On star formation in primordial protoglobular clouds

被引:33
作者
Padoan, P
Jimenez, R
Jones, B
机构
[1] NORDITA, DK-2100 COPENHAGEN, DENMARK
[2] ROYAL OBSERV, EDINBURGH EH9 3HJ, MIDLOTHIAN, SCOTLAND
[3] UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND
关键词
stars; formation; Galaxy; globular clusters; general;
D O I
10.1093/mnras/285.4.711
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Using a new physical model for star formation, we have tested the possibility that globular clusters (GCs) are formed from primordial mass fluctuations, the mass scale of which (10(8)-10(9) M(circle dot)) is selected out of a cold dark matter spectrum by the mechanism of non-equilibrium formation of H-2. We show that such clouds are able to convert about 0.002 of their total mass into a bound system (a GC) and about 0.02 into halo stars. The metal-enriched gas is dispersed from the GC by supernova explosions and forms the Galactic disc. The mass ratios between GCs, halo and disc depend on the predicted initial mass function which is a consequence of the universal statistics of fluid turbulence. They also depend on the ratio of baryonic to non-baryonic mass, X(b), and are comparable to the values observed in typical spiral galaxies for X(b) approximate to 0.1-0.2. The computed mass and radius for a GC (5 x 10(5) M(circle dot) and 30 pc) are in good agreement with the average values in the Galaxy. The model predicts an exponential cut-off in the stellar initial mass function below 0.2 M(circle dot) in GCs and 0.7 M(circle dot) in the halo. The reasonably massive star formation in primordial clouds leads to a large number of supernovae and to a high blue luminosity during the first 2 Gyr of the life of the Galaxy.
引用
收藏
页码:711 / 717
页数:7
相关论文
共 65 条
[1]   THE H-R DIAGRAMS FOR THE GLOBULAR CLUSTERS M92 AND M3 [J].
ARP, HC ;
BAUM, WA ;
SANDAGE, AR .
ASTRONOMICAL JOURNAL, 1952, 57 (01) :4-5
[2]   THE FORMATION OF GLOBULAR-CLUSTERS IN MERGING AND INTERACTING GALAXIES [J].
ASHMAN, KM ;
ZEPF, SE .
ASTROPHYSICAL JOURNAL, 1992, 384 (01) :50-61
[3]  
ASHMAN KM, 1990, MON NOT R ASTRON SOC, V247, P662
[4]   M-DWARFS, MICROLENSING, AND THE MASS BUDGET OF THE GALAXY [J].
BAHCALL, JN ;
FLYNN, C ;
GOULD, A ;
KIRHAKOS, S .
ASTROPHYSICAL JOURNAL, 1994, 435 (01) :L51-L54
[5]  
BAHCALL JN, 1982, APJS, V277, P27
[6]   KINEMATICS OF METAL-POOR STARS IN THE GALAXY [J].
BEERS, TC ;
SOMMERLARSEN, J .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1995, 96 (01) :175-221
[7]   ON THE FORMATION OF GLOBULAR-CLUSTERS .2. EARLY DYNAMICAL EVOLUTION [J].
BROWN, JH ;
BURKERT, A ;
TRURAN, JW .
ASTROPHYSICAL JOURNAL, 1995, 440 (02) :666-673
[8]   ON THE FORMATION OF GLOBULAR-CLUSTERS .1. DYNAMIC LIMITS ON GLOBULAR-CLUSTER METALLICITIES [J].
BROWN, JH ;
BURKERT, A ;
TRURAN, JW .
ASTROPHYSICAL JOURNAL, 1991, 376 (01) :115-122
[9]   AN ESTIMATE OF THE MASS OF ZERO METAL STARS [J].
CARLBERG, RG .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1981, 197 (03) :1021-1029
[10]   Stellar models and luminosity functions for the Population II main sequence down to its lower end [J].
DAntona, F ;
Mazzitelli, I .
ASTROPHYSICAL JOURNAL, 1996, 456 (01) :329-336