Detecting Dark Matter in High Velocity Clouds

Abstract

Many high velocity HI clouds (HVCs) are now believed to be scattered throughout the Galactic halo on scales of tens of kiloparsecs. Some of these clouds appear to contain substantial HI masses (>10^6 Msun). It has been suggested that these structures may be associated with dark matter `mini halos' accreting onto the Galactic halo. For a compact HVC along the sight line to a more distant galaxy, we demonstrate that `pixel gravitational lensing' provides a crucial test for the presence of a dark halo in the form of massive compact objects. The detection of pixel lensing will provide an independent means to map the mass distribution within HVCs.

6 page, to appear in P.A.S.P. Research Notes (Oct 2000)

References in corpus (5)

• Dark Matter Substructure in Galactic Halos
• Gas Rich Dwarf Spheroidals
• A confirmed location in the Galactic halo for the high-velocity cloud 'chain A'
• The Space Density of Primordial Gas Clouds near Galaxies and Groups and their Relation to Galactic HVCs
• Is Galactic Structure Compatible with Microlensing Data?

Cited by in corpus (4)

• The New Galaxy: Signatures of its Formation
• How Lumpy is the Milky Way's Dark Matter Halo?
• SDSS Survey for Resolved Milky Way Satellite Galaxies II: High-Velocity Clouds in the Early Data Release
• Search for dark matter in compact hydrogen clouds