Related papers: Molecular Shattering
Molecular clouds (MC) are the densest and coldest component of the interstellar gas, and the sites of star formation. They are also turbulent and fractal and their masses and sizes span several orders of magnitude. It is also generally…
In order to theoretically understand dust properties in the circum-galactic medium (CGM), we construct a dust evolution model that incorporates the evolution of grain size distribution. We treat each of the galaxy and the CGM as a one-zone…
We describe an overall picture of galactic-scale star formation. Recent high-resolution magneto-hydrodynamical simulations of two-fluid dynamics with cooling/heating and thermal conduction have shown that the formation of molecular clouds…
Giant molecular clouds contain supersonic turbulence and simulations of magnetohydrodynamic turbulence show that these supersonic motions decay in roughly a crossing time, which is less than the estimated lifetimes of molecular clouds. Such…
Recent high resolution numerical simulations have suggested that the interstellar atomic hydrogen clouds have a complex two-phase structure. Since molecular clouds form through the contraction of HI gas, the question arises as to whether…
The circumgalactic medium (CGM) is the largest baryon reservoir around galaxies, but its extent, mass, and temperature distribution remain uncertain. We propose that cool gas ($\sim 10^4$ K) in the CGM resides in clumpy structures referred…
We present semi-analytic dynamical models for giant molecular clouds evolving under the influence of HII regions launched by newborn star clusters. In contrast to previous work, we neither assume that clouds are in virial or energetic…
We present ongoing hydrodynamic and MHD simulations of molecular cloud formation in spiral galaxies. The hydrodynamic results show the formation of molecular gas clouds where spiral shocks compress atomic gas to high densities. The spiral…
We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting…
We discuss constraints on the rates of stirring and dissipation of MHD turbulence in molecular clouds. Recent MHD simulations suggest that turbulence in clouds decays rapidly, thus providing a significant source of energy input,…
Recent years have seen excellent progress in modeling the entrainment of T $\sim$ $10^4$K atomic gas in galactic winds. However, the entrainment of cool, dusty T $\sim$ 10-100K molecular gas, which is also observed outflowing at high…
Properties of candidate stars, forming out of molecular clouds, depend on the ambient conditions of the parent cloud. We present a series of 2D and 3D simulations of fragmentation of molecular clouds in starburst regions as well as clouds…
In galaxy clusters, the hot intracluster medium (ICM) can develop a striking multi-phase structure around the brightest cluster galaxy. Much work has been done on understanding the origin of this central nebula, but less work has studied…
Astrophysical gases such as the interstellar-, circumgalactic- or intracluster-medium are commonly multiphase, which poses the question of the structure of these systems. While there are many known processes leading to fragmentation of cold…
(Abridged). In this paper, we present results from a large set of numerical simulations that demonstrate that H2 formation occurs rapidly in turbulent gas. Starting with purely atomic hydrogen, large quantities of molecular hydrogen can be…
The pervasive presence of warm gas in galaxy halos suggests that the circumgalactic medium (CGM) is multiphase in its ionization structure and complex in its kinematics. Some recent state-of-the-art cosmological galaxy simulations predict…
Using 3D hydrodynamic calculations we simulate formation of molecular clouds in the Galaxy. The simulations take into account molecular hydrogen chemical kinetics, cooling and heating processes. Comprehensive gravitational potential…
(Abridged) We present a series of decaying turbulence simulations that represent a cluster-forming clump within a molecular cloud, investigating the role of magnetic fields on the formation of potential star-forming cores. We present an…
We explore whether observed molecular clouds could include a substantial population of unbound clouds. Using simulations which include only turbulence and gravity, we are able to match observed relations and naturally reproduce the observed…
We discuss molecular cloud formation by large-scale supersonic compressions in the diffuse warm neutral medium (WNM). Initially, a shocked layer forms, and within it, a thin cold layer. An analytical model and high-resolution 1D simulations…