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Related papers: The abundance of HOC+ in diffuse clouds

200 papers

High-Velocity Clouds (HVCs) have radial velocities that cannot be explained by the global Galactic rotation; their distances remain mostly unknown, and their true nature and origin are still a mystery. Some of them could be of galactic…

Astrophysics · Physics 2007-05-23 F. Combes , V. Charmandaris

We detect luminous emission from HCN, HCO+ and HNC 1--0 in the QSO ULIRG Mrk~231 with the IRAM Plateau de Bure Interferometer at 1."55 by 1."28 resolution. All three lines show broad line wings - which are particularly prominent for HCN.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 S. Aalto , S. Garcia-Burillo , S. Muller , J. M. Winters , P. van der Werf , C. Henkel , F. Costagliola , R. Neri

We have combined observations of Galactic high-velocity HI from two surveys: a very sensitive survey from the Green Bank 140ft Telescope with limited sky coverage, and the less sensitive but complete Galactic All Sky Survey from the 64m…

Astrophysics of Galaxies · Physics 2017-01-18 Vanessa A. Moss , Felix J. Lockman , Naomi M. McClure-Griffiths

The FUSE far-ultraviolet interstellar spectra toward seven targets in NGC 6231 show that the molecules H_2, HD, and CO as well as various atomic species are distributed in several clouds. The main absorption component found on the sight…

Astrophysics · Physics 2009-11-10 O. Marggraf , H. Bluhm , K. S. de Boer

We have selected 43 southern massive star-forming regions to study the spatial distribution of HNCO 4$_{04}$-3$_{03}$, SiO 2-1 and HC$_{3}$N 10-9 line emission and to investigate their spatial association with the dust emission. The…

We detect the neutral hydrogen (HI) radial brightness temperature profile in large-scale haloes by stacking 48,430 galaxies selected from the 2dFGRS catalogue onto a set of 21-cm intensity maps obtained with the Parkes radio telescope,…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Denis Tramonte , Yin-Zhe Ma

Up to 90% of the chemical reactions during star formation occurs on ice surfaces, probably including the formation of complex organics. Only the most abundant ice species are however observed directly by infrared spectroscopy. This study…

Solar and Stellar Astrophysics · Physics 2015-05-13 Karin I. Oberg , Sandrine Bottinelli , Ewine F. van Dishoeck

We present a theoretical investigation of the chemistry of fluorine-bearing molecules in diffuse and dense interstellar gas clouds. The chemistry of interstellar fluorine is qualitatively different from that of any other element, because -…

Astrophysics · Physics 2009-11-11 David A. Neufeld , Mark G. Wolfire , Peter Schilke

In recent years we have seen an important increase in the number of protonated molecules detected in cold dense clouds. Here we report the detection in TMC-1 of HCCNCH+, the protonated form of HCCNC, which is a metastable isomer of HC3N.…

Astrophysics of Galaxies · Physics 2022-03-30 M. Agundez , C. Cabezas , N. Marcelino , R. Fuentetaja , B. Tercero , P. de Vicente , J. Cernicharo

Using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) the COS Science Team has conducted a high signal-to-noise survey of 14 bright QSOs. In a previous paper (Savage et al. 2014) these far-UV spectra were used to…

Infrared absorption lines of H3+, including the metastable R(3,3)l line, have been observed toward eight bright infrared sources associated with hot and massive stars located in and between the Galactic Center Cluster and the Quintuplet…

We have carried out a sensitive high-latitude (|b| > 15deg.) HI 21cm-line absorption survey towards 102 sources using the GMRT. With a 3-sigma detection limit in optical depth of ~0.01, this is the most sensitive HI absorption survey. We…

Astrophysics · Physics 2009-11-10 Rekhesh Mohan , K. S. Dwarakanath , G. Srinivasan

The central kiloparsec region of the Andromeda galaxy is relatively gas poor, while the interstellar medium appears to be concentrated in a ring-like structure at about 10 kpc radius. The central gas depletion has been attributed to a…

Astrophysics of Galaxies · Physics 2015-12-16 A. -L. Melchior , F. Combes

The rotational transitions of carbon monoxide (CO) are the primary means of investigating the density and velocity structure of the molecular interstellar medium. Here we study the lowest four rotational transitions of CO towards…

Astrophysics · Physics 2009-10-31 James G. Ingalls , T. M. Bania , Adair P. Lane , Matthias Rumitz , Antony A. Stark

We report new observations of the fundamental $J=1-0$ transition of HCl (at 625.918GHz) toward a sample of 25 galactic star-forming regions, molecular clouds, and evolved stars, carried out using the Caltech Submillimeter Observatory.…

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…

A new method, based on a Reverse Monte Carlo technique and aimed at the inverse problem in the analysis of interstellar (intergalactic) absorption lines is presented. We consider the process of line formation in media with a stochastic…

Astrophysics · Physics 2015-06-24 S. A. Levshakov , W. H. Kegel , F. Takahara

We present the detection analysis of a diffuse molecular cloud at z$_{abs}$=2.4636 towards the quasar SDSS J1513+0352(z$_{em}\,\simeq$ 2.68) observed with the X-shooter spectrograph(VLT). We measure very high column densities of atomic and…

Infrared-dark high-mass clumps are among the most promising objects to study the initial conditions of the formation process of high-mass stars and rich stellar clusters. In this work, we have observed the (3-2) rotational transition of…

Astrophysics of Galaxies · Physics 2015-06-04 F. Fontani , A. Giannetti , M. T. Beltran , R. Dodson , M. Rioja , J. Brand , P. Caselli , R. Cesaroni

Ionized carbon is the main gas-phase reservoir of carbon in the neutral diffuse interstellar medium and its 158 micron fine structure transition [CII] is the most important cooling line of the diffuse interstellar medium (ISM). We combine…