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

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Low-metallicity dwarf galaxies often show no or little CO emission, despite the intense star formation observed in local samples. Both simulations and resolved observations indicate that molecular gas in low-metallicity galaxies may reside…

We study the CO(1-0)-to-H$_2$ conversion factor ($X_{\rm CO}$) and the line ratio of CO(2-1)-to-CO(1-0) ($R_{21}$) across a wide range of metallicity ($0.1 \leq Z/Z_\odot \leq 3$) in high-resolution (~0.2 pc) hydrodynamical simulations of a…

Astrophysics of Galaxies · Physics 2022-06-01 Chia-Yu Hu , Andreas Schruba , Amiel Sternberg , Ewine F. van Dishoeck

New observations of 11 compact galaxies in the 12CO J=2-1 and J=3-2 transitions and literature data have been used to construct accurate line ratios in matched beams allowing LVG modelling of physical parameters. Fitting a single gas…

Astrophysics · Physics 2009-11-11 F. P. Israel

The large scale structure and physics of molecular gas in the Galactic center region is discussed based on the analysis of a 9' resolution survey of the Galactic center region in the J=1->0 line of C^18O. Emphasis is placed on the…

Astrophysics · Physics 2007-05-23 G. Dahmen , S. Huettemeister , T. L. Wilson , R. Mauersberger

Dissociation of molecular hydrogen by secondary electrons produced by cosmic ray or X-ray ionization plays a crucial role in the chemistry of the densest part of molecular clouds. Here we study the effect of the mean kinetic energy of…

Astrophysics of Galaxies · Physics 2020-11-03 Gargi Shaw , G. J. Ferland , S. Ploeckinger

Diffuse emission in the mid-infrared shows a wealth of structure, that lends itself to high-resolution structure analysis of the interstellar gas. A large part of the emission comes from polycyclic aromatic hydrocarbons, excited by nearby…

Astrophysics · Physics 2008-11-26 F. Heitsch , B. Whitney , R. Indebetouw , M. R. Meade , B. L. Babler , E. Churchwell , ;

We present the properties of the 12CO(1-0) and (3-2) line emission from the nuclei of 60 IR luminous SLUGS galaxies. This subsample is flux limited at S60 > 5.24 Jy with FIR luminosities mostly at LFIR > 10^10 Lo. The emission line…

Astrophysics · Physics 2007-05-23 Lihong Yao

We study the relationship between molecular gas and dust in the California Molecular Cloud over an unprecedented dynamic range of cloud depth (Av = 3 - 60 magnitudes). We compare deep Herschel-based measurements of dust extinction with…

Astrophysics of Galaxies · Physics 2021-02-24 John Arban Lewis , Charles Lada , John Bieging , Anoush Kazarians , João Alves , Marco Lombardi

We present the detection of carbon monoxide molecules (CO) at z=1.6408 towards the quasar SDSSJ160457.50+220300.5 using the VLT Ultraviolet and Visual Echelle Spectrograph. CO absorption is detected in at least two components in the first…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 P. Noterdaeme , C. Ledoux , R. Srianand , P. Petitjean , S. Lopez

Our goal is to estimate the total gas mass in the direction of the Central Molecular Zone (CMZ), quantify the various uncertainties associated, and discuss the implications for the estimates of CR energy densities and dust opacities. The…

Astrophysics of Galaxies · Physics 2025-05-07 H. X. Ren , Q. Remy , S. Ravikularaman , M. Bouyahiaoui , F. Conte , J. Djuvsland

In order to study the ISM and the interplay between the atomic and molecular components in a low-metallicity environment, we present a complete high angular and spectral resolution map and data cube of the 12CO(2-1) emission from the Local…

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 present the first statistical survey of the properties of the 12CO(1-0) and 12CO(3-2) line emission from the nuclei of a nearly complete subsample of 60 infrared (IR) luminous galaxies selected from SCUBA Local Universe Galaxy Survey…

Astrophysics · Physics 2009-11-07 Lihong Yao , E. R. Seaquist , Nario Kuno , Loretta Dunne

Using archival, high-resolution far-ultraviolet HST/STIS spectra of 34 Galactic O and B stars, we measure CI column densities and compare them with measurements from the literature of CO and H_2 with regard to understanding the presence of…

Astrophysics of Galaxies · Physics 2014-11-20 Eric B. Burgh , Kevin France , Edward B. Jenkins

We explore the utility of CI as an alternative high-fidelity gas mass tracer for Galactic molecular clouds. We evaluate the X$_{\rm CI}$-factor for the 609 $\mu$m carbon line, the analog of the CO X-factor, which is the ratio of the H$_2$…

Solar and Stellar Astrophysics · Physics 2014-03-05 Stella S. R. Offner , Thomas G. Bisbas , Tom A. Bell , Serena Viti

In this study, we investigate the line emissions from cold molecular gas based on our previous "radiation-driven fountain model" (Wada 2016), which reliably explains the spectral energy distribution of the nearest type 2 Seyfert galaxy, the…

Astrophysics of Galaxies · Physics 2018-01-24 Keiichi Wada , Ryosuke Fukushige , Takuma Izumi , Koji Tomisaka

The role of star formation in luminous and ultraluminous infrared galaxies is a hotly debated issue: while it is clear that starbursts play a large role in powering the IR luminosity in these galaxies, the relative importance of possible…

Astrophysics · Physics 2014-10-13 Desika Narayanan , Christopher K. Walker , Christopher E. Groppi

Methods: 12CO emission is imaged in position and position-velocity space analyzed statistically, and then compared with maps of total reddening and with models of the C+ - CO transition in H2-bearing diffuse clouds. Results: Around Zeta…

Astrophysics of Galaxies · Physics 2015-05-13 H. S. Liszt , J. Pety , K. Tachihara

We analyze the gamma-ray emission from 9 high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope (LAT) between 250 MeV and 10 GeV. Observations of gamma-rays allow us to probe the density and spectrum of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-27 R. D. Abrahams , T. A. D. Paglione

New and archival interferometric 12CO(1->0) datasets from six nearby galaxies are combined with H_2 2.122um and H-alpha maps to explore in detail the interstellar medium in different star-forming galaxies. We investigate the relation…