English
Related papers

Related papers: Modelling CO formation in the turbulent interstell…

200 papers

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

An overview is presented of the main properties of the interstellar medium. Evidence is summarized that the interstellar medium is highly turbulent, driven on different length scales by various energetic processes. Large-scale turbulence…

Astrophysics · Physics 2009-11-11 Andreas Burkert

We extend the non-equilibrium model for the chemical and thermal evolution of diffuse interstellar gas presented in Richings et al. (2014) to account for shielding from the UV radiation field. We attenuate the photochemical rates by dust…

Astrophysics of Galaxies · Physics 2015-06-19 Alexander J. Richings , Joop Schaye , Benjamin D. Oppenheimer

We conducted observations of 12CO(J=5-4) and dust thermal continuum emission toward twenty star-forming galaxies on the main sequence at z~1.4 using ALMA to investigate the properties of the interstellar medium. The sample galaxies are…

The gas-phase CO abundance (relative to hydrogen) in protoplanetary disks decreases by up to 2 orders of magnitude from its ISM value ${\sim}10^{-4}$, even after accounting for freeze-out and photo-dissociation. Previous studies have shown…

Solar and Stellar Astrophysics · Physics 2020-09-02 Sebastiaan Krijt , Arthur D. Bosman , Ke Zhang , Kamber R. Schwarz , Fred J. Ciesla , Edwin A. Bergin

We examine the triggering process of molecular cloud formation around diffuse HII regions. We calculate the time evolution of the shell as well as of the HII region in a two-phase neutral medium, solving the UV and FUV radiative transfer,…

Astrophysics · Physics 2011-02-11 Takashi Hosokawa , Shu-ichiro Inutsuka

Infrared stellar photometry from 2MASS and spectral line imaging observations of 12CO and 13CO J = 1-0 line emission from the FCRAO 14m telescope are analysed to assess the variation of the CO abundance with physical conditions throughout…

Astrophysics of Galaxies · Physics 2015-06-15 F. Ripple , M. H. Heyer , R. Gutermuth , R. L. Snell , C. M. Brunt

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the…

Astrophysics · Physics 2011-02-11 Liubin Pan , Paolo Padoan

We study the properties of giant molecular clouds (GMCs) from a smoothed particle hydrodynamics simulation of a portion of a spiral galaxy, modelled at high resolution, with robust representations of the physics of the interstellar medium.…

Astrophysics of Galaxies · Physics 2016-03-31 A. Duarte-Cabral , C. L. Dobbs

CO is the most widely used observational tracer of molecular gas. The observable CO luminosity is translated to H_2 mass via a conversion factor, X_CO, which is a source of uncertainty and bias. Despite variations in X_CO, the…

Astrophysics of Galaxies · Physics 2020-11-18 Munan Gong , Eve C. Ostriker , Chang-Goo Kim , Jeong-Gyu Kim

Gas in protostellar disks provides the raw material for giant planet formation and controls the dynamics of the planetesimal-building dust grains. Accurate gas mass measurements help map the observed properties of planet-forming disks onto…

Earth and Planetary Astrophysics · Physics 2017-05-31 Mo Yu , Neal J. Evans , Sarah E. Dodson-Robinson , Karen Willacy , Neal J. Turner

Context. In dense clouds, hydrogenation reactions on icy dust grains are key in the formation of molecules, like formaldehyde, methanol, and complex organic molecules (COMs). These species form through the sequential hydrogenation of CO…

Solar and Stellar Astrophysics · Physics 2018-09-28 K. -J. Chuang , G. Fedoseev , D. Qasim , S. Ioppolo , E. F. van Dishoeck , H. Linnartz

(Abridged) We carried out a comprehensive far-ultraviolet (UV) survey of ^12CO and H_2 column densities along diffuse molecular Galactic sight lines in order to explore in detail the relationship between CO and H_2. We measured new CO…

Astrophysics · Physics 2009-11-13 Y. Sheffer , M. Rogers , S. R. Federman , N. P. Abel , R. Gredel , D. L. Lambert , G. Shaw

Observations of molecular gas in high-z star-forming galaxies typically rely on emission from CO lines arising from states with rotational quantum numbers J > 1. Converting these observations to an estimate of the CO J=1-0 intensity, and…

Astrophysics of Galaxies · Physics 2015-06-18 Desika Narayanan , Mark Krumholz

We report on a study of the high-mass star formation in the the HII region W28A2 by investigating the molecular clouds extended over ~5-10 pc from the exciting stars using the 12CO and 13CO (J=1-0) and 12CO (J=2-1) data taken by the NANTEN2…

The abundance of H2 in molecular clouds, relative to the commonly used tracer CO, has only been measured toward a few embedded stars, which may be surrounded by atypical gas. We present observations of near-infrared absorption by H2, CO,…

Astrophysics of Galaxies · Physics 2017-03-30 John H. Lacy , Christopher Sneden , Hwihyun Kim , Daniel T. Jaffe

To complement the optical absorption-line survey of diffuse molecular gas in Paper I, we obtained and analyzed far ultraviolet H$_2$ and CO data on lines of sight toward stars in Cep OB2 and Cep OB3. Possible correlations between column…

Astrophysics · Physics 2009-11-13 K. Pan , S. R. Federman , Y. Sheffer , B. -G. Andersson

The detailed distribution and kinematics of the atomic and the CO-bright molecular hydrogen in the disc of the Milky Way inside the Solar circle are derived under the assumptions of axisymmetry and pure circular motions. We divide the…

Astrophysics of Galaxies · Physics 2017-11-22 A. Marasco , F. Fraternali , J. M. van der Hulst , T. Oosterloo

I examine the possibility that the Cold Neutral Medium of the interstellar medium in galaxies contains a molecular gas phase that may represent a significant and even the dominant amount of its mass in metal-poor regions. In spiral galaxies…

Astrophysics · Physics 2007-05-23 Padeli P. Papadopoulos

Combining observations of multiple CO lines with radiative transfer modeling is a very powerful tool to investigate the physical properties of the molecular gas in galaxies. Using new observations as well as literature data, we provide the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Selcuk Topal , Estelle Bayet , Martin Bureau , Timothy A. Davis , Wilfred Walsh
‹ Prev 1 3 4 5 6 7 10 Next ›