Extreme Dark Matter Dominated Dwarfs
نویسندگان
چکیده
منابع مشابه
Extreme Dark Matter Dominated Dwarfs
The results of a large radial velocity survey of the Draco and Ursa Minor dwarf spheroidal galaxies are presented. The velocity dispersion profiles of both objects are very similar: initially the dispersion increases with radius, while at radii approaching the outer limit of the stellar distribution we observe a sharp fall-off. We present the results of mass modeling based on these new data the...
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We use kinematic data from three new nearby, extremely low luminosity Milky Way dwarf galaxies (Ursa Major II, Willman 1, and Coma Berenices) to constrain the properties of their dark matter halos, and from these we make predictions for the -ray flux from annihilation of dark matter particles in these halos. We show that these 10 L dwarfs are the most dark-matter–dominated galaxies known, with ...
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We discuss the recent discovery by Oppenheimer et al (2001) of old, cool white dwarf stars, which may be the first direct detection of Galactic halo dark matter. We argue here that the contribution of more mundane white dwarfs of the stellar halo and thick disk would contribute sufficiently to explain the new high velocity white dwarfs without invoking putative white dwarfs of the dark halo. Th...
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“Extreme Scattering Events” (ESEs) are attributed to radio-wave refraction by a cloud of free-electrons crossing the line-of-sight. We present a new model in which these electrons form the photo-ionized ‘skin’ of an underlying cool, self-gravitating cloud in the Galactic halo. In this way we avoid the severe over-pressure problem which afflicts other models. The UV flux in the Galactic halo nat...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 2004
ISSN: 0074-1809
DOI: 10.1017/s0074180900183640