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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

Chemical diversity of the gas in low-mass protostellar cores is widely recognized. In order to explore its origin, a survey of chemical composition toward 36 Class 0/I protostars in the Perseus molecular cloud complex, which are selected in…

We report the second study from the FUSE survey of molecular hydrogen in translucent clouds, for the line of sight toward HD 110432. This star lies beyond the Coalsack dark nebula, and with E(B-V) = 0.40, and A_V = 1.32 this line of sight…

How does molecular cloud chemistry change with metallicity? In this work, we study the relation between molecular hydrogen ($H_2$) and carbon monoxide (CO) at $1/2$ and $1/5$ solar metallicity using ultraviolet absorption spectroscopy…

Astrophysics of Galaxies · Physics 2025-08-18 Kirill Tchernyshyov , Jessica K. Werk , Julia Roman-Duval

We present an all-sky catalog of diffuse O VII and O VIII line intensities, extracted from archival XMM observations. The O VII and O VIII intensities are typically ~2-11 and <~3 ph/cm^2/s/sr (LU), respectively, although much brighter…

Astrophysics of Galaxies · Physics 2015-06-11 David B. Henley , Robin L. Shelton

Observations of W51 with the Submillimeter Wave Astronomy Satellite (SWAS) have yielded the first detection of water vapor in a diffuse molecular cloud. The water vapor lies in a foreground cloud that gives rise to an absorption feature at…

We have obtained deep HI observations in the direction of 22 continuum sources without previously detected cold neutral medium (CNM). 18 CNM clouds were detected with the typical HI column density of $3\times10^{18}$ cm$^{-2}$. Our…

Astrophysics · Physics 2007-05-23 Snezana Stanimirovic , Carl Heiles , Nissim Kanekar

We have made a sensitive search for the origin bands in the known electronic transitions of the linear carbon chains C_4 and C_5 at 3789 and 5109 A towards zeta Oph (A_V <= 1). The incentive was a recent detection of C_3 in this…

Astrophysics · Physics 2009-11-07 John P. Maier , Gordon A. H. Walker , David A. Bohlender

Context. Astrochemical modeling requires, as input, the effective column density of gas (or extinction) that attenuates an external, isotropic, far-ultraviolet radiation field. In three-dimensional simulations, this can be calculated…

Astrophysics of Galaxies · Physics 2025-08-20 Brandt A. L. Gaches

We present 2.5-square-degree C$_{2}$H N=1-0 and N$_2$H$^+$ J=1-0 maps of the $\rho$ Ophiuchi molecular cloud complex. These are the first large-scale maps of the $\rho$ Ophiuchi molecular cloud complex with these two tracers. The C$_{2}$H…

Astrophysics of Galaxies · Physics 2017-03-08 Zhichen Pan , Di Li , Qiang Chang , Lei Qian , Edwin A. Bergin , Junzhi Wang

{It is necessary to understand the dynamics of the atomic gas to use complex modeling and to carry out detailed comparisons between theoretical models and observations.}{In a companion paper, we present high resolution bidimensional…

Astrophysics · Physics 2007-05-23 P. Hennebelle , E. Audit , M. -A Miville-Deschenes

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

We present the multi-epoch analysis of 13 variable, nearby (z<0.1), Compton-thin (22<logN_H<24) active galactic nuclei (AGN) selected from the 105-month BAT catalog. Analyzing all available archival soft and hard X-ray observations, we…

High Energy Astrophysical Phenomena · Physics 2024-03-12 A. Pizzetti , N. Torres-Alba , S. Marchesi , J. Buchner , I. Cox , X. Zhao , S. Neal , D. Sengupta , R. Silver , M. Ajello

Context. High latitude molecular clouds (hereafter HLMCs) permit the study of interstellar gas dynamics and astrochemistry with good accuracy due to their proximity, generally clear lines of sight, and lack of internal star-forming activity…

Astrophysics of Galaxies · Physics 2023-01-16 Marco Monaci , Loris Magnani , Steven N. Shore

We derive water vapor column abundances and aerosol properties from Mars Science Laboratory (MSL) ChemCam passive mode observations of scattered sky light. Each ChemCam passive sky observation acquires spectra at two different elevation…

We investigated the chemical evolution of HC3N in six dense molecular clouds, using archival available data from the Herschel infrared Galactic Plane Survey (Hi-GAL) and the Millimeter Astronomy Legacy Team Survey at 90 GHz (MALT90). Radio…

Astrophysics of Galaxies · Physics 2019-10-18 Naiping Yu , Jun-Jie Wang , Jin-Long Xu

To provide constraints on the chemical processes responsible for the observed columns of organic species, we used NOEMA to observe the sight line toward NRAO150 in the 2mm spectral window. We targeted the low excitation lines of o-H2CO…

Astrophysics of Galaxies · Physics 2024-05-29 Maryvonne Gerin , Harvey Liszt , Jerome Pety , Alexandre Faure

We have revisited the chemistry of chlorine-bearing species in the diffuse interstellar medium with new observations of the HCl$^+$ molecular ion and new astrochemical models. Using the GREAT instrument on board SOFIA, we observed the…

We present an analysis of CO molecular gas tracers in a sample of 500{\mu}m-selected Herschel-ATLAS galaxies at z<0.05 (cz<14990km/s). Using 22-500{\mu}m photometry from WISE, IRAS and Herschel, with HI data from the literature, we…

We report the discovery of two unsaturated organic species, trans-(E)-cyanovinylacetylene and vinylcyanoacetylene, using the second data release of the GOTHAM deep survey towards TMC-1 with the 100 m Green Bank Telescope. For both…