Globular clusters in the Fornax dwarf spheroidal galaxy

Citation
Ks. Oh et al., Globular clusters in the Fornax dwarf spheroidal galaxy, ASTROPHYS J, 531(2), 2000, pp. 727-738
Citations number
51
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
531
Issue
2
Year of publication
2000
Part
1
Pages
727 - 738
Database
ISI
SICI code
0004-637X(20000310)531:2<727:GCITFD>2.0.ZU;2-F
Abstract
In the Fornax dwarf spheroidal galaxy, globular dusters preserve their diff use spatial distribution despite the fact that the clusters' orbital decay timescale is much shorter than the estimated age of the host galaxy. We pro pose that this paradox may be resolved if (1) Fornax contains black holes w ith a sizeable fraction of the mass of these clusters or if (2) it is curre ntly undergoing tidal disruption. For the black hole scenario, a centrally peaked velocity-dispersion distribution is anticipated but has not been obs ervationally 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.