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Related papers: Do Spectroscopic Dense Gas Fractions Track Molecul…

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Our aim is to explore the relation between gas, atomic and molecular, and dust in spiral galaxies. Gas surface densities are from atomic hydrogen and CO line emission maps. To estimate the dust content, we use the disk opacity as inferred…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 B. W. Holwerda , R. J. Allen , W. J. G. de Blok , A. Bouchard , R. A. Gonzalez-Lopezlira , P. C. van der Kruit , A. Leroy

Emission from carbon monoxide (CO) is ubiquitously used as a tracer of dense star forming molecular clouds. There is, however, growing evidence that a significant fraction of CO emission originates from diffuse molecular gas. Quantifying…

Astrophysics of Galaxies · Physics 2016-03-09 Julia Roman-Duval , Mark Heyer , Christopher Brunt , Paul Clark , Ralf Klessen , Rahul Shetty

Recent observational results indicate that the functional shape of the spatially-resolved star formation-molecular gas density relation depends on the spatial scale considered. These results may indicate a fundamental role of sampling…

Astrophysics of Galaxies · Physics 2015-06-04 Daniela Calzetti , Guilin Liu , Jin Koda

We investigate the relation between star formation rate (SFR) and gas surface densities in Galactic star forming regions using a sample of YSOs and massive clumps. Our YSO sample consists of objects located in 20 molecular clouds from the…

Astrophysics of Galaxies · Physics 2015-05-19 Amanda Heiderman , Neal J. Evans , Lori E. Allen , Tracy Huard , Mark Heyer

Observations of various molecular lines toward a disk region of a nearby galaxy are now feasible, and they are being employed as diagnostic tools to study star-formation activities there. However, the spatial resolution attainable for a…

Astrophysics of Galaxies · Physics 2019-07-17 Yuri Nishimura , Yoshimasa Watanabe , Nanase Harada , Kotaro Kohno , Satoshi Yamamoto

We derive the physical properties of 580 molecular clouds based on their 12CO and 13CO line emission detected in the University of Massachusetts-Stony Brook (UMSB) and Galactic Ring surveys. We provide a range of values of the physical…

Astrophysics of Galaxies · Physics 2015-05-20 Julia Roman-Duval , James M. Jackson , Mark Heyer , Jill Rathborne , Robert Simon

We show that the mass fraction of GMC gas (n>100 cm^-3) in dense (n>>10^4 cm^-3) star-forming clumps, observable in dense molecular tracers (L_HCN/L_CO(1-0)), is a sensitive probe of the strength and mechanism(s) of stellar feedback. Using…

Astrophysics of Galaxies · Physics 2014-11-13 Philip F. Hopkins , Desika Narayanan , Norman Murray , Eliot Quataert

Understanding mass, size, and surface mass density of giant molecular clouds (GMCs) in galaxies is key to insights into star formation processes. We analyze these in M33 using Herschel dust and archival IRAM 30m telescope data, compared to…

High resolution, multi-wavelength maps of a sizeable set of nearby galaxies have made it possible to study how the surface densities of HI, H2 and star formation rate (Sigma_HI, Sigma_H2, Sigma_SFR) relate on scales of a few hundred…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 F. Bigiel , A. Leroy , F. Walter

We present an analysis of gas densities in the central R=300 parsecs of the Milky Way, focusing on three clouds: GCM-0.02-0.07 (the 50 km/s cloud), GCM-0.13-0.08 (the 20 km/s cloud), and GCM0.25+0.01 (the "Brick"). Densities are determined…

Astrophysics of Galaxies · Physics 2018-11-28 E. A. C. Mills , A. Ginsburg , K. Immer , J. M Barnes , L. Wiesenfeld , A. Faure , M. R. Morris , M. A. Requena-Torres

Spatially resolved HI studies of dwarf galaxies have provided a wealth of precision data. However these high-quality, resolved observations are only possible for handful of dwarf galaxies in the Local Volume. Future HI surveys are unlikely…

Astrophysics of Galaxies · Physics 2018-06-06 A. Lopez-Sanchez , C. D. P. Lagos , T. Young , H. Jerjen

The relationship between the star formation rate surface density and the molecular gas surface density in galaxies is key to understanding galaxy evolution. To investigate the molecular Kennicutt-Schmidt (K-S) relation and its dependence on…

Astrophysics of Galaxies · Physics 2026-04-13 Victoria G. G. Samboco , Ryan P. Keenan

It is still poorly constrained how the densest phase of the interstellar medium varies across galactic environment. A large observing time is required to recover significant emission from dense molecular gas at high spatial resolution, and…

We combine molecular gas masses inferred from CO emission in 500 star forming galaxies (SFGs) between z=0 and 3, from the IRAM-COLDGASS, PHIBSS1/2 and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512…

Stars form in cold molecular clouds. However, molecular gas is difficult to observe because the most abundant molecule (H2) lacks a permanent dipole moment. Rotational transitions of CO are often used as a tracer of H2, but CO is much less…

We examined the relations between molecular gas surface density and star formation rate surface density in a 11 square degree region of the Galactic Plane. Dust continuum at 1.1 mm from the Bolocam Galactic Plane Survey and 22 micron…

Astrophysics of Galaxies · Physics 2015-06-22 Nalin Vutisalchavakul , Neal J. Evans , Cara Battersby

There is a linear relation between the mass of dense gas, traced by the HCN(1-0) luminosity, and the star formation rate (SFR), traced by the far-infrared luminosity. Recent observations of galactic disks have shown some systematic…

Astrophysics of Galaxies · Physics 2017-02-22 Hao Chen , Jonathan Braine , Yu Gao , Jin Koda , Qiusheng Gu

We are conducting COLD GASS, a legacy survey for molecular gas in nearby galaxies. Using the IRAM 30m telescope, we measure the CO(1-0) line in a sample of ~350 nearby (D=100-200 Mpc), massive galaxies (log(M*/Msun)>10.0). The sample is…

Recent observations of the nearby Galactic molecular clouds indicate that the dense gas in molecular clouds have quasi-universal properties on star formation, and observational studies of extra galaxies have shown a galactic-scale…

This study investigated the relation between the surface density of star formation rate (SFR) ($\Sigma_{\mathrm{SFR}}$), stellar mass ($\Sigma_{M_{\ast}}$), and molecular gas mass ($\Sigma_{M_\mathrm{mol}}$) on nearly 1 kpc scales averaged…