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Related papers: Deriving a multivariate CO-to-H$_2$ conversion fun…

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We present three-dimensional astrochemical simulations and synthetic observations of magnetised, turbulent, self-gravitating molecular clouds. We explore various galactic interstellar medium environments, including cosmic-ray ionization…

Astrophysics of Galaxies · Physics 2021-01-20 Thomas G. Bisbas , Jonathan C. Tan , Kei E. I. Tanaka

We present ALLSMOG, the APEX Low-redshift Legacy Survey for MOlecular Gas. ALLSMOG is a survey designed to observe the CO(2-1) emission line with the APEX telescope, in a sample of local galaxies (0.01 < z < 0.03), with stellar masses in…

We present theoretically-established values of the CO-to-H2 and C-to-H2 conversion factors that may be used to estimate the gas masses of external galaxies. We consider four distinct galaxy types, represented by M51, NGC 6946, M82 and SMC…

Astrophysics · Physics 2009-06-23 T. A. Bell , S. Viti , D. A. Williams

We exploit the unprecedented depth of integral field data from the KMOS Ultra-deep Rotational Velocity Survey (KURVS) to analyse the strong (H$\alpha$) and forbidden ([NII], [SII]) emission line ratios in 22 main-sequence galaxies at…

Carbon monoxide (CO) emission is a widely used tracer of molecular hydrogen (H$_2$) in the interstellar medium (ISM), owing to its abundance, low excitation energy, and ease of detection in cold molecular environments, in contrast to…

Astrophysics of Galaxies · Physics 2025-11-24 Mark Gorski , Lena Murchikova

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

The fundamental process of star formation in galaxies involves the interplay between the fueling of star formation via molecular gas and the feedback from recently formed massive stars. This process, by which galaxies evolve, is also…

We analyze the CO-to-H$_2$ conversion factor ($\alpha_{\rm{CO}}$) in the nearby barred spiral galaxy M83. We present new HI observations from the JVLA and single-dish GBT in the disk of the galaxy, and combine them with maps of CO(1-0)…

Astrophysics of Galaxies · Physics 2024-04-24 Amanda M Lee , Jin Koda , Akihiko Hirota , Fumi Egusa , Mark Heyer

We investigate the relationship between the dust-to-metals ratio (D/M) and the local interstellar medium environment at ~2 kpc resolution in five nearby galaxies: IC342, M31, M33, M101, and NGC628. A modified blackbody model with a broken…

Using the Atacama Large Millimeter/submillimeter Array, we have made the first high spatial and spectral resolution observations of the molecular gas and dust in the prototypical blue compact dwarf galaxy II Zw 40. The CO(2-1) and CO(3-2)…

Astrophysics of Galaxies · Physics 2016-09-07 Amanda A. Kepley , Adam K. Leroy , Kelsey E. Johnson , Karin Sandstrom , C. -H. Rosie Chen

The CO-to-H$_2$ conversion factor ($\alpha_\rm{CO}$) is critical to studying molecular gas and star formation in galaxies. The value of $\alpha_\rm{CO}$ has been found to vary within and between galaxies, but the specific environmental…

The rotational transitions of carbon monoxide (CO) are the primary means of investigating the density and velocity structure of the molecular interstellar medium. Here we study the lowest four rotational transitions of CO towards…

Astrophysics · Physics 2009-10-31 James G. Ingalls , T. M. Bania , Adair P. Lane , Matthias Rumitz , Antony A. Stark

We report the detection of the CO J=1-0 emission line in three near-infrared selected star-forming galaxies at z~1.5 with the Very Large Array (VLA) and the Green Bank telescope (GBT). These observations directly trace the bulk of molecular…

We simultaneously measured the spatially-resolved CO-to-H$_{2}$ conversion factor ($\alpha_\mathrm{CO}$) and dust-to-gas ratio (DGR) in nearby galaxies on a kiloparsec scale. In this study, we used $^{12}$CO($J=1-0$) data obtained by the…

Assessments of the cold-gas reservoir in galaxies are a cornerstone for understanding star-formation processes and the role of feedback and baryonic cycling in galaxy evolution. Here we exploit a sample of 392 galaxies (dubbed MAGMA,…

Astrophysics of Galaxies · Physics 2020-11-25 L. K. Hunt , C. Tortora , M. Ginolfi , R. Schneider

The formation of molecular hydrogen (H$_2$) and carbon monoxide (CO) is sensitive to the volume and column density distribution of the turbulent interstellar medium. In this paper, we study H$_2$ and CO formation in a large set of…

Astrophysics of Galaxies · Physics 2019-01-23 P. R. Joshi , S. Walch , D. Seifried , S. C. O. Glover , S. D. Clarke , M. Weis

[Abridged] We present maps of CO 2-1 emission covering the entire star-forming disks of 16 nearby dwarf galaxies observed by the IRAM HERACLES survey. The data have 13 arcsec angular resolution, ~250 pc at our average distance of 4 Mpc, and…

We wish to relate the degree scale structure of galactic diffuse clouds to sub-arcsecond atomic and molecular absorption spectra obtained against extragalactic continuum background sources. To do this, we used the ARO 12m telescope to map…

Astrophysics of Galaxies · Physics 2015-06-04 H. S. Liszt , J. Pety

We study the evolution of the cold gas content of galaxies by splitting the interstellar medium into its atomic and molecular hydrogen components, using the galaxy formation model GALFORM in the LCDM framework. We calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Claudia del P. Lagos , Carlton M. Baugh , Cedric G. Lacey , Andrew J. Benson , Han-Seek Kim , Chris Power

We select a disk-like galaxy sample with observations of the $HI$, $H_{2}$ and dust from Herschel Reference Survey (HRS), and derive inner HI masses within the optical radius. We find that the inner gas-to-dust ratio is almost independent…

Astrophysics of Galaxies · Physics 2023-06-28 Fujia Li , Jing Wang , Fengwei Xu , Xu Kong , Xinkai Chen , Zesen Lin , Shun Wang