2004/07/19 by Stephen Murray, Stephen D. Murray, Douglas N. C. Lin +1 · 4 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/424658
published as Astrophys.J. 615 (2004) 586-594 · 24 pages, 4 color figures, pdf format (figure quality reduced from the original for better download)
arxiv created 2004/07/19 · openalex publication_date 2004/11/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
During the epoch of large galaxy formation, thermal instability leads to the formation of a population of cool fragments that are embedded within a background of tenuous hot gas. The hot gas attains a quasi-hydrostatic equilibrium. Although the cool clouds are pressure confined by the hot gas, they fall into the galactic potential, and their motion is subject to drag from the hot gas. The release of gravitational energy due to the infall of the cool clouds is first converted into their kinetic energy and is subsequently dissipated as heat. The cool clouds therefore represent a potentially significant energy source for the background hot gas, depending on the ratio of thermal energy deposited within the clouds versus the hot gas. In this paper, we show that most of the dissipated energy is deposited in the tenuous hot halo gas, providing a source of internal energy to replenish losses in the hot gas through bremsstrahlung emission and conduction into the cool clouds. The heating from the motion of the cool clouds allows the multiphase structure of the interstellar medium to be maintained.