English
Related papers

Related papers: The CO-to-H2 Conversion Factor across the Perseus …

200 papers

Prestellar cores are unique laboratories for studies of the chemical and physical conditions preceding star formation. We observed the prestellar core L1544 in the fundamental transition of ortho-H2D+ (1_1,0-1_1,1) at different positions…

Astrophysics · Physics 2009-11-11 C. Vastel , P. Caselli , C. Ceccarelli , T. G. Phillips , M. Wiedner , R. peng , M. Houde , C. Dominik

Nearby dwarf irregular galaxies are ideal laboratories for studying the interstellar medium (ISM) at low metallicity, which is expected to be common for galaxies at very high redshift being observed by the James Webb Space Telescope. We…

Astrophysics of Galaxies · Physics 2023-08-02 Chia-Yu Hu , Amiel Sternberg , Ewine F. van Dishoeck

Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds…

We present CO(2-1) and $^{13}$CO(2-1) maps of the Cygnus-X molecular cloud complex using the 10m Heinrich Hertz Submillimeter Telescope (SMT). The maps cover the southern portion of the complex which is strongly impacted by the feedback…

Astrophysics of Galaxies · Physics 2023-12-22 Jonah C. Baade , Shuo Kong , John H. Bieging , Thomas Folkers

We compare the statistical properties of J=1-0 13CO spectra observed in the Perseus Molecular Cloud with synthetic J=1-0 13CO spectra from a 5 pc model cloud. The synthetic spectra are computed solving the non-LTE radiative transfer problem…

Astrophysics · Physics 2007-05-23 Paolo Padoan , John Bally , Youssef Billawala , Mika Juvela , AAke Nordlund

Deuterium fractionation becomes highly efficient in cold, dense cores where CO is frozen out. Cyclopropenylidene (c-C3H2), an early-formed carbon ring, and its deuterated isotopologues trace gas-phase deuteration in these environments. We…

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

Using UV spectra obtained with FUSE, HST, and/or IUE, we determine interstellar column densities of 12CO, 13CO, and/or C_2 for ten Galactic sight lines with 0.37<E(B-V)<0.72. The N(CO)/N(H_2) ratio varies over a factor of 100 in this…

Astrophysics · Physics 2009-05-29 P. Sonnentrucker , D. E. Welty , J. A. Thorburn , D. G. York

Aims: For the first time we investigate the role of the grain surface chemistry in the Horsehead Photo-dissociation region (PDR). Methods: We performed deep observations of several H2CO rotational lines toward the PDR and its associated…

Astrophysics of Galaxies · Physics 2015-05-30 V. Guzmán , J. Pety , J. R. Goicoechea , M. Gerin , E. Roueff

We combine Spitzer and Herschel data of the star-forming region N11 in the Large Magellanic Cloud to produce detailed maps of the dust properties in the complex and study their variations with the ISM conditions. We also compare APEX/LABOCA…

We report the results of a 100 square degree survey of the Taurus Molecular Cloud region in the J = 1-0 transition of 12CO and 13CO. The image of the cloud in each velocity channel includes ~ 3 million Nyquist sampled pixels on a 20" grid.…

Astrophysics · Physics 2009-12-08 Paul F. Goldsmith , Mark Heyer , Gopal Narayanan , Ronald Snell , Di Li , Chris Brunt

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

We aim at determining the spatial distribution of the gas and dust in star-forming regions and address their relative abundances in quantitative terms. We also examine the dust opacity exponent beta for spatial and/or temporal variations.…

Astrophysics of Galaxies · Physics 2015-04-24 R. Liseau , B. Larsson , T. Lunttila , M. Olberg , G. Rydbeck , P. Bergman , K. Justtanont , G. Olofsson , B. L. de Vries

There is ample observational evidence that the star formation rate (SFR) surface density, Sigma_SFR, is closely correlated with the surface density of molecular hydrogen, Sigma_H2. This empirical relation holds both for galaxy-wide averages…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Robert Feldmann , Nickolay Y. Gnedin , Andrey V. Kravtsov

The HRS is a complete volume-limited sample of nearby objects including Virgo cluster and isolated objects. Using a recent compilation of HI and CO data we study the effects of the cluster on the molecular gas content of spiral galaxies. We…

Astrophysics of Galaxies · Physics 2015-06-18 A. Boselli , L. Cortese , M. Boquien , S. Boissier , B. Catinella , G. Gavazzi , C. Lagos , A. Saintonge

There are two major theoretical issues for the star formation law (the relation between the surface densities of molecular gas and star formation rate on a galaxy scale): (i) At low metallicity, it is not obvious that star-forming regions…

Astrophysics of Galaxies · Physics 2018-01-24 Li-Hsin Chen , Hiroyuki Hirashita , Kuan-Chou Hou , Shohei Aoyama , Ikkoh Shimizu , Kentaro Nagamine

We apply photo-dissociation region (PDR) molecular line emission models, that have varying degrees of enhanced mechanical heating rates, to the gaseous component of simulations of star-forming galaxies taken from the literature. Snapshots…

Astrophysics of Galaxies · Physics 2016-11-23 M. V. Kazandjian , I. Pelupessy , R. Meijerink , F. P. Israel , M. Spaans

The radical hydrocarbon molecule C$_2$H is widely detected in various stages of star and planet formation, and has emerged as a useful tracer of high-C/O gas within the photochemically active surface layers of mature (Class II)…

Astrophysics of Galaxies · Physics 2025-08-07 Jack G. Anderson , Jennifer B. Bergner , Yao-Lun Yang , Yichen Zhang , Nami Sakai

Carbon monoxide (CO) provides crucial information about the molecular gas properties of galaxies. While $^{12}$CO has been targeted extensively, isotopologues such as $^{13}$CO have the advantage of being less optically thick and…

Fully sampled degree-scale maps of the 13CO 2-1 and CO 4-3 transitions toward three members of the Lupus Molecular Cloud Complex - Lupus I, III, and IV - trace the column density and temperature of the molecular gas. Comparison with IR…

‹ Prev 1 8 9 10 Next ›