The Role of Pressure in GMC Formation II: The H2‐Pressure Relation
Top Cited Papers
- 20 October 2006
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 650 (2), 933-944
- https://doi.org/10.1086/505417
Abstract
We show that the ratio of molecular to atomic gas in galaxies is determined by hydrostatic pressure and that the relation between the two is nearly linear. The pressure relation is shown to be good over three orders of magnitude for 14 galaxies including dwarfs, HI-rich, and H_2-rich galaxies as well as the Milky Way. The sample spans a factor of five in mean metallicity. The rms scatter of individual points of the relation is only about a factor of two for all the galaxies, though some show much more scatter than others. Using these results, we propose a modified star formation prescription based on pressure determining the degree to which the ISM is molecular. The formulation is different in high and low pressure regimes defined by whether the gas is primarily atomic or primarily molecular. This formulation can be implemented in simulations and provides a more appropriate treatment of the outer regions of spiral galaxies and molecule-poor systems such as dwarf irregulars and damped Lyman-alpha systems.Comment: 14 pages, 7 figures, Accepted to the Astrophysical JournaKeywords
This publication has 60 references indexed in Scilit:
- The Role of Pressure in Giant Molecular Cloud FormationThe Astrophysical Journal, 2004
- Giant Molecular Clouds in M33. I. BIMA All‐Disk SurveyThe Astrophysical Journal Supplement Series, 2003
- Stellar Mass‐to‐Light Ratios and the Tully‐Fisher RelationThe Astrophysical Journal, 2001
- Mass models of the Milky WayMonthly Notices of the Royal Astronomical Society, 1998
- A very large array survey of neutral hydrogen in Virgo Cluster spirals. 3: Surface density profiles of the gasThe Astronomical Journal, 1994
- The H to H2 transition in galaxies - Totally molecular galaxiesThe Astrophysical Journal, 1993
- Radio Emission from Normal GalaxiesAnnual Review of Astronomy and Astrophysics, 1992
- Third Reference Catalogue of Bright GalaxiesPublished by Springer Science and Business Media LLC ,1991
- VLA observations of neutral hydrogen in Virgo Cluster galaxies. I - The AtlasThe Astronomical Journal, 1990
- NGC 1058 - Gas motions in an extended, quiescent spiral diskThe Astrophysical Journal, 1990