2001/09/12 by Philipp Richter, Richter, Philipp
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0109191
6 pages, 1 figure; To be published in the Proceedings of the Meeting on Gaseous Matter in Galactic and Intergalactic Space, XVIIth IAP Colloquium, Paris, 19-23 June, 2001
arxiv created 2001/09/12 · arxiv updated 2009/12/01
I review recent observations of molecular gas in the halo of the Milky Way and in the Magellanic Clouds. Far-ultraviolet absorption line studies of molecular hydrogen (H2) with ORFEUS and FUSE have unveiled the presence of a diffuse molecular hydrogen component in intermediate- and high-velocity clouds in the Galactic halo. Although the number of measurements is still quite small, the data suggests that diffuse H2 in the halo exists only in clouds that contain a sufficient amount of heavy elements and dust, on whose surface the H2 formation proceeds most efficiently. The implications of these observations for our understanding of the Milky Way halo are discussed.