SUPERDENSE MASSIVE GALAXIES IN WINGS LOCAL CLUSTERS

Journal Article · Sat Mar 20 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/712/1/226· OSTI ID:21394269

Valentinuzzi, T; D'Onofrio, M ^[1]; Fritz, J; Poggianti, B M; Bettoni, D; Fasano, G; Moretti, A; Omizzolo, A; Varela, J ^[2]; Cava, A ^[3]; Couch, W J ^[4]; Dressler, A ^[5]; Moles, M ^[6]; Kjaergaard, P ^[7]; Vanzella, E ^[8]

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1. Astronomical Department, University of Padova (Italy)
2. INAF-Astronomical Observatory of Padova (Italy)
3. Instituto de Astrofisica de Canarias La Laguna (Spain)
4. Center for Astrophysics and Supercomputing, Swinburne University of Technology (Australia)
5. Observatories of the Carnegie institution of Washington, Pasadena, CA (United States)
6. Instituto de Astrofisica de Andalucia, Granada (Spain)
7. Copenhagen University Observatory, Niels Bohr Institute for Astronomy, Physics and Geophysics (Denmark)
8. INAF-Astronomical Observatory of Trieste (Italy)

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 x 10{sup 10} M{sub sun}, are mostly S0 galaxies, have a median effective radius (R{sub e} ) = 1.61 +- 0.29 kpc, a median Sersic index (n) = 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 x 10{sup -2} Mpc{sup -3} for superdense galaxies in local clusters, and a hard lower limit of 1.3 x 10{sup -5} Mpc{sup -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 {approx} 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{sub *} > 4 x 10{sup 11} M{sub sun} compared to similarly massive galaxies in WINGS, i.e., the brightest cluster galaxies.

• OSTI ID: 21394269
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 712; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPARATIVE EVALUATIONS
ELECTROMAGNETIC RADIATION
EVALUATION
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
IONIZING RADIATIONS
LUMINOSITY
MASS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
RED SHIFT
X RADIATION