J/ApJ/927/164ivo://CDS.VizieR/J/ApJ/927/164doi:10.26093/cds/vizier.19270164CDSBorghi N.Moresco M.Cimatti A.Huchet A.Quai S.Pozzetti L.2024-11-06T20:23:48Z2024-02-09T13:29:55ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopychemical-abundancesstellar-agesvisible-astronomyWe take advantage of the publicly available LEGA-C spectroscopic survey to measure the stellar population properties of 140 individual massive and passive galaxies at z~0.7. We develop and publicly release PyLick, a flexible Python code to measure UV to near-IR spectral indices. With PyLick we study the H/K ratio as a new diagnostic based on the pseudo-Lick CaII H and K indices and find that a cut in H/K<1.1 can be used jointly with other criteria to select (or verify the purity of) samples of passive galaxies. By combining photometric and spectroscopic criteria, we select a reliable sample of passively evolving galaxies. We constrain single-burst stellar ages, metallicities [Z/H], and [{alpha}/Fe] with an optimized set of Lick indices, exploring in detail the robustness of our measurement against different combinations. Even without imposing cosmological priors, the derived ages follow a clear trend compatible with the expected cosmological aging of the universe. We observe no significant redshift evolution for the metal abundance with respect to the values derived at z=0, with median [Z/H]=0.08+/-0.18 and [{alpha}/Fe]=0.13+/-0.11. Finally, we analyze the relations between log age, [Z/H], [{alpha}/Fe], and the stellar velocity dispersion, finding slopes of (0.5+/-0.1), (0.3+/-0.2), and (0.2+/-0.1), respectively; the small scatter of <0.2dex points to rather homogeneous and short star formation histories. Overall, these results confirm and extend low- redshift findings of a mass-downsizing evolution. This work further strengthens the possibility of selecting pure samples of passive galaxies to be exploited reliably as cosmic chronometers to place independent cosmological constraints.2022ApJ...927..164Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/927/164CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/82/197 : Mean UV Spectra of Stellar Groups (Fanelli+ 1992)J/ApJS/94/687 : Old stellar populations. V. (Worthey+, 1994)J/ApJS/111/377 : H{gamma} & H{delta} absorption features (Worthey+ 1997)J/ApJS/116/1 : Old Stellar Populations. VI. Absorption-Line (Trager+ 1998)J/ApJS/122/51 : Sp. catalog of 10 rich galaxy clusters (Dressler+ 1999)J/A+A/345/419 : Star formation in early-type galaxies (Longhetti+ 1999)J/MNRAS/326/959 : Empirical calibration of the NIR Ca triplet (Cenarro+ 2001)J/ApJ/621/673 : Line indices for 124 early-type galaxies (Thomas+, 2005)J/ApJ/633/174 : Spheroidals and bulge dominated galaxies (Treu+, 2005)J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)J/ApJ/690/1236 : COSMOS photometric redshift catalog (Ilbert+, 2009)J/AJ/145/77 : Imaging and sp. in 3 galaxy clusters (Jorgensen+, 2013)J/ApJ/777/18 : Stellar mass functions of galaxies to z=4 (Muzzin+, 2013)J/ApJS/206/8 : COSMOS/UltraVISTA Ks-selected catalogs v4.1 (Muzzin+, 2013)J/ApJ/788/72 : Observed sample of z~0.7 massive galaxies (Gallazzi+, 2014)J/MNRAS/448/3484 : ATLAS3D Project. XXX (McDermid+, 2015)J/ApJS/224/24 : The COSMOS2015 catalog (Laigle+, 2016)J/ApJS/239/27 : LEGA-C DR2: galaxies in the COSMOS field (Straatman+, 2018)J/MNRAS/490/417 : VANDELS massive quiescent gal. at 1.0<z<1.3 (Carnall+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/927/164https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/927/164http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/927/164https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/927/164https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/927/164http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/927/164GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/927/164/table4 (*Stellar ages, metallicities [Z/H], and [{alpha}/Fe] for 140 massive and passive galaxies at z~0.7)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/927/164/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/927/164/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/927/164/table4?GETtext/xml+votable180.050000true150.16152.362480.0055555555555555565/6814 6/https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/927/164?format=asciiOpticaldefaultJ/ApJ/927/164/table4*Stellar ages, metallicities [Z/H], and [{alpha}/Fe] for 140 massive and passive galaxies at z~0.7SimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[MMS2013][26438/259363] Object identifier (Muzzin+ 2013, J/ApJS/206/8)meta.id;meta.mainintRAJ2000[149.7/150.8] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[1.7/2.8] Declination (J2000)degpos.eq.dec;meta.mainAge[1.2/6.1] Mean stellar age (single-burst star formation history) (1)Gyrtime.age;stat.meanfloate16-Age[0.05/1.1] 16th percentile uncertainty in AgeGyrstat.error;time.agefloate84-Age[0.05/1.4] 84th percentile uncertainty in AgeGyrstat.error;time.agefloat[Z/H][-0.24/0.6] Mean stellar metallicity [Z/H] (1)phys.abund.Z;stat.meanfloate16-[Z/H][0.01/0.15] 16th percentile uncertainty in [Z/H]stat.error;phys.abund.Zfloate84-[Z/H][0.01/0.2] 84th percentile uncertainty in [Z/H]stat.error;phys.abund.Zfloat[a/Fe][-0.2/0.42] Mean stellar alpha-to-iron (1)phys.abund;stat.meanfloate16-[a/Fe][0.007/0.11] 16th percentile uncertainty in [a/Fe]stat.error;phys.abundfloate84-[a/Fe][0.009/0.12] 84th percentile uncertainty in [a/Fe]stat.error;phys.abundfloat