Related papers: Gas phase Elemental abundances in Molecular cloudS…
We present interstellar elemental abundance measurements derived from Space Telescope Imaging Spectrograph echelle observations of 47 sight lines extending up to 6.5 kpc through the Galactic disk. These paths probe a variety of interstellar…
We report results of a project to map HCN and HCO+ J = 1-0 emission toward a sample of molecular clouds in the inner Galaxy, all containing dense clumps that are actively engaged in star formation. We compare these two molecular line…
We are just starting to understand the physical processes driving the dramatic change in cosmic star-formation rate between $z\sim 2$ and the present day. A quantity directly linked to star formation is the molecular gas density, which…
High-density molecular gas plays a vital role in supporting star formation within galaxies. However, traditional tracers of dense gas, such as the low-$J$ transitions of HCN and HCO$^+$, are predominantly optically thick. This…
We present a detailed study of the molecular gas content and stellar population properties of three massive galaxies at 1 < z < 1.3 that are in different stages of quenching. The galaxies were selected to have a quiescent…
Context: How do molecular clouds form out of the atomic phase? And what are the relative fractions of carbon in the ionized, atomic and molecular phase? These are questions at the heart of cloud and star formation. Methods: Using multiple…
(abridged) We use large cosmological simulations to study the origin of primordial star-forming clouds in a Lambda CDM universe, by following the formation of dark matter halos and the cooling of gas within them. To model the physics of…
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…
Elements in the interstellar medium (ISM) exist in the form of gas or dust. The interstellar extinction and elemental abundances provide crucial constraints on the composition, size and quantity of interstellar dust. Most of the extinction…
The thermal and chemical evolution of star-forming clouds is studied for different gas metallicities, Z, using the model of Omukai (2000), updated to include deuterium chemistry and the effects of cosmic microwave background (CMB)…
We study metal depletion due to dust in the interstellar medium (ISM) to infer the properties of dust grains and characterize the metal and dust content of galaxies, down to low metallicity and intermediate redshift z. We provide metal…
It is important to understand the origin of molecular line intensities and chemical composition in the molecular-cloud scale in the Galactic sources because it serves as a benchmark to compare with the chemical compositions of extragalactic…
The polytropic equation of state (EOS) of primordial gas clouds with modest enrichment is computed, motivated by the recent observations of very Fe-deficient stars, [Fe/H]~10^{-3.5}-10^{-5}, such as HE 0107-5240 and CS 29498-043. These…
We present an analysis of 55 central galaxies in clusters and groups with molecular gas masses and star formation rates lying between $10^{8}-10^{11}\ M_{\odot}$ and $0.5-270$ $M_{\odot}\ yr^{-1}$, respectively. We have used Chandra…
Infrared Dark Clouds are expected to harbor sources in different, very young evolutionary stages. To better characterize these differences, we observed a sample of 43 massive Infrared Dark Clouds, originally selected as candidate high-mass…
Much of what we know about molecular clouds, and by extension star formation, comes from molecular line observations. Interpreting these correctly requires knowledge of the underlying molecular abundances. Simulations of molecular clouds…
We present and analyze deep Herschel/HIFI observations of the [CII] 158um, [CI] 609um, and [CI] 370um lines towards 54 lines-of-sight (LOS) in the Large and Small Magellanic clouds. These observations are used to determine the physical…
A major challenge in CGM studies is determining the three-dimensional (3D) properties from the observed projected observations. Here, we decompose the 3D gas density and spatial distribution of cool clouds by fitting a cool CGM model with…
The objective of this paper is to construct a catalog providing the dust properties and the star formation efficiency (SFE) of the molecular clouds in the Large Magellanic Cloud (LMC). We use the infrared (IR) data obtained with the Spitzer…
The results of a survey of 63 galactic star-forming regions in the 6_K-5_K and 5_K-4_K methyl acetylene lines at 102 and 85 GHz, respectively, are presented. Fourty-three sources were detected at 102 GHz, and twenty-five at 85 GHz. Emission…