相关论文: A Model for the Internal Structure of Molecular Cl…
We present an analysis of the systematic CO(2-1) survey at 12" resolution covering most of the local group spiral M 33 which, at a distance of 840 kpc, is close enough that individual giant molecular clouds (GMCs) can be identified. The…
The probability distribution function (PDF) of the mass surface density of molecular clouds provides essential information about the structure of molecular cloud gas and condensed structures out of which stars may form. In general, the PDF…
We present an analysis of the large-scale molecular cloud structure and of the stability of clumpy structures in nearby molecular clouds. In our recent work, we identified a structural transition in molecular clouds by studying the…
Modern extragalactic molecular gas surveys now reach the scales of star-forming giant molecular clouds (GMCs, 20-50 pc). Systematic variations in GMC properties with galaxy environment imply that clouds are not universally self-gravitating…
We present an analysis comparing the properties of 45 giant molecular clouds (GMCs) in M33 and the atomic hydrogen (HI) with which they are associated. High-resolution VLA observations are used to measure the properties of HI in the…
We present 12CO(1->0) observations of 45 giant molecular clouds in M33 made with the BIMA array. The observations have a linear resolution of 20 pc, sufficient to measure the sizes of most GMCs in the sample. We place upper limits on the…
We demonstrate the utility of dendrograms at representing the essential features of the hierarchical structure of the isosurfaces for molecular line data cubes. The dendrogram of a data cube is an abstraction of the changing topology of the…
Using local 3D MHD simulations, we investigate ways in which galactic turbulence associated with the magnetorotational instability (MRI) may influence the formation and properties of GMCs. Our disk models are vertically stratified and…
We study the linear evolution of small perturbations in self-gravitating fluid systems with magnetic fields. We consider wave-like perturbations to nonuniform filamentary and sheet-like hydrostatic equilibria in the presence of a uniform…
The core structure of galaxy clusters is fundamentally important. Even though self-gravitating systems have no stable equilibrium state due to their negative heat capacity, numerical simulations find density profiles which are universal in…
Despite decades of direct and indirect searches within the Weakly Interacting Massive Particle (WIMP) framework, no conclusive results have been found in the GeV--TeV range. This has motivated exploring alternatives, including new particles…
We study the equilibrium of pressure truncated, filamentary molecular clouds that are threaded by rather general helical magnetic fields. We first derive a new virial equation appropriate for magnetized filamentary clouds, which includes…
We present an analytic description of the spherically symmetric gravitational collapse of radiatively cooling gas clouds, which illustrates the mechanism by which radiative cooling induces gravitational instability at a characteristic mass…
The dynamic properties of molecular clouds are set by the interplay of their self-gravity, turbulence, external pressure and magnetic fields. Extended surveys of Galactic molecular clouds typically find that their kinetic energy ($E_{\rm…
We investigate physical properties of molecular clouds in disc galaxies with different morphology: a galaxy without prominent structure, a spiral barred galaxy and a galaxy with flocculent structure. Our $N$-body/hydrodynamical simulations…
We present a numerical study of the balance between the gravitational (Eg), kinetic (Ek), and magnetic (Em) energies of structures within a hub-filament system in a simulation of the formation and global hierarchical collapse (GHC) of a…
We present virial models for the global evolution of giant molecular clouds. Focusing on the presence of an accretion flow, and accounting for the amount of mass, momentum, and energy supplied by accretion and star formation feedback, we…
Molecular clouds have complex density structures produced by processes including turbulence and gravity. We propose a triangulation-based method to dissect the density structure of a molecular cloud and study the interactions between dense…
We present simulations of the evolution of self-gravitating dense gas on kiloparsec-size scales in a galactic disk, designed to study dense clump formation from giant molecular clouds (GMCs). These dense clumps are expected to be the…
In order to understand the origin of observed molecular cloud properties, it is critical to understand how clouds interact with their environments during their formation, growth, and collapse. It has been suggested that accretion-driven…