Globular clusters in the Fornax dwarf spheroidal galaxy

被引:54
作者
Oh, KS [1 ]
Lin, DNC
Richer, HB
机构
[1] Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305764, South Korea
[2] Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Board Studies Astron & Astrophys, Santa Cruz, CA 95064 USA
[3] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada
关键词
galaxies : individual (Fornax); galaxies : interactions; galaxies : star clusters; galaxies : structure;
D O I
10.1086/308477
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
In the Fornax dwarf spheroidal galaxy, globular dusters preserve their diffuse spatial distribution despite the fact that the clusters' orbital decay timescale is much shorter than the estimated age of the host galaxy. We propose that this paradox may be resolved if (1) Fornax contains black holes with a sizeable fraction of the mass of these clusters or if (2) it is currently undergoing tidal disruption. For the black hole scenario, a centrally peaked velocity-dispersion distribution is anticipated but has not been observationally confirmed. The second scenario requires Fornax to have lost a significant fraction of its original mass. The second scenario is possible if the mass of the Galactic dark matter is similar to 10(12) M. out to the present distance of the Fornax dwarf spheroidal galaxy or if Fornax is near its apogalacticon and has an orbit similar to that of the Large Magellanic Cloud. The inferred proper motion, less than or equal to 0 ".16 century(-1), for Fornax and the anticipated stream of tidally stripped stars outside its tidal radius may be used to test this scenario.
引用
收藏
页码:727 / 738
页数:12
相关论文
共 51 条
[2]  
AARONSON M, 1987, IAU S, V117, P153
[3]  
AARSETH SJ, 1985, MULTIPLE TIME SCALES, P377
[4]  
Binney J., 2008, GALACTIC DYNAMICS
[5]   The ages of the globular clusters in the Fornax dwarf galaxy [J].
Buonanno, R ;
Corsi, CE ;
Zinn, R ;
Pecci, FF ;
Hardy, E ;
Suntzeff, NB .
ASTROPHYSICAL JOURNAL, 1998, 501 (01) :L33-L36
[6]   Dynamical friction - I. General considerations: The coefficient of dynamical friction [J].
Chandrasekhar, S .
ASTROPHYSICAL JOURNAL, 1943, 97 (02) :255-262
[7]   LARGE-SCALE PHOTOGRAPHIC SURVEY OF FORNAX [J].
DEMERS, S ;
IRWIN, MJ ;
KUNKEL, WE .
ASTRONOMICAL JOURNAL, 1994, 108 (05) :1648-1657
[8]   CORE VELOCITY DISPERSIONS AND METALLICITIES OF 3 GLOBULAR-CLUSTERS BELONGING TO THE FORNAX DWARF SPHEROIDAL GALAXY [J].
DUBATH, P ;
MEYLAN, G ;
MAYOR, M .
ASTROPHYSICAL JOURNAL, 1992, 400 (02) :510-515
[9]   IS THERE NONLUMINOUS MATTER IN DWARF SPHEROIDAL GALAXIES [J].
FABER, SM ;
LIN, DNC .
ASTROPHYSICAL JOURNAL, 1983, 266 (01) :L17-L20
[10]  
Genzel R., 1997, Monthly Notices of the Royal Astronomical Society, V291, P219