How small were the first cosmological objects?

被引:721
作者
Tegmark, M
Silk, J
Rees, MJ
Blanchard, A
Abel, T
Palla, F
机构
[1] UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720
[2] UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720
[3] UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720
[4] UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND
[5] UNIV STRASBOURG 1,OBSERV STRASBOURG,F-67000 STRASBOURG,FRANCE
[6] MAX PLANCK INST ASTROPHYS,D-85740 GARCHING,GERMANY
[7] OSSERV ASTROFIS ARCETRI,I-50125 FLORENCE,ITALY
关键词
cosmology; theory; early universe; galaxies; formation;
D O I
10.1086/303434
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The minimum mass that a virialized gas cloud must have in order to be able to cool in a Hubble time is computed, using a detailed treatment of the chemistry of molecular hydrogen. With a simple model for halo profiles, we reduce the problem to that of numerically integrating a system of chemical equations. The results agree well with numerically expensive three-dimensional simulations, and our approach has the advantage of being able to explore large regions of parameter space rapidly. The minimum baryonic mass M(b) is found to be strongly redshift dependent, dropping from 10(6) M. at z similar to 15 to 5 x 10(3) M. at z similar to 100 as molecular cooling becomes effective. For z much greater than 100, M(b) rises again, as cosmic microwave background photons inhibit H-2 formation through the H- channel. Finally, for z much greater than 200, the H-2(+) channel for H-2 formation becomes effective, driving M(b) down toward M(b) similar to 10(3) M.. With a standard cold dark matter power spectrum with sigma(8) = 0.7, this implies that a fraction 10(-3) of all baryons may have formed luminous objects by z = 30, which could be sufficient to reheat the universe.
引用
收藏
页码:1 / 12
页数:12
相关论文
共 56 条
[41]   SCHEMES FOR BIASED GALAXY FORMATION [J].
SILK, J .
ASTROPHYSICAL JOURNAL, 1985, 297 (01) :1-8
[42]   FRAGMENTATION OF COSMIC GAS CLOUDS .1. FORMATION OF GALAXIES AND 1ST GENERATION OF STARS [J].
SILK, J .
ASTROPHYSICAL JOURNAL, 1977, 211 (03) :638-648
[43]   STRUCTURE IN THE COBE DIFFERENTIAL MICROWAVE RADIOMETER 1ST-YEAR MAPS [J].
SMOOT, GF ;
BENNETT, CL ;
KOGUT, A ;
WRIGHT, EL ;
AYMON, J ;
BOGGESS, NW ;
CHENG, ES ;
DEAMICI, G ;
GULKIS, S ;
HAUSER, MG ;
HINSHAW, G ;
JACKSON, PD ;
JANSSEN, M ;
KAITA, E ;
KELSALL, T ;
KEEGSTRA, P ;
LINEWEAVER, C ;
LOEWENSTEIN, K ;
LUBIN, P ;
MATHER, J ;
MEYER, SS ;
MOSELEY, SH ;
MURDOCK, T ;
ROKKE, L ;
SILVERBERG, RF ;
TENORIO, L ;
WEISS, R ;
WILKINSON, DT .
ASTROPHYSICAL JOURNAL, 1992, 396 (01) :L1-&
[44]   CONTINUOUS ABSORPTION BY HE-2+ AND HE-2+ IN COOL WHITE-DWARFS [J].
STANCIL, PC .
ASTROPHYSICAL JOURNAL, 1994, 430 (01) :360-370
[45]   A NEW UPPER LIMIT ON THE DENSITY OF GENERALLY DISTRIBUTED INTERGALACTIC NEUTRAL HYDROGEN [J].
STEIDEL, CC ;
SARGENT, WLW .
ASTROPHYSICAL JOURNAL, 1987, 318 (01) :L11-L13
[46]   A SEARCH FOR ARCMIN-SCALE ANISOTROPY IN THE COSMIC MICROWAVE BACKGROUND [J].
SUBRAHMANYAN, R ;
EKERS, RD ;
SINCLAIR, M ;
SILK, J .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1993, 263 (02) :416-424
[47]   REIONIZATION IN AN OPEN COLD DARK-MATTER UNIVERSE - IMPLICATIONS FOR COSMIC MICROWAVE BACKGROUND FLUCTUATIONS [J].
TEGMARK, M ;
SILK, J .
ASTROPHYSICAL JOURNAL, 1995, 441 (02) :458-464
[48]   ON THE INEVITABILITY OF REIONIZATION - IMPLICATIONS FOR COSMIC MICROWAVE BACKGROUND FLUCTUATIONS [J].
TEGMARK, M ;
SILK, J ;
BLANCHARD, A .
ASTROPHYSICAL JOURNAL, 1994, 420 (02) :484-496
[49]   DID THE UNIVERSE RECOMBINE - NEW SPECTRAL CONSTRAINTS ON REHEATING [J].
TEGMARK, M ;
SILK, J .
ASTROPHYSICAL JOURNAL, 1994, 423 (02) :529-533
[50]  
TEGMARK M, 1994, ASTROPHYS J, V434, P395, DOI 10.1086/174740