相关论文: The Column Density Variance-Sonic Mach Number Rela…

(abridged) We report a study of the relation between dust and gas over a 100deg^2 area in the Taurus molecular cloud. We compare the H2 column density derived from dust extinction with the CO column density derived from the 12CO and 13CO J=…

We have carried out model calculations of the photoionized intergalactic medium (IGM) to determine the effects on the predicted ionic column densities due to uncertainties in the published dielectronic recombination (DR) rate coefficients.…

Constraining the physical and chemical evolution of molecular clouds is essential to our understanding of star formation. These investigations often necessitate knowledge of some local representative number density of the gas along the line…

We investigate the nature and spatial variations of turbulence in the Small Magellanic Cloud (SMC) by applying several statistical methods on the neutral hydrogen (HI) column density image of the SMC and a database of isothermal numerical…

Using hydrodynamical simulations of entire galactic discs similar to the Milky Way, reaching 4.6pc resolution, we study the origins of observed physical properties of giant molecular clouds (GMCs). We find that efficient stellar feedback is…

Supersonic flows in the interstellar medium (ISM) are believed to be a key driver of the molecular cloud formation and evolution. Among molecular clouds' properties, the ratio between the solenoidal and compressive modes of turbulence plays…

We used archival data acquired with the Copernicus satellite to reexamine CO column densities because self-consistent oscillator strengths are now available. Our focus is on lines of sight containing modest amounts of molecular species. Our…

I apply the well controlled Hydro-PM approximation of Gnedin & Hui to model the column density distribution of the Lyman-alpha forest for 25 different flat cosmological scenarios, including variants of the standard CDM, tilted CDM, CDM with…

The $^{13}$CO molecule is often used as a column density tracer in regions where the $^{12}$CO emission saturates. The $^{13}$CO column density is then related to that of $^{12}$CO by a uniform isotopic ratio. A similar approximation is…

The structure of molecular clouds can be characterized with the probability distribution function (PDF) of the mass surface density. In particular, the properties of the distribution can reveal the nature of the turbulence and star…

We run numerical simulations of molecular clouds (MCs), adopting properties similar to those found in the Central Molecular Zone (CMZ) of the Milky Way. For this, we employ the moving mesh code Arepo and perform simulations which account…

Colliding supersonic bulk flows shape observable properties and internal physics of various astrophysical objects, like O-star winds, molecular clouds, galactic sheets, binaries, or gamma-ray bursts. Using numerical simulations, we show…

To measure interstellar atomic deuterium abundances, we used the Interstellar Medium Absorption Profile Spectrograph (IMAPS) to obtain spectra of gamma2 Vel and zeta Pup over the wavelength interval 930-1150 A at a resolving power of…

We calculate the cosmic Mach number M - the ratio of the bulk flow of the velocity field on scale R to the velocity dispersion within regions of scale R. M is effectively a measure of the ratio of large-scale to small-scale power and can be…

Colliding hypersonic flows play a decisive role in many astrophysical objects. In this paper, we look at the idealized model of a 2D plane parallel isothermal slab (CDL) and at symmetric settings, where both flows have equal parameters. We…

We numerically study the volume density probability distribution function (n-PDF) and the column density probability distribution function (Sigma-PDF) resulting from thermally bistable turbulent flows. We analyze three-dimensional…

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which…

Simulations generally show that non-self-gravitating clouds have a lognormal column density ($\Sigma$) probability distribution function (PDF), while self-gravitating clouds with active star formation develop a distinct power-law tail at…

Supersonic turbulence results in strong density fluctuations in the interstellar medium (ISM), which have a profound effect on the chemical structure. Particularly useful probes of the diffuse ISM are the ArH$^+$, OH$^+$, H$_2$O$^+$…

Mass models of 15 nearby dwarf and spiral galaxies are presented. The galaxies are selected to be homogeneous in terms of the method used to determine their distances, the sampling of their rotation curves (RCs) and the mass-to-light ratio…