Institution
European Southern Observatory
Facility•Garching bei München, Germany•
About: European Southern Observatory is a facility organization based out in Garching bei München, Germany. It is known for research contribution in the topics: Galaxy & Stars. The organization has 3594 authors who have published 16157 publications receiving 823095 citations. The organization is also known as: The European Southern Observatory,ESO & ESO.
Topics: Galaxy, Stars, Star formation, Redshift, Population
Papers published on a yearly basis
Papers
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INAF1, University of Colorado Boulder2, University College London3, University of Toulouse4, University of Toronto5, Liverpool John Moores University6, California Institute of Technology7, University of Calgary8, European Southern Observatory9, University of Provence10, University of Paris-Sud11, Paris Diderot University12, Katholieke Universiteit Leuven13, University of Bordeaux14, University of Exeter15, University of New South Wales16, University of Leeds17, Spanish National Research Council18, Sapienza University of Rome19, University of Rome Tor Vergata20, Nagoya University21, University of Manchester22, University of Paris23, Jet Propulsion Laboratory24, Cardiff University25, Chinese Academy of Sciences26, Laval University27, University of Helsinki28, Harvard University29, Max Planck Society30, University of Hertfordshire31, University of Cologne32, University of Kent33, Open University34
TL;DR: In this paper, the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key program that will map the inner Galactic plane of the Milky Way in 5 bands, were presented.
Abstract: We present the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key program that will map the inner Galactic plane of the Milky Way in 5 bands. We outline our data reduction strategy and present some science highlights on the two observed 2° × 2° tiles approximately centered at l = 30° and l = 59°. The two regions are extremely rich in intense and highly structured extended emission which shows a widespread organization in filaments. Source SEDs can be built for hundreds of objects in the two fields, and physical parameters can be extracted, for a good fraction of them where the distance could be estimated. The compact sources (which we will call cores' in the following) are found for the most part to be associated with the filaments, and the relationship to the local beam-averaged column density of the filament itself shows that a core seems to appear when a threshold around AV ~ 1 is exceeded for the regions in the l = 59° field; a AV value between 5 and 10 is found for the l = 30° field, likely due to the relatively higher distances of the sources. This outlines an exciting scenario where diffuse clouds first collapse into filaments, which later fragment to cores where the column density has reached a critical level. In spite of core L/M ratios being well in excess of a few for many sources, we find core surface densities between 0.03 and 0.5 g cm-2. Our results are in good agreement with recent MHD numerical simulations of filaments forming from large-scale converging flows.
752 citations
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Lund University1, European Space Agency2, Heidelberg University3, Dresden University of Technology4, Telespazio5, California Institute of Technology6, University of Geneva7, PSL Research University8, University of Porto9, INAF10, Institut de mécanique céleste et de calcul des éphémérides11, Centre national de la recherche scientifique12, University of Barcelona13, University of Edinburgh14, University of Padua15, Chinese Academy of Sciences16, Astrophysics Research Institute17, European Space Research and Technology Centre18, European Southern Observatory19, Altec Lansing20
TL;DR: Gaia Data Release 1 (Gaia DR1) as discussed by the authors contains a large amount of data collected by the Gaia satellite during the first 14 months of its operational phase, including positions, parallaxes, and proper motions to Hipparcos-type precision or better.
Abstract: Gaia Data Release 1 (Gaia DR1) contains astrometric results for more than 1 billion stars brighter than magnitude 20.7 based on observations collected by the Gaia satellite during the first 14 months of its operational phase. We give a brief overview of the astrometric content of the data release and of the model assumptions, data processing, and validation of the results. For stars in common with the Hipparcos and Tycho-2 catalogues, complete astrometric single-star solutions are obtained by incorporating positional information from the earlier catalogues. For other stars only their positions are obtained by neglecting their proper motions and parallaxes. The results are validated by an analysis of the residuals, through special validation runs, and by comparison with external data. Results. For about two million of the brighter stars (down to magnitude ~11.5) we obtain positions, parallaxes, and proper motions to Hipparcos-type precision or better. For these stars, systematic errors depending e.g. on position and colour are at a level of 0.3 milliarcsecond (mas). For the remaining stars we obtain positions at epoch J2015.0 accurate to ~10 mas. Positions and proper motions are given in a reference frame that is aligned with the International Celestial Reference Frame (ICRF) to better than 0.1 mas at epoch J2015.0, and non-rotating with respect to ICRF to within 0.03 mas/yr. The Hipparcos reference frame is found to rotate with respect to the Gaia DR1 frame at a rate of 0.24 mas/yr. Based on less than a quarter of the nominal mission length and on very provisional and incomplete calibrations, the quality and completeness of the astrometric data in Gaia DR1 are far from what is expected for the final mission products. The results nevertheless represent a huge improvement in the available fundamental stellar data and practical definition of the optical reference frame.
737 citations
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TL;DR: In this article, the authors presented deep VLT/NACO infrared imaging and spectroscopic observations of the brown dwarf 2MASSWJ 1207334−393254, obtained during the on-going adaptive optics survey of southern young, nearby associations.
Abstract: We present deep VLT/NACO infrared imaging and spectroscopic observations of the brown dwarf 2MASSWJ 1207334−393254, obtained during our on-going adaptive optics survey of southern young, nearby associations. This ∼25 MJup brown dwarf, located ∼70 pc from Earth, has been recently identified as a member of the TW Hydrae Association (age ∼ 8 Myr). Using adaptive optics infrared wavefront sensing to acquire sharp images of its circumstellar environment, we discovered a very faint and very red object at a close separation of ∼780 mas (∼55 AU). Photometry in the H, Ks and Lbands and upper limit in J-band are compatible with a spectral type L5−L9.5. Near-infrared spectroscopy is consistent with this spec- tral type estimate. Different evolutionary models predict an object within the planetary regime with a mass of M = 5 ± 2 MJup and an effective temperature of Teff = 1250 ± 200 K.
724 citations
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University of Bologna1, University of Barcelona2, INAF3, University of Edinburgh4, Centre national de la recherche scientifique5, University of Toulouse6, European Southern Observatory7, California Institute of Technology8, ETH Zurich9, Max Planck Society10, Paris Diderot University11, University of Vienna12, Spanish National Research Council13, University of Insubria14, Institute for the Physics and Mathematics of the Universe15, University of Nottingham16, National Taiwan Normal University17, Johns Hopkins University18, Space Telescope Science Institute19, Institut d'Astrophysique de Paris20, University of California, Santa Cruz21, Lawrence Livermore National Laboratory22, University of California, Davis23
TL;DR: In this paper, the authors presented new improved constraints on the Hubble parameter H(z) in the redshift range 0.15 -1.1, obtained from the differential spectroscopic evolution of early-type galaxies as a function of redshift.
Abstract: We present new improved constraints on the Hubble parameter H(z) in the redshift range 0.15 \textless z \textless 1.1, obtained from the differential spectroscopic evolution of early-type galaxies as a function of redshift. We extract a large sample of early-type galaxies ( 11000) from several spectroscopic surveys, spanning almost 8 billion years of cosmic lookback time (0.15 \textless z \textless 1.42). We select the most massive, red elliptical galaxies, passively evolving and without signature of ongoing star formation. Those galaxies can be used as standard cosmic chronometers, as firstly proposed by Jimenez & Loeb (2002), whose (life! Nit age evolution as a function of cosmic time directly probes H (z). We analyze the 4000 angstrom break (D4000) as a function of redshift, use stellar population synthesis models to theoretically calibrate the dependence of the differential age evolution on the differential D4000, and estimate the Hubble parameter taking into account both statistical and systematical errors. We provide 8 new measurements of H(z) (see table 4), and determine its change in H(z) to a precision of 5-12% mapping homogeneously the redshift range up to z 1.1; for the first time, we place a constraint on 11(z) at z not equal 0 with a precision comparable with the one achieved for the Hubble constant (about 5-6% at z similar to 0.2), and covered a redshift range (0.5 \textless z \textless 0.8) which is crucial to distinguish many different quintessence cosmologies. These measurements have been tested to best match a ACDM model, clearly providing a statistically robust indication that the Universe is undergoing an accelerated expansion. This method shows the potentiality to open a new avenue in constrain a variety of alternative cosmologies, especially when future surveys (e.g. Euclid) will open the possibility to extend it up to z similar to 2.
724 citations
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European Southern Observatory1, Yale University2, Leiden University3, Max Planck Society4, Harvard University5, University of Wisconsin–Milwaukee6, University of Arizona7, University of California, Santa Cruz8, Tufts University9, Carnegie Learning10, California Institute of Technology11, University of Wisconsin-Madison12
TL;DR: 3D-HST as discussed by the authors is a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe.
Abstract: We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying
the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for
a sample of ∼7000 galaxies at 1 < z < 3.5, the epoch when ∼60% of all star formation took place, the number
density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in
galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin^2) of the CANDELS Treasury
survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L
grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of ∼5 per resolution element
at H_140 ∼ 23.1 and a 5σ emission-line sensitivity of ∼5 × 10^(−17) erg s^−1 cm^(−2) for typical objects, improving by
a factor of ∼2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide
continuous wavelength coverage from 1.1 to 1.6μm at a spatial resolution of ∼0."13, which, combined with their
depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary
reduction and analysis of the grism observations, including emission-line and redshift measurements from combined
fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis
yields redshift estimates with a precision of σ(z) = 0.0034(1 + z), or σ(v) ≈ 1000 km s^(−1). We illustrate how
the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types
of objects, including a quasar at z = 4.7, quiescent galaxies at z ∼ 2, and the most distant T-type brown dwarf
star known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and
spectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space Telescope.
723 citations
Authors
Showing all 3617 results
Name | H-index | Papers | Citations |
---|---|---|---|
Robert C. Nichol | 187 | 851 | 162994 |
Richard S. Ellis | 169 | 882 | 136011 |
Rob Ivison | 166 | 1161 | 102314 |
Alvio Renzini | 162 | 908 | 95452 |
Timothy C. Beers | 156 | 934 | 102581 |
Krzysztof M. Gorski | 132 | 380 | 105912 |
Emanuele Daddi | 129 | 581 | 63187 |
P. R. Christensen | 127 | 313 | 88445 |
Mark Dickinson | 124 | 389 | 66770 |
Christopher W. Stubbs | 122 | 622 | 109429 |
Eva K. Grebel | 118 | 863 | 83915 |
Martin Asplund | 118 | 612 | 52527 |
Jesper Sollerman | 118 | 726 | 53436 |
E. F. van Dishoeck | 115 | 742 | 49190 |
Jørgen Christensen-Dalsgaard | 114 | 585 | 48272 |