English
Related papers

Related papers: The thinnest cold HI clouds in the diffuse interst…

200 papers

This paper is a numerical study of the condensation of the warm neutral medium (WNM) into cold neutral medium (CNM) structures under the effect of turbulence and thermal instability. Using low resolution simulations we explored the impact…

Astrophysics of Galaxies · Physics 2014-07-09 E. Saury , M. -A. Miville-Deschênes , P. Hennebelle , E. Audit , W. Schmidt

Context. The earliest phases of high-mass star formation are poorly understood. Aims. Our goal is to determine the physical conditions and kinematic structure of massive star-forming cloud clumps. Methods. We analyze H$_2$O 557 GHz line…

Solar and Stellar Astrophysics · Physics 2014-10-15 Russell F. Shipman , Floris F. S van der Tak , Friedrich Wyrowski , Fabrice Herpin , Wilfred Frieswijk

We report the results of initial FUSE observations of molecular hydrogen (H2) in translucent clouds. These clouds have greater optical depth than any of the diffuse clouds previously observed for far-UV H2 absorption, and provide new…

We present a new, uniform analysis of the HI transmitted flux (F) and HI column density (N(HI)) distribution in the low-density IGM as a function of redshift z for 0<z<3.6 using 55 HST/COS FUV (Delta(z)=7.2 at z<0.5), five HST/STIS+COS NUV…

The results of a CO line survey in central cluster galaxies with cooling flows are presented. Cold molecular gas is detected with the IRAM 30m telescope, through CO(1-0) and CO(2-1) emission lines in 6-10 among 32 galaxies. The…

Astrophysics · Physics 2009-11-10 P. Salome , F. Combes

We study a small sample of z=0.1-0.6 core-collapse supernova (CCSN) host galaxies. Continuum observations at 250GHz have been performed with MAMBO at the IRAM-30m telescope. None of these sources has been detected and the error-weighted…

Astrophysics · Physics 2009-11-13 A. -L. Melchior , F. Combes

Surprisingly large column densities of H3+ have been detected using infrared absorption spectroscopy in seven diffuse cloud sightlines (Cygnus OB2 12, Cygnus OB2 5, HD 183143, HD 20041, WR 104, WR 118, and WR 121), demonstrating that H3+ is…

Hydrocarbons are ubiquitous in the interstellar medium, observed in diverse environments ranging from diffuse to molecular dark clouds and strong photon-dominated regions near HII regions. Recently, two broad diffuse interstellar bands…

Astrophysics of Galaxies · Physics 2015-06-05 Harvey Liszt , Paule Sonnentrucker , Martin Cordiner , Maryvonne Gerin

Simulations predict that galaxies grow primarily through the accretion of gas that has not gone through an accretion shock near the virial radius and that this cold gas flows towards the central galaxy along dense filaments and streams.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Freeke van de Voort , Joop Schaye , Gabriel Altay , Tom Theuns

The observed star formation rates of galaxies in the Local Universe suggests that they are replenishing their gas reservoir across cosmic time. Cosmological simulations predict that this accretion of fresh gas can occur in a hot or a cold…

We report the first detection of C$^{15}$N in diffuse molecular gas from a detailed examination of CN absorption lines in archival VLT/UVES spectra of stars probing local diffuse clouds. Absorption from the C$^{15}$N isotopologue is…

Astrophysics of Galaxies · Physics 2018-06-07 Adam M. Ritchey , Steven R. Federman , David L. Lambert

The precise characteristics of clouds and the nature of dust in the diffuse interstellar medium can only be extracted by inspecting the rare cases of single-cloud sightlines. In our nomenclature such objects are identified by interstellar…

Astrophysics of Galaxies · Physics 2020-09-09 R. Siebenmorgen , J. Krełowski , J. Smoker , G. Galazutdinov , S. Bagnulo

Cyanogen (NCCN) is the simplest member of the series of dicyanopolyynes. It has been hypothesized that this family of molecules can be important constituents of interstellar and circumstellar media, although the lack of a permanent electric…

We present a theoretical investigation of CN and HCN molecule formation in dense interstellar clouds. We study the gas-phase CN and HCN production efficiencies from the outer photon-dominated regions (PDRs) into the opaque cosmic-ray…

Astrophysics · Physics 2009-11-13 Gai I. Boger , Amiel Sternberg

We present the first $z=0$ HI column density distribution function, $f(N_\mathrm{HI})$, extending down to $\log (N_\mathrm{HI}/\mathrm{cm}^{-2})=17.8$. This was derived from high-sensitivity 21-cm emission-line imaging at $\sim$1 kpc…

We have identified 41 infrared dark clouds from the 8 micron maps of the Midcourse Space Experiment (MSX), selected to be found within one square degree areas centered on known ultracompact HII regions. We have mapped these infrared dark…

We develop a semi-analytic model to explore the physical properties of cool pressure-confined circumgalactic clouds with mass ranging from $10$ to $10^{8} \, \rm M_{\odot}$ in a hot diffuse halo. We consider physical effects that control…

Astrophysics of Galaxies · Physics 2019-04-10 Ting-Wen Lan , Houjun Mo

Tracing the transition between the diffuse atomic interstellar medium (ISM) and cold, dense gas is crucial for deciphering the star formation cycle in galaxies. Here we present MACH, a new survey of cold neutral hydrogen (HI) absorption at…

We investigate the column density distribution function of neutral hydrogen at redshift z = 3 using a cosmological simulation of galaxy formation from the OverWhelmingly Large Simulations (OWLS) project. The base simulation includes…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-04 Gabriel Altay , Tom Theuns , Joop Schaye , Neil H. M. Crighton , Claudio Dalla Vecchia

We have mapped the C I 3P1-3P0 line at 492 GHzin three molecular clouds immersed in weak ultraviolet radiation fields, TMC-1, L134N, and IC 5146. In all three clouds, the CI peak TA* ~ 1 K, with very small dispersion. The spatial C I…

Astrophysics · Physics 2009-10-31 K. Tatematsu , D. T. Jaffe , R. Plume , N. J. Evans , J. Keene
‹ Prev 1 4 5 6 7 8 10 Next ›