Mass-to-Light Ratios of Field Early-Type Galaxies at z~1 from Ultra-Deep Spectroscopy: Evidence for Mass-dependent Evolution

dc.creatorvan der Wel, A.
dc.creatorFranx, M.
dc.creatorvan Dokkum, P. G.
dc.creatorRix, H. -W.
dc.creatorIllingworth, G. D.
dc.creatorRosati, P.
dc.date2005-02-10
dc.date2005-02-14
dc.date.accessioned2026-07-07T11:29:34Z
dc.date.available2026-07-07T11:29:34Z
dc.descriptionWe present an analysis of the Fundamental Plane for a sample of 27 field early-type galaxies in the redshift range 0.6<z<1.15. The galaxies in this sample have high S/N spectra obtained at the VLT and high resolution imaging from the ACS. We find that the mean evolution in M/L of our sample is $Delta ln (M/L_B) = -1.74+/-0.16z$, with a large galaxy-to-galaxy scatter. This value can be too low by 0.3 due to selection effects, resulting in $Delta ln (M/L_B) = -1.43+/-0.16z$. The strong correlation between M/L and rest-frame color indicates that the observed scatter is not due to measurement errors, but due to intrinsic differences between the stellar populations of the galaxies. This pace of evolution is much faster than the evolution of cluster galaxies. However, we find that the measured M/L evolution strongly depends on galaxy mass. For galaxies with masses $M>2 x 10^11 Msol$, we find no significant difference between the evolution of field and cluster galaxies: $Delta ln (M/L_B) = -1.20+/-0.18z for field galaxies and $Delta ln (M/L_B) = -1.12+/-0.06z$ for cluster galaxies. The relation between the measured M/L evolution and mass is partially due to selection effects. However, even when taking selection effects into account, we still find a relation between M/L evolution and mass, which is most likely caused by a lower mean age and a larger intrinsic scatter for low mass galaxies. Results from lensing early-type galaxies, which are mass-selected, show a very similar trend with mass. This, combined with our findings, provides evidence for down-sizing. Previous studies of the rate of evolution of field early-type galaxies found a large range of mutually exclusive values. We show that these differences are largely caused by the differences between fitting methods. (Abridged)
dc.descriptionfigures 3 and 4 available at http://www.strw.leidenuniv.nl/~vdwel/private/FPpaper/
dc.identifierhttps://arxiv.org/abs/astro-ph/0502228
dc.identifierhttp://arxiv.org/abs/astro-ph/0502228
dc.identifierAstrophys.J.631:145-162,2005
dc.identifierdoi:10.1086/430464
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/196752
dc.subjectAstrophysics
dc.titleMass-to-Light Ratios of Field Early-Type Galaxies at z~1 from Ultra-Deep Spectroscopy: Evidence for Mass-dependent Evolution
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