MacArthur, Lauren A. and Ellis, Richard S. and Treu, Tommaso and Moran, Sean M. (2010) Environmental Effects in the Evolution of Galactic Bulges. Astrophysical Journal Letters, 709 (1). L53-L57. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20100129-082538763
- Published Version
Restricted to Repository administrators only
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20100129-082538763
We investigate possible environmental trends in the evolution of galactic bulges over the redshift range 0 < z < 0.6. For this purpose, we construct the fundamental plane (FP) for cluster and field samples at redshifts <z> = 0.4 and <z> = 0.54 using surface photometry based on Hubble Space Telescope imaging and velocity dispersions based on Keck spectroscopy. As a reference point for our study, we include data for pure ellipticals, which we model as single-component Sérsic profiles; whereas for multi-component galaxies we undertake decompositions using Sérsic and exponential models for the bulge and disk, respectively. Although the FP for both distant cluster and field samples is offset from the local relation, consistent with evolutionary trends found in earlier studies, we detect significant differences in the zero point of ≃0.2 dex between the field and cluster samples at a given redshift. For both clusters, the environmentally dependent offset is in the sense expected for an accelerated evolution of bulges in dense environments. By matching the mass range of our samples, we confirm that this difference does not arise as a result of the mass-dependent downsizing effects seen in larger field samples. Our result is also consistent with the hypothesis that—at fixed mass and environment—the star formation histories of galactic bulges and pure spheroids are indistinguishable and difficult to reconcile with the picture whereby the majority of large bulges form primarily via secular processes within spiral galaxies.
|Additional Information:||© 2010 American Astronomical Society. Received 2009 July 3; accepted 2009 December 7; published 2010 January 4. L.A.M. acknowledges financial support from the National Science and Engineering Council of Canada. T.T. acknowledges support from the NSF through CAREER award NSF-0642621, by the Sloan Foundation and by the Packard Foundation. R.S.E. acknowledges financial support from the Royal Society. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. This work is partly based on archival data from the Hubble Space Telescope, obtained from the data archive at the Space Telescope Institute, which is operated by the association of Universities for Research in Astronomy, Inc. for NASA under contract NAS5-26555.|
|Subject Keywords:||galaxies: evolution; galaxies: formation; galaxies: spiral; galaxies: stellar content|
|Official Citation:||Environmental Effects in the Evolution of Galactic Bulges Lauren A. MacArthur, Richard S. Ellis, Tommaso Treu, and Sean M. Moran 2010 ApJ 709 L53-L57 doi: 10.1088/2041-8205/709/1/L53|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||01 Feb 2010 02:40|
|Last Modified:||26 Dec 2012 11:44|
Repository Staff Only: item control page