J/ApJ/749/77ivo://CDS.VizieR/J/ApJ/749/77doi:10.26093/cds/vizier.17490077CDSSchlaufman K.C.Rockosi C.M.Lee Y.S.Beers T.C.Allende Prieto C.,Rashkov V.Madau P.Bizyaev D.2013-12-28T22:04:31Z2013-12-09T09:18:11ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmetallicityhalo-starsmilky-way-galaxyWe find that the relative contribution of satellite galaxies accreted at high redshift to the stellar population of the Milky Way's smooth halo increases with distance, becoming observable relative to the classical smooth halo about 15 kpc from the Galactic center. In particular, we determine line-of-sight-averaged [Fe/H] and [{alpha}/Fe] in the metal-poor main-sequence turnoff (MPMSTO) population along every Sloan Extension for Galactic Understanding and Exploration (SEGUE) spectroscopic line of sight. Restricting our sample to those lines of sight along which we do not detect elements of cold halo substructure (ECHOS), we compile the largest spectroscopic sample of stars in the smooth component of the halo ever observed in situ beyond 10 kpc. We find significant spatial autocorrelation in [Fe/H] in the MPMSTO population in the distant half of our sample beyond about 15 kpc from the Galactic center. Inside of 15 kpc however, we find no significant spatial autocorrelation in [Fe/H]. At the same time, we perform SEGUE-like observations of N-body simulations of Milky Way analog formation. While we find that halos formed entirely by accreted satellite galaxies provide a poor match to our observations of the halo within 15 kpc of the Galactic center, we do observe spatial autocorrelation in [Fe/H] in the simulations at larger distances. This observation is an example of statistical chemical tagging and indicates that spatial autocorrelation in metallicity is a generic feature of stellar halos formed from accreted satellite galaxies.2012ApJ...749...77Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/749/77CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/522/A26 : Fe Abundances in metal-poor stars (Sbordone+ 2010)J/ApJ/706/1095 : Chemical compositions of 26 outer halo stars (Zhang+, 2009)J/ApJ/703/2177 : Pap. I. Metal-poor MS turnoff stars (Schlaufman+, 2009)J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)J/A+A/501/519 : Metal-poor turnoff stars abundances (Bonifacio+, 2009)J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)J/AJ/126/1362 : Century Survey Galactic Halo Project. I. (Brown+, 2003)J/AJ/125/2502 : Spectral indices of Galactic halo (Morrison+, 2003)J/AJ/117/2329 : Spectroscopy of hot stars in the halo. III (Wilhelm+, 1999)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/749/77https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/749/77http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/749/77https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/749/77https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/749/77http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/749/77GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/749/77/abund (Spatial and radial distribution of [Fe/H] (table 1) and [{alpha}/Fe] (table2) in the smooth component of the halo)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/749/77/abund?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/749/77/abund?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/749/77/abund?GETtext/xml+votable180.050000true207.2218.620.0055555555555555566/28 48 715 996 2066 2094 2297 4166 4769 4796 4950 5106 5249 5354 5434 5891 6095 6301 6384 6392 6568 7250 7515 7553 7784 8164 8265 8353 8517 8671 8846 9156 9583 9607 9863 10144 10410 10535 10618 10823 10914 10989 11137 11224 11331 11448 11453 11572 11601 11882 12391 12662 13329 13415 13648 16187 17231 17370 17513 17516 17561 17830 17907 18069 18170 18233 18388 18523 18777 18854 19113 19269 19329 19411 19599 19691 19760 19777 19941 20169 20251 20285 20455 21783 22740 23054 23057 23193 23209 23274 23467 25291 25334 25530 26115 26169 26202 26262 26266 26282 26467 26981 27045 27238 27454 27643 27754 27818 28006 28075 28266 30041 32447 32501 32536 32699 36781 49017https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/749/77?format=asciiOpticaldefaultJ/ApJ/749/77/abundSpatial and radial distribution of [Fe/H] (table 1) and [{alpha}/Fe] (table2) in the smooth component of the halorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainGLON[3.16/358.72] Galactic longitudedegpos.galactic.lonGLAT[-71.74/87.02] Galactic latitudedegpos.galactic.latfloatbplate[1880/2963]? SEGUE bplate (Cat. J/AJ/137/4377) \linkRole{list of SEGUE plate pairs}obs.fieldintnullablefplate[1881/2965] SEGUE fplate (Cat. J/AJ/137/4377)obs.fieldintFe12i[-2.2/-0.9]? [Fe/H]_in_ split at d=12.1kpclog(Sun)phys.abund.Fefloatnullablee_Fe12i[0.08/0.3]? Fe12i uncertaintylog(Sun)stat.errorfloatnullableFe12o[-2.1/-0.6]? [Fe/H]_out_ split at d=12.1kpclog(Sun)phys.abund.Fefloatnullablee_Fe12o[0.07/0.3]? Fe12o uncertaintylog(Sun)stat.errorfloatnullableFe14i[-2.5/-0.9]? [Fe/H]_in_ split at d=14.1kpclog(Sun)phys.abund.Fefloatnullablee_Fe14i[0.07/0.2]? Fe14i uncertaintylog(Sun)stat.errorfloatnullableFe14o[-2/-0.6]? [Fe/H]_out_ split at d=14.1kpclog(Sun)phys.abund.Fefloatnullablee_Fe14o[0.07/0.3]? Fe14o uncertaintylog(Sun)stat.errorfloatnullableFe16i[-2.2/-0.9]? [Fe/H]_in_ split at d=16.8kpclog(Sun)phys.abund.Fefloatnullablee_Fe16i[0.07/0.2]? Fe16i uncertaintylog(Sun)stat.errorfloatnullableFe16o[-2.6/-0.6]? [Fe/H]_out_ split at d=16.8kpclog(Sun)phys.abund.Fefloatnullablee_Fe16o[0.07/0.3]? Fe16o uncertaintylog(Sun)stat.errorfloatnullablea12i[0.1/0.5]? [{alpha}/Fe]_in_ at d=12.1kpclog(Sun)phys.abundfloatnullablee_a12i[0.06/0.3]? a12i uncertaintylog(Sun)stat.errorfloatnullablea12o[0.02/0.6]? [{alpha}/Fe]_out_ at d=12.1kpclog(Sun)phys.abundfloatnullablee_a12o[0.05/0.3]? a12o uncertaintylog(Sun)stat.errorfloatnullablea14i[0.1/0.6]? [{alpha}/Fe]_in_ at d=14.1kpclog(Sun)phys.abundfloatnullablee_a14i[0.06/0.3]? a14i uncertaintylog(Sun)stat.errorfloatnullablea14o[0/0.6]? [{alpha}/Fe]_out_ at d=14.1kpclog(Sun)phys.abundfloatnullablee_a14o[0.06/0.3]? a14o uncertaintylog(Sun)stat.errorfloatnullablea16i[0.04/0.5]? [{alpha}/Fe]_in_ at d=16.8kpclog(Sun)phys.abundfloatnullablee_a16i[0.06/0.3]? a16i uncertaintylog(Sun)stat.errorfloatnullablea16o[-0.02/0.6]? [{alpha}/Fe]_out_ at d=16.8kpclog(Sun)phys.abundfloatnullablee_a16o[0.1/0.3]? a16o uncertaintylog(Sun)stat.errorfloatnullable