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Related papers: The CO-H2 conversion factor of diffuse ISM: Bright…

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We present a study on the molecular gas towards a bright-rimmed cloud located to the north of the infrared dust bubble N30. Using the emission from the 12CO, 13CO, and C18O J=3-2 line, together with infrared and radio continuum data, we…

Astrophysics of Galaxies · Physics 2020-01-09 A. Solernó , M. B. Areal , S. Paron

We investigate the molecular gas content and the excitation and fragmentation properties in the central region of the spiral galaxy Messier 81 in both the ^{12}CO(1-0) and ^{12}CO(2-1) transitions. We have recently observed the two…

Astrophysics · Physics 2009-11-13 V. Casasola , F. Combes , D. Bettoni , G. Galletta

Using the Planck far-infrared and Arecibo GALFA 21-cm line surveys, we identified a set of isolated interstellar clouds (approximately degree-sized on the sky and comprising 100 solar masses) and assessed the ratio of gas mass to dust mass.…

Astrophysics of Galaxies · Physics 2015-10-07 William T. Reach , Carl Heiles , Jean-Philippe Bernard

To understand the environment and extended structure of the host galactic gas whose molecular absorption line chemistry, we previously observed along the microscopic line of sight to the blazar/radiocontinuum source NRAO150 (aka B0355+508),…

Astrophysics · Physics 2009-11-13 Jérôme Pety , Robert Lucas , Harvey S. Liszt

We present CO velocity fields and rotation curves for a sample of nearby galaxies, based on data from the HERACLES survey. We combine our data with literature THINGS, SINGS and KINGFISH results to provide a comprehensive sample of mass…

Astrophysics of Galaxies · Physics 2016-04-06 Bradley S. Frank , W. J. G. de Blok , F. Walter , A. Leroy , C Carignan

We have investigated the two-dimensional (R,Z) distribution of deuterated molecular species in circumstellar disks around young stellar objects. The abundance ratios between singly deuterated and normal molecules (``D/H ratios'') in disks…

Astrophysics · Physics 2009-11-07 Y. Aikawa , E. Herbst

CO emission has been widely used as a tracer of molecular gas mass. However, it is a long-standing issue to accurately constrain the CO-to-H$_2$ conversion factor ($\alpha_{\mathrm{CO}}$) that converts CO luminosity to molecular gas mass,…

Astrophysics of Galaxies · Physics 2024-06-11 Hao He , Christine D. Wilson , Jiayi Sun , Yu-Hsuan Teng , Erik Rosolowsky , Ashley R. Bemis

Many recent models consider the structure of individual interstellar medium (ISM) clouds as a way to explain observations of large parts of galaxies. To compare such models to observations, one must understand how to translate between…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Adam K. Leroy , Cheoljong Lee , Andreas Schruba , Alberto Bolatto , Annie Hughes , Jerome Pety , Karin Sandstrom , Eva Schinnerer , Fabian Walter

We have derived the column densities of heavy elements in three gamma-ray burst (GRB) optical transients, associated with the circumburst or interstellar medium (ISM) of the host galaxy. In comparison with the same elements observed in…

Astrophysics · Physics 2009-11-07 S. Savaglio , S. M. Fall , F. Fiore

We investigate the chemical evolution of a forming molecular cloud behind an interstellar shock wave. We conduct three-dimensional magnetohydrodynamics simulations of the converging flow of atomic gas, including a simple chemical network…

Astrophysics of Galaxies · Physics 2026-01-08 Yuto Komichi , Yuri Aikawa , Kazunari Iwasaki , Kenji Furuya

The reliability of modeling the far-IR continuum to 13CO J=1-0 spectral line ratios applied to the Orion clouds (Wall 2006) is tested by applying the models to simulated data. The two-component models are found to give the dust-gas…

Astrophysics · Physics 2008-11-26 W. F. Wall

Surveying eighteen 12CO-bright galaxies from the ATLAS3D early-type galaxy sample with the Institut de Radio Astronomie Millim\'etrique (IRAM) 30m telescope, we detect 13CO(1-0) and 13CO(2-1) in all eighteen galaxies, HCN(1-0) in 12/18 and…

Observations of translucent molecular gas in $^{12}$CO and $^{13}$CO emission lines, at high spectral and spatial resolutions, evidence different kinds of structures at small scales: (1) optically thin $^{12}$CO emission, (2) optically…

Astrophysics · Physics 2007-05-23 Pierre Hily-Blant , Jerome Pety , Edith Falgarone

The content of interstellar clouds, in particular the inventory of diffuse molecular gas, remains uncertain. We identified a sample of isolated clouds, approximately 100 solar masses in size, and used the dust content to estimate the total…

Astrophysics of Galaxies · Physics 2017-07-25 William T. Reach , Carl Heiles , Jean-Philippe Bernard

We have observed several cloud cores in the Orion B (L1630) molecular cloud in the 2-1 transitions of C18O, C17O and 13C18O. We use these data to show that a model where the cores consist of very optically thick C18O clumps cannot explain…

Astrophysics · Physics 2009-11-07 D. Savva , L. T. Little , R. R. Phillips , A. G. Gibb

Gas outflows are believed to play a pivotal role in shaping galaxies, as they regulate both star formation and black hole growth. Despite their ubiquitous presence, the origin and the acceleration mechanism of such powerful and extended…

In the last few years new evidence has been presented for the presence of ongoing massive star formation in the outer HI disks of galaxies. These discoveries strongly suggest that precursor molecular gas must also be present in some…

Astrophysics · Physics 2007-05-23 Ronald J. Allen , Rosa Diaz-Miller

We present CO observations of 9 ULIRGs at z~2 with S(24\mu m)>1mJy, previously confirmed with the mid-IR spectra in the Spitzer First Look Survey. All targets are required to have accurate redshifts from Keck/GEMINI near-IR spectra. Using…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Lin Yan , L. ~J. Tacconi , N. Fiolet , A. Sajina , A. Omont , D. Lutz , M. Zamojski , R. Neri , P. Cox , K. ~M. Dasyra

The ISM is a turbulent, multi-phase, and multi-scale medium following scaling relations. Analytical models of galactic gaseous disks need to take into account the multi-scale and multi-phase nature of the interstellar medium. They can be…

Astrophysics of Galaxies · Physics 2022-07-27 T. Lizée , B. Vollmer , J. Braine , P. Gratier , F. Bigiel

We present a cross-calibration of CO- and dust-based molecular gas masses at $z \leqslant 0.2$. Our results are based on a survey with the IRAM 30-m telescope collecting CO(1-0) measurements of 78 massive ($\log M_{\star} / M_{\odot} > 10$)…