The Evolution of the Global Stellar Mass Density at 0<z<3
Abstract
The buildup of stellar mass in galaxies is the consequence of their past star formation and merging histories. Here we report measurements of rest-frame optical light and calculations of stellar mass at high redshift based on an infrared-selected sample of galaxies from the Hubble Deep Field-North. The bright envelope of rest-frame B-band galaxy luminosities is similar in the range 0<z<3, and the comoving luminosity density is constant to within a factor of 3 over that redshift range. However, galaxies at higher redshifts are bluer, and stellar population modeling indicates that they had significantly lower mass-to-light ratios than those of present-day L* galaxies. This leads to a global stellar mass density, Ω*(z), that rises with time from z=3 to the present. This measurement essentially traces the integral of the cosmic star formation history that has been the subject of previous investigations. Between 50% and 75% of the present-day stellar mass density had formed by z~1, but at z~2.7 we find that only 3%-14% of today's stars were present. This increase in Ω* with time is broadly consistent with observations of the evolving global star formation rate, once dust extinction is taken into account, but is steeper at 1<z<3 than predicted by some recent semianalytic models of galaxy formation. The observations appear to be inconsistent with scenarios in which the bulk of stars in present-day galactic spheroids formed at z>>2.
Based on observations taken with the NASA/ESA Hubble Space Telescope (HST), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555.- Publication:
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The Astrophysical Journal
- Pub Date:
- April 2003
- DOI:
- 10.1086/368111
- arXiv:
- arXiv:astro-ph/0212242
- Bibcode:
- 2003ApJ...587...25D
- Keywords:
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- Cosmology: Early Universe;
- Galaxies: Evolution;
- Galaxies: High-Redshift;
- Galaxies: Stellar Content;
- Infrared: Galaxies;
- Astrophysics
- E-Print:
- To appear in the Astrophysical Journal. 35 pages, 8 figures, some in color