MERGING AND FAST GALAXY EVOLUTION

被引:37
作者
CARLBERG, RG
机构
[1] Department of Astronomy, University of Toronto, Toronto, Ont. M5S 1A1
关键词
COSMOLOGY; THEORY; GALAXIES; EVOLUTION; INTERACTIONS;
D O I
10.1086/186599
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The small numbers of z > 1 galaxies in new faint galaxy samples challenges the assumption that their mass function does not evolve significantly up to z = 1. A " maximal " evolutionary model for the faint galaxy population is proposed, wherein galaxies form in preexisting halos, and merger dynamics is used to allow for interaction induced star formation and the change in M*. Interactions at z less than or similar 0.5 mainly brighten and blue galaxies, with little change in numbers. Beyond z greater than or similar to 0.5, merging begins to reduce the characteristic mass and increase the numbers of galaxies. As observational predictions the model requires that (1) the current mass doubling time scale of M* galaxies is congruent 1.5t0, which is uncomfortably short; (2) the merger rate, at low redshift, increases approximately as (1 + z)4 (for OMEGA = 1); and (3) at z = 1, the characteristic galaxy mass is about 25% of the z = 0 value; hence, galaxies having circular velocities of greater than or similar to 200 km s-1 are relatively rare beyond z > 1, although such halos likely exist in abundance. The spirit of the calculation is to provide a testable, but perhaps somewhat extreme, hypothesis in which gravitational interactions limit the rate of formation activity.
引用
收藏
页码:L31 / L34
页数:4
相关论文
共 29 条
[1]   COSMOLOGICAL N-BODY SIMULATIONS OF GALAXY MERGING [J].
AARSETH, SJ ;
FALL, SM .
ASTROPHYSICAL JOURNAL, 1980, 236 (01) :43-57
[2]   THE STATISTICS OF PEAKS OF GAUSSIAN RANDOM-FIELDS [J].
BARDEEN, JM ;
BOND, JR ;
KAISER, N ;
SZALAY, AS .
ASTROPHYSICAL JOURNAL, 1986, 304 (01) :15-61
[3]   A COMPLETE GALAXY REDSHIFT SAMPLE .1. THE PECULIAR VELOCITIES BETWEEN GALAXY PAIRS AND THE MEAN MASS DENSITY OF THE UNIVERSE [J].
BEAN, AJ ;
EFSTATHIOU, G ;
ELLIS, RS ;
PETERSON, BA ;
SHANKS, T .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1983, 205 (02) :605-624
[4]   THE DURHAM ANGLO-AUSTRALIAN TELESCOPE FAINT GALAXY REDSHIFT SURVEY [J].
BROADHURST, TJ ;
ELLIS, RS ;
SHANKS, T .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1988, 235 (03) :827-856
[5]   FAINT GALAXIES - EVOLUTION AND COSMOLOGICAL CURVATURE [J].
BROADHURST, TJ ;
ELLIS, RS ;
GLAZEBROOK, K .
NATURE, 1992, 355 (6355) :55-58
[6]  
BRUZUAL AG, 1992, IN PRESS APJ
[7]   QUASAR EVOLUTION VIA GALAXY MERGERS [J].
CARLBERG, RG .
ASTROPHYSICAL JOURNAL, 1990, 350 (02) :505-511
[8]   MERGERS AND BIAS IN A COLD DARK MATTER COSMOLOGY [J].
CARLBERG, RG ;
COUCHMAN, HMP .
ASTROPHYSICAL JOURNAL, 1989, 340 (01) :47-68
[9]   FAINT GALAXY EVOLUTION VIA INTERACTIONS [J].
CARLBERG, RG ;
CHARLOT, S .
ASTROPHYSICAL JOURNAL, 1992, 397 (01) :5-13
[10]  
COLINS CA, 1992, IN PRESS MNRAS