Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 10, 2012 | Published
Journal Article Open

The Correlated Formation Histories of Massive Galaxies and Their Dark Matter Halos

Abstract

Using observations in the COSMOS field, we report an intriguing correlation between the star formation activity of massive (~10^(11.4) M_☉) central galaxies, their stellar masses, and the large-scale (~10 Mpc) environments of their group-mass (~10^(13.6) M_☉) dark matter halos. Probing the redshift range z = [0.2, 1.0], our measurements come from two independent sources: an X-ray-detected group catalog and constraints on the stellar-to-halo mass relation derived from a combination of clustering and weak lensing statistics. At z = 1, we find that the stellar mass in star-forming (SF) centrals is a factor of two less than in passive centrals at the same halo mass. This implies that the presence or lack of star formation in group-scale centrals cannot be a stochastic process. By z = 0, the offset reverses, probably as a result of the different growth rates of these objects. A similar but weaker trend is observed when dividing the sample by morphology rather than star formation. Remarkably, we find that SF centrals at z ~ 1 live in groups that are significantly more clustered on 10 Mpc scales than similar mass groups hosting passive centrals. We discuss this signal in the context of halo assembly and recent simulations, suggesting that SF centrals prefer halos with higher angular momentum and/or formation histories with more recent growth; such halos are known to evolve in denser large-scale environments. If confirmed, this would be evidence of an early established link between the assembly history of halos on large scales and the future properties of the galaxies that form inside them.

Additional Information

© 2012 American Astronomical Society. Received 2012 March 30; accepted 2012 June 13; published 2012 July 20. We thank Charlie Conroy and Tom Theuns for useful discussions. This work was supported by World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan. The initial HST-COSMOS Treasury program was supported through NASA grant HST-GO-09822. We gratefully acknowledge contributions of the entire COSMOS collaboration consisting of more than 140 scientists. More information on COSMOS is available at http://cosmos.astro.caltech.edu/ and the data archive is at IPAC/IRSA. J.R. was supported by JPL, run under contract for NASA by Caltech.

Attached Files

Published - 2041-8205_755_1_L5.pdf

Files

2041-8205_755_1_L5.pdf
Files (282.3 kB)
Name Size Download all
md5:6629be83b77322d9db8a5cfeb3abd00f
282.3 kB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 18, 2023