Year: 2002
Type: article
Abstract: We use three-dimensional hydrodynamic numerical simulations to study phase transformations occurring in a clumpy interstellar gas exposed to time-dependent volumetric heating. To mimic conditions in the Galactic interstellar medium, we take a numerical model of a turbulent multiphase medium from Kritsuk & Norman computed in a periodic box with mean density n 0 = 0.25 cm -3 and mean pressure P 0 / k ~ 10 3.4 K cm -3 . A second model with n 0 = 1 cm -3 is also considered. Variations of the heating rate on a timescale of 1-10 Myr applied thereafter cause pressure variations in the gas and shifting of the thermal equilibrium curve in the phase plane. This stimulates mass transfer between the gas phases via thermal instability, converting 5%-10% of the thermal energy into kinetic energy of gas motions. The experiments demonstrate that recurrent substantial heating episodes can maintain turbulence at this level. Possible applications to the interstellar gas heated by variable far-ultraviolet background radiation produced by short-living massive stars are discussed.
Source: The Astrophysical Journal
DOI: 10.1086/345388
Authors: Alexei G. Kritsuk, Michael L. Norman
Institution: University of California San Diego
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2004980938