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Related papers: The Structure of a Low-Metallicity Giant Molecular…

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The factor relating CO emission to molecular hydrogen column density, XCO, is still subject to uncertainty, in particular at low metallicity. Here, to quantify XCO at two different spatial resolutions, we exploit a dust-based method…

Context. High latitude molecular clouds (hereafter HLMCs) permit the study of interstellar gas dynamics and astrochemistry with good accuracy due to their proximity, generally clear lines of sight, and lack of internal star-forming activity…

Astrophysics of Galaxies · Physics 2023-01-16 Marco Monaci , Loris Magnani , Steven N. Shore

The data from the Nobeyama Radio Observatory 45 m telescope Galactic Center CO survey have been analyzed to generate a compilation of molecular clouds with intense CO emission in this region. Clouds are identified in an automated manner…

Astrophysics · Physics 2009-10-31 T. Oka , T. Hasegawa , F. Sato , M. Tsuboi , A. Miyazaki

We present an analysis of Giant Molecular Clouds (GMCs) within hydrodynamic simulations of isolated, low-mass (M* ~ 10^9 M_sol) disc galaxies. We study the evolution of molecular abundances and the implications for CO emission and the X_CO…

Astrophysics of Galaxies · Physics 2016-07-27 Alexander J. Richings , Joop Schaye

In this review, I discuss recent detailed studies of individual molecular clouds in M33 in higher rotational transitions of CO, 13CO, and the fine structure line of atomic carbon. These data reveal that the temperature and density of the…

Astrophysics · Physics 2007-05-23 C. D. Wilson

We aim to explore the capabilities of dust emission and rays for probing the properties of the interstellar medium in the nearby anti-centre region, using gamma-ray observations with the Fermi Large Area Telescope (LAT), and the thermal…

High Energy Astrophysical Phenomena · Physics 2017-05-10 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

We present the ALMA survey of CO(2-1) emission from the 1/5 solar metallicity, Local Group dwarf galaxy NGC 6822. We achieve high (0.9 arcsec ~ 2 pc) spatial resolution while covering large area: four 250 pc x 250 pc regions that encompass…

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial…

Astrophysics · Physics 2009-11-13 M. Dessauges-Zavadsky , F. Combes , D. Pfenniger

Theoretical and observational investigations have indicated that the abundance of carbon monoxide (CO) is very sensitive to intrinsic properties of the gaseous medium, such as density, metallicity, and the background UV field. In order to…

Astrophysics of Galaxies · Physics 2015-05-20 Rahul Shetty , Simon C. Glover , Cornelis P. Dullemond , Ralf S. Klessen

We modelled recent observations of UV absorption of HD and \HH\ in the Milky Way and toward damped/sub-damped Lyman alpha systems at z=0.18 and z $>$ 1.7. N(HD)/N(\HH) ratios reflect the separate self-shieldings of HD and \HH\ and the…

Astrophysics of Galaxies · Physics 2015-06-23 H. S. Liszt

We aim to better understand the emission of molecular tracers of the diffuse and dense gas in giant molecular clouds and the influence that metallicity, optical extinction, density, far-UV field, and star formation rate have on these…

We study a population of significantly sub-solar enrichment galaxies at z=1.99, to investigate how molecular gas, dust and star-formation relate in low-metallicity galaxies at the peak epoch of star-formation. We target our sample with…

Astrophysics of Galaxies · Physics 2019-02-20 R. T. Coogan , M. T. Sargent , E. Daddi , F. Valentino , V. Strazzullo , M. Béthermin , R. Gobat , D. Liu , G. Magdis

We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC, together -- the MCs) as measured by UV absorption spectroscopy. We have measured P II and Fe II along 85 sightlines toward the MCs…

We model the effect of grain size distribution in a galaxy on the evolution of CO and H$_2$ abundances. The formation and dissociation of CO and H$_2$ in typical dense clouds are modelled in a manner consistent with the grain size…

Astrophysics of Galaxies · Physics 2023-05-10 Hiroyuki Hirashita

We report the results of our observations of the 12CO (J=1-0) and 12CO (J=3-2) line emission of 74 major giant molecular clouds (GMCs) within the galactocentric distance of 5.1 kpc in the Local Group galaxy M33. The observations have been…

Understanding the molecular gas content in the interstellar medium (ISM) is crucial for studying star formation and galaxy evolution. The CO-to-H$_2$ ($X_{\rm CO}$) and the [CI]-to-H$_2$ ($X_{\rm CI}$) conversion factors are widely used to…

We present a morphological and physical analysis of a Giant Molecular Cloud (GMC) using the carbon monoxide isotopologues ($^{12}$CO, $^{13}$CO, C$^{18}$O $^{3}P_{2}\rightarrow$ $^{3}P_{1}$) survey of the Galactic Plane (Mopra CO Southern…

We analyze the conditions for detection of CO(1-0) emission in the Large Magellanic Cloud (LMC), using the recently completed second NANTEN CO survey. In particular, we investigate correlations between CO integrated intensity and HI…

Astrophysics of Galaxies · Physics 2011-02-11 T. Wong , A. Hughes , Y. Fukui , A. Kawamura , N. Mizuno , J. Ott , E. Muller , J. L. Pineda , D. E. Welty , S. Kim , Y. Mizuno , M. Murai , T. Onishi

Do molecular clouds collapse to form stars at the same rate in all environments? In large spiral galaxies, the rate of transformation of H2 into stars (hereafter SFE) varies little. However, the SFE in distant objects (z~1) is much higher…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 P. Gratier , J. Braine , N. J. Rodriguez-Fernandez , F. P. Israel , K. F. Schuster , N. Brouillet , E. Gardan