Bibcode
Valentinuzzi, T.; Fritz, J.; Poggianti, B. M.; Cava, A.; Bettoni, D.; Fasano, G.; D'Onofrio, M.; Couch, W. J.; Dressler, A.; Moles, M.; Moretti, A.; Omizzolo, A.; Kjærgaard, P.; Vanzella, E.; Varela, J.
Bibliographical reference
The Astrophysical Journal, Volume 712, Issue 1, pp. 226-237 (2010).
Advertised on:
3
2010
Journal
Citations
163
Refereed citations
151
Description
Massive quiescent galaxies at z > 1 have been found to have small
physical sizes, and 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 < z < 0.07. We discover a significant population
of superdense massive galaxies with masses and sizes comparable to those
observed at high redshift. They approximately represent 22% of all
cluster galaxies more massive than 3 × 1010 M
sun, are mostly S0 galaxies, have a median effective radius
langRe rang = 1.61 ± 0.29 kpc, a median Sersic index
langnrang = 3.0 ± 0.6, and very old stellar populations with a
median mass-weighted age of 12.1 ± 1.3 Gyr. We calculate a number
density of 2.9 × 10-2 Mpc-3 for superdense
galaxies in local clusters, and a hard lower limit of 1.3 ×
10-5 Mpc-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 * > 4 ×
1011 M sun compared to similarly massive galaxies
in WINGS, i.e., the brightest cluster galaxies.
Related projects
Formation and Evolution of Galaxies: Observations in Infrared and other Wavelengths
This IAC research group carries out several extragalactic projects in different spectral ranges, using space as well as ground-based telescopes, to study the cosmological evolution of galaxies and the origin of nuclear activity in active galaxies. The group is a member of the international consortium which built the SPIRE instrument for the
Ismael
Pérez Fournon