SUPERDENSE MASSIVE GALAXIES IN WINGS LOCAL CLUSTERS
| Autor: | Alan Dressler, Mauro D'Onofrio, Alessia Moretti, Eros Vanzella, Jacopo Fritz, Antonio Cava, A. Omizzolo, Daniela Bettoni, G. Fasano, T. Valentinuzzi, Bianca M. Poggianti, Mariano Moles, Per Kjaergaard, Warrick J. Couch, Jesus Varela |
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| Rok vydání: | 2010 |
| Předmět: |
PASSIVE GALAXIES
SIMILAR-TO 2 Cosmology and Nongalactic Astrophysics (astro-ph.CO) SIZE EVOLUTION STRUCTURAL-PROPERTIES COMPACT QUIESCENT GALAXIES FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics HIGH-REDSHIFT GALAXIES Lower limit ELLIPTIC GALAXIES Cluster (physics) clusters: general [galaxies] fundamental parameters [galaxies] Astrophysics::Galaxy Astrophysics evolution [galaxies] Galaxy cluster STAR-FORMATION HISTORIES Physics Effective radius Number density Astronomy and Astrophysics Radius Redshift Galaxy Space and Planetary Science Earth and Environmental Sciences structure [galaxies] DIGITAL SKY SURVEY VELOCITY DISPERSION Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | ASTROPHYSICAL JOURNAL |
| ISSN: | 1538-4357 0004-637X |
| Popis: | Massive quiescent galaxies at z>1 have been found to have small physical sizes, hence to be superdense. Several mechanisms, including minor mergers, have been proposed for increasing galaxy sizes from high- to low-z. We search for superdense massive galaxies in the WIde-field Nearby Galaxy-cluster Survey (WINGS) of X-ray selected galaxy clusters at 0.04 =1.61+/-0.29kpc, a median Sersic index = 3.0+/-0.6, and very old stellar populations with a median mass-weighted age of 12.1+/-1.3Gyr. We calculate a number density of 2.9x10^-2Mpc^-3 for superdense galaxies in local clusters, and a hard lower limit of 1.3x10^-5Mpc^-3 in the whole comoving volume between z = 0.04 and z = 0.07. We find a relation between mass, effective radius and luminosity-weighted age in our cluster galaxies, which can mimic the claimed evolution of the radius with redshift, if not properly taken into account. We compare our data with spectroscopic high-z surveys and find that -when stellar masses are considered- there is consistency with the local WINGS galaxy sizes out to z~2, while a discrepancy of a factor of 3 exists with the only spectroscopic z>2 study. In contrast, there is strong evidence for a large evolution in radius for the most massive galaxies with M*>4x10^11Msol compared to similarly massive galaxies in WINGS, i.e. the BCGs. Comment: 14 pages, 7 figures, 3 tables, accepted for pubblication in ApJ |
| Databáze: | OpenAIRE |
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