Related papers: Molecular Line Profiles of Collapsing Gas Clouds
We investigate the uncertainties affecting the temperature profiles of dense cores of interstellar clouds. In regions shielded from external ultraviolet radiation, the problem is reduced to the balance between cosmic ray heating, line…
Radial density profiles for the sample of dense cores associated with high-mass star-forming regions from southern hemisphere have been derived using the data of observations in continuum at 250 GHz. Radial density profiles for the inner…
Our understanding of how molecular clouds form in the interstellar medium (ISM) would be greatly helped if we had a reliable observational tracer of the gas flows responsible for forming the clouds. Fine structure emission from singly…
A fundamental issue in star formation is understanding the precise mechanisms leading to the formation of prestellar cores, and their subsequent gravitationally unstable evolution. To address this question, we carefully construct a suite of…
We present the results of a three-dimensional Monte Carlo radiative transfer code for starless molecular cloud cores heated by an external isotropic or non-isotropic interstellar radiation field. The code computes the dust temperature…
We study the prospects for observing H$_2$ and HD emission during the assembly of primordial molecular cloud cores. The primordial molecular cloud cores, which resemble those at the present epoch, can emerge around $1+z \sim 20$ according…
The $\rm H_2$ mass of molecular clouds has traditionally been traced by the CO(J=1-0) rotational transition line. This said, CO is relatively easily photodissociated, and can also be destroyed by cosmic rays, thus rendering some fraction of…
We present results from the first three-dimensional calculations ever to follow the collapse of a molecular cloud core (~ 10^{-18} g cm^{-3}) to stellar densities (> 0.01 g cm^{-3}). The calculations resolve structures over 7 orders of…
This paper considers the phenomenon of deep core collapse in collisional stellar systems, with stars of equal mass. The collapse takes place on some multiple, $\xi ^{-1}$, of the central relaxation time, and produces a density profile in…
The physical structure of hot molecular cores, where forming massive stars have heated up dense dust and gas, but have not yet ionized the molecules, poses a prominent challenge in the research of high-mass star formation and…
The study of multiple molecular spectral lines in gas infalling sources can provide the physical and chemical properties of these sources and help us estimate their evolutionary stages. We report line detections within the 3 mm band using…
Hot molecular cores (HMCs) are intermediate stages of high-mass star formation and are also known for their rich emission line spectra at (sub-)mm wavebands. The observed spectral feature of HMCs such as total number of emission lines and…
We present the detection analysis of a diffuse molecular cloud at z$_{abs}$=2.4636 towards the quasar SDSS J1513+0352(z$_{em}\,\simeq$ 2.68) observed with the X-shooter spectrograph(VLT). We measure very high column densities of atomic and…
The density profile of a cool core of intracluster gas is investigated for a cluster of galaxies that is initially in the virial equilibrium state, and then undergoes radiative cooling. The initial gas profile is derived under the…
Using a source selection biased towards high mass star forming regions, we used a Large Velocity Gradient (LVG) code to calculate the H2 densities and CS column densities for a sample of Midcourse Space Experiment (MSX) 8 micron infrared…
We study four lines of sight that probe the transition from diffuse molecular gas to molecular cloud material in Taurus. Measurements of atomic and molecular absorption are used to infer the distribution of species and the physical…
We use numerical hydrodynamic simulations to investigate prestellar core formation in the dynamic environment of giant molecular clouds, focusing on planar post-shock layers produced by colliding turbulent flows. A key goal is to test how…
We present a catalogue of molecular cloud cores drawn from high latitude, medium opacity clouds, using the all-sky IRAS Sky Survey Atlas (ISSA) images at 60 and 100~$\mu$m. The typical column densities of the cores are $ N(H_2)\sim 3.8…
This paper presents results from modelling 450 micron and 850 micron continuum and HCO+ line observations of three distinct cores of an infrared dark cloud (IRDC) directed toward the W51 GMC. In the sub-mm continuum these cores appear as…
Molecular emission arising from the interactions of supernova remnant (SNR) shock waves and molecular clouds provide a tool for studying the dispersion and compression that might kick-start star formation as well as understanding cosmic ray…