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Related papers: The densities in diffuse and translucent molecular…

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We use 3-dimensional numerical simulations of self-gravitating compressible turbulent gas in combination with Lagrangian tracer particles to investigate the mixing process of molecular hydrogen (H2) in interstellar clouds. Tracer particles…

Astrophysics · Physics 2009-06-23 C Federrath , S C O Glover , R S Klessen , W Schmidt

There is a robust polyatomic chemistry in diffuse, partially-molecular interstellar gas that is readily accessible in absorption at radio/mm/sub-mm wavelengths. Accurate column densities are derived owing to the weak internal excitation, so…

Astrophysics of Galaxies · Physics 2023-02-15 Harvey Liszt , Maryvonne Gerin

We present a comprehensive examination of interstellar P and Cl abundances based on an analysis of archival spectra acquired with the Space Telescope Imaging Spectrograph of the Hubble Space Telescope and the Far Ultraviolet Spectroscopic…

Astrophysics of Galaxies · Physics 2023-05-30 Adam M. Ritchey , J. M. Brown , S. R. Federman , Paule Sonnentrucker

We present analytic theory for the total column density of singly ionized carbon (C+) in the optically thick photon dominated regions (PDRs) of far-UV irradiated (star-forming) molecular clouds. We derive a simple formula for the C+ column…

Astrophysics of Galaxies · Physics 2016-08-31 Raanan Nordon , Amiel Sternberg

Debris disks are second generation dusty disks thought to be devoid of gas. However, this idea has been challenged in the last years by gas detections in some systems. We compiled a database of 301 debris disks and collected…

Solar and Stellar Astrophysics · Physics 2018-07-11 D. Iglesias , A. Bayo , J. Olofsson , Z. Wahhaj , C. Eiroa , B. Montesinos , I. Rebollido , J. Smoker , L. Sbordone , M. R. Schreiber , Th. Henning

We present results of analysis of physical conditions (number density, intensity of UV field, kinetic temperature) in the cold H$_2$-bearing interstellar medium of local and high redshift galaxies. Our measurements based on the fit to the…

Astrophysics of Galaxies · Physics 2020-10-07 V. V. Klimenko , S. A. Balashev

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

Astrophysics of Galaxies · Physics 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

We report the discovery of large amounts of cold (T ~ 10^4 K), chemically young gas in an overdensity of galaxies at redshift z ~ 1.6 in the Great Observatories Origins Deep Survey southern field (GOODS-S). The gas is identified thanks to…

We have determined column densities of H I and/or H_2 for sight lines in the Magellanic Clouds from archival HST and FUSE spectra of H I Lyman-alpha and H_2 Lyman-band absorption. Together with some similar data from the literature, we now…

Astrophysics of Galaxies · Physics 2015-06-03 Daniel E. Welty , Rui Xue , Tony Wong

We present a numerical code for continuum radiative transfer that is based on the idea of a `library' describing the relation between the intensity of the local radiation field and the resulting dust emission. With this information and…

Astrophysics · Physics 2009-11-07 M. Juvela , P. Padoan

Molecular nitrogen is one of the key species in the chemistry of interstellar clouds and protoplanetary disks and the partitioning of nitrogen between N and N2 controls the formation of more complex prebiotic nitrogen-containing species.…

Astrophysics of Galaxies · Physics 2015-06-15 Xiaohu Li , Alan N. Heays , Ruud Visser , Wim Ubachs , Brenton R. Lewis , Stephen T. Gibson , Ewine F. van Dishoeck

We present the analysis of a sub-DLA system (log N(H^0)=20.0+/-0.15, z_abs=2.69) toward SDSS J123714+064759 (z_em=2.78). Using the VLT/UVES and X-shooter spectrographs, we detect H2, HD and CO molecules in absorption with log…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 P. Noterdaeme , P. Petitjean , C. Ledoux , S. Lopez , R. Srianand , S. D. Vergani

OH is a cornerstone molecule in the chemistry of interstellar and circumstellar media and is ubiquitously detected in warm gas thanks to its infrared rotational lines. However, the excitation processes of OH remain poorly characterized. We…

From the rate of hydrogen ionization and the gamma ray flux, we derived the spectrum of relativistic and subrelativistic cosmic rays (CRs) nearby and inside the molecular cloud Sgr B2 near the Galactic Center (GC). We studied two cases of…

High Energy Astrophysical Phenomena · Physics 2015-08-19 V. A. Dogiel , D. O. Chernyshov , A. M. Kiselev , M. Nobukawa , K. S. Cheng , C. Y. Hui , C. M. Ko , K. K. Nobukawa , T. G. Tsuru

We reanalyzed interstellar Cl I and Cl II spectra acquired with the Copernicus satellite. The directions for this study come from those of Crenny & Federman and sample the transition from atomic to molecular rich clouds where the unique…

Astrophysics of Galaxies · Physics 2015-05-30 Daniel Moomey , S. R. Federman , Y. Sheffer

ABRIDGED: Context: HI and CO large scale surveys of the Milky Way trace the diffuse atomic clouds and the dense shielded regions of molecular hydrogen clouds. However, until recently, we have not had spectrally resolved C+ surveys to…

Astrophysics of Galaxies · Physics 2015-06-18 W. D. Langer , T. Velusamy , J. L. Pineda , K. Willacy , P. F. Goldsmith

FUSE spectra of the four brightest H II regions in M 33 show absorption by interstellar gas in the Galaxy and in M 33. On three lines of sight molecular hydrogen in M 33 is detected. This is the first measurement of diffuse H_2 in…

Astrophysics · Physics 2009-11-07 Hartmut Bluhm , Klaas S. de Boer , Ole Marggraf , Philipp Richter , Bart P. Wakker

Among all closed-shell species observed in molecular clouds, molecules with C$_{3v}$ symmetry play a crucial role, as their rotational spectroscopy allows them to behave as a gas thermometer. In the interstellar medium, methyl cyanide…

Astrophysics of Galaxies · Physics 2023-09-22 M. Ben Khalifa , P. J. Dagdigian , J. Loreau

The nature of the Local Interstellar Cloud (LIC) is highly constrained by the combination of in situ heliospheric and line-of-sight data towards nearby stars. We present a new interpretation of the LIC components of the absorption line data…

Astrophysics · Physics 2011-02-11 Jonathan D. Slavin , Priscilla C. Frisch

Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS1830-211. Obtaining average radial velocities and performing Large Velocity Gradient…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Henkel , K. M. Menten , M. T. Murphy , N. Jethava , V. V. Flambaum , J. A. Braatz , S. Muller , J. Ott , R. Q. Mao