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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TL;DR: In this article, the authors present the results of a survey of 45 young (P250Myr), close (P50pc) stars with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT for direct detection of extrasolar planets.
Abstract: Wepresent theresultsof asurveyof 45young(P250Myr), close(P50pc) starswiththeSimultaneous Differential Imager (SDI) implemented at the VLT and the MMT for the direct detection of extrasolar planets. As part of the survey, we observed 54 objects, consisting of 45 close, young stars; two more distant ( 2 � which behaved consistently like a real object. From our survey null result,we can rule out (with 93% confidence) a model planet population where N(a) / constant out to a distance of 45 AU.
181 citations
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High Altitude Observatory1, University of Porto2, University of Sheffield3, Las Cumbres Observatory Global Telescope Network4, Space Telescope Science Institute5, Ames Research Center6, Search for extraterrestrial intelligence7, University of Toulouse8, INAF9, Spanish National Research Council10, University of Geneva11, Beijing Normal University12, Harvard University13, Indian Institute of Astrophysics14, Canadian Space Agency15, Los Alamos National Laboratory16, Pierre-and-Marie-Curie University17, Konkoly Thege Miklós Astronomical Institute18, Halifax19, University of Birmingham20, University of Sydney21, Hungarian Academy of Sciences22, Center for Turbulence Research23, University of Vienna24, European Southern Observatory25, University of Liège26, University of South Africa27, Kiepenheuer Institut für Sonnenphysik28, Paris Diderot University29, Max Planck Society30, Romanian Academy31, University of Colorado Boulder32, University of Oslo33
TL;DR: In this article, preliminary asteroseismic results from Kepler on three G-type stars are presented, made at one-minute cadence during the first 33.5 days of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: about 20 modes of oscillation may be clearly distinguished in each star.
Abstract: We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5 days of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: about 20 modes of oscillation may be clearly distinguished in each star. We discuss the appearance of the oscillation spectra, use the frequencies and frequency separations to provide first results on the radii, masses, and ages of the stars, and comment in the light of these results on prospects for inference on other solar-type stars that Kepler will observe.
181 citations
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TL;DR: In this article, an ultradeep optical spectroscopy obtained with FORS2 on VLT of seven Lyman break galaxy (LBG) candidates at z > 6:5 selected in the GOODS{S eld from Hawk{I/VLT and WFC3/HST imaging.
Abstract: We present ultradeep optical spectroscopy obtained with FORS2 on VLT of seven Lyman{break galaxy (LBG) candidates at z > 6:5 selected in the GOODS{S eld from Hawk{I/VLT and WFC3/HST imaging. For one galaxy we detect a low signicance emission line ( S=N 7), located at = 9691:5 0:5 A and with ux 3 :4 10 18 erg cm 2 s 1 . If identied as Ly , it places the LBG at redshift z = 6:972 0:002, with a rest{frame equivalent width EWrf = 13 A. Using Monte Carlo simulations and conservative EW distribution functions at 2 10 is’ 2%, and that of observing only one galaxy out of seven with S=N = 5 is’ 4%, but these can be as small as 10 3 , depending on the details of the EW distribution. We conclude that either a signicant fraction of the candidates is not at high redshift or that some physical mechanism quenches the Ly emission emerging from the galaxies at z > 6:5, abruptly reversing the trend of the increasing fraction of strong emitters with increasing redshift observed up to z 6:5. We discuss the possibility that an increasingly neutral intergalactic medium is responsible for such quenching. Subject headings: galaxies: distances and redshifts - galaxies: high-redshift - galaxies: formation
181 citations
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TL;DR: In this paper, the mass of the XMMU J2235 galaxy cluster has been characterized using Chandra data with high accuracy and the X-ray surface brightness profile can be traced out to 500 kpc.
Abstract: Context. The galaxy cluster XMMU J2235.3−2557 (hereafter XMM2235), spectroscopically confirmed at z = 1.39, is one of the most distant X-ray selected galaxy clusters. It has been at the center of a multi-wavelength observing campaign with ground and space facilities. Aims. We characterize the galaxy populations of passive members, the thermodynamical properties and metal abundance of the hot gas, and the total mass of the system using imaging data with HST/ACS (i775 and z850 bands) and VLT/ISAAC (J and KS bands), extensive spectroscopic data obtained with VLT/FORS2, and deep (196 ks) Chandra observations. Methods. Chandra data allow temperature and metallicity to be measured with good accuracy and the X-ray surface brightness profile to be traced out to 1 � (or 500 kpc), thus allowing the mass to be reliably estimated. Out of a total sample of 34 spectroscopically confirmed cluster members, we selected 16 passive galaxies (without detectable [OII]) within the central 2 � (or 1 Mpc) with ACS coverage, and inferred star formation histories for subsamples of galaxies inside and outside the core by modeling their spectrophotometric data with spectral synthesis models. Results. Chandra data show a regular elongated morphology, closely resembling the distribution of core galaxies, with a significant cool core. We measure a global X-ray temperature of kT = 8.6 +1.3 −1.2 keV (68% confidence), which we find to be robust against several systematics involved in the X-ray spectral analysis. By detecting the rest frame 6.7 keV Iron K line in the Chandra spectrum, we measure a metallicity Z = 0.26 +0.20 −0.16 Z� . In the likely hypothesis of hydrostatic equilibrium, we obtain a total mass of Mtot( 1, with a baryonic content, both its galaxy population and intracluster gas, in a significantly advanced evolutionary stage at 1/ 3o f the current age of the Universe.
180 citations
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University of Arizona1, Max Planck Society2, University of California, Santa Barbara3, University of California, Irvine4, European Southern Observatory5, Carnegie Learning6, California Institute of Technology7, Lawrence Berkeley National Laboratory8, INAF9, Massachusetts Institute of Technology10, Peking University11, University of Michigan12
TL;DR: In this paper, the authors reported the discovery of a luminous quasar at $z=7.642, J0313$-$1806, the most distant quasar yet known.
Abstract: Distant quasars are unique tracers to study the formation of the earliest supermassive black holes (SMBHs) and the history of cosmic reionization. Despite extensive efforts, only two quasars have been found at $z\ge7.5$, due to a combination of their low spatial density and the high contamination rate in quasar selection. We report the discovery of a luminous quasar at $z=7.642$, J0313$-$1806, the most distant quasar yet known. This quasar has a bolometric luminosity of $3.6\times10^{13} L_\odot$. Deep spectroscopic observations reveal a SMBH with a mass of $(1.6\pm0.4) \times10^9M_\odot$ in this quasar. The existence of such a massive SMBH just $\sim$670 million years after the Big Bang challenges significantly theoretical models of SMBH growth. In addition, the quasar spectrum exhibits strong broad absorption line (BAL) features in CIV and SiIV, with a maximum velocity close to 20% of the speed of light. The relativistic BAL features, combined with a strongly blueshifted CIV emission line, indicate that there is a strong active galactic nucleus (AGN) driven outflow in this system. ALMA observations detect the dust continuum and [CII] emission from the quasar host galaxy, yielding an accurate redshift of $7.6423 \pm 0.0013$ and suggesting that the quasar is hosted by an intensely star-forming galaxy, with a star formation rate of $\rm\sim 200 ~M_\odot ~yr^{-1}$ and a dust mass of $\sim7\times10^7~M_\odot$. Followup observations of this reionization-era BAL quasar will provide a powerful probe of the effects of AGN feedback on the growth of the earliest massive galaxies.
180 citations
Authors
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Name | H-index | Papers | Citations |
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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 |