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 paper, the first low-and intermediate-mass stars have been polluted by a no-no carbon-enhanced metal-poor (CEMP) environment. But the properties of CEMP stars are known to have properties that reflect the nucleosynthesis of the very first low and intermediate mass stars.
Abstract: Context. Carbon-enhanced metal-poor (CEMP) stars are known to have properties that reflect the nucleosynthesis of the first low- and intermediate-mass stars, because most have been polluted by a no ...
255 citations
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California Institute of Technology1, University of Massachusetts Amherst2, Smith College3, University of Georgia4, Space Science Institute5, Institut Universitaire de France6, University of Exeter7, European Space Agency8, Centre national de la recherche scientifique9, European Southern Observatory10, New Mexico State University11, University of California, Berkeley12, Search for extraterrestrial intelligence13, Harvard University14, Lowell Observatory15, California State University16, University of Toledo17, Villanova University18, Spanish National Research Council19, Centro de Investigaciones de Astronomia20, University of Hawaii at Hilo21, University of St Andrews22
TL;DR: In this article, the authors presented initial results from time-series imaging at infrared wavelengths of 0.9 deg^2 in the Orion Nebula Cluster (ONC) during Fall 2009 and obtained 81 epochs of Spitzer 3.6 and 4.5 μm data over 40 consecutive days.
Abstract: We present initial results from time-series imaging at infrared wavelengths of 0.9 deg^2 in the Orion Nebula Cluster (ONC). During Fall 2009 we obtained 81 epochs of Spitzer 3.6 and 4.5 μm data over 40 consecutive days. We extracted light curves with ~3% photometric accuracy for ~2000 ONC members ranging from several solar masses down to well below the hydrogen-burning mass limit. For many of the stars, we also have time-series photometry obtained at optical (I_c) and/or near-infrared (JK_s ) wavelengths. Our data set can be mined to determine stellar rotation periods, identify new pre-main-sequence eclipsing binaries, search for new substellar Orion members, and help better determine the frequency of circumstellar disks as a function of stellar mass in the ONC. Our primary focus is the unique ability of 3.6 and 4.5 μm variability information to improve our understanding of inner disk processes and structure in the Class I and II young stellar objects (YSOs). In this paper, we provide a brief overview of the YSOVAR Orion data obtained in Fall 2009 and highlight our light curves for AA-Tau analogs—YSOs with narrow dips in flux, most probably due to disk density structures passing through our line of sight. Detailed follow-up observations are needed in order to better quantify the nature of the obscuring bodies and what this implies for the structure of the inner disks of YSOs.
254 citations
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Max Planck Society1, Association of Universities for Research in Astronomy2, New Mexico State University3, University of California, Santa Cruz4, University of Hawaii5, European Southern Observatory6, University of Concepción7, University of Florida8, University of Michigan9, Case Western Reserve University10
TL;DR: In this article, the authors present a systematic and homogeneous analysis of population gradients for the Local Group dwarf spheroidal galaxies (dSph's) Carina, Sculptor, Sextans, Tucana, and Andromeda I-III, V, and VI.
Abstract: We present a systematic and homogeneous analysis of population gradients for the Local Group dwarf spheroidal galaxies (dSph's) Carina, Sculptor, Sextans, Tucana, and Andromeda I–III, V, and VI. For all of the Milky Way companions studied here, we find significant population gradients. The same is true for the remote dSph Tucana located at the outskirts of the Local Group. Among the M31 dSph companions, only Andromeda I and VI show obvious gradients. In all cases where a horizontal-branch (HB) morphology gradient is visible, the red HB stars are more centrally concentrated. The occurrence of a HB morphological gradient shows a correlation with a morphology gradient in the red giant branch. It seems likely that metallicity is the driver of the gradients in Sextans, Sculptor, Tucana, and Andromeda VI, while age is an important factor in Carina. We find no evidence that the vicinity of a nearby massive spiral galaxy influences the formation of the population gradients.
254 citations
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Max Planck Society1, Queen's University Belfast2, University of Ferrara3, European Southern Observatory4, Brera Astronomical Observatory5, University of Milan6, The Racah Institute of Physics7, University of Tokyo8, Institute for the Physics and Mathematics of the Universe9, Space Telescope Science Institute10
TL;DR: It is concluded that SN 2008D was originally a ∼30 times the mass of the Sun star, and when it collapsed, a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF.
Abstract: The only supernovae (SNe) to show gamma-ray bursts (GRBs) or early x-ray emission thus far are overenergetic, broad-lined type Ic SNe (hypernovae, HNe). Recently, SN 2008D has shown several unusual features: (i) weak x-ray flash (XRF), (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SN Ic HNe, and (iv) development of helium lines as in SNe Ib. Detailed analysis shows that SN 2008D was not a normal supernova: Its explosion energy (E approximately 6x10(51) erg) and ejected mass [ approximately 7 times the mass of the Sun (M(middle dot in circle))] are intermediate between normal SNe Ibc and HNe. We conclude that SN 2008D was originally a approximately 30 M(middle dot in circle) star. When it collapsed, a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.
254 citations
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TL;DR: In this paper, the early-time afterglow light curve carries information about 0, which determines the time of the peak of the gamma-ray burst (GRB) peak.
Abstract: Context. Gamma-ray burst (GRB) emission is believed to originate in highly relativistic fireballs. Aims. Currently, only lower limits were securely set to the initia l fireball Lorentz factor 0. We aim to provide a direct measure of 0. Methods. The early-time afterglow light curve carries information about 0, which determines the time of the afterglow peak. We have obtained early observations of the near-infrared afte rglows of GRB 060418 and GRB 060607A with the REM robotic telescope. Results. For both events, the afterglow peak could be clearly singled out, allowing a firm determination of the fireball Lorentz of 0∼ 400, fully confirming the highly relativistic nature of GRB fi reballs. The deceleration radius was inferred to be Rdec≈ 10 17 cm. This is much larger than the internal shocks radius (believed to power the prompt emission), thus providing further evidence for a different origin of the prompt and afterglow stages of the GRB.
253 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 |