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Constraints on baryonic dark matter in the Galactic halo and Local GroupA four-color method and deep CCD data are used to search for very faint metal-poor stars in the direction of the south Galactic pole. The results make it possible to limit the contribution of ordinary old, metal-poor stars to the dynamical halo of the Galaxy or to the Local Group. The ratio of the mass of the halo to its ordinary starlight must be more than about 2000, unless the halo is very small. For the Local Group, this ratio is greater than about 400. If this local dark matter is baryonic, the process of compact-object formation must produce very few 'impurities' in the form of stars similar to those found in globular clusters. The expected number of unbound stars with MV not greater than 6 within 100 pc of the sun is less than 1 based on the present 90-percent upper limit to the Local Group starlight.
Document ID
19920050390
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Richstone, Douglas (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Gould, Andrew (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Guhathakurta, Puragra (Institute for Advanced Study Princeton, NJ, United States)
Flynn, Chris (Astronomisches Rechen-Institut Heidelberg, Federal Republic of Germany, United States)
Date Acquired
August 15, 2013
Publication Date
April 1, 1992
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 388
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF PHY-86-20266
CONTRACT_GRANT: NAS5-29225
CONTRACT_GRANT: NSF AST-87-20028
CONTRACT_GRANT: NSF AST-88-02533
Distribution Limits
Public
Copyright
Other