Title: A deep band I-band selected galaxy sample - Implications for galaxy evolution
Abstract: view Abstract Citations (119) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Deep I-Band Selected Galaxy Sample: Implications for Galaxy Evolution Lilly, Simon J. Abstract New spectroscopic observations of a statistically complete sample of 50 very faint I-band selected galaxies with I_AB_ < 22.5 show that, although they extend out to Z ~ 1, the redshifts are generally low, <Z>Z_obs_ ~ 0.5 + 0.1. This is the same as simple "no-evolution" predictions, despite a roughly threefold excess in the number-magnitude counts relative to a no-evolution q_0_ = 0.5 model. Within this cosmological framework, this supports the idea that the faint field galaxy population is dominated by a rapidly evolving population of numerous and presumably relatively low-mass galaxies with the spectral energy distributions of Irr galaxies and rest-frame V-band luminosities around M_V_ ~ -20.0, i.e., about 1 mag below the present-day L^*^. On the other hand, a {DELTA}-dominated universe with q_0_ ~ -0.85 would require little evolution in the luminosity function at rest wavelengths λ ~ 5500 A back to z ~ 0.5, although substantial evolution of the luminosity function at shorter wavelengths is still required. The morphologies of half of the blue galaxies at z ~0.4 are peculiar in some way, possibly indicating interactions. The number of high-redshift luminous galaxies, with z > 0.7 and M_B_~ -21.5, i.e., up to a magnitude above present-day L^*,^ is roughly as expected from the present-day rest- frame B-band luminosity function without substantial luminosity evolution back to z ~ 1. However, these galaxies are much bluer than present-day galaxies of similar luminosities, and there are no galaxies in the sample with (V - I) colors as red or redder than those of present-day Sbc galaxies. This could simply indicate that normal massive spiral galaxies are forming stars more vigorously at z ~ 0.8 than at present. Alternatively, if the blue galaxies at high redshift are more luminous versions of the evolving population seen at z ~ 0.5, then the absence of redder objects at high redshifts would support the idea that most massive galaxies have been built up by mergers over the last half-Hubble time. Publication: The Astrophysical Journal Pub Date: July 1993 DOI: 10.1086/172851 Bibcode: 1993ApJ...411..501L Keywords: Astrometry; Astronomical Spectroscopy; Galactic Evolution; Galactic Mass; Red Shift; Spectral Bands; Cosmology; Hubble Constant; Spectral Energy Distribution; Astrophysics; GALAXIES: DISTANCES AND REDSHIFTS; GALAXIES: EVOLUTION; GALAXIES: FORMATION; INFRARED: GALAXIES full text sources ADS | data products SIMBAD (50) NED (43)
Publication Year: 1993
Publication Date: 1993-07-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 53
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