OBSERVATIONAL PROPERTIES OF THE METAL-POOR THICK DISK OF THE MILKY WAY AND INSIGHTS INTO ITS ORIGINS
Identifieur interne : 006884 ( Main/Exploration ); précédent : 006883; suivant : 006885OBSERVATIONAL PROPERTIES OF THE METAL-POOR THICK DISK OF THE MILKY WAY AND INSIGHTS INTO ITS ORIGINS
Auteurs : Gregory R. Ruchti [États-Unis] ; Jon P. Fulbright [États-Unis] ; Rosemary F. G. Wyse [États-Unis] ; Gerard F. Gilmore [Royaume-Uni] ; Olivier Bienayme [France] ; Joss Bland-Hawthorn [Australie] ; Brad K. Gibson [Royaume-Uni] ; Eva K. Grebel [Allemagne] ; Amina Helmi [Pays-Bas] ; Ulisse Munari [Italie] ; Juho F. Navarro [Canada] ; Quentin A. Parker [Australie] ; Warren Reid [Australie] ; George M. Seabroke [Royaume-Uni] ; Arnaud Siebert [France] ; Alessandro Siviero [Italie, Allemagne] ; Matthias Steinmetz [Allemagne] ; Fred G. Watson [Australie] ; Mary Williams [Allemagne] ; Tomaz Zwitter [Slovénie]Source :
- The Astrophysical journal [ 0004-637X ] ; 2011.
Descripteurs français
- Pascal (Inist)
- Voie lactée, Abondance élément, Cinématique, Vitesse radiale, Etoile brillante, Géante rouge, Etoile pauvre en métal, Etoile géante, Gradient radial, Gradient vertical, Excentricité, Modèle, Galaxies naines, Accrétion stellaire, Etoile naine, Déplacement vers le rouge, Galaxies disques, Abondance stellaire, Etoile type avancé.
English descriptors
- KwdEn :
Abstract
We have undertaken the study of the elemental abundances and kinematic properties of a metal-poor sample of candidate thick-disk stars selected from the Radial Velocity Experiment spectroscopic survey of bright stars to differentiate among the present scenarios of the formation of the thick disk. In this paper, we report on a sample of 214 red giant branch, 31 red clump/horizontal branch, and 74 main-sequence/sub-giant branch metal-poor stars, which serves to augment our previous sample of only giant stars. We find that the thick disk [α/Fe] ratios are enhanced and have little variation (<0.1 dex), in agreement with our previous study. The augmented sample further allows, for the first time, investigation of the gradients in the metal-poor thick disk. For stars with [Fe/H] < -1.2, the thick disk shows very small gradients, <0.03 ± 0.02 dex kpc-1, in α-enhancement, while we find a +0.01 ± 0.04 dex kpc-1 radial gradient and a -0.09 ± 0.05 dex kpc-1 vertical gradient in iron abundance. In addition, we show that the peak of the distribution of orbital eccentricities for our sample agrees better with models in which the stars that comprise the thick disk were formed primarily in the Galaxy, with direct accretion of stars contributing little. Our results thus disfavor direct accretion of stars from dwarf galaxies into the thick disk as a major contributor to the thick-disk population, but cannot discriminate between alternative models for the thick disk, such as those that invoke high-redshift (gas-rich) mergers, heating of a pre-existing thin stellar disk by a minor merger, or efficient radial migration of stars.
Affiliations:
- Allemagne, Australie, Canada, France, Italie, Pays-Bas, Royaume-Uni, Slovénie, États-Unis
- Alsace (région administrative), Angleterre, Angleterre de l'Est, Bade-Wurtemberg, District de Karlsruhe, Grand Est, Grand Londres, Groningue (province), Nouvelle-Galles du Sud
- Cambridge, Groningue (ville), Heidelberg, Londres, Strasbourg, Sydney
- University College de Londres, Université de Cambridge, Université de Groningue, Université de Sydney
Links toward previous steps (curation, corpus...)
- to stream PascalFrancis, to step Corpus: 001A56
- to stream PascalFrancis, to step Curation: 004488
- to stream PascalFrancis, to step Checkpoint: 001852
- to stream Main, to step Merge: 006D03
- to stream Main, to step Curation: 006884
Le document en format XML
<record><TEI><teiHeader><fileDesc><titleStmt><title xml:lang="en" level="a">OBSERVATIONAL PROPERTIES OF THE METAL-POOR THICK DISK OF THE MILKY WAY AND INSIGHTS INTO ITS ORIGINS</title><author><name sortKey="Ruchti, Gregory R" sort="Ruchti, Gregory R" uniqKey="Ruchti G" first="Gregory R." last="Ruchti">Gregory R. Ruchti</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Bloomberg Center for Physics & Astronomy, Johns Hopkins University, 3400 North Charles Street</s1><s2>Baltimore, MD 21218</s2><s3>USA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ><sZ>3 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>Baltimore, MD 21218</wicri:noRegion></affiliation></author><author><name sortKey="Fulbright, Jon P" sort="Fulbright, Jon P" uniqKey="Fulbright J" first="Jon P." last="Fulbright">Jon P. Fulbright</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Bloomberg Center for Physics & Astronomy, Johns Hopkins University, 3400 North Charles Street</s1><s2>Baltimore, MD 21218</s2><s3>USA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ><sZ>3 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>Baltimore, MD 21218</wicri:noRegion></affiliation></author><author><name sortKey="Wyse, Rosemary F G" sort="Wyse, Rosemary F G" uniqKey="Wyse R" first="Rosemary F. G." last="Wyse">Rosemary F. G. Wyse</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Bloomberg Center for Physics & Astronomy, Johns Hopkins University, 3400 North Charles Street</s1><s2>Baltimore, MD 21218</s2><s3>USA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ><sZ>3 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>Baltimore, MD 21218</wicri:noRegion></affiliation></author><author><name sortKey="Gilmore, Gerard F" sort="Gilmore, Gerard F" uniqKey="Gilmore G" first="Gerard F." last="Gilmore">Gerard F. Gilmore</name><affiliation wicri:level="4"><inist:fA14 i1="02"><s1>Institute of Astronomy, University of Cambridge, Madingley Road</s1><s2>Cambridge CB3 0HA</s2><s3>GBR</s3><sZ>4 aut.</sZ></inist:fA14><country>Royaume-Uni</country><wicri:noRegion>Cambridge CB3 0HA</wicri:noRegion><orgName type="university">Université de Cambridge</orgName><placeName><settlement type="city">Cambridge</settlement><region type="country">Angleterre</region><region type="région" nuts="1">Angleterre de l'Est</region></placeName></affiliation></author><author><name sortKey="Bienayme, Olivier" sort="Bienayme, Olivier" uniqKey="Bienayme O" first="Olivier" last="Bienayme">Olivier Bienayme</name><affiliation wicri:level="3"><inist:fA14 i1="03"><s1>Observatoire de Strasbourg, 11 Rue de L'Université</s1><s2>67000 Strasbourg</s2><s3>FRA</s3><sZ>5 aut.</sZ><sZ>15 aut.</sZ></inist:fA14><country>France</country><placeName><region type="region" nuts="2">Grand Est</region><region type="old region" nuts="2">Alsace (région administrative)</region><settlement type="city">Strasbourg</settlement></placeName></affiliation></author><author><name sortKey="Bland Hawthorn, Joss" sort="Bland Hawthorn, Joss" uniqKey="Bland Hawthorn J" first="Joss" last="Bland-Hawthorn">Joss Bland-Hawthorn</name><affiliation wicri:level="4"><inist:fA14 i1="04"><s1>Sydney Institute for Astronomy, School of Physics A28, University of Sydney</s1><s2>NSW 2006</s2><s3>AUS</s3><sZ>6 aut.</sZ></inist:fA14><country>Australie</country><placeName><settlement type="city">Sydney</settlement><region type="état">Nouvelle-Galles du Sud</region></placeName><orgName type="university">Université de Sydney</orgName></affiliation></author><author><name sortKey="Gibson, Brad K" sort="Gibson, Brad K" uniqKey="Gibson B" first="Brad K." last="Gibson">Brad K. Gibson</name><affiliation wicri:level="1"><inist:fA14 i1="05"><s1>Jeremiah Horrocks Institute for Astrophysics & Super-computing, University of Central Lancashire</s1><s2>Preston PR1 2HE</s2><s3>GBR</s3><sZ>7 aut.</sZ></inist:fA14><country>Royaume-Uni</country><wicri:noRegion>Preston PR1 2HE</wicri:noRegion></affiliation></author><author><name sortKey="Grebel, Eva K" sort="Grebel, Eva K" uniqKey="Grebel E" first="Eva K." last="Grebel">Eva K. Grebel</name><affiliation wicri:level="3"><inist:fA14 i1="06"><s1>Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14</s1><s2>69120 Heidelberg</s2><s3>DEU</s3><sZ>8 aut.</sZ></inist:fA14><country>Allemagne</country><placeName><region type="land" nuts="1">Bade-Wurtemberg</region><region type="district" nuts="2">District de Karlsruhe</region><settlement type="city">Heidelberg</settlement></placeName></affiliation></author><author><name sortKey="Helmi, Amina" sort="Helmi, Amina" uniqKey="Helmi A" first="Amina" last="Helmi">Amina Helmi</name><affiliation wicri:level="4"><inist:fA14 i1="07"><s1>Kapteyn Astronomical Institute, University of Groningen, Postbus 800</s1><s2>9700 AV Groningen</s2><s3>NLD</s3><sZ>9 aut.</sZ></inist:fA14><country>Pays-Bas</country><wicri:noRegion>9700 AV Groningen</wicri:noRegion><orgName type="university">Université de Groningue</orgName><placeName><settlement type="city">Groningue (ville)</settlement><region>Groningue (province)</region></placeName></affiliation></author><author><name sortKey="Munari, Ulisse" sort="Munari, Ulisse" uniqKey="Munari U" first="Ulisse" last="Munari">Ulisse Munari</name><affiliation wicri:level="1"><inist:fA14 i1="08"><s1>INAF Osservatorio Astronomico di Padova, Via dell'Osservatorio 8</s1><s2>Asiago 36012</s2><s3>ITA</s3><sZ>10 aut.</sZ></inist:fA14><country>Italie</country><wicri:noRegion>Asiago 36012</wicri:noRegion></affiliation></author><author><name sortKey="Navarro, Juho F" sort="Navarro, Juho F" uniqKey="Navarro J" first="Juho F." last="Navarro">Juho F. Navarro</name><affiliation wicri:level="1"><inist:fA14 i1="09"><s1>Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Station CSC</s1><s2>Victoria, BC V8W 3P6</s2><s3>CAN</s3><sZ>11 aut.</sZ></inist:fA14><country>Canada</country><wicri:noRegion>Victoria, BC V8W 3P6</wicri:noRegion></affiliation></author><author><name sortKey="Parker, Quentin A" sort="Parker, Quentin A" uniqKey="Parker Q" first="Quentin A." last="Parker">Quentin A. Parker</name><affiliation wicri:level="1"><inist:fA14 i1="10"><s1>Department of Physics and Astronomy, Macquarie University</s1><s2>Sydney, NSW 2109</s2><s3>AUS</s3><sZ>12 aut.</sZ><sZ>13 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Sydney, NSW 2109</wicri:noRegion></affiliation></author><author><name sortKey="Reid, Warren" sort="Reid, Warren" uniqKey="Reid W" first="Warren" last="Reid">Warren Reid</name><affiliation wicri:level="1"><inist:fA14 i1="10"><s1>Department of Physics and Astronomy, Macquarie University</s1><s2>Sydney, NSW 2109</s2><s3>AUS</s3><sZ>12 aut.</sZ><sZ>13 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Sydney, NSW 2109</wicri:noRegion></affiliation></author><author><name sortKey="Seabroke, George M" sort="Seabroke, George M" uniqKey="Seabroke G" first="George M." last="Seabroke">George M. Seabroke</name><affiliation wicri:level="4"><inist:fA14 i1="11"><s1>Mullard Space Science Laboratory, University College London, Holmbury St. Mary</s1><s2>Dorking RH5 6NT</s2><s3>GBR</s3><sZ>14 aut.</sZ></inist:fA14><country>Royaume-Uni</country><wicri:noRegion>Dorking RH5 6NT</wicri:noRegion><orgName type="university">University College de Londres</orgName><placeName><settlement type="city">Londres</settlement><region type="country">Angleterre</region><region type="région" nuts="1">Grand Londres</region></placeName></affiliation></author><author><name sortKey="Siebert, Arnaud" sort="Siebert, Arnaud" uniqKey="Siebert A" first="Arnaud" last="Siebert">Arnaud Siebert</name><affiliation wicri:level="3"><inist:fA14 i1="03"><s1>Observatoire de Strasbourg, 11 Rue de L'Université</s1><s2>67000 Strasbourg</s2><s3>FRA</s3><sZ>5 aut.</sZ><sZ>15 aut.</sZ></inist:fA14><country>France</country><placeName><region type="region" nuts="2">Grand Est</region><region type="old region" nuts="2">Alsace (région administrative)</region><settlement type="city">Strasbourg</settlement></placeName></affiliation></author><author><name sortKey="Siviero, Alessandro" sort="Siviero, Alessandro" uniqKey="Siviero A" first="Alessandro" last="Siviero">Alessandro Siviero</name><affiliation wicri:level="1"><inist:fA14 i1="12"><s1>Department of Astronomy, Padova University, Vicolo dell'Osservatorio 2</s1><s2>Padova 35122</s2><s3>ITA</s3><sZ>16 aut.</sZ></inist:fA14><country>Italie</country><wicri:noRegion>Padova 35122</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="13"><s1>Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16</s1><s2>14482 Potsdam</s2><s3>DEU</s3><sZ>16 aut.</sZ><sZ>17 aut.</sZ><sZ>19 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>14482 Potsdam</wicri:noRegion><wicri:noRegion>An der Sternwarte 16</wicri:noRegion><wicri:noRegion>14482 Potsdam</wicri:noRegion></affiliation></author><author><name sortKey="Steinmetz, Matthias" sort="Steinmetz, Matthias" uniqKey="Steinmetz M" first="Matthias" last="Steinmetz">Matthias Steinmetz</name><affiliation wicri:level="1"><inist:fA14 i1="13"><s1>Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16</s1><s2>14482 Potsdam</s2><s3>DEU</s3><sZ>16 aut.</sZ><sZ>17 aut.</sZ><sZ>19 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>14482 Potsdam</wicri:noRegion><wicri:noRegion>An der Sternwarte 16</wicri:noRegion><wicri:noRegion>14482 Potsdam</wicri:noRegion></affiliation></author><author><name sortKey="Watson, Fred G" sort="Watson, Fred G" uniqKey="Watson F" first="Fred G." last="Watson">Fred G. Watson</name><affiliation wicri:level="1"><inist:fA14 i1="14"><s1>Australian Astronomical Observatory</s1><s2>Coonabarabran, NSW 2357</s2><s3>AUS</s3><sZ>18 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Australian Astronomical Observatory</wicri:noRegion></affiliation></author><author><name sortKey="Williams, Mary" sort="Williams, Mary" uniqKey="Williams M" first="Mary" last="Williams">Mary Williams</name><affiliation wicri:level="1"><inist:fA14 i1="13"><s1>Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16</s1><s2>14482 Potsdam</s2><s3>DEU</s3><sZ>16 aut.</sZ><sZ>17 aut.</sZ><sZ>19 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>14482 Potsdam</wicri:noRegion><wicri:noRegion>An der Sternwarte 16</wicri:noRegion><wicri:noRegion>14482 Potsdam</wicri:noRegion></affiliation></author><author><name sortKey="Zwitter, Tomaz" sort="Zwitter, Tomaz" uniqKey="Zwitter T" first="Tomaz" last="Zwitter">Tomaz Zwitter</name><affiliation wicri:level="1"><inist:fA14 i1="15"><s1>Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19</s1><s2>Ljubljana</s2><s3>SVN</s3><sZ>20 aut.</sZ></inist:fA14><country>Slovénie</country><wicri:noRegion>Ljubljana</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="16"><s1>Center of Excellence SPACE-SI</s1><s2>Ljubljana</s2><s3>SVN</s3><sZ>20 aut.</sZ></inist:fA14><country>Slovénie</country><wicri:noRegion>Center of Excellence SPACE-SI</wicri:noRegion></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">INIST</idno><idno type="inist">11-0364527</idno><date when="2011">2011</date><idno type="stanalyst">PASCAL 11-0364527 INIST</idno><idno type="RBID">Pascal:11-0364527</idno><idno type="wicri:Area/PascalFrancis/Corpus">001A56</idno><idno type="wicri:Area/PascalFrancis/Curation">004488</idno><idno type="wicri:Area/PascalFrancis/Checkpoint">001852</idno><idno type="wicri:explorRef" wicri:stream="PascalFrancis" wicri:step="Checkpoint">001852</idno><idno type="wicri:doubleKey">0004-637X:2011:Ruchti G:observational:properties:of</idno><idno type="wicri:Area/Main/Merge">006D03</idno><idno type="wicri:Area/Main/Curation">006884</idno><idno type="wicri:Area/Main/Exploration">006884</idno></publicationStmt><sourceDesc><biblStruct><analytic><title xml:lang="en" level="a">OBSERVATIONAL PROPERTIES OF THE METAL-POOR THICK DISK OF THE MILKY WAY AND INSIGHTS INTO ITS ORIGINS</title><author><name sortKey="Ruchti, Gregory R" sort="Ruchti, Gregory R" uniqKey="Ruchti G" first="Gregory R." last="Ruchti">Gregory R. Ruchti</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Bloomberg Center for Physics & Astronomy, Johns Hopkins University, 3400 North Charles Street</s1><s2>Baltimore, MD 21218</s2><s3>USA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ><sZ>3 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>Baltimore, MD 21218</wicri:noRegion></affiliation></author><author><name sortKey="Fulbright, Jon P" sort="Fulbright, Jon P" uniqKey="Fulbright J" first="Jon P." last="Fulbright">Jon P. Fulbright</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Bloomberg Center for Physics & Astronomy, Johns Hopkins University, 3400 North Charles Street</s1><s2>Baltimore, MD 21218</s2><s3>USA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ><sZ>3 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>Baltimore, MD 21218</wicri:noRegion></affiliation></author><author><name sortKey="Wyse, Rosemary F G" sort="Wyse, Rosemary F G" uniqKey="Wyse R" first="Rosemary F. G." last="Wyse">Rosemary F. G. Wyse</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Bloomberg Center for Physics & Astronomy, Johns Hopkins University, 3400 North Charles Street</s1><s2>Baltimore, MD 21218</s2><s3>USA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ><sZ>3 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>Baltimore, MD 21218</wicri:noRegion></affiliation></author><author><name sortKey="Gilmore, Gerard F" sort="Gilmore, Gerard F" uniqKey="Gilmore G" first="Gerard F." last="Gilmore">Gerard F. Gilmore</name><affiliation wicri:level="4"><inist:fA14 i1="02"><s1>Institute of Astronomy, University of Cambridge, Madingley Road</s1><s2>Cambridge CB3 0HA</s2><s3>GBR</s3><sZ>4 aut.</sZ></inist:fA14><country>Royaume-Uni</country><wicri:noRegion>Cambridge CB3 0HA</wicri:noRegion><orgName type="university">Université de Cambridge</orgName><placeName><settlement type="city">Cambridge</settlement><region type="country">Angleterre</region><region type="région" nuts="1">Angleterre de l'Est</region></placeName></affiliation></author><author><name sortKey="Bienayme, Olivier" sort="Bienayme, Olivier" uniqKey="Bienayme O" first="Olivier" last="Bienayme">Olivier Bienayme</name><affiliation wicri:level="1"><inist:fA14 i1="03"><s1>Observatoire de Strasbourg, 11 Rue de L'Université</s1><s2>67000 Strasbourg</s2><s3>FRA</s3><sZ>5 aut.</sZ><sZ>15 aut.</sZ></inist:fA14><country>France</country><wicri:noRegion>67000 Strasbourg</wicri:noRegion><placeName><settlement type="city">Strasbourg</settlement><region type="region" nuts="2">Grand Est</region><region type="old region" nuts="2">Alsace (région administrative)</region></placeName></affiliation></author><author><name sortKey="Bland Hawthorn, Joss" sort="Bland Hawthorn, Joss" uniqKey="Bland Hawthorn J" first="Joss" last="Bland-Hawthorn">Joss Bland-Hawthorn</name><affiliation wicri:level="4"><inist:fA14 i1="04"><s1>Sydney Institute for Astronomy, School of Physics A28, University of Sydney</s1><s2>NSW 2006</s2><s3>AUS</s3><sZ>6 aut.</sZ></inist:fA14><country>Australie</country><placeName><settlement type="city">Sydney</settlement><region type="état">Nouvelle-Galles du Sud</region></placeName><orgName type="university">Université de Sydney</orgName></affiliation></author><author><name sortKey="Gibson, Brad K" sort="Gibson, Brad K" uniqKey="Gibson B" first="Brad K." last="Gibson">Brad K. Gibson</name><affiliation wicri:level="1"><inist:fA14 i1="05"><s1>Jeremiah Horrocks Institute for Astrophysics & Super-computing, University of Central Lancashire</s1><s2>Preston PR1 2HE</s2><s3>GBR</s3><sZ>7 aut.</sZ></inist:fA14><country>Royaume-Uni</country><wicri:noRegion>Preston PR1 2HE</wicri:noRegion></affiliation></author><author><name sortKey="Grebel, Eva K" sort="Grebel, Eva K" uniqKey="Grebel E" first="Eva K." last="Grebel">Eva K. Grebel</name><affiliation wicri:level="3"><inist:fA14 i1="06"><s1>Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14</s1><s2>69120 Heidelberg</s2><s3>DEU</s3><sZ>8 aut.</sZ></inist:fA14><country>Allemagne</country><placeName><region type="land" nuts="1">Bade-Wurtemberg</region><region type="district" nuts="2">District de Karlsruhe</region><settlement type="city">Heidelberg</settlement></placeName></affiliation></author><author><name sortKey="Helmi, Amina" sort="Helmi, Amina" uniqKey="Helmi A" first="Amina" last="Helmi">Amina Helmi</name><affiliation wicri:level="4"><inist:fA14 i1="07"><s1>Kapteyn Astronomical Institute, University of Groningen, Postbus 800</s1><s2>9700 AV Groningen</s2><s3>NLD</s3><sZ>9 aut.</sZ></inist:fA14><country>Pays-Bas</country><wicri:noRegion>9700 AV Groningen</wicri:noRegion><orgName type="university">Université de Groningue</orgName><placeName><settlement type="city">Groningue (ville)</settlement><region>Groningue (province)</region></placeName></affiliation></author><author><name sortKey="Munari, Ulisse" sort="Munari, Ulisse" uniqKey="Munari U" first="Ulisse" last="Munari">Ulisse Munari</name><affiliation wicri:level="1"><inist:fA14 i1="08"><s1>INAF Osservatorio Astronomico di Padova, Via dell'Osservatorio 8</s1><s2>Asiago 36012</s2><s3>ITA</s3><sZ>10 aut.</sZ></inist:fA14><country>Italie</country><wicri:noRegion>Asiago 36012</wicri:noRegion></affiliation></author><author><name sortKey="Navarro, Juho F" sort="Navarro, Juho F" uniqKey="Navarro J" first="Juho F." last="Navarro">Juho F. Navarro</name><affiliation wicri:level="1"><inist:fA14 i1="09"><s1>Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Station CSC</s1><s2>Victoria, BC V8W 3P6</s2><s3>CAN</s3><sZ>11 aut.</sZ></inist:fA14><country>Canada</country><wicri:noRegion>Victoria, BC V8W 3P6</wicri:noRegion></affiliation></author><author><name sortKey="Parker, Quentin A" sort="Parker, Quentin A" uniqKey="Parker Q" first="Quentin A." last="Parker">Quentin A. Parker</name><affiliation wicri:level="1"><inist:fA14 i1="10"><s1>Department of Physics and Astronomy, Macquarie University</s1><s2>Sydney, NSW 2109</s2><s3>AUS</s3><sZ>12 aut.</sZ><sZ>13 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Sydney, NSW 2109</wicri:noRegion></affiliation></author><author><name sortKey="Reid, Warren" sort="Reid, Warren" uniqKey="Reid W" first="Warren" last="Reid">Warren Reid</name><affiliation wicri:level="1"><inist:fA14 i1="10"><s1>Department of Physics and Astronomy, Macquarie University</s1><s2>Sydney, NSW 2109</s2><s3>AUS</s3><sZ>12 aut.</sZ><sZ>13 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Sydney, NSW 2109</wicri:noRegion></affiliation></author><author><name sortKey="Seabroke, George M" sort="Seabroke, George M" uniqKey="Seabroke G" first="George M." last="Seabroke">George M. Seabroke</name><affiliation wicri:level="4"><inist:fA14 i1="11"><s1>Mullard Space Science Laboratory, University College London, Holmbury St. Mary</s1><s2>Dorking RH5 6NT</s2><s3>GBR</s3><sZ>14 aut.</sZ></inist:fA14><country>Royaume-Uni</country><wicri:noRegion>Dorking RH5 6NT</wicri:noRegion><orgName type="university">University College de Londres</orgName><placeName><settlement type="city">Londres</settlement><region type="country">Angleterre</region><region type="région" nuts="1">Grand Londres</region></placeName></affiliation></author><author><name sortKey="Siebert, Arnaud" sort="Siebert, Arnaud" uniqKey="Siebert A" first="Arnaud" last="Siebert">Arnaud Siebert</name><affiliation wicri:level="3"><inist:fA14 i1="03"><s1>Observatoire de Strasbourg, 11 Rue de L'Université</s1><s2>67000 Strasbourg</s2><s3>FRA</s3><sZ>5 aut.</sZ><sZ>15 aut.</sZ></inist:fA14><country>France</country><placeName><region type="region" nuts="2">Grand Est</region><region type="old region" nuts="2">Alsace (région administrative)</region><settlement type="city">Strasbourg</settlement></placeName></affiliation></author><author><name sortKey="Siviero, Alessandro" sort="Siviero, Alessandro" uniqKey="Siviero A" first="Alessandro" last="Siviero">Alessandro Siviero</name><affiliation wicri:level="1"><inist:fA14 i1="12"><s1>Department of Astronomy, Padova University, Vicolo dell'Osservatorio 2</s1><s2>Padova 35122</s2><s3>ITA</s3><sZ>16 aut.</sZ></inist:fA14><country>Italie</country><wicri:noRegion>Padova 35122</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="13"><s1>Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16</s1><s2>14482 Potsdam</s2><s3>DEU</s3><sZ>16 aut.</sZ><sZ>17 aut.</sZ><sZ>19 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>14482 Potsdam</wicri:noRegion><wicri:noRegion>An der Sternwarte 16</wicri:noRegion><wicri:noRegion>14482 Potsdam</wicri:noRegion></affiliation></author><author><name sortKey="Steinmetz, Matthias" sort="Steinmetz, Matthias" uniqKey="Steinmetz M" first="Matthias" last="Steinmetz">Matthias Steinmetz</name><affiliation wicri:level="1"><inist:fA14 i1="13"><s1>Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16</s1><s2>14482 Potsdam</s2><s3>DEU</s3><sZ>16 aut.</sZ><sZ>17 aut.</sZ><sZ>19 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>14482 Potsdam</wicri:noRegion><wicri:noRegion>An der Sternwarte 16</wicri:noRegion><wicri:noRegion>14482 Potsdam</wicri:noRegion></affiliation></author><author><name sortKey="Watson, Fred G" sort="Watson, Fred G" uniqKey="Watson F" first="Fred G." last="Watson">Fred G. Watson</name><affiliation wicri:level="1"><inist:fA14 i1="14"><s1>Australian Astronomical Observatory</s1><s2>Coonabarabran, NSW 2357</s2><s3>AUS</s3><sZ>18 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Australian Astronomical Observatory</wicri:noRegion></affiliation></author><author><name sortKey="Williams, Mary" sort="Williams, Mary" uniqKey="Williams M" first="Mary" last="Williams">Mary Williams</name><affiliation wicri:level="1"><inist:fA14 i1="13"><s1>Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16</s1><s2>14482 Potsdam</s2><s3>DEU</s3><sZ>16 aut.</sZ><sZ>17 aut.</sZ><sZ>19 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>14482 Potsdam</wicri:noRegion><wicri:noRegion>An der Sternwarte 16</wicri:noRegion><wicri:noRegion>14482 Potsdam</wicri:noRegion></affiliation></author><author><name sortKey="Zwitter, Tomaz" sort="Zwitter, Tomaz" uniqKey="Zwitter T" first="Tomaz" last="Zwitter">Tomaz Zwitter</name><affiliation wicri:level="1"><inist:fA14 i1="15"><s1>Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19</s1><s2>Ljubljana</s2><s3>SVN</s3><sZ>20 aut.</sZ></inist:fA14><country>Slovénie</country><wicri:noRegion>Ljubljana</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="16"><s1>Center of Excellence SPACE-SI</s1><s2>Ljubljana</s2><s3>SVN</s3><sZ>20 aut.</sZ></inist:fA14><country>Slovénie</country><wicri:noRegion>Center of Excellence SPACE-SI</wicri:noRegion></affiliation></author></analytic><series><title level="j" type="main">The Astrophysical journal</title><title level="j" type="abbreviated">Astrophys. j.</title><idno type="ISSN">0004-637X</idno><imprint><date when="2011">2011</date></imprint></series></biblStruct></sourceDesc><seriesStmt><title level="j" type="main">The Astrophysical journal</title><title level="j" type="abbreviated">Astrophys. j.</title><idno type="ISSN">0004-637X</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Bright star</term><term>Disk galaxies</term><term>Dwarf galaxies</term><term>Dwarf stars</term><term>Eccentricity</term><term>Element abundance</term><term>Giant stars</term><term>Kinematics</term><term>Late type stars</term><term>Metal-poor stars</term><term>Milky Way</term><term>Models</term><term>Radial gradient</term><term>Radial velocity</term><term>Red giant stars</term><term>Red shift</term><term>Star accretion</term><term>Stellar abundance</term><term>Vertical gradient</term></keywords><keywords scheme="Pascal" xml:lang="fr"><term>Voie lactée</term><term>Abondance élément</term><term>Cinématique</term><term>Vitesse radiale</term><term>Etoile brillante</term><term>Géante rouge</term><term>Etoile pauvre en métal</term><term>Etoile géante</term><term>Gradient radial</term><term>Gradient vertical</term><term>Excentricité</term><term>Modèle</term><term>Galaxies naines</term><term>Accrétion stellaire</term><term>Etoile naine</term><term>Déplacement vers le rouge</term><term>Galaxies disques</term><term>Abondance stellaire</term><term>Etoile type avancé</term></keywords></textClass></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">We have undertaken the study of the elemental abundances and kinematic properties of a metal-poor sample of candidate thick-disk stars selected from the Radial Velocity Experiment spectroscopic survey of bright stars to differentiate among the present scenarios of the formation of the thick disk. In this paper, we report on a sample of 214 red giant branch, 31 red clump/horizontal branch, and 74 main-sequence/sub-giant branch metal-poor stars, which serves to augment our previous sample of only giant stars. We find that the thick disk [α/Fe] ratios are enhanced and have little variation (<0.1 dex), in agreement with our previous study. The augmented sample further allows, for the first time, investigation of the gradients in the metal-poor thick disk. For stars with [Fe/H] < -1.2, the thick disk shows very small gradients, <0.03 ± 0.02 dex kpc<sup>-1</sup>, in α-enhancement, while we find a +0.01 ± 0.04 dex kpc<sup>-1</sup> radial gradient and a -0.09 ± 0.05 dex kpc<sup>-1</sup> vertical gradient in iron abundance. In addition, we show that the peak of the distribution of orbital eccentricities for our sample agrees better with models in which the stars that comprise the thick disk were formed primarily in the Galaxy, with direct accretion of stars contributing little. Our results thus disfavor direct accretion of stars from dwarf galaxies into the thick disk as a major contributor to the thick-disk population, but cannot discriminate between alternative models for the thick disk, such as those that invoke high-redshift (gas-rich) mergers, heating of a pre-existing thin stellar disk by a minor merger, or efficient radial migration of stars.</div></front></TEI><affiliations><list><country><li>Allemagne</li><li>Australie</li><li>Canada</li><li>France</li><li>Italie</li><li>Pays-Bas</li><li>Royaume-Uni</li><li>Slovénie</li><li>États-Unis</li></country><region><li>Alsace (région administrative)</li><li>Angleterre</li><li>Angleterre de l'Est</li><li>Bade-Wurtemberg</li><li>District de Karlsruhe</li><li>Grand Est</li><li>Grand Londres</li><li>Groningue (province)</li><li>Nouvelle-Galles du Sud</li></region><settlement><li>Cambridge</li><li>Groningue (ville)</li><li>Heidelberg</li><li>Londres</li><li>Strasbourg</li><li>Sydney</li></settlement><orgName><li>University College de Londres</li><li>Université de Cambridge</li><li>Université de Groningue</li><li>Université de Sydney</li></orgName></list><tree><country name="États-Unis"><noRegion><name sortKey="Ruchti, Gregory R" sort="Ruchti, Gregory R" uniqKey="Ruchti G" first="Gregory R." last="Ruchti">Gregory R. Ruchti</name></noRegion><name sortKey="Fulbright, Jon P" sort="Fulbright, Jon P" uniqKey="Fulbright J" first="Jon P." last="Fulbright">Jon P. Fulbright</name><name sortKey="Wyse, Rosemary F G" sort="Wyse, Rosemary F G" uniqKey="Wyse R" first="Rosemary F. G." last="Wyse">Rosemary F. G. Wyse</name></country><country name="Royaume-Uni"><region name="Angleterre"><name sortKey="Gilmore, Gerard F" sort="Gilmore, Gerard F" uniqKey="Gilmore G" first="Gerard F." last="Gilmore">Gerard F. Gilmore</name></region><name sortKey="Gibson, Brad K" sort="Gibson, Brad K" uniqKey="Gibson B" first="Brad K." last="Gibson">Brad K. Gibson</name><name sortKey="Seabroke, George M" sort="Seabroke, George M" uniqKey="Seabroke G" first="George M." last="Seabroke">George M. Seabroke</name></country><country name="France"><region name="Grand Est"><name sortKey="Bienayme, Olivier" sort="Bienayme, Olivier" uniqKey="Bienayme O" first="Olivier" last="Bienayme">Olivier Bienayme</name></region><name sortKey="Siebert, Arnaud" sort="Siebert, Arnaud" uniqKey="Siebert A" first="Arnaud" last="Siebert">Arnaud Siebert</name></country><country name="Australie"><region name="Nouvelle-Galles du Sud"><name sortKey="Bland Hawthorn, Joss" sort="Bland Hawthorn, Joss" uniqKey="Bland Hawthorn J" first="Joss" last="Bland-Hawthorn">Joss Bland-Hawthorn</name></region><name sortKey="Parker, Quentin A" sort="Parker, Quentin A" uniqKey="Parker Q" first="Quentin A." last="Parker">Quentin A. Parker</name><name sortKey="Reid, Warren" sort="Reid, Warren" uniqKey="Reid W" first="Warren" last="Reid">Warren Reid</name><name sortKey="Watson, Fred G" sort="Watson, Fred G" uniqKey="Watson F" first="Fred G." last="Watson">Fred G. Watson</name></country><country name="Allemagne"><region name="Bade-Wurtemberg"><name sortKey="Grebel, Eva K" sort="Grebel, Eva K" uniqKey="Grebel E" first="Eva K." last="Grebel">Eva K. Grebel</name></region><name sortKey="Siviero, Alessandro" sort="Siviero, Alessandro" uniqKey="Siviero A" first="Alessandro" last="Siviero">Alessandro Siviero</name><name sortKey="Steinmetz, Matthias" sort="Steinmetz, Matthias" uniqKey="Steinmetz M" first="Matthias" last="Steinmetz">Matthias Steinmetz</name><name sortKey="Williams, Mary" sort="Williams, Mary" uniqKey="Williams M" first="Mary" last="Williams">Mary Williams</name></country><country name="Pays-Bas"><region name="Groningue (province)"><name sortKey="Helmi, Amina" sort="Helmi, Amina" uniqKey="Helmi A" first="Amina" last="Helmi">Amina Helmi</name></region></country><country name="Italie"><noRegion><name sortKey="Munari, Ulisse" sort="Munari, Ulisse" uniqKey="Munari U" first="Ulisse" last="Munari">Ulisse Munari</name></noRegion><name sortKey="Siviero, Alessandro" sort="Siviero, Alessandro" uniqKey="Siviero A" first="Alessandro" last="Siviero">Alessandro Siviero</name></country><country name="Canada"><noRegion><name sortKey="Navarro, Juho F" sort="Navarro, Juho F" uniqKey="Navarro J" first="Juho F." last="Navarro">Juho F. Navarro</name></noRegion></country><country name="Slovénie"><noRegion><name sortKey="Zwitter, Tomaz" sort="Zwitter, Tomaz" uniqKey="Zwitter T" first="Tomaz" last="Zwitter">Tomaz Zwitter</name></noRegion><name sortKey="Zwitter, Tomaz" sort="Zwitter, Tomaz" uniqKey="Zwitter T" first="Tomaz" last="Zwitter">Tomaz Zwitter</name></country></tree></affiliations></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Asie/explor/AustralieFrV1/Data/Main/Exploration
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 006884 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd -nk 006884 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Wicri/Asie
|area= AustralieFrV1
|flux= Main
|étape= Exploration
|type= RBID
|clé= Pascal:11-0364527
|texte= OBSERVATIONAL PROPERTIES OF THE METAL-POOR THICK DISK OF THE MILKY WAY AND INSIGHTS INTO ITS ORIGINS
}}
| This area was generated with Dilib version V0.6.33. |  |