released all high-level data mosaics and IRAC empirical point-spread function models. In the future we plan to release these data products for the entire survey.

  15. Image Stacking Method Application for Low Earth Orbit Faint Objects

    NASA Astrophysics Data System (ADS)

    Tagawa, M.; Matsumoto, H.; Yanagisawa, T.; Kurosaki, H.; Oda, H.; Kitazawa, Y.; Hanada, T.

    2013-09-01

    Space situational awareness is one of the most important actions for safe and sustainable space development and its utilization. Tracking and maintaining debris catalog are the basis of the actions. Current minimum size of objects in the catalog that routinely tracked and updated is approximately 10 cm in the Low Earth Orbit region. This paper proposes collaborative observation of space-based sensors and ground facilities to improve tracking capability in low Earth orbit. This observation geometry based on role-sharing idea. A space-based sensor has advantage in sensitivity and observation opportunity however, it has disadvantages in periodic observation which is essential for catalog maintenance. On the other hand, a ground facility is inferior to space-based sensors in sensitivity however; observation network composed of facilities has an advantage in periodic observation. Whole observation geometry is defined as follows; 1) space-based sensors conduct initial orbit estimation for a target 2) ground facility network tracks the target based on estimated orbit 3) the network observes the target periodically and updates its orbit information. The second phase of whole geometry is based on image stacking method developed by the Japan aerospace exploration agency and this method is verified for objects in geostationary orbit. This method enables to detect object smaller than a nominal size limitation by stacking faint light spot along archived time-series frames. The principle of this method is prediction and searching target's motion on the images. It is almost impossible to apply the method to objects in Low Earth Orbit without proper orbit information because Low Earth Orbit objects have varied orbital characteristics. This paper discusses whether or not initial orbit estimation results given by space-based sensors have enough accuracy to apply image stacking method to Low Earth Orbit objects. Ground-based observation procedure is assumed as being composed of

  16. Time series photometry of faint cataclysmic variables with a CCD

    NASA Astrophysics Data System (ADS)

    Abbott, Timothy Mark Cameron

    1992-08-01

    I describe a new hardware and software environment for the practice of time-series stellar photometry with the CCD systems available at McDonald Observatory. This instrument runs suitable CCD's in frame transfer mode and permits windowing on the CCD image to maximize the duty cycle of the photometer. Light curves may be extracted and analyzed in real time at the telescope and image data are stored for later, more thorough analysis. I describe a star tracking algorithm, which is optimized for a timeseries of images of the same stellar field. I explore the extraction of stellar brightness measures from these images using circular software apertures and develop a complete description of the noise properties of this technique. I show that scintillation and pixelization noise have a significant effect on high quality observations. I demonstrate that optimal sampling and profile fitting techniques are unnecessarily complex or detrimental methods of obtaining stellar brightness measures under conditions commonly encountered in timeseries CCD photometry. I compare CCD's and photomultiplier tubes as detectors for timeseries photometry using light curves of a variety of stars obtained simultaneously with both detectors and under equivalent conditions. A CCD can produce useful data under conditions when a photomultiplier tube cannot, and a CCD will often produce more reliable results even under photometric conditions. I prevent studies of the cataclysmic variables (CV's) AL Com, CP Eri, V Per, and DO Leo made using the time series CCD photometer. AL Com is a very faint CV at high Galactic latitude and a bona fide Population II CV. Some of the properties of AL Com are similar to the dwarf nova WZ Sge and others are similar to the intermediate polar EX Hya, but overall AL Com is unlike any other well-studied cataclysmic variable. CP Eri is shown to be the fifth known interacting binary white dwarf. V Per was the first CV found to have an orbital period near the middle of the

  17. Spectrum from Faint Galaxy IRAS F00183-7111

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's Spitzer Space Telescope has detected the building blocks of life in the distant universe, albeit in a violent milieu. Training its powerful infrared eye on a faint object located at a distance of 3.2 billion light-years, Spitzer has observed the presence of water and organic molecules in the galaxy IRAS F00183-7111. With an active galactic nucleus, this is one of the most luminous galaxies in the universe, rivaling the energy output of a quasar. Because it is heavily obscured by dust (see visible-light image in the inset), most of its luminosity is radiated at infrared wavelengths.

    The infrared spectrograph instrument onboard Spitzer breaks light into its constituent colors, much as a prism does for visible light. The image shows a low-resolution spectrum of the galaxy obtained by the spectrograph at wavelengths between 4 and 20 microns. Spectra are graphical representations of a celestial object's unique blend of light. Characteristic patterns, or fingerprints, within the spectra allow astronomers to identify the object's chemical composition and to determine such physical properties as temperature and density.

    The broad depression in the center of the spectrum denotes the presence of silicates (chemically similar to beach sand) in the galaxy. An emission peak within the bottom of the trough is the chemical signature for molecular hydrogen. The hydrocarbons (orange) are organic molecules comprised of carbon and hydrogen, two of the most common elements on Earth. Since it has taken more than three billion years for the light from the galaxy to reach Earth, it is intriguing to note the presence of organics in a distant galaxy at a time when life is thought to have started forming on our home planet.

    Additional features in the spectrum reveal the presence of water ice (blue), carbon dioxide ice (green) and carbon monoxide (purple) in both gas and solid forms. The magenta peak corresponds to singly ionized neon gas, a spectral line often used by

  18. FAINT SUBMILLIMETER GALAXY COUNTS AT 450 {mu}m

    SciTech Connect

    Chen, Chian-Chou; Cowie, Lennox L.; Barger, Amy J.; Casey, Caitlin M.; Lee, Nicholas; Sanders, David B.; Williams, Jonathan P.; Wang, Wei-Hao

    2013-01-10

    We present the results of SCUBA-2 observations at 450 {mu}m and 850 {mu}m of the field lensed by the massive cluster A370. With a total survey area >100 arcmin{sup 2} and 1{sigma} sensitivities of 3.92 and 0.82 mJy beam{sup -1} at 450 and 850 {mu}m, respectively, we find a secure sample of 20 sources at 450 {mu}m and 26 sources at 850 {mu}m with a signal-to-noise ratio (S/N) > 4. Using the latest lensing model of A370 and Monte Carlo simulations, we derive the number counts at both wavelengths. The 450 {mu}m number counts probe a factor of four deeper than the counts recently obtained from the Herschel Space Telescope at similar wavelengths, and we estimate that {approx}47%-61% of the 450 {mu}m extragalactic background light resolved into individual sources with 450 {mu}m fluxes greater than 4.5 mJy. The faint 450 {mu}m sources in the 4{sigma} sample have positional accuracies of 3 arcsec, while brighter sources (S/N >6{sigma}) are good to 1.4 arcsec. Using a deep radio map (1{sigma} {approx} 6 {mu}Jy) we find that the percentage of submillimeter sources having secure radio counterparts is 85% for 450 {mu}m sources with intrinsic fluxes >6 mJy and 67% for 850 {mu}m sources with intrinsic fluxes >4 mJy. We also find that 67% of the >4{sigma} 450 {mu}m sources are detected at 850 {mu}m, while the recovery rate at 450 {mu}m of >4{sigma} 850 {mu}m sources is 54%. Combined with the source redshifts estimated using millimetric flux ratios, the recovered rate is consistent with the scenario where both 450 {mu}m and 20 cm emission preferentially select lower redshift dusty sources, while 850 {mu}m emission traces a higher fraction of dusty sources at higher redshifts. We identify potential counterparts in various wavelengths from X-ray to mid-infrared and measure the multiwavelength photometry, which we then use to analyze the characteristics of the sources. We find three X-ray counterparts to our robust submillimeter sample (S/N > 5), giving an active galactic nucleus

  19. Red Sky with Red Mesa

    SciTech Connect

    2011-04-14

    The Red Sky/Red Mesa supercomputing platform dramatically reduces the time required to simulate complex fuel models, from 4-6 months to just 4 weeks, allowing researchers to accelerate the pace at which they can address these complex problems. Its speed also reduces the need for laboratory and field testing, allowing for energy reduction far beyond data center walls.

  20. Red Sky with Red Mesa

    ScienceCinema

    None

    2016-07-12

    The Red Sky/Red Mesa supercomputing platform dramatically reduces the time required to simulate complex fuel models, from 4-6 months to just 4 weeks, allowing researchers to accelerate the pace at which they can address these complex problems. Its speed also reduces the need for laboratory and field testing, allowing for energy reduction far beyond data center walls.

  1. Preliminary analysis on faint luminous lightning events recorded by multiple high speed cameras

    NASA Astrophysics Data System (ADS)

    Alves, J.; Saraiva, A. V.; Pinto, O.; Campos, L. Z.; Antunes, L.; Luz, E. S.; Medeiros, C.; Buzato, T. S.

    2013-12-01

    The objective of this work is the study of some faint luminous events produced by lightning flashes that were recorded simultaneously by multiple high-speed cameras during the previous RAMMER (Automated Multi-camera Network for Monitoring and Study of Lightning) campaigns. The RAMMER network is composed by three fixed cameras and one mobile color camera separated by, in average, distances of 13 kilometers. They were located in the Paraiba Valley (in the cities of São José dos Campos and Caçapava), SP, Brazil, arranged in a quadrilateral shape, centered in São José dos Campos region. This configuration allowed RAMMER to see a thunderstorm from different angles, registering the same lightning flashes simultaneously by multiple cameras. Each RAMMER sensor is composed by a triggering system and a Phantom high-speed camera version 9.1, which is set to operate at a frame rate of 2,500 frames per second with a lens Nikkor (model AF-S DX 18-55 mm 1:3.5 - 5.6 G in the stationary sensors, and a lens model AF-S ED 24 mm - 1:1.4 in the mobile sensor). All videos were GPS (Global Positioning System) time stamped. For this work we used a data set collected in four RAMMER manual operation days in the campaign of 2012 and 2013. On Feb. 18th the data set is composed by 15 flashes recorded by two cameras and 4 flashes recorded by three cameras. On Feb. 19th a total of 5 flashes was registered by two cameras and 1 flash registered by three cameras. On Feb. 22th we obtained 4 flashes registered by two cameras. Finally, in March 6th two cameras recorded 2 flashes. The analysis in this study proposes an evaluation methodology for faint luminous lightning events, such as continuing current. Problems in the temporal measurement of the continuing current can generate some imprecisions during the optical analysis, therefore this work aim to evaluate the effects of distance in this parameter with this preliminary data set. In the cases that include the color camera we analyzed the RGB

  2. Revisiting the concept of behavior patterns in animal behavior with an example from food-caching sequences in wolves (Canis lupus), coyotes (Canis latrans), and red foxes (Vulpes vulpes).

    PubMed

    Gadbois, Simon; Sievert, Olivia; Reeve, Catherine; Harrington, F H; Fentress, J C

    2015-01-01

    We discuss the history, conceptualization, and relevance of behavior patterns in modern ethology by explaining the evolution of the concepts of fixed action patterns and modal action patterns. We present the movement toward a more flexible concept of natural action sequences with significant degrees of (production and expressive) freedom. An example is presented with the food caching behavior of three Canidae species: red fox (Vulpes vulpes), coyote (Canis latrans) and gray wolf (Canis lupus). Evolutionary, ecological, and neuroecological/neuroethological arguments are presented to explain the difference in levels of complexity and stereotypy between Canis and Vulpes. This article is part of a Special Issue entitled: Canine Behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. BOO-1137-AN EXTREMELY METAL-POOR STAR IN THE ULTRA-FAINT DWARF SPHEROIDAL GALAXY BOOeTES I

    SciTech Connect

    Norris, John E.; Yong, David; Gilmore, Gerard; Wyse, Rosemary F. G.

    2010-03-01

    We present high-resolution (R {approx} 40,000), high-signal-to-noise ratio (20-90) spectra of an extremely metal-poor giant star Boo-1137 in the 'ultra-faint' dwarf spheroidal galaxy (dSph) Booetes I, absolute magnitude M{sub V} {approx} -6.3. We derive an iron abundance of [Fe/H] = -3.7, making this the most metal-poor star as yet identified in an ultra-faint dSph. Our derived effective temperature and gravity are consistent with its identification as a red giant in Booetes I. Abundances for a further 15 elements have also been determined. Comparison of the relative abundances, [X/Fe], with those of the extremely metal-poor red giants of the Galactic halo shows that Boo-1137 is 'normal' with respect to C and N, the odd-Z elements Na and Al, the iron-peak elements, and the neutron-capture elements Sr and Ba, in comparison with the bulk of the Milky Way halo population having [Fe/H] {approx}<-3.0. The alpha-elements Mg, Si, Ca, and Ti are all higher by DELTA[X/Fe] {approx} 0.2 than the average halo values. Monte Carlo analysis indicates that DELTA[alpha/Fe] values this large are expected with a probability {approx}0.02. The elemental abundance pattern in Boo-1137 suggests inhomogeneous chemical evolution, consistent with the wide internal spread in iron abundances we previously reported. The similarity of most of the Boo-1137 relative abundances with respect to halo values, and the fact that the alpha-elements are all offset by a similar small amount from the halo averages, points to the same underlying galaxy-scale stellar initial mass function, but that Boo-1137 likely originated in a star-forming region where the abundances reflect either poor mixing of supernova (SN) ejecta, or poor sampling of the SN progenitor mass range, or both.

  4. Red Hill

    EPA Pesticide Factsheets

    Information about the Red Hill Bulk Fuel Storage Facility in Hawaii Administrative Order on Consent (AOC), an enforceable agreement of the Hawaii Department of Health, the Environmental Protection Agency, and the U.S. Navy -- Defense Logistics Agency.

  5. The cDNA Sequence of Two Hemocyanin Subunits from Red Swamp Crayfish Procambarus clarkii and their Responses to White Spot Syndrome Virus Infection.

    PubMed

    Zeng, Yong

    2016-03-01

    Hemocyanin, the respiratory protein of crustaceans, participates in the innate immune defense in these organisms. We cloned two hemocyanin subunit genes (PcHc1 and PcHc2), by using a degenerate primer PCR and rapid amplification of cDNA ends (RACE) approach, from the hepatopancreas of red swamp crayfish Procambarus clarkii. The transcripts of these two subunits were only detected in the hepatopancreas by reverse transcriptase quantitative PCR (RT-qPCR) analysis. The neighbor-joining and maximum parsimony phylogenetic analyses indicated that PcHc2 associated with a clade belong to the α-type hemocyanins and PcHc1 associated with another clade belonging to the β-type hemocyanins. The data obtained from the RT-qPCR indicated that the mRNA expression levels of these subunit genes followed almost the same regulation pattern in the crayfish challenged with white spot syndrome virus (WSSV). The fluctuation of mRNA expression levels of these two subunits after the WSSV challenge indicated that both of them may participate in the antiviral immune response of crayfish. Received April 12, 2015; accepted November 22, 2015.

  6. Population genetic structure and molecular diversity of the red swamp crayfish in China based on mtDNA COI gene sequences.

    PubMed

    Liu, Gang; Zhou, Lizhi

    2016-08-23

    Population genetic structure and molecular diversity are closely related to adaptability, potential and evolutionary of a species, which also reflects its population history. We analyzed the molecular variability and genetic structure among 24 populations of the red swamp crayfish in China based on the COI region. The COI of 687 bp aligned across 44 haplotypes, the average AT content (68.1%) was slightly higher than the AT content (31.9%). AMOVA indicated that a high proportion of the total genetic variance was attributable to variations within populations (87.57%), whereas only 12.43% occurred among populations. The Fst values were between 0.016 and 0.585, and the Nm values were between 0.178 and 15.182 in each population. All of the AMOVA, Fst statistics and Nm values suggested low genetic differentiation, but a high level genetic diversity existed in Chinese populations of Procambarus clarkii. The phylogenetic trees showed that some geographical populations were irregularly distributed according to the river systems while others were matched well, suggesting that genetic differentiation is created largely by geographic isolation.

  7. A single prolific r-process event preserved in an ultra-faint dwarf galaxy

    NASA Astrophysics Data System (ADS)

    Ji, Alexander; Frebel, Anna; Chiti, Anirudh; Simon, Joshua

    2016-03-01

    The heaviest elements in the periodic table are synthesized through the r-process, but the astrophysical site for r-process nucleosynthesis is still unknown. Ultra-faint dwarf galaxies contain a simple fossil record of early chemical enrichment that may determine this site. Previous measurements found very low levels of neutron-capture elements in ultra-faint dwarfs, preferring supernovae as the r-process site. I present high-resolution chemical abundances of nine stars in the recently discovered ultra-faint dwarf Reticulum II, which display extremely enhanced r-process abundances 2-3 orders of magnitude higher than the other ultra-faint dwarfs. Stars with such extreme r-process enhancements are only rarely found in the Milky Way halo. The r-process abundances imply that the neutron-capture material in Reticulum II was synthesized in a single prolific event that is incompatible with r-process yields from ordinary core-collapse supernovae. Reticulum II provides an opportunity to discriminate whether the source of this pure r-process signature is a neutron star merger or magnetorotationally driven supernova. The single event is also a uniquely stringent constraint on the metal mixing and star formation history of this ultra-faint dwarf galaxy.

  8. Solar Features Faint but Still Present in 2009

    NASA Astrophysics Data System (ADS)

    Cookson, Angela; Preminger, D.; Chapman, G.

    2009-05-01

    The San Fernando Observatory (SFO) full-disk photometric image archive spans twenty years and includes the cycle 22/23 minimum and the current cycle 23/24 extended minimum. We measure sunspot deficit, faculae/plage/network excess, and disk-integrated variability on red continuum (672.3 nm) and Ca II K-line (393.4 nm) images. A combined plage/network index shows excess remaining above zero as the cycle 23/24 minimum progresses while plage excess alone drops to zero, indicating an absence of large-scale bright regions but a continuing presence of diffuse network. We construct feature-based models of TSI variability and compare our models to the PMOD, ACRIM, and IRMB TSI Composites to determine whether our data reflect the extremely low TSI levels deduced from spacecraft measurements during the current extended solar minimum.

  9. A very faint core-collapse supernova in M85.

    PubMed

    Pastorello, A; Della Valle, M; Smartt, S J; Zampieri, L; Benetti, S; Cappellaro, E; Mazzali, P A; Patat, F; Spiro, S; Turatto, M; Valenti, S

    2007-10-18

    An anomalous transient in the early Hubble-type (S0) galaxy Messier 85 (M85) in the Virgo cluster was discovered by Kulkarni et al. on 7 January 2006 that had very low luminosity (peak absolute R-band magnitude M(R) of about -12) that was constant over more than 80 days, red colour and narrow spectral lines, which seem inconsistent with those observed in any known class of transient events. Kulkarni et al. suggest an exotic stellar merger as the possible origin. An alternative explanation is that the transient in M85 was a type II-plateau supernova of extremely low luminosity, exploding in a lenticular galaxy with residual star-forming activity. This intriguing transient might be the faintest supernova that has ever been discovered.

  10. Estimating sizes of faint, distant galaxies in the submillimetre regime

    NASA Astrophysics Data System (ADS)

    Lindroos, L.; Knudsen, K. K.; Fan, L.; Conway, J.; Coppin, K.; Decarli, R.; Drouart, G.; Hodge, J. A.; Karim, A.; Simpson, J. M.; Wardlow, J.

    2016-10-01

    We measure the sizes of redshift ˜2 star-forming galaxies by stacking data from the Atacama Large Millimeter/submillimeter Array (ALMA). We use a uv-stacking algorithm in combination with model fitting in the uv-domain and show that this allows for robust measures of the sizes of marginally resolved sources. The analysis is primarily based on the 344 GHz ALMA continuum observations centred on 88 submillimetre galaxies in the LABOCA ECDFS Submillimeter Survey (ALESS). We study several samples of galaxies at z ≈ 2 with M* ≈ 5 × 1010 M⊙, selected using near-infrared photometry (distant red galaxies, extremely red objects, sBzK-galaxies, and galaxies selected on photometric redshift). We find that the typical sizes of these galaxies are ˜0.6 arcsec which corresponds to ˜5 kpc at z = 2, this agrees well with the median sizes measured in the near-infrared z band (˜0.6 arcsec). We find errors on our size estimates of ˜0.1-0.2 arcsec, which agree well with the expected errors for model fitting at the given signal-to-noise ratio. With the uv-coverage of our observations (18-160 m), the size and flux density measurements are sensitive to scales out to 2 arcsec. We compare this to a simulated ALMA Cycle 3 data set with intermediate length baseline coverage, and we find that, using only these baselines, the measured stacked flux density would be an order of magnitude fainter. This highlights the importance of short baselines to recover the full flux density of high-redshift galaxies.

  11. THE AGN, STAR-FORMING, AND MORPHOLOGICAL PROPERTIES OF LUMINOUS IR-BRIGHT/OPTICALLY-FAINT GALAXIES

    SciTech Connect

    Donley, J. L.; Rieke, G. H.; Egami, E.; Perez-Gonzalez, P. G.; Alexander, D. M.

    2010-08-20

    We present the active galactic nucleus (AGN), star-forming, and morphological properties of a sample of 13 MIR-luminous (f {sub 24} {approx}> 700 {mu}Jy) IR-bright/optically-faint galaxies (IRBGs, f{sub 24}/f {sub R} {approx}> 1000). While these z {approx} 2 sources were drawn from deep Chandra fields with >200 ks X-ray coverage, only seven are formally detected in the X-ray and four lack X-ray emission at even the 2{sigma} level. Spitzer InfraRed Spectrograph (IRS) spectra, however, confirm that all of the sources are AGN-dominated in the mid-IR, although half have detectable polycyclic aromatic hydrocarbon (PAH) emission responsible for {approx}25% of their mid-infrared flux density. When combined with other samples, this indicates that at least 30%-40% of luminous IRBGs have star formation rates in the ultraluminous infrared galaxy (ULIRG) range ({approx}100-2000 M{sub sun} yr{sup -1}). X-ray hardness ratios and MIR to X-ray luminosity ratios indicate that all members of the sample contain heavily X-ray obscured AGNs, 80% of which are candidates to be Compton thick. Furthermore, the mean X-ray luminosity of the sample, log L{sub 2-10keV}(erg s{sup -1}) {approx}44.6, indicates that these IRBGs are Type 2 QSOs, at least from the X-ray perspective. While those sources most heavily obscured in the X-ray are also those most likely to display strong silicate absorption in the mid-IR, silicate absorption does not always accompany X-ray obscuration. Finally, {approx}70% of the IRBGs are merger candidates, a rate consistent with that of sub-mm galaxies (SMGs), although SMGs appear to be physically larger than IRBGs. These characteristics are consistent with the proposal that these objects represent a later, AGN-dominated, and more relaxed evolutionary stage following soon after the star-formation-dominated one represented by the SMGs.

  12. VARIABLE STARS IN THE ULTRA-FAINT DWARF SPHEROIDAL GALAXY URSA MAJOR I

    SciTech Connect

    Garofalo, Alessia; Moretti, Maria Ida; Cusano, Felice; Clementini, Gisella; Ripepi, Vincenzo; Dall'Ora, Massimo; Coppola, Giuseppina; Musella, Ilaria; Marconi, Marcella E-mail: fcusano@na.astro.it E-mail: ripepi@na.astro.it E-mail: imoretti@na.astro.it E-mail: ilaria@na.astro.it

    2013-04-10

    We have performed the first study of the variable star population of Ursa Major I (UMa I), an ultra-faint dwarf satellite recently discovered around the Milky Way (MW) by the Sloan Digital Sky Survey. Combining time series observations in the B and V bands from four different telescopes, we have identified seven RR Lyrae stars in UMa I, of which five are fundamental-mode (RRab) and two are first-overtone pulsators (RRc). Our V, B - V color-magnitude diagram of UMa I reaches V {approx} 23 mag (at a signal-to-noise ratio of {approx}6) and shows features typical of a single old stellar population. The mean pulsation period of the RRab stars (P{sub ab}) = 0.628, {sigma} = 0.071 days (or (P{sub ab}) = 0.599, {sigma} = 0.032 days, if V4, the longest period and brightest variable, is discarded) and the position on the period-amplitude diagram suggest an Oosterhoff-intermediate classification for the galaxy. The RR Lyrae stars trace the galaxy horizontal branch (HB) at an average apparent magnitude of (V(RR)) = 20.43 {+-} 0.02 mag (average on six stars and discarding V4), giving in turn a distance modulus for UMa I of (m - M){sub 0} = 19.94 {+-} 0.13 mag, distance d = 97.3{sup +6.0}{sub -5.7} kpc, in the scale where the distance modulus of the Large Magellanic Cloud is 18.5 {+-} 0.1 mag. Isodensity contours of UMa I red giants and HB stars (including the RR Lyrae stars identified in this study) show that the galaxy has an S-shaped structure, which is likely caused by the tidal interaction with the MW. Photometric metallicities were derived for six of the UMa I RR Lyrae stars from the parameters of the Fourier decomposition of the V-band light curves, leading to an average metal abundance of [Fe/H] = -2.29 dex ({sigma} = 0.06 dex, average on six stars) on the Carretta et al. metallicity scale.

  13. ɛ Ophiuchi: Revisiting a Red Giant

    NASA Astrophysics Data System (ADS)

    Kallinger, T.; Matthews, J. M.; Guenther, D. B.; Gruberbauer, M.; Kuschnig, R.; Weiss, W. W.; MOST Team

    2012-09-01

    In only a decade, seismology of red-giant stars has grown from infancy to adulthood in the study of stellar structure and evolution. The stimulants for this accelerated growth have been space observations, first provided by the WIRE star-tracker and MOST, and continuing with CoRoT and Kepler, having detected oscillations in thousands of cool giants. However, almost all of the stars in this impressive sample are faint, with little known about their basic properties. Even reliable spectral classifications are lacking for many of them. MOST is the only space-based photometer capable of continuous observations of bright red giants for which we have independent constraints (e.g., spectroscopy) essential to extract the internal structure from the stars' p-modes.

  14. The faint limit of the Hubble Space Telescope faint object spectrograph and rejection of the cosmic-ray background

    NASA Technical Reports Server (NTRS)

    Tytler, David; Davis, Christopher

    1995-01-01

    The faintest object which can be observed with the Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) is set by the detector cosmic-ray background and not by object flux. We use data from Beaver and Lyons to show that 48% of the background counts are from cosmic rays which each generate a near instantaneous burst of two or more counts. Setting the FOS threshold parameter REJLIM = 1, which rejects all frames with more than one count increases the ratio of signal-to-dark counts (S/D) by a factor of 1.94, regardless of the frame time or the object signal, because half of the dark counts which arrive in single counts (from either cosmic-ray bursts or thermal dark current photoemission) are rejected at the same rate as the object signal. But the signal-to-noise ratio (SNR proportional to S/square root of S + D) increases by at most a factor of 1.35, and for realistic parameters and taking into account dead time, we expect a gain in SNR of only 1.18. If a diode has failed and now emits noise, no data at all will be recorded. The chance of this occurring is approximately = 10% , and for this reason we do not recommend the use of REJLIM. The two-point correlation function of dark counts per pixel has strong peaks every four pixels, caused by the action of quarter-stepping on the counts from large bursts. The counts from such bursts spread over at least 80-100 diodes, and we show that such bursts can be rejected during data reduction if the data are recorded in RAPID mode with individual exposures of about 35 seconds. The SNR of the spectrum can also be improved by weighting each exposure by its SNR (a function ofthe mean dark count rate at that time), since dark varies by a factor of 2 around an orbit. These two procedures together increase the SNR by a factor of 1.1.3 (a 28% gain in exposure time) in regions of a spectrum where the object is much fainter than the background. We find that the Ly-alpha and O I sky emission lines give at most 4 (counts

  15. Determination of astrometry and photometry of faint companions in the presence of residual speckle noise

    NASA Astrophysics Data System (ADS)

    Burke, Daniel; Devaney, Nicholas; Gladysz, Szymon

    In this paper we examine approaches to faint companion detection and estimation in multi-spectral images. We will employ the Hotelling observer which is the optimal linear algorithm for signal detection. We have shown how to use this observer to estimate faint object position and brightness in the presence of residual speckle which usually limit astrometric and photometric techniques. These speckles can be reduced by differential imaging techniques such as Angular Differential Imaging and Spectral Differential Imaging. Here we present results based on simulations of adaptive optics corrected images from an ELT which contain quasi-static speckle noise. The simulation includes Angular Differential Imaging to reduce the residual speckle and subsequent multi-wavelenght processing. We examine the feasibility of this approach on simulated ELT observations of faint companions.

  16. Searching for Faint cataclysmic Variables: Seeking the truth about their Space Density

    NASA Astrophysics Data System (ADS)

    Howell, S. B.; Clowes, R.

    1996-12-01

    The current view of cataclysmic variables is based on theory and observation attempting to reach agreement. However recent work in both these areas has conclusively shown that the present observational sample of CVs is severely limited to intrinsically bright systems, while theory predicts that most should be intrinsically faint. We have begun a program designed to discover faint CVs, ones belonging to the predicted majority population. Using H-alpha and broadband R plates from the UK Schmidt digitized with SuperCOSMOS, we have begun sample selection of candidates to a faint limit of near 20th magnitude. The first spectroscopic results obtained using the ARGUS multi-fiber spectrograph at CTIO will be presented.

  17. Serendipitous Discovery of RR Lyrae Stars in the Leo V Ultra-faint Galaxy

    NASA Astrophysics Data System (ADS)

    Medina, Gustavo E.; Muñoz, Ricardo R.; Vivas, A. Katherina; Förster, Francisco; Carlin, Jeffrey L.; Martinez, Jorge; Galbany, Lluis; González-Gaitán, Santiago; Hamuy, Mario; de Jaeger, Thomas; Maureira, Juan Carlos; San Martín, Jaime

    2017-08-01

    During the analysis of RR Lyrae stars (RRLs) discovered in the High Cadence Transient Survey (HiTS) taken with the Dark Energy Camera at the 4 m telescope at Cerro Tololo Inter-American Observatory, we found a group of three very distant, fundamental mode pulsator RR Lyrae (type ab). The location of these stars agrees with them belonging to the Leo V ultra-faint satellite galaxy, for which no variable stars have been reported to date. The heliocentric distance derived for Leo V based on these stars is 173 ± 5 kpc. The pulsational properties (amplitudes and periods) of these stars locate them within the locus of the Oosterhoff II group, similar to most other ultra-faint galaxies with known RRLs. This serendipitous discovery shows that distant RRLs may be used to search for unknown faint stellar systems in the outskirts of the Milky Way.

  18. The very soft X-ray emission of X-ray-faint early-type galaxies

    NASA Technical Reports Server (NTRS)

    Pellegrini, S.; Fabbiano, G.

    1994-01-01

    A recent reanaylsis of Einstein data, and new ROSAT observations, have revealed the presence of at least two components in the X-ray spectra of X-ray faint early-type galaxies: a relatively hard component (kT greater than 1.5 keV), and a very soft component (kT approximately 0.2-0.3 keV). In this paper we address the problem of the nature of the very soft component and whether it can be due to a hot interstellar medium (ISM), or is most likely originated by the collective emission of very soft stellar sources. To this purpose, hydrodynamical evolutionary sequences for the secular behavior of gas flows in ellipticals have been performed, varying the Type Ia supernovae rate of explosion, and the dark matter amount and distribution. The results are compared with the observational X-ray data: the average Einstein spectrum for six X-ray faint early-type galaxies (among which are NGC 4365 and NGC 4697), and the spectrum obtained by the ROSAT pointed observation of NGC 4365. The very soft component could be entirely explained with a hot ISM only in galaxies such as NGC 4697, i.e., when the depth of the potential well-on which the average ISM temperature strongly depends-is quite shallow; in NGC 4365 a diffuse hot ISM would have a temperature larger than that of the very soft component, because of the deeper potential well. So, in NGC 4365 the softest contribution to the X-ray emission comes certainly from stellar sources. As stellar soft X-ray emitters, we consider late-type stellar coronae, supersoft sources such as those discovered by ROSAT in the Magellanic Clouds and M31, and RS CVn systems. All these candidates can be substantial contributors to the very soft emission, though none of them, taken separately, plausibly accounts entirely for its properties. We finally present a model for the X-ray emission of NGC 4365, to reproduce in detail the results of the ROSAT pointed observation, including the Position Sensitive Proportional Counter (PSPC) spectrum and radial

  19. Digital image profilers for detecting faint sources which have bright companions, phase 2

    NASA Technical Reports Server (NTRS)

    Morris, Elena; Flint, Graham

    1991-01-01

    A breadboard image profiling system developed for the first phase of this project demonstrated the potential for detecting extremely faint optical sources in the presence of light companions. Experimental data derived from laboratory testing of the device supports the theory that image profilers of this type may approach the theoretical limit imposed by photon statistics. The objective of Phase 2 of this program is the development of a ground-based multichannel image profiling system capable of detecting faint stellar objects slightly displaced from brighter stars. We have finalized the multichannel image profiling system and attempted three field tests.

  20. A study of the effects of faint dust comae on the spectra of asteroids

    NASA Astrophysics Data System (ADS)

    Rondón-Briceño, Eduardo; Carvano, Jorge M.; Lorenz-Martins, Silvia

    2017-06-01

    The presence of dust comae on asteroids and centaurs is a phenomenon that became accepted in the last decades and which challenges the traditional definitions of asteroids and comets. A possible way of improving the chances of discovery of active asteroids is to use large multicolour surveys or catalogues, like SDSS Moving Object Catalogue. In this paper, we analyse the effects of faint dust comae on asteroid spectra and then use it to investigate the effects that a faint dust comae would have over the spectrum, magnitude and radial profile of asteroids.

  1. Big Fish, Little Fish: Two New Ultra-faint Satellites of the Milky Way

    NASA Astrophysics Data System (ADS)

    Belokurov, V.; Walker, M. G.; Evans, N. W.; Gilmore, G.; Irwin, M. J.; Just, D.; Koposov, S.; Mateo, M.; Olszewski, E.; Watkins, L.; Wyrzykowski, L.

    2010-03-01

    We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of ~180 kpc, some 15° away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of ~60 pc, while Segue 3 is 20 times smaller at only 3 pc.

  2. Phylogeny for the faint of heart: a tutorial.

    PubMed

    Baldauf, Sandra L

    2003-06-01

    Phylogenetic trees seem to be finding ever broader applications, and researchers from very different backgrounds are becoming interested in what they might have to say. This tutorial aims to introduce the basics of building and interpreting phylogenetic trees. It is intended for those wanting to understand better what they are looking at when they look at someone else's trees or to begin learning how to build their own. Topics covered include: how to read a tree, assembling a dataset, multiple sequence alignment (how it works and when it does not), phylogenetic methods, bootstrap analysis and long-branch artefacts, and software and resources.

  3. Searching for Faint Exozodiacal Disks: Keck Results and LBTI Status

    NASA Astrophysics Data System (ADS)

    Defrère, D.; Hinz, P.; Mennesson, B.; Millan-Gabet, R.; Skemer, A.; Bailey, V.; Rodigas, T. J.

    2014-01-01

    The possible presence of dust in the habitable zone around nearby main-sequence stars is considered as a major hurdle toward the direct imaging of Earth-like extrasolar planets with future dedicated space-based telescopes (e.g., Roberge et al. 2012). In this context, NASA has funded two ground-based mid-infrared nulling interferometers to combine the large apertures available at the Keck Observatory and the Large Binocular Telescope (LBT). In this poster, we present the preliminary results of the extended survey carried out with the Keck Interferometer Nuller (KIN) between 2008 and 2011 and describe the forthcoming LBTI survey.

  4. Why Are Rapidly Rotating M Dwarfs in the Pleiades so (Infra)red? New Period Measurements Confirm Rotation-dependent Color Offsets From the Cluster Sequence

    NASA Astrophysics Data System (ADS)

    Covey, Kevin R.; Agüeros, Marcel A.; Law, Nicholas M.; Liu, Jiyu; Ahmadi, Aida; Laher, Russ; Levitan, David; Sesar, Branimir; Surace, Jason

    2016-05-01

    Stellar rotation periods (P rot) measured in open clusters have proved to be extremely useful for studying stars’ angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While P rot measurements have been obtained for hundreds of solar-mass members of the Pleiades, measurements exist for only a few low-mass (<0.5 M ⊙) members of this key laboratory for stellar evolution theory. To fill this gap, we report P rot for 132 low-mass Pleiades members (including nearly 100 with M ≤ 0.45 M ⊙), measured from photometric monitoring of the cluster conducted by the Palomar Transient Factory in late 2011 and early 2012. These periods extend the portrait of stellar rotation at 125 Myr to the lowest-mass stars and re-establish the Pleiades as a key benchmark for models of the transport and evolution of stellar angular momentum. Combining our new P rot with precise BVIJHK photometry reported by Stauffer et al. and Kamai et al., we investigate known anomalies in the photometric properties of K and M Pleiades members. We confirm the correlation detected by Kamai et al. between a star's P rot and position relative to the main sequence in the cluster's color-magnitude diagram. We find that rapid rotators have redder (V - K) colors than slower rotators at the same V, indicating that rapid and slow rotators have different binary frequencies and/or photospheric properties. We find no difference in the photometric amplitudes of rapid and slow rotators, indicating that asymmetries in the longitudinal distribution of starspots do not scale grossly with rotation rate.

  5. DISSECTING THE RED SEQUENCE. IV. THE ROLE OF TRUNCATION IN THE TWO-DIMENSIONAL FAMILY OF EARLY-TYPE GALAXY STAR FORMATION HISTORIES

    SciTech Connect

    Graves, Genevieve J.; Faber, S. M.

    2010-09-20

    In the three-dimensional parameter space defined by velocity dispersion ({sigma}), effective radius (R{sub e}), and effective surface brightness (I{sub e}), early-type galaxies are observed to populate a two-dimensional fundamental plane (FP) with finite thickness. In Paper III of this series, we showed that the thickness of the FP is predominantly due to variations in the stellar mass surface density ({Sigma}{sub *}) inside the effective radius R{sub e} . These variations represent differences in the dark matter fraction inside R{sub e} (or possibly differences in the initial mass function) from galaxy to galaxy. This means that galaxies do not wind up below the FP at lower surface brightness due to the passive fading of their stellar populations; they are structurally different. Here, we show that these variations in {Sigma}{sub *} at fixed dynamical mass (M{sub dyn}) are linked to differences in the galaxy stellar populations, and therefore to differences in their star formation histories. We demonstrate that the ensemble of stellar population and {Sigma}{sub *} variations through the FP thickness can be explained by a model in which early-type galaxies at fixed M{sub dyn} have their star formation truncated at different times. The thickness of the FP can therefore be interpreted as a sequence of truncation times. Galaxies below the FP have earlier truncation times for a given M{sub dyn}, resulting in lower {Sigma}{sub *}, older ages, lower metallicities in both [Fe/H] and [Mg/H], and higher [Mg/Fe]. We show that this model is quantitatively consistent with simple expectations for chemical enrichment in galaxies. We also present fitting functions for luminosity-weighted age, [Fe/H], [Mg/H], and [Mg/Fe] as functions of the FP parameters {sigma}, R{sub e} , and I{sub e} . These provide a new tool for estimating the stellar population properties of quiescent early-type galaxies for which high-quality spectra are not available.

  6. Fainting Fanconi syndrome clarified by proxy: a case report.

    PubMed

    Walsh, Stephen Benedict; Unwin, Robert; Kleta, Robert; Van't Hoff, William; Bass, Paul; Hussain, Khalid; Ellard, Sian; Bockenhauer, Detlef

    2017-07-11

    Rare diseases may elude diagnosis due to unfamiliarity of the treating physicians with the specific disorder. Yet, advances in genetics have tremendously enhanced our ability to establish specific and sometimes surprising diagnoses. We report a case of renal Fanconi syndrome associated with intermittent hypoglycemic episodes, the specific cause for which remained elusive for over 30 years, despite numerous investigations, including three kidney and one liver biopsy. The most recent kidney biopsy showed dysmorphic mitochondria, suggesting a mitochondrial disorder. When her son presented with hypoglycemia in the neonatal period, he underwent routine genetic testing for hyperinsulinemic hypoglycemia, which revealed a specific mutation in HNF4A. Subsequent testing of the mother confirmed the diagnosis also in her. Modern sequencing technologies that test multiple genes simultaneously enable specific diagnoses, even if the underlying disorder was not clinically suspected. The finding of mitochondrial dysmorphology provides a potential clue for the mechanism, by which the identified mutation causes renal Fanconi syndrome.

  7. VizieR Online Data Catalog: 72 faint CV candidates in CRTS (Breedt+, 2014)

    NASA Astrophysics Data System (ADS)

    Breedt, E.; Gansicke, B. T.; Drake, A. J.; Rodriguez-Gil, P.; Parsons, S. G.; Marsh, T. R.; Szkody, P.; Schreiber, M. R.; Djorgovski, S. G.

    2016-04-01

    We obtained identification spectra of a total of 72 faint CV candidates identified by the CRTS, using the Gran Telescopio Canarias (GTC; La Palma, Spain) and the Gemini telescopes (North: Mauna Kea, Hawaii and South: Cerro Pachon, Chile). The observations were carried out in service mode during 2010, 2011 and 2013. (5 data files).

  8. Chemical evolution of classical and ultra-faint dwarf spheroidal galaxies

    NASA Astrophysics Data System (ADS)

    Vincenzo, F.; Matteucci, F.; Vattakunnel, S.; Lanfranchi, G. A.

    2014-07-01

    We present updated chemical evolution models of two dwarf spheroidal galaxies (Sculptor and Carina) and the first detailed chemical evolution models of two ultra-faint dwarfs (Hercules and Boötes I). Our results suggest that the dwarf spheroidals evolve with a low efficiency of star formation, confirming previous results, and the ultra-faint dwarfs with an even lower one. Under these assumptions, we can reproduce the stellar metallicity distribution function, the [α/Fe] versus [Fe/H] abundance patterns and the total stellar and gas masses observed at the present time in these objects. In particular, for the ultra-faint dwarfs we assume a strong initial burst of star formation, with the mass of the system being already in place at early times. On the other hand, for the classical dwarf spheroidals the agreement with the data is found by assuming the star formation histories suggested by the colour-magnitude diagrams and a longer time-scale of formation via gas infall. We find that all these galaxies should experience galactic winds, starting in all cases before 1 Gyr from the beginning of their evolution. From comparison with Galaxy data, we conclude that it is unlikely that the ultra-faint dwarfs have been the building blocks of the whole Galactic halo, although more data are necessary before drawing firm conclusions.

  9. View of southeast side, faint "141" sign, Cranes P76 and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of southeast side, faint "141" sign, Cranes P-76 and P-71 are behind, view facing northwest - U.S. Naval Base, Pearl Harbor, Dry Dock No. 1, Latrine, Sixth Street, adjacent to Dry Dock No. 1, Pearl City, Honolulu County, HI

  10. Constraints on MACHO Dark Matter from Compact Stellar Systems in Ultra-Faint Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Brandt, Timothy

    2017-01-01

    I show that a recently discovered star cluster near the center of the ultra-faint dwarf galaxy Eridanus II provides strong constraints on massive compact halo objects (MACHOs) of >5 M⊙ as the main component of dark matter. MACHO dark matter will dynamically heat the cluster, driving it to larger sizes and higher velocity dispersions until it dissolves into its host galaxy. The stars in compact ultra-faint dwarf galaxies themselves will be subject to the same dynamical heating; the survival of at least ten such galaxies places independent limits on MACHO dark matter of masses >10 M⊙. Both Eri II's cluster and the compact ultra-faint dwarfs are characterized by stellar masses of just a few thousand M⊙ and half-light radii of 13 pc (for the cluster) and 30 pc (for the ultra-faint dwarfs). These systems close the 20 -100 M⊙ window of allowed MACHO dark matter and combine with existing constraints from microlensing, wide binaries, and disk kinematics to rule out dark matter composed entirely of MACHOs from 10-7 M⊙ up to arbitrarily high masses. NASA Sagan Fellow.

  11. On the Dearth of Ultra-faint Extremely Metal-poor Galaxies

    NASA Astrophysics Data System (ADS)

    Sánchez Almeida, J.; Filho, M. E.; Dalla Vecchia, C.; Skillman, E. D.

    2017-02-01

    Local extremely metal-poor galaxies (XMPs) are of particular astrophysical interest since they allow us to look into physical processes characteristic of the early universe, from the assembly of galaxy disks to the formation of stars in conditions of low metallicity. Given the luminosity-metallicity relationship, all galaxies fainter than Mr ≃ -13 are expected to be XMPs. Therefore, XMPs should be common in galaxy surveys. However, they are not common, because several observational biases hamper their detection. This work compares the number of faint XMPs in the SDSS-DR7 spectroscopic survey with the expected number, given the known biases and the observed galaxy luminosity function (LF). The faint end of the LF is poorly constrained observationally, but it determines the expected number of XMPs. Surprisingly, the number of observed faint XMPs (˜10) is overpredicted by our calculation, unless the upturn in the faint end of the LF is not present in the model. The lack of an upturn can be naturally understood if most XMPs are central galaxies in their low-mass dark matter halos, which are highly depleted in baryons due to interaction with the cosmic ultraviolet background and to other physical processes. Our result also suggests that the upturn toward low luminosity of the observed galaxy LF is due to satellite galaxies.

  12. First results from the Faint Object Camera - Images of the gravitational lens system G2237 + 0305

    NASA Technical Reports Server (NTRS)

    Crane, P.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

    1991-01-01

    Images of the gravitational lens system G2237 + 0305 have been obtained with the Faint Object Camera on board the Hubble Space Telescope. A preliminary analysis of these images is reported here and includes measurements of the relative positions and magnitudes of the lensed images of the QSO, and of the lensing galaxy. No evidence is found for a fifth lensed image.

  13. A VIRUS-P Survey of Galaxy Clusters to Find Faint Lyα-emitting Galaxies

    NASA Astrophysics Data System (ADS)

    McLinden, Emily; Finkelstein, S. L.; Siana, B. D.; Alavi, A.

    2014-01-01

    The VIRUS-P instrument on the 2.7m telescope at the McDonald Observatory was originally built as a prototype of the larger VIRUS instrument that will be used for HETDEX. We demonstrate that this multi-fiber, optical integral field unit spectrograph can be efficiently used to detect faint Lyα-emitting galaxies (LAEs) at intermediate redshift (z = 2-3) with the aid of gravitational lensing from galaxy clusters. The bulk z=2-3 LAEs to date have been discovered with narrowband imaging campaigns, which are highly efficient only at selecting L > L_star galaxies and only over a narrow redshift slice. By making use of gravitational lensing, however, we are able to observe intrinsically very faint galaxies that only appear to have brightnesses ≥ L_star. Gravitationally lensed faint LAEs, such as our sample from VIRUS-P, allow us to go fainter than existing narrowband surveys and therefore allow for better constraints at the faint end of the Lyα luminosity function at these intermediate redshifts.

  14. Photoelectric Photometry of Faint M-Type Stars in the Direction of the South Galactic Pole

    NASA Astrophysics Data System (ADS)

    Pesch, P.

    1982-04-01

    Photoelectric V (Johnson-Morgan UBV system) and (V I) (Kron-Mayall PVI system) photometry is presented for 54 faint M-type stars from Pesch and Sanduleak's catalog of probable dwarf stars of type M3 and later in the direction of the south galactic pole. The observations were made in November 1978 with the 1.5-m CTIO reflector.

  15. Faints, fits, and fatalities from emotion in Shakespeare's characters: survey of the canon

    PubMed Central

    2006-01-01

    Objectives To determine how often Shakespeare's characters faint, fit, or die from extreme emotion; to assess Shakespeare's uniqueness in this regard; and to examine the plausibility of these dramatised events. Design Line by line search through modern editions of these late 16th and early 17th century works for accounts of characters fainting, fitting, or dying while under strong emotion and for no other apparent reason. Data sources All 39 canonical plays by Shakespeare and his three long narrative poems; 18 similar works by seven of Shakespeare's best known contemporaries. Results 10 deaths from strong emotion are recorded by Shakespeare (three occur on stage); all are due to grief, typically at the loss of a loved one. All but two of the deaths are in the playwright's late works. Some deaths are sudden. Another 29 emotion induced deaths are mentioned as possible, but the likelihood of some can be challenged. Transient loss of consciousness is staged or reported in 18 cases (sounding like epilepsy in two) and near fainting in a further 13. Extreme joy is sometimes depicted as a factor in these events. Emotional death and fainting also occur occasionally in works by Shakespeare's contemporaries. Conclusions These dramatic phenomena are part of the early modern belief system but are also plausible by modern understanding of physiology and disease. They teach us not to underestimate the power of the emotions to disturb bodily functions. PMID:17185734

  16. Study on the faint star extraction technology with MEMS gyro aided APS star tracker

    NASA Astrophysics Data System (ADS)

    Xing, Fei; Zhao, Borui; Sun, Ting; Xu, Wei; You, Zheng

    2013-08-01

    Star tracker is the most accurate attitude sensor for satellite. Generally speaking, the higher the accuracy, the fainter the star can be sensed by the star tracker. How to extract the faint star from a star image is becoming a critical technology in dynamic condition for star tracker, especially using the APS (Active Pixels Sensor) detector. A novel APS star tracker with MEMS Gyroscope aided system was proposed in this paper that could extremely improve the detection effect and capability for the faint stars. During the exposure time of star tracker, the trajectory of star projection on the detector maybe occupy more than ten pixels due to the satellite rotation. In this situation, the signal-to-noise ratio will decline sharply, and the traditional star extraction method for faint star will take no effect. As a result, the accuracy of star tracker would decline sharply, even more, couldn't work. Using the MEMS Gyroscope, the track of star projection can be predicated and measured, on the basis of which the deconvolution algorithm could be taken to recover the faint star signal. The accuracy of the star projection centroid could be improved obviously, and the dynamic performance of the star tracker would be improved by a magnitude. Meanwhile, the MEMS gyroscope has not less volume, mass and power consumption, which make it more suitable for the application of APS star tracker.

  17. DISCOVERY OF A FAINT QUASAR AT z ∼ 6 AND IMPLICATIONS FOR COSMIC REIONIZATION

    SciTech Connect

    Kim, Yongjung; Im, Myungshin; Jeon, Yiseul; Choi, Changsu; Hong, Jueun; Hyun, Minhee; Jun, Hyunsung David; Kim, Dohyeong; Kim, Duho; Kim, Jae-Woo; Lee, Seong-Kook; Taak, Yoon Chan; Yoon, Yongmin; Kim, Minjin; Park, Won-Kee; Karouzos, Marios; Kim, Ji Hoon; Pak, Soojong E-mail: mim@astro.snu.ac.kr

    2015-11-10

    Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars (M{sub 1450} > −24 mag) at z ≳ 6, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z ∼ 6 in a 12.5 deg{sup 2} region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at ∼8443 Å, with emission lines redshifted to z = 5.944 ± 0.002 and rest-frame ultraviolet continuum magnitude M{sub 1450} = −23.59 ± 0.10 AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z ∼ 6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified low-luminosity quasars. This suggests that the number of M{sub 1450} ∼ −23 mag quasars at z ∼ 6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.

  18. Genetic Basis for Red Coloration in Birds.

    PubMed

    Lopes, Ricardo J; Johnson, James D; Toomey, Matthew B; Ferreira, Mafalda S; Araujo, Pedro M; Melo-Ferreira, José; Andersson, Leif; Hill, Geoffrey E; Corbo, Joseph C; Carneiro, Miguel

    2016-06-06

    The yellow and red feather pigmentation of many bird species [1] plays pivotal roles in social signaling and mate choice [2, 3]. To produce red pigments, birds ingest yellow carotenoids and endogenously convert them into red ketocarotenoids via an oxidation reaction catalyzed by a previously unknown ketolase [4-6]. We investigated the genetic basis for red coloration in birds using whole-genome sequencing of red siskins (Spinus cucullata), common canaries (Serinus canaria), and "red factor" canaries, which are the hybrid product of crossing red siskins with common canaries [7]. We identified two genomic regions introgressed from red siskins into red factor canaries that are required for red coloration. One of these regions contains a gene encoding a cytochrome P450 enzyme, CYP2J19. Transcriptome analysis demonstrates that CYP2J19 is significantly upregulated in the skin and liver of red factor canaries, strongly implicating CYP2J19 as the ketolase that mediates red coloration in birds. Interestingly, a second introgressed region required for red feathers resides within the epidermal differentiation complex, a cluster of genes involved in development of the integument. Lastly, we present evidence that CYP2J19 is involved in ketocarotenoid formation in the retina. The discovery of the carotenoid ketolase has important implications for understanding sensory function and signaling mediated by carotenoid pigmentation.

  19. THE FAINT END OF THE LUMINOSITY FUNCTION AND LOW SURFACE BRIGHTNESS GALAXIES

    SciTech Connect

    Geller, Margaret J.; Kurtz, Michael J.; Fabricant, Daniel G.; Diaferio, Antonaldo; Dell'Antonio, Ian P. E-mail: mkurtz@cfa.harvard.edu E-mail: adiaferio@cfa.harvard.edu

    2012-04-15

    Smithsonian Hectospec Lensing Survey (SHELS) is a dense redshift survey covering a 4 deg{sup 2} region to a limiting R = 20.6. In the construction of the galaxy catalog and in the acquisition of spectroscopic targets, we paid careful attention to the survey completeness for lower surface brightness dwarf galaxies. Thus, although the survey covers a small area, it is a robust basis for computation of the slope of the faint end of the galaxy luminosity function to a limiting M{sub R} = -13.3 + 5log h. We calculate the faint-end slope in the R band for the subset of SHELS galaxies with redshifts in the range 0.02 {<=}z < 0.1, SHELS{sub 0.1}. This sample contains 532 galaxies with R < 20.6 and with a median surface brightness within the half-light radius of SB{sub 50,R} = 21.82 mag arcsec{sup -2}. We used this sample to make one of the few direct measurements of the dependence of the faint end of the galaxy luminosity function on surface brightness. For the sample as a whole the faint-end slope, {alpha} = -1.31 {+-} 0.04, is consistent with both the Blanton et al. analysis of the Sloan Digital Sky Survey and the Liu et al. analysis of the COSMOS field. This consistency is impressive given the very different approaches of these three surveys. A magnitude-limited sample of 135 galaxies with optical spectroscopic redshifts with mean half-light surface brightness, SB{sub 50,R} {>=} 22.5 mag arcsec{sup -2} is unique to SHELS{sub 0.1}. The faint-end slope is {alpha}{sub 22.5} = -1.52 {+-} 0.16. SHELS{sub 0.1} shows that lower surface brightness objects dominate the faint-end slope of the luminosity function in the field, underscoring the importance of surface brightness limits in evaluating measurements of the faint-end slope and its evolution.

  20. Are the Faint Structures Ahead of Solar Coronal Mass Ejections Real Signatures of Driven Shocks?

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Ok; Moon, Y.-J.; Lee, Jin-Yi; Lee, Kyoung-Sun; Kim, Sujin; Lee, Kangjin

    2014-11-01

    Recently, several studies have assumed that the faint structures ahead of coronal mass ejections (CMEs) are caused by CME-driven shocks. In this study, we have conducted a statistical investigation to determine whether or not the appearance of such faint structures depends on CME speeds. For this purpose, we use 127 Solar and Heliospheric Observatory/Large Angle Spectroscopic COronagraph (LASCO) front-side halo (partial and full) CMEs near the limb from 1997 to 2011. We classify these CMEs into two groups by visual inspection of CMEs in the LASCO-C2 field of view: Group 1 has the faint structure ahead of a CME and Group 2 does not have such a structure. We find the following results. (1) Eighty-seven CMEs belong to Group 1 and 40 CMEs belong to Group 2. (2) Group 1 events have much higher speeds (average = 1230 km s-1 and median = 1199 km s-1) than Group 2 events (average = 598 km s-1 and median = 518 km s-1). (3) The fraction of CMEs with faint structures strongly depends on CME speeds (V): 0.93 (50/54) for fast CMEs with V >= 1000 km s-1, 0.65 (34/52) for intermediate CMEs with 500 km s-1 <= V < 1000 km s-1, and 0.14 (3/21) for slow CMEs with V < 500 km s-1. We also find that the fraction of CMEs with deca-hecto metric type II radio bursts is consistent with the above tendency. Our results indicate that the observed faint structures ahead of fast CMEs are most likely an enhanced density manifestation of CME-driven shocks.

  1. ARE THE FAINT STRUCTURES AHEAD OF SOLAR CORONAL MASS EJECTIONS REAL SIGNATURES OF DRIVEN SHOCKS?

    SciTech Connect

    Lee, Jae-Ok; Moon, Y.-J.; Lee, Kangjin; Lee, Jin-Yi; Lee, Kyoung-Sun; Kim, Sujin E-mail: moonyj@khu.ac.kr

    2014-11-20

    Recently, several studies have assumed that the faint structures ahead of coronal mass ejections (CMEs) are caused by CME-driven shocks. In this study, we have conducted a statistical investigation to determine whether or not the appearance of such faint structures depends on CME speeds. For this purpose, we use 127 Solar and Heliospheric Observatory/Large Angle Spectroscopic COronagraph (LASCO) front-side halo (partial and full) CMEs near the limb from 1997 to 2011. We classify these CMEs into two groups by visual inspection of CMEs in the LASCO-C2 field of view: Group 1 has the faint structure ahead of a CME and Group 2 does not have such a structure. We find the following results. (1) Eighty-seven CMEs belong to Group 1 and 40 CMEs belong to Group 2. (2) Group 1 events have much higher speeds (average = 1230 km s{sup –1} and median = 1199 km s{sup –1}) than Group 2 events (average = 598 km s{sup –1} and median = 518 km s{sup –1}). (3) The fraction of CMEs with faint structures strongly depends on CME speeds (V): 0.93 (50/54) for fast CMEs with V ≥ 1000 km s{sup –1}, 0.65 (34/52) for intermediate CMEs with 500 km s{sup –1} ≤ V < 1000 km s{sup –1}, and 0.14 (3/21) for slow CMEs with V < 500 km s{sup –1}. We also find that the fraction of CMEs with deca-hecto metric type II radio bursts is consistent with the above tendency. Our results indicate that the observed faint structures ahead of fast CMEs are most likely an enhanced density manifestation of CME-driven shocks.

  2. Track-Before-Detect Algorithm for Faint Moving Objects based on Random Sampling and Consensus

    NASA Astrophysics Data System (ADS)

    Dao, P.; Rast, R.; Schlaegel, W.; Schmidt, V.; Dentamaro, A.

    2014-09-01

    There are many algorithms developed for tracking and detecting faint moving objects in congested backgrounds. One obvious application is detection of targets in images where each pixel corresponds to the received power in a particular location. In our application, a visible imager operated in stare mode observes geostationary objects as fixed, stars as moving and non-geostationary objects as drifting in the field of view. We would like to achieve high sensitivity detection of the drifters. The ability to improve SNR with track-before-detect (TBD) processing, where target information is collected and collated before the detection decision is made, allows respectable performance against dim moving objects. Generally, a TBD algorithm consists of a pre-processing stage that highlights potential targets and a temporal filtering stage. However, the algorithms that have been successfully demonstrated, e.g. Viterbi-based and Bayesian-based, demand formidable processing power and memory. We propose an algorithm that exploits the quasi constant velocity of objects, the predictability of the stellar clutter and the intrinsically low false alarm rate of detecting signature candidates in 3-D, based on an iterative method called "RANdom SAmple Consensus” and one that can run real-time on a typical PC. The technique is tailored for searching objects with small telescopes in stare mode. Our RANSAC-MT (Moving Target) algorithm estimates parameters of a mathematical model (e.g., linear motion) from a set of observed data which contains a significant number of outliers while identifying inliers. In the pre-processing phase, candidate blobs were selected based on morphology and an intensity threshold that would normally generate unacceptable level of false alarms. The RANSAC sampling rejects candidates that conform to the predictable motion of the stars. Data collected with a 17 inch telescope by AFRL/RH and a COTS lens/EM-CCD sensor by the AFRL/RD Satellite Assessment Center is

  3. Evaluation of integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor for decolorization and biodegradation of azo dye acid red 18: comparison of using two types of packing media.

    PubMed

    Hosseini Koupaie, E; Alavi Moghaddam, M R; Hashemi, S H

    2013-01-01

    Two integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor (FB-SBBR) were operated to evaluate decolorization and biodegradation of azo dye Acid Red 18 (AR18). Volcanic pumice stones and a type of plastic media made of polyethylene were used as packing media in FB-SBBR1 and FB-SBBR2, respectively. Decolorization of AR18 in both reactors followed first-order kinetic with respect to dye concentration. More than 63.7% and 71.3% of anaerobically formed 1-naphthylamine-4-sulfonate (1N-4S), as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase in FB-SBBR1 and FB-SBBR2, respectively. Based on statistical analysis, performance of FB-SBBR2 in terms of COD removal as well as biodegradation of 1N-4S was significantly higher than that of FB-SBBR1. Spherical and rod shaped bacteria were the dominant species of bacteria in the biofilm grown on the pumice stones surfaces, while, the biofilm grown on surfaces of the polyethylene media had a fluffy structure.

  4. NASA Space Observatories Glimpse Faint Afterglow of Nearby Stellar Explosion

    NASA Astrophysics Data System (ADS)

    2005-10-01

    creation of chemical elements such as oxygen through nuclear reactions in their cores. Such observations also help reveal how the interstellar medium (the gas that occupies the vast spaces between the stars) is enriched with chemical elements because of supernova explosions. Later on, these elements are incorporated into new generations of stars and their accompanying planets. Visible only from Earth's southern hemisphere, the LMC is an irregular galaxy lying about 160,000 light-years from the Milky Way. The supernova remnant appears to be about 3,000 years old, but since its light took 160,000 years to reach us, the explosion actually occurred some 163,000 years ago. This composite image of N132D was created by the Hubble Heritage team from visible-light data taken in January 2004 with Hubble's Advanced Camera for Surveys, and X-ray images obtained in July 2000 by Chandra's Advanced CCD Imaging Spectrometer. This marks the first Hubble Heritage image that combines pictures taken by two separate space observatories. The Hubble data include color filters that sample starlight in the blue, green, and red portions of the spectrum, as well as the pink emission from glowing hydrogen gas. The Chandra data are assigned blue in the color composite, in accordance with the much higher energy of the X-rays, emitted from extremely hot gas. This gas does not emit a significant amount of optical light, and was only detected by Chandra. Image Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA) Acknowledgment: J.C. Green (Univ. of Colorado) and the Cosmic Origins Spectrograph (COS) GTO team; NASA/CXO/SAO Electronic image files, video, illustrations and additional information are available at: http://hubblesite.org/news/2005/30 http://heritage.stsci.edu/2005/30 The Space Telescope Science Institute (STScI) is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The Hubble

  5. Parapoxvirus infections of red deer, Italy.

    PubMed

    Scagliarini, Alessandra; Vaccari, Francesca; Turrini, Filippo; Bianchi, Alessandro; Cordioli, Paolo; Lavazza, Antonio

    2011-04-01

    To characterize parapoxviruses causing severe disease in wild ruminants in Stelvio Park, Italy, we sequenced and compared the DNA of several isolates. Results demonstrated that the red deer isolates are closely related to the parapox of red deer in New Zealand virus.

  6. Parapoxvirus Infections of Red Deer, Italy

    PubMed Central

    Vaccari, Francesca; Turrini, Filippo; Bianchi, Alessandro; Cordioli, Paolo; Lavazza, Antonio

    2011-01-01

    To characterize parapoxviruses causing severe disease in wild ruminants in Stelvio Park, Italy, we sequenced and compared the DNA of several isolates. Results demonstrated that the red deer isolates are closely related to the parapox of red deer in New Zealand virus. PMID:21470460

  7. Day Pass Down the Red Sea

    NASA Image and Video Library

    This video over the southeastern Mediterranean Sea and down the coastline of the Red Sea was taken by the crew of Expedition 29 aboard the International Space Station. This sequence of shots was ta...

  8. THE SUBARU HIGH-z QUASAR SURVEY: DISCOVERY OF FAINT z ∼ 6 QUASARS

    SciTech Connect

    Kashikawa, Nobunari; Furusawa, Hisanori; Niino, Yuu; Ishizaki, Yoshifumi; Onoue, Masafusa; Toshikawa, Jun; Ishikawa, Shogo; Willott, Chris J.; Im, Myungshin; Shimasaku, Kazuhiro; Ouchi, Masami; Hibon, Pascale

    2015-01-01

    We present the discovery of one or two extremely faint z ∼ 6 quasars in 6.5 deg{sup 2} utilizing a unique capability of the wide-field imaging of the Subaru/Suprime-Cam. The quasar selection was made in (i'-z{sub B} ) and (z{sub B} -z{sub R} ) colors, where z{sub B} and z{sub R} are bandpasses with central wavelengths of 8842 Å and 9841 Å, respectively. The color selection can effectively isolate quasars at z ∼ 6 from M/L/T dwarfs without the J-band photometry down to z{sub R} < 24.0, which is 3.5 mag deeper than the Sloan Digital Sky Survey (SDSS). We have selected 17 promising quasar candidates. The follow-up spectroscopy for seven targets identified one apparent quasar at z = 6.156 with M {sub 1450} = –23.10. We also identified one possible quasar at z = 6.041 with a faint continuum of M {sub 1450} = –22.58 and a narrow Lyα emission with HWHM =427 km s{sup –1}, which cannot be distinguished from Lyman α emitters. We derive the quasar luminosity function at z ∼ 6 by combining our faint quasar sample with the bright quasar samples by SDSS and CFHQS. Including our data points invokes a higher number density in the faintest bin of the quasar luminosity function than the previous estimate employed. This suggests a steeper faint-end slope than lower z, though it is yet uncertain based on a small number of spectroscopically identified faint quasars, and several quasar candidates still remain to be diagnosed. The steepening of the quasar luminosity function at the faint end does increase the expected emission rate of the ionizing photon; however, it only changes by a factor of approximately two to six. This was found to still be insufficient for the required photon budget of reionization at z ∼ 6.

  9. Correlation between low level fluctuations in the x ray background and faint galaxies

    NASA Technical Reports Server (NTRS)

    Tolstoy, Eline; Griffiths, R. E.

    1993-01-01

    A correlation between low-level x-ray fluctuations in the cosmic x-ray background flux and the large numbers of galaxies found in deep optical imaging, to m(sub v) is less than or equal to 24 - 26, is desired. These (faint) galaxies by their morphology and color in deep multi-color CCD images and plate material were optically identified. Statistically significant correlations between these galaxies and low-level x-ray fluctuations at the same positions in multiple deep Einstein HRI observations in PAVO and in a ROSAT PSPC field were searched for. Our aim is to test the hypothesis that faint 'star burst' galaxies might contribute significantly to the cosmic x-ray background (at approximately 1 keV).

  10. Strongly lensed gravitational waves from intrinsically faint double compact binaries—prediction for the Einstein Telescope

    SciTech Connect

    Ding, Xuheng; Biesiada, Marek; Zhu, Zong-Hong E-mail: marek.biesiada@us.edu.pl

    2015-12-01

    With a fantastic sensitivity improving significantly over the advanced GW detectors, Einstein Telescope (ET) will be able to observe hundreds of thousand inspiralling double compact objects per year. By virtue of gravitational lensing effect, intrinsically unobservable faint sources can be observed by ET due to the magnification by intervening galaxies. We explore the possibility of observing such faint sources amplified by strong gravitational lensing. Following our previous work, we use the merger rates of DCO (NS-NS,BH-NS,BH-BH systems) as calculated by Dominik et al.(2013). It turns out that tens to hundreds of such (lensed) extra events will be registered by ET. This will strongly broaden the ET's distance reach for signals from such coalescences to the redshift range z = 2 − 8. However, with respect to the full inspiral event catalog this magnification bias is at the level of 0.001 and should not affect much cosmological inferences.

  11. Variable Stars in the Field of the Hydra II Ultra-Faint Dwarf Galaxy

    NASA Astrophysics Data System (ADS)

    Vivas, Anna Katherina; Olsen, Knut A.; Blum, Robert D.; Nidever, David L.; Walker, Alistair R.; Martin, Nicolas; Besla, Gurtina; Gallart, Carme; Van Der Marel, Roeland P.; Majewski, Steven R.; Munoz, Ricardo; Kaleida, Catherine C.; Saha, Abhijit; Conn, Blair; Jin, Shoko

    2016-06-01

    We searched for variable stars in Hydra II, one of the recently discovered ultra-faint dwarf satellites of the Milky Way, using gri time-series obtained with the Dark Energy Camera (DECam) at Cerro Tololo Inter-American Observatory, Chile. We discovered one RR Lyrae star in the galaxy which was used to derive a distance of 154±8 kpc to this system and to re-calculate its absolute magnitude and half-light radius.A comparison with other RR Lyrae stars in ultra-faint systems indicates similar pulsational properties among them, which are different to those found among halo field stars and those in the largest of the Milky Way satellites. We also report the discovery of 31 additional short period variables in the field of view (RR Lyrae, SX Phe, eclipsing binaries, and a likely anomalous cepheid) which are likely not related with Hydra II.

  12. Hubble Space Telescope Faint Object Camera calculated point-spread functions.

    PubMed

    Lyon, R G; Dorband, J E; Hollis, J M

    1997-03-10

    A set of observed noisy Hubble Space Telescope Faint Object Camera point-spread functions is used to recover the combined Hubble and Faint Object Camera wave-front error. The low-spatial-frequency wave-front error is parameterized in terms of a set of 32 annular Zernike polynomials. The midlevel and higher spatial frequencies are parameterized in terms of set of 891 polar-Fourier polynomials. The parameterized wave-front error is used to generate accurate calculated point-spread functions, both pre- and post-COSTAR (corrective optics space telescope axial replacement), suitable for image restoration at arbitrary wavelengths. We describe the phase-retrieval-based recovery process and the phase parameterization. Resultant calculated precorrection and postcorrection point-spread functions are shown along with an estimate of both pre- and post-COSTAR spherical aberration.

  13. BIG FISH, LITTLE FISH: TWO NEW ULTRA-FAINT SATELLITES OF THE MILKY WAY

    SciTech Connect

    Belokurov, V.; Walker, M. G.; Evans, N. W.; Gilmore, G.; Irwin, M. J.; Koposov, S.; Watkins, L.; Wyrzykowski, L.; Just, D.; Olszewski, E.; Mateo, M. E-mail: walker@ast.cam.ac.uk

    2010-03-20

    We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of {approx}180 kpc, some 15 deg. away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of {approx}60 pc, while Segue 3 is 20 times smaller at only 3 pc.

  14. Fits, faints and funny turns. Could it be a mental disorder?

    PubMed

    Morgan, Hugh; Blashki, Grant

    2003-04-01

    Patients who present to primary care with symptoms of fainting and dizziness, for which there is no adequate physical explanation, are frequently suffering from an undiagnosed psychiatric disorder. This article aims to improve the recognition of common mental disorders presenting as 'fits, faints and funny turns' (FFFTs) and to encourage general practitioners to view these disorders as a positive diagnosis in need of treatment. Psychiatric disorders, particularly panic attacks and depression, are common in the setting of FFFTs and should be a positive diagnosis rather than a diagnosis of exclusion. A detailed description of the episode, with corroborating information from a witness if possible, and psychiatric rating scales can assist in this process. Identifying a physical cause for the episode does not exclude a psychiatric diagnosis and vice versa. Specific psychological and pharmacological therapies are effective for anxiety and depression.

  15. Stellar wind paleontology. II - Faint halos and historical mass ejection in planetary nebulae

    NASA Astrophysics Data System (ADS)

    Balick, Bruce; Gonzalez, Guillermo; Frank, Adam; Jacoby, George

    1992-06-01

    The large, faint, generally circular, and limb-brightened nebular structures (called "halos") surrounding some planetary nebulae (PN) are explored using deep CCD images of NGC 40, 650-1, 1535, 2392, 6210, 6543, 6720, 6803, 6804, 6826, 6853, 6891, 6894, 7009, 7662, IC 1454, 3568, 4593, Abell 1, 2, 3, and BD +30 deg 3639. New halos have been discovered in a few objects (IC 1454, 4593, and possibly NGC 40, 6210, and 6803), and known halos have been mapped in detail in several PN (e.g., NGC 6543, 6720, 6826, 6853 and 7662). The present deep search does not reveal similar large and faint halos in NGC 1535, 2392, 6894, 7009, and IC 3568-PN whose inner regions are morphologically similar to others with easily observable halos.

  16. The Ultra-Faint Dwarfs: Fossils From the Epoch of Reionization?

    NASA Astrophysics Data System (ADS)

    Simon, Josh

    2013-02-01

    We propose to obtain larger samples of spectroscopic metallicity measurements in six ultra-faint dwarf galaxies in order to discern any cosmologically-driven synchronization of their formation histories. Combined with our deep HST photometry of the same galaxies, these data will enable us to measure the age of each galaxy to ~200 Myr. Hierarchical galaxy formation models predict that the ultra-faint dwarfs formed their stars before reionization. We will test whether suppression of star formation in low-mass halos by reionization could be responsible for the missing satellite problem. We will also place improved constraints on the dark matter content of UFDs and search for the most metal-poor stars ever found beyond the Milky Way.

  17. Optical and near-IR observations of the faint and fast 2008ha-like supernova 2010ae

    NASA Astrophysics Data System (ADS)

    Stritzinger, M. D.; Hsiao, E.; Valenti, S.; Taddia, F.; Rivera-Thorsen, T. J.; Leloudas, G.; Maeda, K.; Pastorello, A.; Phillips, M. M.; Pignata, G.; Baron, E.; Burns, C. R.; Contreras, C.; Folatelli, G.; Hamuy, M.; Höflich, P.; Morrell, N.; Prieto, J. L.; Benetti, S.; Campillay, A.; Haislip, J. B.; LaClutze, A. P.; Moore, J. P.; Reichart, D. E.

    2014-01-01

    A comprehensive set of optical and near-infrared (NIR) photometry and spectroscopy is presented for the faint and fast 2008ha-like supernova (SN) 2010ae. Contingent on the adopted value of host extinction, SN 2010ae reached a peak brightness of -13.8 > MV > -15.3 mag, while modeling of the UVOIR light curve suggests it produced 0.003-0.007 M⊙ of 56Ni, ejected 0.30-0.60 M⊙ of material, and had an explosion energy of 0.04-0.30 × 1051 erg. The values of these explosion parameters are similar to the peculiar SN 2008ha -for which we also present previously unpublished early phase optical and NIR light curves - and places these two transients at the faint end of the 2002cx-like SN population. Detailed inspection of the post-maximum NIR spectroscopic sequence indicates the presence of a multitude of spectral features, which are identified through SYNAPPS modeling to be mainly attributed to Co ii. Comparison with a collection of published and unpublished NIR spectra of other 2002cx-like SNe, reveals that a Co ii footprint is ubiquitous to this subclass of transients, providing a link to Type Ia SNe. A visual-wavelength spectrum of SN 2010ae obtained at +252 days past maximum shows a striking resemblance to a similar epoch spectrum of SN 2002cx. However, subtle differences in the strength and ratio of calcium emission features, as well as diversity among similar epoch spectra of other 2002cx-like SNe indicates a range of physical conditions of the ejecta, highlighting the heterogeneous nature of thispeculiar class of transients. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programs 082.A-0526, 084.D-0719, 088.D-0222, 184.D-1140, and 386.D-0966); the Gemini Observatory, Cerro Pachon, Chile (Gemini Programs GS-2010A-Q-14 and GS-2010A-Q-38); the Magellan 6.5 m telescopes at Las Campanas Observatory; and the SOAR telescope.Tables 1-5 and Appendix A are available in electronic form at http

  18. A comparison of photon counting and current measuring techniques in spectrophotometry of faint sources.

    PubMed

    Tull, R G

    1968-10-01

    The component of dark noise produced by Cerenkov pulses in photomultipliers due to cosmic ray mu mesons is discussed. It is shown by integration of pulse height spectra that this source of noise can be the limiting factor in de measuring spectrophotometry of faint astronomical sources. Direct current methods of photometry are compared with photon counting, and the advantage of photon counting is demonstrated under various operating conditions.

  19. Eight ultra-faint galaxy candidates discovered in year two of the Dark Energy Survey

    DOE PAGES

    Drlica-Wagner, A.

    2015-11-04

    Here, we report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > –4.7more » $$\\mathrm{mag}$$) and span a range of physical sizes (17 $$\\mathrm{pc}$$ < r1/2 < 181 $$\\mathrm{pc}$$) and heliocentric distances (25 kpc < D⊙ < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ ≳ 27.5 $$\\mathrm{mag}$$ $$\\mathrm{arcsec}$$–2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10–3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Our model predicts that the full sky may hold ~100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%–30% of these would be spatially associated with the Magellanic Clouds.« less

  20. Eight ultra-faint galaxy candidates discovered in year two of the Dark Energy Survey

    SciTech Connect

    Drlica-Wagner, A.

    2015-11-04

    Here, we report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > –4.7 $\\mathrm{mag}$) and span a range of physical sizes (17 $\\mathrm{pc}$ < r1/2 < 181 $\\mathrm{pc}$) and heliocentric distances (25 kpc < D < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ ≳ 27.5 $\\mathrm{mag}$ $\\mathrm{arcsec}$–2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10–3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Our model predicts that the full sky may hold ~100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%–30% of these would be spatially associated with the Magellanic Clouds.

  1. On the faint-end of the high-z galaxy luminosity function

    NASA Astrophysics Data System (ADS)

    Yue, Bin; Ferrara, Andrea; Xu, Yidong

    2016-12-01

    Recent measurements of the luminosity function (LF) of galaxies in the Epoch of Reionization (EoR, z ≳ 6) indicate a very steep increase of the number density of low-mass galaxies populating the LF faint-end. However, as star formation in low-mass haloes can be easily depressed or even quenched by ionizing radiation, a turnover is expected at some faint UV magnitudes. Using a physically motivated analytical model, we quantify reionization feedback effects on the LF faint-end shape. We find that if reionization feedback is neglected, the power-law Schechter parametrization characterizing the LF faint-end remains valid up to absolute UV magnitude ˜-9. If instead radiative feedback is strong enough that quenches star formation in haloes with circular velocity smaller than 50 km s-1, the LF starts to drop at absolute UV magnitude ˜-15, i.e. slightly below the detection limits of current (unlensed) surveys at z ˜ 5. The LFs may rise again at higher absolute UV magnitude, where, as a result of interplay between reionization process and galaxy formation, most of the galaxy light is from relic stars formed before the EoR. We suggest that the galaxy number counts data, particularly in lensed fields, can put strong constraints on reionization feedback. In models with stronger reionization feedback, stars in galaxies with absolute UV magnitude higher than ˜-13 and smaller than ˜-8 are typically older. Hence, the stellar age-UV magnitude relation can be used as an alternative feedback probe.

  2. Faint electric treatment-induced rapid and efficient delivery of extraneous hydrophilic molecules into the cytoplasm.

    PubMed

    Hasan, Mahadi; Nishimoto, Akinori; Ohgita, Takashi; Hama, Susumu; Kashida, Hiromu; Asanuma, Hiroyuki; Kogure, Kentaro

    2016-04-28

    Effective delivery of extraneous molecules into the cytoplasm of the target cells is important for several drug therapies. Previously, we showed effective in vivo transdermal delivery of naked siRNA into skin cells induced by faint electric treatment (ET) iontophoresis, and significant suppression of target mRNA levels (Kigasawa et al., Int. J. Pharm., 2010). This result indicates that electricity promoted the delivery of siRNA into cytoplasm. In the present study, we analyzed the intracellular delivery of naked anti-luciferase siRNA by faint ET, and found that the luciferase activity of cells expressing luciferase was reduced by in vitro ET like in vivo iontophoresis. Cellular uptake of fluorescent-label siRNA was increased by ET, while low temperature exposure, macropinocytosis inhibitor amiloride and caveolae-mediated endocytosis inhibitor filipin significantly prevented siRNA uptake. These results indicate that the cellular uptake mechanism involved endocytosis. In addition, voltage sensitive fluorescent dye DiBAC4 (3) penetration was increased by ET, and the transient receptor potential channel inhibitor SKF96365 reduced siRNA uptake, suggesting that faint ET reduced membrane potentials by changing intracellular ion levels. Moreover, to analyze cytoplasmic delivery, we used in-stem molecular beacon (ISMB), which fluoresces upon binding to target mRNA in the cytoplasm. Surprisingly, cytoplasmic ISMB fluorescence appeared rapidly and homogeneously after ET, indicating that cytoplasmic delivery is markedly enhanced by ET. In conclusion, we demonstrated for the first time that faint ET can enhance cellular uptake and cytoplasmic delivery of extraneous molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Faint Radio Sources in the NOAO Bootes Field. VLBA Imaging And Optical Identifications

    SciTech Connect

    Wrobel, J.M.; Taylor, Greg B.; Rector, T.A.; Myers, S.T.; Fassnacht, C.D.; /UC, Davis

    2005-06-13

    As a step toward investigating the parsec-scale properties of faint extragalactic radio sources, the Very Long Baseline Array (VLBA) was used at 5.0 GHz to obtain phase-referenced images of 76 sources in the NOAO Booetes field. These 76 sources were selected from the FIRST catalog to have peak flux densities above 10 mJy at 5'' resolution and deconvolved major diameters of less than 3'' at 1.4 GHz. Fifty-five of these faint radio sources were identified with accretion-powered radio galaxies and quasars brighter than 25.5 mag in the optical I band. On VLA scales at 1.4 GHz, a measure of the compactness of the faint sources (the ratio of the peak flux density from FIRST to the integrated flux density from the NVSS catalog) spans the full range of possibilities arising from source-resolution effects. Thirty of the faint radio sources, or 39{sub -7}{sup +9}%, were detected with the VLBA at 5.0 GHz with peak flux densities above 6 {sigma} {approx} 2 mJy at 2 mas resolution. The VLBA detections occur through the full range of compactness ratios. The stronger VLBA detections can themselves serve as phase-reference calibrators, boding well for opening up much of the radio sky to VLBA imaging. For the adopted cosmology, the VLBA resolution corresponds to 17 pc or finer. Most VLBA detections are unresolved or slightly resolved but one is diffuse and five show either double or core-jet structures; the properties of these latter six are discussed in detail. Eight VLBA detections are unidentified and fainter than 25.5 mag in the optical I band; their properties are highlighted because they likely mark optically-obscured active nuclei at high redshift.

  4. Blind Search of Faint Moving Objects in 3D Data Sets

    DTIC Science & Technology

    2013-09-01

    Blind Search of Faint Moving Objects in 3D Data Sets Phan Dao*, Peter Crabtree and Patrick McNicholl AFRL/RVBYC Tamar Payne Applied...using a simulated object signature superimposed on measured background, and show that the limiting magnitude can be improved by up to 6 visual...magnitudes. A quasi blind search algorithm that identifies the streak of photons, assuming no prior knowledge of orbital information, will be discussed

  5. Astrometric Observations of the Faint Outer Satellites of Jupiter During the 1994 and 1995 Oppositions

    NASA Astrophysics Data System (ADS)

    Whipple, Arthur L.; Shelus, Peter J.; Whited, Randy W.; Cochran, Anita L.; MacQueen, Phillip J.; Benedict, George F.

    1996-07-01

    We present astrometric positions for the faint outer satellites of Jupiter VI-XIII during the 1994 and 1995 oppositions. These positions have been obtained from measurements of photographic plates taken with the 2.1 m Otto Struve reflector and from wide field CCD frames taken with the 0.76 m reflector. Both telescopes are located at McDonald Observatory. The new CCD-based instrumentation and astrometric reduction system is described.

  6. Astrometric observations of the faint satellites of Jupiter and minor planets, 1974-1977

    NASA Technical Reports Server (NTRS)

    Benedict, G. R.; Shelus, P. J.; Mulholland, J. D.

    1978-01-01

    Precise positions of the faint satellites VI-XII of Jupiter during the 1974 opposition, and for Jupiter XIII during the 1976-1977 and 1977-1978 oppositions, have been obtained from plates taken with the 2.1-m Otto Struve reflector of the McDonald Observatory by the use of a new quasi-automatic plate measurement and reduction procedure on a PDS microdensitometer. Observations of selected asteroids, including two of 1977 UB (Chiron) are given also.

  7. The Carnegie-Chicago Hubble Program: Discovery of the Most Distant Ultra-faint Dwarf Galaxy in the Local Universe

    NASA Astrophysics Data System (ADS)

    Lee, Myung Gyoon; Jang, In Sung; Beaton, Rachael; Seibert, Mark; Bono, Giuseppe; Madore, Barry

    2017-02-01

    Ultra-faint dwarf galaxies (UFDs) are the faintest known galaxies, and due to their incredibly low surface brightness, it is difficult to find them beyond the Local Group. We report a serendipitous discovery of a UFD, Fornax UFD1, in the outskirts of NGC 1316, a giant galaxy in the Fornax cluster. The new galaxy is located at a projected radius of 55 kpc in the south-east of NGC 1316. This UFD is found as a small group of resolved stars in the Hubble Space Telescope images of a halo field of NGC 1316, obtained as part of the Carnegie-Chicago Hubble Program. Resolved stars in this galaxy are consistent with being mostly metal-poor red giant branch (RGB) stars. Applying the tip of the RGB method to the mean magnitude of the two brightest RGB stars, we estimate the distance to this galaxy, 19.0 ± 1.3 Mpc. Fornax UFD1 is probably a member of the Fornax cluster. The color-magnitude diagram of these stars is matched by a 12 Gyr isochrone with low metallicity ([Fe/H] ≈ -2.4). Total magnitude and effective radius of Fornax UFD1 are MV ≈ -7.6 ± 0.2 mag and reff = 146 ± 9 pc, which are similar to those of Virgo UFD1 that was discovered recently in the intracluster field of Virgo by Jang & Lee. Fornax UFD1 is the most distant known UFD that is confirmed by resolved stars. This indicates that UFDs are ubiquitous and that more UFDs remain to be discovered in the Fornax cluster. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #10505 and #13691.

  8. DISCOVERY OF AN ULTRA-FAINT DWARF GALAXY IN THE INTRACLUSTER FIELD OF THE VIRGO CENTER: A FOSSIL OF THE FIRST GALAXIES?

    SciTech Connect

    Jang, In Sung; Lee, Myung Gyoon E-mail: mglee@astro.snu.ac.kr

    2014-11-01

    Ultra-faint dwarf galaxies (UFDs) are newcomers among galaxies, and are the faintest galaxies in the observed universe. To date, they have only been found around the Milky Way Galaxy and M31 in the Local Group. We present the discovery of a UFD in the intracluster field in the core of the Virgo cluster (Virgo UFD1), which is far from any massive galaxies. The color-magnitude diagram of the resolved stars in this galaxy shows a narrow red giant branch, similar to those of metal-poor globular clusters in the Milky Way. We estimate its distance by comparing the red giant branch with isochrones, and we obtain a value 16.4 ± 0.4 Mpc. This shows that it is indeed a member of the Virgo cluster. From the color of the red giants we estimate its mean metallicity to be very low, [Fe/H] =–2.4 ± 0.4. Its absolute V-band magnitude and effective radius are derived to be M{sub V} = –6.5 ± 0.2 and r {sub eff} = 81 ± 7 pc, much fainter and smaller than the classical dwarf spheroidal galaxies. Its central surface brightness is estimated to be as low as μ {sub V,} {sub 0} = 26.37 ± 0.05 mag arcsec{sup –2}. Its properties are similar to those of the Local Group analogs. No evidence of tidal features are found in this galaxy. Considering its narrow red giant branch with no asymptotic giant branch stars, low metallicity, and location, it may be a fossil remnant of the first galaxies.

  9. Discovery of an Ultra-faint Dwarf Galaxy in the Intracluster Field of the Virgo Center: A Fossil of the First Galaxies?

    NASA Astrophysics Data System (ADS)

    Jang, In Sung; Lee, Myung Gyoon

    2014-11-01

    Ultra-faint dwarf galaxies (UFDs) are newcomers among galaxies, and are the faintest galaxies in the observed universe. To date, they have only been found around the Milky Way Galaxy and M31 in the Local Group. We present the discovery of a UFD in the intracluster field in the core of the Virgo cluster (Virgo UFD1), which is far from any massive galaxies. The color-magnitude diagram of the resolved stars in this galaxy shows a narrow red giant branch, similar to those of metal-poor globular clusters in the Milky Way. We estimate its distance by comparing the red giant branch with isochrones, and we obtain a value 16.4 ± 0.4 Mpc. This shows that it is indeed a member of the Virgo cluster. From the color of the red giants we estimate its mean metallicity to be very low, [Fe/H] =-2.4 ± 0.4. Its absolute V-band magnitude and effective radius are derived to be MV = -6.5 ± 0.2 and r eff = 81 ± 7 pc, much fainter and smaller than the classical dwarf spheroidal galaxies. Its central surface brightness is estimated to be as low as μ V, 0 = 26.37 ± 0.05 mag arcsec-2. Its properties are similar to those of the Local Group analogs. No evidence of tidal features are found in this galaxy. Considering its narrow red giant branch with no asymptotic giant branch stars, low metallicity, and location, it may be a fossil remnant of the first galaxies.

  10. An ultra-faint galaxy candidate discovered in early data from the Magellanic Satellites Survey

    DOE PAGES

    Drlica-Wagner, A.; Bechtol, Keith; Allam, S.; ...

    2016-11-30

    Here, we report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644–5953 (Pictor II or Pic II) is a low surface brightness (more » $$\\mu ={28.5}_{-1}^{+1}\\,\\mathrm{mag}\\,\\,\\mathrm{arcsec}{}^{-2}$$ within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of $${45}_{-4}^{+5}\\,\\mathrm{kpc}$$. The physical size ($${r}_{1/2}={46}_{-11}^{+15}\\,\\mathrm{pc}\\,$$) and low luminosity ($${M}_{V}=-{3.2}_{-0.5}^{+0.4}\\,\\mathrm{mag}\\,$$) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS J0644–5953 (Pic II) is located $${11.3}_{-0.9}^{+3.1}\\,\\mathrm{kpc}\\,$$ from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS J0644–5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.« less

  11. An ultra-faint galaxy candidate discovered in early data from the Magellanic Satellites Survey

    SciTech Connect

    Drlica-Wagner, A.; Bechtol, Keith; Allam, S.; Tucker, D. L.; Gruendl, R. A.; Johnson, M. D.; Walker, A. R.; James, D. J.; Nidever, D. L.; Olsen, K. A. G.; Wechsler, R. H.; Cioni, M. R. L.; Conn, B. C.; Kuehn, K.; Li, T. S.; Mao, Y. -Y.; Martin, N. F.; Neilsen, E.; Noel, N. E. D.; Pieres, A.; Simon, J. D.; Stringfellow, G. S.; Marel, R. P. van der; Yanny, B.

    2016-11-30

    Here, we report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644–5953 (Pictor II or Pic II) is a low surface brightness ($\\mu ={28.5}_{-1}^{+1}\\,\\mathrm{mag}\\,\\,\\mathrm{arcsec}{}^{-2}$ within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of ${45}_{-4}^{+5}\\,\\mathrm{kpc}$. The physical size (${r}_{1/2}={46}_{-11}^{+15}\\,\\mathrm{pc}\\,$) and low luminosity (${M}_{V}=-{3.2}_{-0.5}^{+0.4}\\,\\mathrm{mag}\\,$) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS J0644–5953 (Pic II) is located ${11.3}_{-0.9}^{+3.1}\\,\\mathrm{kpc}\\,$ from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS J0644–5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.

  12. The Evolution of Faint Field Galaxies: Implications from the Hubble Deep Field

    NASA Astrophysics Data System (ADS)

    Gronwall, C.

    1996-12-01

    The Hubble Deep Field (HDF) is a four square arcminute area of the sky imaged for ten consecutive days with the Hubble Space Telescope. It is the deepest optical imaging survey of field galaxies in existence, reaching ~ 2-3 mag fainter than the deepest ground-based observations. In addition to its unprecedented depth, the spatial resolution of the HDF enables the measurement of structural and morphological parameters for an extremely faint sample of galaxies. We (see Gronwall & Koo 1995) have developed a modeling technique which differs from previous work by adopting the very simple assumption that the local galaxy luminosity function and galaxy mix are not well-defined. Instead, we use a non-negative least squares fitting technique to derive a set of best-fitting local luminosity functions for different galaxy spectral types. By only including traditional luminosity evolution (i.e., the photometric evolution of stars over time given reasonable assumptions of the star formation history of various galaxy types), plus the addition of galaxy reddening, we are able to fit the observed optical and near-IR galaxy counts, B-R colors, and redshifts of faint field galaxies extremely well to B ~ 25. We present the extension of the obove modeling technique to the multicolor photometric information and structural parameters (in particular, angular sizes) provided by the HDF. Our newst models also include additional evolutionary components -- merging and starbursting -- to try to constrain the relative importances of different forms of evolution in faint field galaxies.

  13. Calibration of HST wide field camera for quantitative analysis of faint galaxy images

    NASA Technical Reports Server (NTRS)

    Ratnatunga, Kavan U.; Griffiths, Richard E.; Casertano, Stefano; Neuschaefer, Lyman W.; Wyckoff, Eric W.

    1994-01-01

    We present the methods adopted to optimize the calibration of images obtained with the Hubble Space Telescope (HST) Wide Field Camera (WFC) (1991-1993). Our main goal is to improve quantitative measurement of faint images, with special emphasis on the faint (I approximately 20-24 mag) stars and galaxies observed as a part of the Medium-Deep Survey. Several modifications to the standard calibration procedures have been introduced, including improved bias and dark images, and a new supersky flatfield obtained by combining a large number of relatively object-free Medium-Deep Survey exposures of random fields. The supersky flat has a pixel-to-pixel rms error of about 2.0% in F555W and of 2.4% in F785LP; large-scale variations are smaller than 1% rms. Overall, our modifications improve the quality of faint images with respect to the standard calibration by about a factor of five in photometric accuracy and about 0.3 mag in sensitivity, corresponding to about a factor of two in observing time. The relevant calibration images have been made available to the scientific community.

  14. An Ultra-faint Galaxy Candidate Discovered in Early Data from the Magellanic Satellites Survey

    NASA Astrophysics Data System (ADS)

    Drlica-Wagner, A.; Bechtol, K.; Allam, S.; Tucker, D. L.; Gruendl, R. A.; Johnson, M. D.; Walker, A. R.; James, D. J.; Nidever, D. L.; Olsen, K. A. G.; Wechsler, R. H.; Cioni, M. R. L.; Conn, B. C.; Kuehn, K.; Li, T. S.; Mao, Y.-Y.; Martin, N. F.; Neilsen, E.; Noel, N. E. D.; Pieres, A.; Simon, J. D.; Stringfellow, G. S.; van der Marel, R. P.; Yanny, B.

    2016-12-01

    We report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644-5953 (Pictor II or Pic II) is a low surface brightness (μ ={28.5}-1+1 {mag} {arcsec}{}-2 within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of {45}-4+5 {kpc}. The physical size ({r}1/2={46}-11+15 {pc} ) and low luminosity ({M}V=-{3.2}-0.5+0.4 {mag} ) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS J0644-5953 (Pic II) is located {11.3}-0.9+3.1 {kpc} from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS J0644-5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.

  15. An ultra-faint galaxy candidate discovered in early data from the Magellanic Satellites Survey

    SciTech Connect

    Drlica-Wagner, A.; Bechtol, Keith; Allam, S.; Tucker, D. L.; Gruendl, R. A.; Johnson, M. D.; Walker, A. R.; James, D. J.; Nidever, D. L.; Olsen, K. A. G.; Wechsler, R. H.; Cioni, M. R. L.; Conn, B. C.; Kuehn, K.; Li, T. S.; Mao, Y. -Y.; Martin, N. F.; Neilsen, E.; Noel, N. E. D.; Pieres, A.; Simon, J. D.; Stringfellow, G. S.; Marel, R. P. van der; Yanny, B.

    2016-11-30

    Here, we report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644–5953 (Pictor II or Pic II) is a low surface brightness ($\\mu ={28.5}_{-1}^{+1}\\,\\mathrm{mag}\\,\\,\\mathrm{arcsec}{}^{-2}$ within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of ${45}_{-4}^{+5}\\,\\mathrm{kpc}$. The physical size (${r}_{1/2}={46}_{-11}^{+15}\\,\\mathrm{pc}\\,$) and low luminosity (${M}_{V}=-{3.2}_{-0.5}^{+0.4}\\,\\mathrm{mag}\\,$) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS J0644–5953 (Pic II) is located ${11.3}_{-0.9}^{+3.1}\\,\\mathrm{kpc}\\,$ from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS J0644–5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.

  16. An ultra-faint galaxy candidate discovered in early data from the Magellanic Satellites Survey

    DOE PAGES

    Drlica-Wagner, A.; Bechtol, Keith; Allam, S.; ...

    2016-11-30

    Here, we report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644–5953 (Pictor II or Pic II) is a low surface brightness (more » $$\\mu ={28.5}_{-1}^{+1}\\,\\mathrm{mag}\\,\\,\\mathrm{arcsec}{}^{-2}$$ within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of $${45}_{-4}^{+5}\\,\\mathrm{kpc}$$. The physical size ($${r}_{1/2}={46}_{-11}^{+15}\\,\\mathrm{pc}\\,$$) and low luminosity ($${M}_{V}=-{3.2}_{-0.5}^{+0.4}\\,\\mathrm{mag}\\,$$) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS J0644–5953 (Pic II) is located $${11.3}_{-0.9}^{+3.1}\\,\\mathrm{kpc}\\,$$ from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS J0644–5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.« less

  17. Exploring three faint source detections methods for aperture synthesis radio images

    NASA Astrophysics Data System (ADS)

    Peracaula, M.; Torrent, A.; Masias, M.; Lladó, X.; Freixenet, J.; Martí, J.; Sánchez-Sutil, J. R.; Muñoz-Arjonilla, A. J.; Paredes, J. M.

    2015-04-01

    Wide-field radio interferometric images often contain a large population of faint compact sources. Due to their low intensity/noise ratio, these objects can be easily missed by automated detection methods, which have been classically based on thresholding techniques after local noise estimation. The aim of this paper is to present and analyse the performance of several alternative or complementary techniques to thresholding. We compare three different algorithms to increase the detection rate of faint objects. The first technique consists of combining wavelet decomposition with local thresholding. The second technique is based on the structural behaviour of the neighbourhood of each pixel. Finally, the third algorithm uses local features extracted from a bank of filters and a boosting classifier to perform the detections. The methods' performances are evaluated using simulations and radio mosaics from the Giant Metrewave Radio Telescope and the Australia Telescope Compact Array. We show that the new methods perform better than well-known state of the art methods such as SEXTRACTOR, SAD and DUCHAMP at detecting faint sources of radio interferometric images.

  18. Calibration of HST wide field camera for quantitative analysis of faint galaxy images

    NASA Technical Reports Server (NTRS)

    Ratnatunga, Kavan U.; Griffiths, Richard E.; Casertano, Stefano; Neuschaefer, Lyman W.; Wyckoff, Eric W.

    1994-01-01

    We present the methods adopted to optimize the calibration of images obtained with the Hubble Space Telescope (HST) Wide Field Camera (WFC) (1991-1993). Our main goal is to improve quantitative measurement of faint images, with special emphasis on the faint (I approximately 20-24 mag) stars and galaxies observed as a part of the Medium-Deep Survey. Several modifications to the standard calibration procedures have been introduced, including improved bias and dark images, and a new supersky flatfield obtained by combining a large number of relatively object-free Medium-Deep Survey exposures of random fields. The supersky flat has a pixel-to-pixel rms error of about 2.0% in F555W and of 2.4% in F785LP; large-scale variations are smaller than 1% rms. Overall, our modifications improve the quality of faint images with respect to the standard calibration by about a factor of five in photometric accuracy and about 0.3 mag in sensitivity, corresponding to about a factor of two in observing time. The relevant calibration images have been made available to the scientific community.

  19. Local Group ultra-faint dwarf galaxies in the reionization era

    NASA Astrophysics Data System (ADS)

    Weisz, Daniel R.; Boylan-Kolchin, Michael

    2017-07-01

    Motivated by the stellar fossil record of Local Group (LG) dwarf galaxies, we show that the star-forming ancestors of the faintest ultra-faint dwarf galaxies (UFDs; MV ˜ -2 or M⋆ ˜ 102 at z = 0) had ultraviolet (UV) luminosities of MUV ˜ -3 to -6 during reionization (z ˜ 6-10). The existence of such faint galaxies has substantial implications for early epochs of galaxy formation and reionization. If the faint-end slopes of the UV luminosity functions (UVLFs) during reionization are steep (α ≲ -2) to MUV ˜ -3, then (i) the ancestors of UFDs produced >50 per cent of UV flux from galaxies; (ii) galaxies can maintain reionization with escape fractions that are more than two times lower than currently adopted values; (iii) direct Hubble Space Telescope and James Webb Space Telescope observations may detect only ˜10-50 per cent of the UV light from galaxies; and (iv) the cosmic star formation history increases by ≳ 4-6 at z ≳ 6. Significant flux from UFDs, and resultant tensions with LG dwarf galaxy counts, is reduced if the high-redshift UVLF turns over. Independent of the UVLF shape, the existence of a large population of UFDs requires a non-zero luminosity function to MUV ˜ -3 during reionization.

  20. Infrared-faint radio sources are at high redshifts. Spectroscopic redshift determination of infrared-faint radio sources using the Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Herzog, A.; Middelberg, E.; Norris, R. P.; Sharp, R.; Spitler, L. R.; Parker, Q. A.

    2014-07-01

    Context. Infrared-faint radio sources (IFRS) are characterised by relatively high radio flux densities and associated faint or even absent infrared and optical counterparts. The resulting extremely high radio-to-infrared flux density ratios up to several thousands were previously known only for high-redshift radio galaxies (HzRGs), suggesting a link between the two classes of object. However, the optical and infrared faintness of IFRS makes their study difficult. Prior to this work, no redshift was known for any IFRS in the Australia Telescope Large Area Survey (ATLAS) fields which would help to put IFRS in the context of other classes of object, especially of HzRGs. Aims: This work aims at measuring the first redshifts of IFRS in the ATLAS fields. Furthermore, we test the hypothesis that IFRS are similar to HzRGs, that they are higher-redshift or dust-obscured versions of these massive galaxies. Methods: A sample of IFRS was spectroscopically observed using the Focal Reducer and Low Dispersion Spectrograph 2 (FORS2) at the Very Large Telescope (VLT). The data were calibrated based on the Image Reduction and Analysis Facility (IRAF) and redshifts extracted from the final spectra, where possible. This information was then used to calculate rest-frame luminosities, and to perform the first spectral energy distribution modelling of IFRS based on redshifts. Results: We found redshifts of 1.84, 2.13, and 2.76, for three IFRS, confirming the suggested high-redshift character of this class of object. These redshifts and the resulting luminosities show IFRS to be similar to HzRGs, supporting our hypothesis. We found further evidence that fainter IFRS are at even higher redshifts. Conclusions: Considering the similarities between IFRS and HzRGs substantiated in this work, the detection of IFRS, which have a significantly higher sky density than HzRGs, increases the number of active galactic nuclei in the early universe and adds to the problems of explaining the formation of

  1. Solutions to the faint young Sun paradox simulated by a general circulation model

    NASA Astrophysics Data System (ADS)

    Wolf, Eric Theodore

    The faint young Sun paradox has dominated our thinking regarding early climate. Geological evidence abounds for warm, possibly hot, seawater temperatures and the proliferation of early life during the Archean period of Earth's history (3.8-2.5 Ga). However the standard solar model indicates that the Sun was only 75 to 82 percent as bright as today, implying an apparent contradiction between warm surface temperatures and weak solar irradiance. Geological evidence also places constraints on the amount of atmospheric carbon dioxide present early in Earth's history. Over the past four decades there has been much debate amongst geological, planetary, and climate science communities regarding how to properly resolve the issue of the faint young Sun. Up until very recently, 1-dimensional radiative convective models were the standard tool for deep paleoclimate modeling studies. These studies have notably lacked the ability to treat clouds, surface ice, and meridional energy transport. However, advancements in computing technology now allow us to tackle the faint young Sun paradox using a three-dimensional climate model. Here we use a modified version of the Community Atmosphere Model version 3 from the National Center for Atmospheric Research to study early climate. We find that resolving the faint young Sun paradox becomes less problematic when viewing a full representation of the climate system. Modest amounts of carbon dioxide and methane can provide adequate warming for the Archean within given constraints. Cooler climates with large ice caps but temperate tropical regions can be supported with even less carbon dioxide. The incorporation of systematic climate system differences expected during the Archean, such as fewer cloud condensation nuclei, reduced land albedos, and increased atmospheric nitrogen, can provide additional non-greenhouse means of warming the early Earth. A warm Archean no longer appears at odds with a faint young Sun. Here, we will also discuss the

  2. RED AND DEAD: THE PROGENITOR OF SN 2012aw IN M95

    SciTech Connect

    Fraser, M.; Maund, J. R.; Smartt, S. J.; Inserra, C.; Kotak, R.; Reilly, E.; Botticella, M.-T.; Dall'Ora, M.; Tomasella, L.; Benetti, S.; Ciroi, S.; Ochner, P.; Pastorello, A.; Valenti, S.; Eldridge, J. J.; Ergon, M.; Sollerman, J.; Taddia, F.; Mattila, S.; Stephens, A.

    2012-11-01

    Core-collapse supernovae (SNe) are the spectacular finale to massive stellar evolution. In this Letter, we identify a progenitor for the nearby core-collapse SN 2012aw in both ground-based near-infrared and space-based optical pre-explosion imaging. The SN itself appears to be a normal Type II Plateau event, reaching a bolometric luminosity of 10{sup 42} erg s{sup -1} and photospheric velocities of {approx}11,000 km s{sup -1} from the position of the H{beta} P-Cygni minimum in the early SN spectra. We use an adaptive optics image to show that the SN is coincident to within 27 mas with a faint, red source in pre-explosion HST+WFPC2, VLT+ISAAC, and NTT+SOFI images. The source has magnitudes F555W = 26.70 {+-} 0.06, F814W = 23.39 {+-} 0.02, J = 21.1 {+-} 0.2, K = 19.1 {+-} 0.4, which, when compared to a grid of stellar models, best matches a red supergiant. Interestingly, the spectral energy distribution of the progenitor also implies an extinction of A{sub V} > 1.2 mag, whereas the SN itself does not appear to be significantly extinguished. We interpret this as evidence for the destruction of dust in the SN explosion. The progenitor candidate has a luminosity between 5.0 and 5.6 log L/L{sub Sun }, corresponding to a zero-age main-sequence mass between 14 and 26 M{sub Sun} (depending on A{sub V} ), which would make this one of the most massive progenitors found for a core-collapse SN to date.

  3. Syncope (Fainting)

    MedlinePlus

    ... is syncope? Syncope is a temporary loss of consciousness usually related to insufficient blood flow to the ... in a reclining position restores blood flow and consciousness, and ends the seizure. Situational syncope, which is ...

  4. Extreme Red Quasars in SDSS-BOSS

    NASA Astrophysics Data System (ADS)

    Hamann, Fred; Zakamska, Nadia; Paris, Isabelle; Herbst, Hanna; Villforth, Carolin; Alexandroff, Rachael; Ross, Nicholas; Greene, Jenny; Strauss, Michael

    2015-08-01

    Red quasars are believed to mark a critical transition stage of massive galaxy evolution when a blowout of gas and dust truncates the initial starburst and provides our first visible views of a luminous central AGN. Red quasars could therefore have unusual properties associated with a young evolution stage, such as higher accretion rates, higher rates of mergers and interactions, and more common or more powerful outflows capable of driving a galaxy-wide blowout (e.g., compared to normal blue quasars in presumably more evolved galaxy hosts). The recently completed Baryon Oscillation Spectroscopy Survey (BOSS) of SDSS-III has discovered many more faint quasars with higher redshifts and redder colors than any previous large survey. We combine BOSS spectra with SDSS and Wide-Field Infrared Survey Explorer (WISE) photometry of nearly 100,000 quasars to identify and characterize the red quasar population at redshifts >2. We find a number of strong trends with the amount of reddening/obscuration. For example, red quasars are 5 to 8 times more likely to have broad absorption lines and other "intrinsic" absorption lines that identify quasar-driven outflows. Perhaps most interesting is that extreme red quasars (ERQs), selected via rest-frame UV to near-IR colors similar to Dust Obscured Galaxies (DOGs), have uniquely exotic emission line properties that include extreme velocity shifts between lines and the broadest and most blueshifted [OIII] lines yet discovered (with FWHMs reaching >3000 km/s). We will discuss the implications of these results for models of the structure and evolution of quasars and their host galaxy environments.

  5. The SWIRE-VVDS-CFHTLS surveys: stellar mass assembly over the last 10 Gyr. Evidence for a major build up of the red sequence between z = 2 and z = 1

    NASA Astrophysics Data System (ADS)

    Arnouts, S.; Walcher, C. J.; Le Fèvre, O.; Zamorani, G.; Ilbert, O.; Le Brun, V.; Pozzetti, L.; Bardelli, S.; Tresse, L.; Zucca, E.; Charlot, S.; Lamareille, F.; McCracken, H. J.; Bolzonella, M.; Iovino, A.; Lonsdale, C.; Polletta, M.; Surace, J.; Bottini, D.; Garilli, B.; Maccagni, D.; Picat, J. P.; Scaramella, R.; Scodeggio, M.; Vettolani, G.; Zanichelli, A.; Adami, C.; Cappi, A.; Ciliegi, P.; Contini, T.; de la Torre, S.; Foucaud, S.; Franzetti, P.; Gavignaud, I.; Guzzo, L.; Marano, B.; Marinoni, C.; Mazure, A.; Meneux, B.; Merighi, R.; Paltani, S.; Pellò, R.; Pollo, A.; Radovich, M.; Temporin, S.; Vergani, D.

    2007-12-01

    , which balances the major fraction of new stars born according to our best SFR estimate (dotρ = 0.025(±0.003) M⊙/Mpc^3/yr). From z = 2 to z = 1.2, we observe a major build-up of the quiescent population with an increase by a factor of 10 in stellar mass (a mass growth rate of 0.063 M⊙/Mpc^3/yr). This rapid evolution suggests that we are observing the epoch when, for the first time in the history of the universe, an increasing fraction of galaxies end their star formation activity and start to build up the red sequence. Based on data obtained with the European southern observatory Very Large Telescope, Paranal, Chile, program 070A-9007(A) and on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS and on data obtained as part of the UKIRT Infrared Deep Sky Survey.

  6. Red blood cell production

    MedlinePlus

    ... to one part of the body or another. Red blood cells are an important element of blood. Their job ... is carried to and eliminated by the lungs. Red blood cells are formed in the red bone marrow of ...

  7. Galaxy populations in the Antlia cluster - III. Properties of faint early-type galaxies

    NASA Astrophysics Data System (ADS)

    Smith Castelli, Analía. V.; Cellone, Sergio A.; Faifer, Favio R.; Bassino, Lilia P.; Richtler, Tom; Romero, Gisela A.; Calderón, Juan Pablo; Caso, Juan Pablo

    2012-01-01

    We present a new analysis of the early-type galaxy population in the central region of the Antlia cluster, focusing on the faint systems such as dwarf ellipticals (dEs) and dwarf spheroidals (dSphs). The colour-magnitude relation (CMR) and the relation between luminosity and mean effective surface brightness for galaxies in the central region of Antlia have been previously studied in Paper I of the present series. Now we confirm 22 early-type galaxies as Antlia members, using Gemini-GMOS and Magellan-MIKE spectra. Among them, 15 are dEs from the FS90 Antlia Group catalogue, two belong to the rare type of compact ellipticals (cEs) and five are new faint dwarfs that had never been catalogued before. In addition, we present 16 newly identified low-surface-brightness galaxy candidates, almost half of them displaying morphologies consistent with being Antlia's counterparts of Local Group dSphs, which extend the faint luminosity limit of our study down to MB=-10.1(BT= 22.6) mag. With these new data, we built an improved CMR in the Washington photometric system, i.e. integrated T1 magnitudes versus (C-T1) colours, which extends ˜4 mag faintwards the limit of spectroscopically confirmed Antlia members. When only confirmed early-type members are considered, this relation extends over 10 mag in luminosity with no apparent change in slope or increase in colour dispersion towards its faint end. The intrinsic colour scatter of the relation is compared with those reported for other clusters of galaxies; we argue that it is likely that the large scatter of the CMR, usually reported at faint magnitudes, is mostly due to photometric errors along with an improper membership/morphological classification. The distinct behaviour of the luminosity versus mean effective surface brightness relation at the bright and faint ends is analysed, while it is confirmed that dE galaxies on the same relation present a very similar effective radius, regardless of their colour. The projected spatial

  8. The VVDS type-1 AGN sample: the faint end of the luminosity function

    NASA Astrophysics Data System (ADS)

    Bongiorno, A.; Zamorani, G.; Gavignaud, I.; Marano, B.; Paltani, S.; Mathez, G.; Møller, P.; Picat, J. P.; Cirasuolo, M.; Lamareille, F.; Bottini, D.; Garilli, B.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Arnouts, S.; Bardelli, S.; Bolzonella, M.; Cappi, A.; Charlot, S.; Ciliegi, P.; Contini, T.; Foucaud, S.; Franzetti, P.; Guzzo, L.; Ilbert, O.; Iovino, A.; McCracken, H. J.; Marinoni, C.; Mazure, A.; Meneux, B.; Merighi, R.; Pellò, R.; Pollo, A.; Pozzetti, L.; Radovich, M.; Zucca, E.; Hatziminaoglou, E.; Polletta, M.; Bondi, M.; Brinchmann, J.; Cucciati, O.; de la Torre, S.; Gregorini, L.; Mellier, Y.; Merluzzi, P.; Temporin, S.; Vergani, D.; Walcher, C. J.

    2007-09-01

    In a previous paper (Gavignaud et al. 2006, A&A, 457, 79), we presented the type-1 Active Galactic Nuclei (AGN) sample obtained from the first epoch data of the VIMOS-VLT Deep Survey (VVDS). The sample consists of 130 faint, broad-line AGN with redshift up to z=5 and 17.5faint AGN. In this paper we present the measurement of the Optical Luminosity Function up to z=3.6 derived from this sample, we compare our results with previous results from brighter samples both at low and at high redshift and finally, through the estimate of the bolometric luminosity function, we compare them also with the results from X-ray and mid-IR selected samples. Our data, more than one magnitude fainter than previous optical surveys, allow us to constrain the faint part of the luminosity function up to high redshift. A comparison of our data with the 2dF sample at low redshift (1 < z < 2.1) shows that the VVDS data can not be well fitted with the PLE models derived by previous samples. Qualitatively, this appears to be due to the fact that our data suggest the presence of an excess of faint objects at low redshift (1.0faint VVDS sample with the large sample of bright AGN extracted from the SDSS DR3 (Richards et al. 2006b, AJ, 131, 2766) and testing a number of different evolutionary models, we find that the model which better represents the combined luminosity functions, over a wide range of redshift and luminosity, is a luminosity dependent density evolution (LDDE) model, similar to those derived from the major X-surveys. Such a parameterization allows the redshift of the AGN space density peak to change as a function of luminosity and explains the excess of faint AGN that we find at 1.0 < z < 1.5. On the basis of this model we find, for the

  9. Faint progenitors of luminous z ˜ 6 quasars: Why do not we see them?

    NASA Astrophysics Data System (ADS)

    Pezzulli, Edwige; Valiante, Rosa; Orofino, Maria C.; Schneider, Raffaella; Gallerani, Simona; Sbarrato, Tullia

    2017-04-01

    Observational searches for faint active nuclei at z > 6 have been extremely elusive, with a few candidates whose high-z nature is still to be confirmed. Interpreting this lack of detections is crucial to improve our understanding of high-z supermassive black holes (SMBHs) formation and growth. In this work, we present a model for the emission of accreting black holes (BHs) in the X-ray band, taking into account super-Eddington accretion, which can be very common in gas-rich systems at high-z. We compute the spectral energy distribution for a sample of active galaxies simulated in a cosmological context, which represent the progenitors of a z ˜ 6 SMBH with MBH ˜ 109 M⊙. We find an average Compton-thick fraction of ˜45 per cent and large typical column densities (NH ≳ 1023 cm2). However, faint progenitors are still luminous enough to be detected in the X-ray band of current surveys. Even accounting for a maximum obscuration effect, the number of detectable BHs is reduced at most by a factor of 2. In our simulated sample, observations of faint quasars are mainly limited by their very low active fraction (fact ˜ 1 per cent), which is the result of short, supercritical growth episodes. We suggest that to detect high-z SMBHs progenitors, large area surveys with shallower sensitivities, such as COSMOS Legacy and XMM-LSS+XXL, are to be preferred with respect to deep surveys probing smaller fields, such as Chandra Deep Field South.

  10. The Search for Faint Infrared Calibration Standards - Extending Landolt's Standards to V=19

    NASA Astrophysics Data System (ADS)

    Kidger, M.; González-Pérez, J. N.; Martín-Luis, F.; Cohen, M.

    ISO has shown the need to obtain a reliable calibration network of good pedigree to permit data from a wide range of instruments, covering an enormous wavelength range, to be calibrated on a consistent scale. We describe the first results of a programme to extend the Landolt calibration standards to at least V=19. At the same time we calibrate into the near-infrared JHK bands and measure fields separated from the celestial equator. This programme is one of several coordinated efforts to find faint type AV and KIII stars suitable for the mid-IR calibration of the Spanish 10-m Gran Telescopio Canarias (GTC). We have obtained a total of 34 712 measurements of 373 stars in 26 quasar fields between Declination -30o and +70o, calculating magnitudes with high precision in the visible and near-infrared (UBVRIJHK). We describe the results obtained and the characteristics of the sample of stars. The typical error on the magnitude in a single band is <1%, including all error sources. Very few candidate type AV or KIII stars are found, either in our sample, or amongst the fainter Landolt stars. We conclude that both samples are increasingly dominated by local dwarfs at increasingly faint magnitudes. We discuss the implications for taking mid-infrared calibration to the increasingly faint limits required by post-ISO instrumentation. The next steps in this project will be: -- To increase significantly the number of fields covered to ˜40. -- To take additional observations of all poorly covered fields and to add JHK data where none is available. -- To use our existing database to extend Landolt photometry of Selected Areas to include many stars not previously measured. -- To assign a spectral type to all candidate KIII and AV stars in our sample.

  11. THE FAINT END OF THE CLUSTER-GALAXY LUMINOSITY FUNCTION AT HIGH REDSHIFT

    SciTech Connect

    Mancone, Conor L.; Baker, Troy; Gonzalez, Anthony H.; Ashby, Matthew L. N.; Snyder, Greg; Stanford, Spencer A.; Brodwin, Mark; Eisenhardt, Peter R. M.; Stern, Daniel; Wright, Edward L.

    2012-12-20

    We measure the faint-end slope of the galaxy luminosity function (LF) for cluster galaxies at 1 < z < 1.5 using Spitzer IRAC data. We investigate whether this slope, {alpha}, differs from that of the field LF at these redshifts, and with the cluster LF at low redshifts. The latter is of particular interest as low-luminosity galaxies are expected to undergo significant evolution. We use seven high-redshift spectroscopically confirmed galaxy clusters drawn from the IRAC Shallow Cluster Survey to measure the cluster-galaxy LF down to depths of M* + 3 (3.6 {mu}m) and M* + 2.5 (4.5 {mu}m). The summed LF at our median cluster redshift (z = 1.35) is well fit by a Schechter distribution with {alpha}{sub 3.6{mu}m} = -0.97 {+-} 0.14 and {alpha}{sub 4.5{mu}m} = -0.91 {+-} 0.28, consistent with a flat faint-end slope and is in agreement with measurements of the field LF in similar bands at these redshifts. A comparison to {alpha} in low-redshift clusters finds no statistically significant evidence of evolution. Combined with past studies which show that M* is passively evolving out to z {approx} 1.3, this means that the shape of the cluster LF is largely in place by z {approx} 1.3. This suggests that the processes that govern the buildup of the mass of low-mass cluster galaxies have no net effect on the faint-end slope of the cluster LF at z {approx}< 1.3.

  12. Variable Stars in the Field of the Hydra II Ultra-faint Dwarf Galaxy

    NASA Astrophysics Data System (ADS)

    Vivas, A. Katherina; Olsen, Knut; Blum, Robert; Nidever, David L.; Walker, Alistair R.; Martin, Nicolas F.; Besla, Gurtina; Gallart, Carme; van der Marel, Roeland P.; Majewski, Steven R.; Kaleida, Catherine C.; Muñoz, Ricardo R.; Saha, Abhijit; Conn, Blair C.; Jin, Shoko

    2016-05-01

    We report the discovery of one RR Lyrae star in the ultra-faint satellite galaxy Hydra II based on time series photometry in the g, r and i bands obtained with the Dark Energy Camera at Cerro Tololo Inter-American Observatory, Chile. The association of the RR Lyrae star discovered here with Hydra II is clear because is located at 42\\prime\\prime from the center of the dwarf, well within its half-light radius of 102\\prime\\prime . The RR Lyrae star has a mean magnitude of i=21.30+/- 0.04 which is too faint to be a field halo star. This magnitude translates to a heliocentric distance of 151 ± 8 kpc for Hydra II; this value is ∼ 13% larger than the estimate from the discovery paper based on the average magnitude of several blue horizontal branch star candidates. The new distance implies a slightly larger half-light radius of {76}-10+12 pc and a brighter absolute magnitude of {M}V=-5.1+/- 0.3, which keeps this object within the realm of the dwarf galaxies. A comparison with other RR Lyrae stars in ultra-faint systems indicates similar pulsational properties among them, which are different to those found among halo field stars and those in the largest of the Milky Way satellites. We also report the discovery of 31 additional short period variables in the field of view (RR Lyrae, SX Phe, eclipsing binaries, and a likely anomalous cepheid) which are likely not related with Hydra II.

  13. Finding faint H I structure in and around galaxies: Scraping the barrel

    NASA Astrophysics Data System (ADS)

    Punzo, D.; van der Hulst, J. M.; Roerdink, J. B. T. M.

    2016-10-01

    Soon to be operational H I survey instruments such as APERTIF and ASKAP will produce large datasets. These surveys will provide information about the H I in and around hundreds of galaxies with a typical signal-to-noise ratio of ∼10 in the inner regions and ∼1 in the outer regions. In addition, such surveys will make it possible to probe faint H I structures, typically located in the vicinity of galaxies, such as extra-planar-gas, tails and filaments. These structures are crucial for understanding galaxy evolution, particularly when they are studied in relation to the local environment. Our aim is to find optimized kernels for the discovery of faint and morphologically complex H I structures. Therefore, using H I data from a variety of galaxies, we explore state-of-the-art filtering algorithms. We show that the intensity-driven gradient filter, due to its adaptive characteristics, is the optimal choice. In fact, this filter requires only minimal tuning of the input parameters to enhance the signal-to-noise ratio of faint components. In addition, it does not degrade the resolution of the high signal-to-noise component of a source. The filtering process must be fast and be embedded in an interactive visualization tool in order to support fast inspection of a large number of sources. To achieve such interactive exploration, we implemented a multi-core CPU (OpenMP) and a GPU (OpenGL) version of this filter in a 3D visualization environment (SlicerAstro).

  14. Rocket instrument for far-UV spectrophotometry of faint astronomical objects.

    PubMed

    Hartig, G F; Fastie, W G; Davidsen, A F

    1980-03-01

    A sensitive sounding rocket instrument for moderate (~10-A) resolution far-UV (lambda1160-lambda1750-A) spectrophotometry of faint astronomical objects has been developed. The instrument employs a photon-counting microchannel plate imaging detector and a concave grating spectrograph behind a 40-cm Dall-Kirkham telescope. A unique remote-control pointing system, incorporating an SIT vidicon aspect camera, two star trackers, and a tone-encoded command telemetry link, permits the telescope to be oriented to within 5 arc sec of any target for which suitable guide stars can be found. The design, construction, calibration, and flight performance of the instrument are discussed.

  15. Rocket instrument for far-UV spectrophotometry of faint astronomical objects

    NASA Technical Reports Server (NTRS)

    Hartig, G. F.; Fastie, W. G.; Davidsen, A. F.

    1980-01-01

    A sensitive sounding rocket instrument for moderate (about 10-A) resolution far-UV (1160-1750-A) spectrophotometry of faint astronomical objects has been developed. The instrument employes a photon-counting microchannel plate imaging detector and a concave grating spectrograph behind a 40-cm Dall-Kirkham telescope. A unique remote-control pointing system, incorporating an SIT vidicon aspect camera, two star trackers, and a tone-encoded command telemetry link, permits the telescope to be oriented to within 5 arc sec of any target for which suitable guide stars can be found. The design, construction, calibration, and flight performance of the instrument are discussed.

  16. The early faint sun paradox: organic shielding of ultraviolet-labile greenhouse gases

    NASA Technical Reports Server (NTRS)

    Sagan, C.; Chyba, C.

    1997-01-01

    Atmospheric mixing ratios of approximately 10(-5 +/- 1) for ammonia on the early Earth would have been sufficient, through the resulting greenhouse warming, to counteract the temperature effects of the faint early sun. One argument against such model atmospheres has been the short time scale for ammonia photodissociation by solar ultraviolet light. Here it is shown that ultraviolet absorption by steady-state amounts of high-altitude organic solids produced from methane photolysis may have shielded ammonia sufficiently that ammonia resupply rates were able to maintain surface temperatures above freezing.

  17. Studying the diverse nature of faint galaxies in nearby clusters of the WINGS sample

    NASA Astrophysics Data System (ADS)

    Bettoni, D.; Kjærgaard, P.; Milvang-Jensen, B.; D'Onofrio, M.; Moretti, A.; Poggianti, B. M.; Fasano, G.; Moles, M.

    2011-03-01

    We present the first results of our X-shooter observations for a sample of dwarf (-17 faint early-type galaxies.

  18. The Properties of Faint Galaxies in Nearby Clusters of the WINGS Sample

    NASA Astrophysics Data System (ADS)

    Bettoni, D.; Kjærgaard, P.; Milvan-Jensen, B.; D'Onofrio, M.; Moretti, A.; Poggianti, B. M.; Fasano, G.; Cava, A.; Couch, W.; Fritz, J.; Moles, M.

    We present the results of our X-shooter observations for a sample of dwarf (-17 < MB < -15) galaxies in nearby (0. 040 < z < 0. 068) galaxy clusters of the WINGS sample. The study of galaxies in this faint luminosity range is fundamental to trace the evolution of high-z star-forming cluster galaxies down to the present day. We measure the velocity dispersion of 22 galaxies in this range of luminosity and we explore their scaling relations. We found that the Fundamental Plane has a peculiar feature, suggesting the existence of some kind of warping at low luminosities.

  19. First results from the Faint Object Camera - Observations of PKS 0521 - 36

    NASA Technical Reports Server (NTRS)

    Macchetto, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

    1991-01-01

    The Faint Object Camera on the Hubble Space Telescope was used to observe the radio galaxy PKS 0521 - 36 which hosts a prominent radio jet. Images of the jet show spatial structure comparable to VLA data and significantly better than optical ground-based observations. The jet structure is resolved at FOC resolution. In addition to the radio knot, well resolved by the FOC, an extension of the jet toward the nucleus is apparent. The rest of the jet does not show much clumpiness, implying that the synchrotron electrons must be accelerated all along the jet to account for the extent in the optical region.

  20. In-flight performance of the Faint Object Camera of the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Greenfield, P.; Paresce, F.; Baxter, D.; Hodge, P.; Hook, R.; Jakobsen, P.; Jedrzejewski, R.; Nota, A.; Sparks, W. B.; Towers, N.

    1991-01-01

    An overview of the Faint Object Camera and its performance to date is presented. In particular, the detector's efficiency, the spatial uniformity of response, distortion characteristics, detector and sky background, detector linearity, spectrography, and operation are discussed. The effect of the severe spherical aberration of the telescope's primary mirror on the camera's point spread function is reviewed, as well as the impact it has on the camera's general performance. The scientific implications of the performance and the spherical aberration are outlined, with emphasis on possible remedies for spherical aberration, hardware remedies, and stellar population studies.

  1. Digital image profilers for detecting faint sources which have bright companions

    NASA Technical Reports Server (NTRS)

    Morris, Elena; Flint, Graham; Slavey, Robert

    1992-01-01

    For this program, an image profiling system was developed which offers the potential for detecting extremely faint optical sources that are located in close proximity to bright companions. The approach employed is novel in three respects. First, it does not require an optical system wherein extraordinary measures must be taken to minimize diffraction and scatter. Second, it does not require detectors possessing either extreme uniformity in sensitivity or extreme temporal stability. Finally, the system can readily be calibrated, or nulled, in space by testing against an unresolved singular stellar source.

  2. Application of digital image processing techniques to faint solar flare phenomena

    NASA Technical Reports Server (NTRS)

    Glackin, D. L.; Martin, S. F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature.

  3. The early faint sun paradox: Organic shielding of ultraviolet-labile greenhouse gases

    SciTech Connect

    Sagan, C.; Chyba, C.

    1997-05-23

    Atmospheric mixing ratios of {approximately}10{sup -5 {+-}1} for ammonia on the early Earth would have been sufficient, through the resulting greenhouse warming, to counteract the temperature effects of the faint early sun. One argument against such model atmospheres has been the short time scale for ammonia photodissociation by solar ultraviolet light. Here it is shown that ultraviolet absorption by steady-state amounts of high-altitude organic solids produced from methane photolysis may have shielded ammonia sufficiently that ammonia resupply rates were able to maintain surface temperatures above freezing. 78 refs., 2 figs., 1 tab.

  4. Faint-meteor survey with a large-format CMOS sensor

    NASA Astrophysics Data System (ADS)

    Watanabe, J.; Enomoto, T.; Terai, T.; Kasuga, T.; Miyazaki, S.; Oota, K.; Muraoka, F.; Onishi, T.; Yamasaki, T.; Mito, H.; Aoki, T.; Soyano, T.; Tarusawa, K.; Matsunaga, N.; Sako, S.; Kobayashi, N.; Doi, M.

    2014-07-01

    For observing faint meteors, we need a large telescope or similar optics, which always give a restriction of the field of view. It is a kind of trade-off between the high sensitivity by using larger telescope and narrower field of view. Reconciling this contradiction, we need a large-format imaging detector together with fast readout for meteor observations. A high-sensitivity CMOS sensor of the large format was developed by Canon Inc. in 2010[1]. Its size is 202 mm×205 mm which makes it the largest one-chip CMOS sensor in the world, and approximately 40 times the size of Canon's largest commercial CMOS sensor as shown in the figure. The number of pixel is 1280×1248. Because the increased size of the new CMOS sensor allows more light to be gathered, it enables shooting in low-light environments. The sensor makes image capture possible in one-hundredth the amount of light required by a 35 mm full-frame CMOS sensor, facilitating the shooting of 60 frame-per-second video with a mere 0.3 lux of illumination. We tried to use this large-format CMOS sensor attached to the prime focus of the 1.05-m (F3.1) Schmidt telescope at the Kiso Observatory, University of Tokyo, for surveying faint meteors. The field of view is 3.3 by 3.3 degrees. Test observations including operation check of the system were carried out in January 2011, September 2011,and December 2012. Images were obtained at a time resolution of 60 frames per second. In this system, the limiting magnitude is estimated to be about 11-12. Because of the limitation of the data storage, full-power observations (14-bit data per 1/60 second) were performed for about one or two hours each night. During the first period, we can count a sporadic meteor every 5 seconds. This is about one order higher detection rate of the faint meteors compared with the previous work[2]. Assuming the height of faint meteors at 100 km, the derived flux of the sporadic meteors is about 5 × 10^{-4} km^{-2} sec^{-1}. The last run was

  5. Faint (and bright) variable stars in the satellites of the Milky Way

    NASA Astrophysics Data System (ADS)

    Vivas, A. Katherina

    2017-09-01

    I describe two ongoing projects related with variable stars in the satellites of the MilkyWay. In the first project, we are searching for dwarf Cepheid stars (a.k.a δ Scuti and/or SX Phe) in some of the classical dwarf spheroidal galaxies. Our goal is to characterize the population of these variable stars under different environments (age, metallicity) in order to study their use as standard candles in systems for which the metallicity is not necessarily known. In the second project we search for RR Lyrae stars in the new ultra-faint satellite galaxies that have been discovered around the Milky Way in recent years.

  6. Astrometric and Photometric Follow-up of Faint Near Earth Objects

    NASA Technical Reports Server (NTRS)

    Morgan, T. (Technical Monitor); Spahr, Timothy

    2005-01-01

    During the period April 2003 - April 2005, roughly 150 different faint NEO's were observed using the 1.2-m telescope at Mt. Hopkins. Among these were a couple of spacecraft/radar targets, including support observations in support of the Deep Impact mission. While not strictly an NEO target, comet P/Tempel 1 was nonetheless observed as an object of very high importance. During this time and independent contractor, Kyle Smalley, was trained in the use of the telescope and provided some basic software support for the project.

  7. Alignment statistics of clusters with their brightest members at bright and faint isophotes

    SciTech Connect

    Struble, M.F.

    1987-06-01

    For a sample of 21 first-ranked cluster galaxies with published isophotal photometry and position angles of these isophotes, it is found that the major axes of both the bright and faint isophotal contours tend to be aligned within about 30 deg of the major axis of the parent cluster. This supports the hypothesis that first-ranked galaxies are formed already aligned with their parent clusters rather than the hypothesis that only outer envelopes which accreted after formation are aligned with the cluster. 21 references.

  8. Application of digital image processing techniques to faint solar flare phenomena

    NASA Technical Reports Server (NTRS)

    Glackin, D. L.; Martin, S. F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature.

  9. Infrared Faint Radio Sources in the Extended Chandra Deep Field South

    NASA Astrophysics Data System (ADS)

    Huynh, Minh T.

    2009-01-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey (ATLAS) which have no observable counterpart in the Spitzer Wide-area Infrared Extragalactic Survey (SWIRE). The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6 to 70 micron) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the SED of these objects shows that they are consistent with high redshift AGN (z > 2).

  10. Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

  11. Boo-1137—an Extremely Metal-Poor Star in the Ultra-Faint Dwarf Spheroidal Galaxy Boötes I

    NASA Astrophysics Data System (ADS)

    Norris, John E.; Yong, David; Gilmore, Gerard; Wyse, Rosemary F. G.

    2010-03-01

    We present high-resolution (R ~ 40,000), high-signal-to-noise ratio (20-90) spectra of an extremely metal-poor giant star Boo-1137 in the "ultra-faint" dwarf spheroidal galaxy (dSph) Boötes I, absolute magnitude M V ~ -6.3. We derive an iron abundance of [Fe/H] = -3.7, making this the most metal-poor star as yet identified in an ultra-faint dSph. Our derived effective temperature and gravity are consistent with its identification as a red giant in Boötes I. Abundances for a further 15 elements have also been determined. Comparison of the relative abundances, [X/Fe], with those of the extremely metal-poor red giants of the Galactic halo shows that Boo-1137 is "normal" with respect to C and N, the odd-Z elements Na and Al, the iron-peak elements, and the neutron-capture elements Sr and Ba, in comparison with the bulk of the Milky Way halo population having [Fe/H] lsim-3.0. The α-elements Mg, Si, Ca, and Ti are all higher by Δ[X/Fe] ~ 0.2 than the average halo values. Monte Carlo analysis indicates that Δ[α/Fe] values this large are expected with a probability ~0.02. The elemental abundance pattern in Boo-1137 suggests inhomogeneous chemical evolution, consistent with the wide internal spread in iron abundances we previously reported. The similarity of most of the Boo-1137 relative abundances with respect to halo values, and the fact that the α-elements are all offset by a similar small amount from the halo averages, points to the same underlying galaxy-scale stellar initial mass function, but that Boo-1137 likely originated in a star-forming region where the abundances reflect either poor mixing of supernova (SN) ejecta, or poor sampling of the SN progenitor mass range, or both. Observations obtained for ESO program P383.B-0038, using VLT-UT2/UVES.

  12. An XMM-Newton view of the young open cluster NGC 6231 - III. Optically faint X-ray sources

    NASA Astrophysics Data System (ADS)

    Sana, H.; Rauw, G.; Sung, H.; Gosset, E.; Vreux, J.-M.

    2007-05-01

    We discuss the properties of the X-ray sources with faint optical counterparts in the very young open cluster NGC 6231. From their positions in the Hertzsprung-Russell diagram, we find that the bulk of these objects probably consists of low-mass pre-main-sequence (PMS) stars with masses in the range 0.3-3.0 Msolar. The age distribution of these objects indicates that low-mass star formation in NGC 6231 started more than 10Myr ago and culminated in a starburst-like event about 1-4Myr ago when the bulk of the low-mass PMS stars as well as the massive cluster members formed. We find no evidence for a spatial age gradient that could point towards a sequential star formation process. Only a few X-ray sources have counterparts with a reddening exceeding the average value of the cluster or with infrared colours indicating the presence of a moderate near-IR excess. The X-ray spectra of the brightest PMS sources are best fitted by rather hard thermal plasma models and a significant fraction of these sources display flares in their light curve. The X-ray brightest flaring sources have decay times between 2 and 16ks. The X-ray selected PMS stars in NGC 6231 have logLX/Lbol values that increase strongly with decreasing bolometric luminosity and can reach a saturation level (logLX/Lbol ~ -2.4) for non-flaring sources and even more extreme values during flares. Based on observations with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and the USA (NASA). E-mail: hsana@eso.org ‡ FNRS Research Associate (Belgium).

  13. TURNING THE TIDES ON THE ULTRA-FAINT DWARF SPHEROIDAL GALAXIES: COMA BERENICES AND URSA MAJOR II

    SciTech Connect

    Munoz, Ricardo R.; Geha, Maria; Willman, Beth E-mail: marla.geha@yale.ed

    2010-07-15

    We present deep CFHT/MegaCam photometry of the ultra-faint Milky Way satellite galaxies: Coma Berenices (ComBer) and Ursa Major II (UMa II). These data extend to r {approx} 25, corresponding to 3 mag below the main-sequence turn-offs in these galaxies. We robustly calculate a total luminosity of M{sub V} = -3.8 {+-} 0.6 for ComBer and M{sub V} = -3.9 {+-} 0.5 for UMa II, in agreement with previous results and confirming that these galaxies are among the faintest of the known dwarf satellites of the Milky Way. ComBer shows a fairly regular morphology with no signs of active tidal stripping down to a surface brightness limit of 32.4 mag arcsec{sup -2}. Using a maximum likelihood analysis, we calculate the half-light radius of ComBer to be r{sub half} = 74 {+-} 4 pc (5.8 {+-} 0.'3) and its ellipticity {epsilon} = 0.36 {+-} 0.04. In contrast, UMa II shows signs of ongoing disruption. We map its morphology down to {mu}{sub V} = 32.6 mag arcsec{sup -2} and found that UMa II is larger than previously determined, extending at least {approx}600 pc (1.{sup 0}1 on the sky) and it is also quite elongated with an overall ellipticity of {epsilon} = 0.50 {+-} 0.2. However, our estimate for the half-light radius, 123 {+-} 3 pc (14.1 {+-} 0.'3) is similar to previous results. We discuss the implications of these findings in the context of potential indirect dark matter detections and galaxy formation. We conclude that while ComBer appears to be a stable dwarf galaxy, UMa II shows signs of ongoing tidal interaction.

  14. DISCOVERY OF A NEW PHOTOMETRIC SUB-CLASS OF FAINT AND FAST CLASSICAL NOVAE

    SciTech Connect

    Kasliwal, M. M.; Kulkarni, S. R.; Ofek, E. O.; Quimby, R.; Cenko, S. B.; Rau, A.

    2011-07-10

    We present photometric and spectroscopic follow-up of a sample of extragalactic novae discovered by the Palomar 60 inch telescope during a search for 'Fast Transients In Nearest Galaxies' (P60-FasTING). Designed as a fast cadence (1 day) and deep (g < 21 mag) survey, P60-FasTING was particularly sensitive to short-lived and faint optical transients. The P60-FasTING nova sample includes 10 novae in M 31, 6 in M 81, 3 in M 82, 1 in NGC 2403, and 1 in NGC 891. This significantly expands the known sample of extragalactic novae beyond the Local Group, including the first discoveries in a starburst environment. Surprisingly, our photometry shows that this sample is quite inconsistent with the canonical maximum-magnitude-rate-of-decline (MMRD) relation for classical novae. Furthermore, the spectra of the P60-FasTING sample are indistinguishable from classical novae. We suggest that we have uncovered a sub-class of faint and fast classical novae in a new phase space in luminosity-timescale of optical transients. Thus, novae span two orders of magnitude in both luminosity and time. Perhaps the MMRD, which is characterized only by the white dwarf mass, was an oversimplification. Nova physics appears to be characterized by a relatively rich four-dimensional parameter space in white dwarf mass, temperature, composition, and accretion rate.

  15. Discovery of a New Photometric Sub-class of Faint and Fast Classical Novae

    NASA Astrophysics Data System (ADS)

    Kasliwal, M. M.; Cenko, S. B.; Kulkarni, S. R.; Ofek, E. O.; Quimby, R.; Rau, A.

    2011-07-01

    We present photometric and spectroscopic follow-up of a sample of extragalactic novae discovered by the Palomar 60 inch telescope during a search for "Fast Transients In Nearest Galaxies" (P60-FasTING). Designed as a fast cadence (1 day) and deep (g < 21 mag) survey, P60-FasTING was particularly sensitive to short-lived and faint optical transients. The P60-FasTING nova sample includes 10 novae in M 31, 6 in M 81, 3 in M 82, 1 in NGC 2403, and 1 in NGC 891. This significantly expands the known sample of extragalactic novae beyond the Local Group, including the first discoveries in a starburst environment. Surprisingly, our photometry shows that this sample is quite inconsistent with the canonical maximum-magnitude-rate-of-decline (MMRD) relation for classical novae. Furthermore, the spectra of the P60-FasTING sample are indistinguishable from classical novae. We suggest that we have uncovered a sub-class of faint and fast classical novae in a new phase space in luminosity-timescale of optical transients. Thus, novae span two orders of magnitude in both luminosity and time. Perhaps the MMRD, which is characterized only by the white dwarf mass, was an oversimplification. Nova physics appears to be characterized by a relatively rich four-dimensional parameter space in white dwarf mass, temperature, composition, and accretion rate.

  16. THE DISCOVERY OF AN ULTRA-FAINT STAR CLUSTER IN THE CONSTELLATION OF URSA MINOR

    SciTech Connect

    Munoz, R. R.; Geha, M.; Vargas, L. C.; Cote, P.; Stetson, P.; Santana, F. A.; Simon, J. D.; Djorgovski, S. G.

    2012-07-01

    We report the discovery of a new ultra-faint globular cluster in the constellation of Ursa Minor, based on stellar photometry from the MegaCam imager at the Canada-France-Hawaii Telescope. We find that this cluster, Munoz 1, is located at a distance of 45 {+-} 5 kpc and at a projected distance of only 45' from the center of the Ursa Minor dwarf spheroidal galaxy. Using a maximum-likelihood technique we measure a half-light radius of 0.'5, or equivalently 7 pc, and an ellipticity consistent with being zero. We estimate its absolute magnitude to be M{sub V} -0.4 {+-} 0.9, which corresponds to L{sub V} = 120{sup +160}{sub -65} L{sub Sun} and we measure a heliocentric radial velocity of -137 {+-} 4 km s{sup -1} based on Keck/DEIMOS spectroscopy. This new satellite is separate from Ursa Minor by {approx}30 kpc and 110 km s{sup -1} suggesting the cluster is not obviously associated with the dSph, despite the very close angular separation. Based on its photometric properties and structural parameters we conclude that Munoz 1 is a new ultra-faint stellar cluster. Along with Segue 3 this is one of the faintest stellar clusters known to date.

  17. A multifrequency radio continuum and IRAS faint source survey of markarian galaxies

    NASA Technical Reports Server (NTRS)

    Bicay, M. D.; Kojoian, G.; Seal, J.; Dickinson, D. F.; Malkan, M. A.

    1995-01-01

    Results are presented from a multifrequency radio continumm survey of Markarian galaxies (MRKs) and are supplemented by IRAS infrared data from the Faint Source Survey. Radio data are presented for 899 MRKs observed at nu = 4.755 GHz with the National Radio Astronomy Observatory (NRAO)-Green Bank 300 foot (91 m) telescope, including nearly 88% of those objects in Markarian lists VI-XIV. In addition, 1.415 GHz measurements of 258 MRKs, over 30% of the MRKs accessible from the National Aeronomy and Ionosphere Center (NAIC)-Arecibo, are reported. Radio continuum observations of smaller numbers of MRKs were made at 10.63 GHz and at 23.1 GHz and are also presented. Infrared data from the IRAS Faint Source Survey (Ver. 2) are presented for 944 MRKs, with reasonably secure identifications extracted from the NASA/IPAC Extragalactic Database. MRKs exhibit the same canonical infrared characteristics as those reported for various other galaxy samples, that is well-known enhancement of the 25 micrometer/60 micrometer color ratio among Seyfert MRKs, and a clear tendency for MRKs with warmer 60 micrometer/100 micrometer colors to also possess cooler 12 micrometer/25 micrometer colors. In addition, non-Seyfert are found to obey the well-documented infrared/radio luminosity correlation, with the tightest correlation seen for starburst MRKs.

  18. A Study of the Emission Line Properties of Faint Field Galaxies

    NASA Astrophysics Data System (ADS)

    Gronwall, C.; Koo, D. C.

    1994-05-01

    Measurements of the equivalent width (EW) of [OII]lambda 3727 line in faint field galaxies have been used by some workers to claim that there is an increase in star-formation activity at z >= 0.1 which can only be explained by galaxies with short-lived bursts of star formation. Others maintain that there is currently no evidence for an increase in [OII] EW with redshift due to uncertainties in the local comparison samples and to a possible correlation of EW with absolute magnitude, such that low luminosity galaxies have larger EWs. We will present preliminary results based on the inclusion of nebular emission into the models of spectrophotometric evolution models of Bruzual & Charlot (1993, ApJ 405, 538). Kennicutt (1992, ApJ, 388, 310) has shown that there is a strong correlation between [OII] and Hα EWs. Thus, given the known star formation rates of our spectrophotometric evolution models as a function of time, we can calculate predicted [OII] EWs versus redshift, apparent magnitude, or color for galaxies with varying star formation histories. Incorporating such knowledge into our currently existing non-negative least squares fitting routines (Koo, Gronwall, & Bruzual 1993, ApJ, 415, L21), we will compute whether bursts of star formation are necessary to explain the observed [OII] EWs as well as the counts, colors, and redshifts of faint field galaxies.

  19. The ALHAMBRA survey: Discovery of a faint QSO at z = 5.41

    NASA Astrophysics Data System (ADS)

    Matute, I.; Masegosa, J.; Márquez, I.; Fernández-Soto, A.; Husillos, C.; del Olmo, A.; Perea, J.; Pović, M.; Ascaso, B.; Alfaro, E. J.; Moles, M.; Aguerri, J. A. L.; Aparicio-Villegas, T.; Benítez, N.; Broadhurst, T.; Cabrera-Cano, J.; Castander, F. J.; Cepa, J.; Cerviño, M.; Cristóbal-Hornillos, D.; Infante, L.; González Delgado, R. M.; Martínez, V. J.; Molino, A.; Prada, F.; Quintana, J. M.

    2013-09-01

    Aims: We aim to illustrate the potentiality of the Advanced Large, Homogeneous Area, Medium-Band Redshift Astronomical (ALHAMBRA) survey to investigate the high-redshift universe through the detection of quasi stellar objects (QSOs) at redshifts higher than 5. Methods: We searched for QSOs candidates at high redshift by fitting an extensive library of spectral energy distributions - including active and non-active galaxy templates, as well as stars - to the photometric database of the ALHAMBRA survey (composed of 20 optical medium-band plus the 3 broad-band JHKs near-infrared filters). Results: Our selection over ≈1 square degree of ALHAMBRA data (~1/4 of the total area covered by the survey), combined with GTC/OSIRIS spectroscopy, has yielded identification of an optically faint QSO at very high redshift (z = 5.41). The QSO has an absolute magnitude of ~-24 at the 1450 Å continuum, a bolometric luminosity of ≈2 × 1046 erg s-1, and an estimated black hole mass of ≈108 M⊙. This QSO adds itself to a reduced number of known UV faint sources at these redshifts. The preliminary derived space density is compatible with the most recent determinations of the high-z QSO luminosity functions. This new detection shows how ALHAMBRA, as well as forthcoming well-designed photometric surveys, can provide a wealth of information on the origin and early evolution of this kind of object.

  20. A multifrequency radio continuum and IRAS faint source survey of markarian galaxies

    NASA Technical Reports Server (NTRS)

    Bicay, M. D.; Kojoian, G.; Seal, J.; Dickinson, D. F.; Malkan, M. A.

    1995-01-01

    Results are presented from a multifrequency radio continumm survey of Markarian galaxies (MRKs) and are supplemented by IRAS infrared data from the Faint Source Survey. Radio data are presented for 899 MRKs observed at nu = 4.755 GHz with the National Radio Astronomy Observatory (NRAO)-Green Bank 300 foot (91 m) telescope, including nearly 88% of those objects in Markarian lists VI-XIV. In addition, 1.415 GHz measurements of 258 MRKs, over 30% of the MRKs accessible from the National Aeronomy and Ionosphere Center (NAIC)-Arecibo, are reported. Radio continuum observations of smaller numbers of MRKs were made at 10.63 GHz and at 23.1 GHz and are also presented. Infrared data from the IRAS Faint Source Survey (Ver. 2) are presented for 944 MRKs, with reasonably secure identifications extracted from the NASA/IPAC Extragalactic Database. MRKs exhibit the same canonical infrared characteristics as those reported for various other galaxy samples, that is well-known enhancement of the 25 micrometer/60 micrometer color ratio among Seyfert MRKs, and a clear tendency for MRKs with warmer 60 micrometer/100 micrometer colors to also possess cooler 12 micrometer/25 micrometer colors. In addition, non-Seyfert are found to obey the well-documented infrared/radio luminosity correlation, with the tightest correlation seen for starburst MRKs.

  1. The First Science Flight of the Faint Intergalactic medium Redshifted Emission Balloon (FIREBALL)

    NASA Astrophysics Data System (ADS)

    Martin, Christopher; Milliard, Bruno; Schiminovich, David; Tuttle, Sarah; Matuszewski, Matt; Rahman, Shahin; Evrard, Jean; Frank, Stephan; Deharveng, Jean-Michel; Peroux, Celine

    We have completed the second flight of the path-finding experiment, the Faint Intergalactic medium Redshifted Emission Balloon (FIREBALL), designed to discover and map faint emis-sion from the Intergalactic Medium (IGM). The second flight was fully successful, proving a fully functional fine pointing gondola with arcsec level capability, a 1 meter diameter (fixed) parabola primary telescope with planar sidereostat for pointing, a complete closed loop guide camera and control software, and a fiber fed UV integral field spectrograph feeding a spare GALEX Near UV detector. Three scientific targets were observed, and analysis of the data shows that the instrument performed as expected. The flux measurements obtained will be compared to models for IGM emission. We discuss future modifications to the payload that will achieve a 10-to 30-fold increase in sensitivity over science flight 1. We also discuss other instrument configurations that can utilize the 1-meter UV telescope and arcsecond pointing platform, and their corresponding science objectives. FIREBALL is a collaboration of NASA, Caltech, Columbia University, CNES, and Laboratorie Astrophysique Marseille, and is sup-ported by NASA, CNES, and CNRS.

  2. Analysis of a Close Pair of Faint Sources Near a Massive Young Star

    NASA Astrophysics Data System (ADS)

    Kamon, Saki; Kraus, Adam L.; Rizzuto, Aaron C.; Ireland, Michael; Carpenter, John M.

    2017-01-01

    Directly imaged exoplanets are rare but important, because they provide a rare glimpse at how planet interiors and atmospheres evolve over time via direct measurement of planetary luminosities and spectra. The details of individual planetary system architectures directly inform our understanding of planet formation and evolution. We present our findings from a high-resolution imaging survey of a nearby star-forming region that indicate the presence of a close pair of faint sources near a massive, A-type young star. From multiple epochs of AO imaging obtained with NIRC2, we test for association of each faint source with the host star via measurement of common proper motion. We also assess whether the sources are two planetary mass objects, or a more massive object obscured by an edge on disk. In the case of two planetary mass objects, we estimate the component masses from their luminosities and colors.We conclude by discussing possible future observations to further determine the nature of this complicated system.

  3. Star/galaxy separation at faint magnitudes: Application to a simulated Dark Energy Survey

    SciTech Connect

    Soumagnac, M.T.; et al.

    2013-06-21

    We address the problem of separating stars from galaxies in future large photometric surveys. We focus our analysis on simulations of the Dark Energy Survey (DES). In the first part of the paper, we derive the science requirements on star/galaxy separation, for measurement of the cosmological parameters with the Gravitational Weak Lensing and Large Scale Structure probes. These requirements are dictated by the need to control both the statistical and systematic errors on the cosmological parameters, and by Point Spread Function calibration. We formulate the requirements in terms of the completeness and purity provided by a given star/galaxy classifier. In order to achieve these requirements at faint magnitudes, we propose a new method for star/galaxy separation in the second part of the paper. We first use Principal Component Analysis to outline the correlations between the objects parameters and extract from it the most relevant information. We then use the reduced set of parameters as input to an Artificial Neural Network. This multi-parameter approach improves upon purely morphometric classifiers (such as the classifier implemented in SExtractor), especially at faint magnitudes: it increases the purity by up to 20% for stars and by up to 12% for galaxies, at i-magnitude fainter than 23.

  4. The Intensity Distribution of Faint Gamma-Ray Bursts Detected with BATSE

    NASA Technical Reports Server (NTRS)

    Kommers, Jefferson; Lewin, Walter H.; Kouveliotou, Chryssa; vanParadijs, Jan; Pendleton, Geoffrey N.; Meegan, Charles A.; Fishman, Gerald J.

    1998-01-01

    We have recently completed a search of 6 years of archival Burst and Transient Source Experiment (BATSE) data for gamma-ray bursts (GRBS) that were too faint to activate the real-time burst detection system running onboard the spacecraft. These "non-triggered" bursts can be combined with the "triggered" bursts detected onboard to produce a GRB intensity distribution that reaches peak fluxes a factor of approximately 2 lower than could be studied previously. The value of the (V/V(max)) statistic (in Euclidean space) for the bursts we detect is 0.177 +/- 0.006. This surprisingly low value is obtained because we detected very few bursts on the 4.096 s and 8.192 s time scales (where most bursts have their highest signal-to-noise ratio) that were not already detected on the 1.024 s time scale. If allowance is made for a power-law distribution of intrinsic peak luminosities, the extended peak flux distribution is consistent with models in which the redshift distribution of the gamma-ray burst rate approximately traces the star formation history of the Universe. We argue that this class of models is preferred over those in which the burst rate is independent of redshift. These results lend support to the conclusions of previous studies predicting that relatively few faint bursts are waiting to be found below the BATSE onboard detection threshold.

  5. Deadly Dark Matter Cusps versus Faint and Extended Star Clusters: Eridanus II and Andromeda XXV

    NASA Astrophysics Data System (ADS)

    Amorisco, Nicola C.

    2017-07-01

    The recent detection of two faint and extended star clusters in the central regions of two Local Group dwarf galaxies, Eridanus II and Andromeda XXV, raises the question of whether clusters with such low densities can survive the tidal field of cold dark matter halos with central density cusps. Using both analytic arguments and a suite of collisionless N-body simulations, I show that these clusters are extremely fragile and quickly disrupted in the presence of central cus