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Related papers: First Detection of HCO$^+$ Absorption in the Magel…

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Molecular hydrogen (H$_2$) is by far the most abundant molecule in the Universe. However, due to the low emissivity of H$_2$, carbon monoxide (CO) is widely used instead to trace molecular gas in galaxies. The relative abundances of these…

Astrophysics of Galaxies · Physics 2025-04-30 Sergei Balashev , Daria Kosenko , Pasquier Noterdaeme

The Mopra 22m and SEST 15m telescopes have been used to detect and partially map a region of 12CO(1-0) line emission within the Magellanic Bridge, a region lying between the Large and Small Magellanic Clouds. The emission appears to be…

Astrophysics · Physics 2009-11-07 E. Muller , L. Staveley-Smith , W. Zealey

We report a detection of cold atomic hydrogen in the Magellanic Bridge using 21-cm absorption spectroscopy toward the radio source B0312-770. With a column density of N_HI=1.2E20 cm^-2, a maximum absorption optical depth of tau=0.10 and a…

Astrophysics · Physics 2009-10-31 Henry A. Kobulnicky , John Dickey

HI 21-cm absorption lines are investigated to determine the origin of the neutral atomic hydrogen (HI) of the Magellanic Bridge (MB). Using the MeerKat Absorption Line Survey (MALS) data we report the detection of an HI absorption line at a…

Astrophysics of Galaxies · Physics 2025-10-22 A. P. M. Morelli , J. Kerp , N. Gupta , F. Combes , S. A. Balashev , P. Noterdaeme , H. Chen , K. L. Emig , E. Momjian

This work presents a new detection of H$_2$ absorption arising in a high velocity cloud (HVC) associated with either the Milky Way or the Large Magellanic Cloud (LMC). The absorber was found in an archival Far Ultraviolet Spectroscopic…

Astrophysics of Galaxies · Physics 2022-06-01 Kirill Tchernyshyov

We present the first direct detection of cold atomic gas in the Magellanic Stream, through 21 cm line absorption toward a background radio source, J0119 - 6809, using the Australia Telescope Compact Array. Two absorption components were…

Astrophysics of Galaxies · Physics 2011-02-11 D. Matthews , L. Staveley-Smith , P. Dyson , E. Muller

As part of the search for the "dark molecular gas (DMG)," we report on the results of HCO$^+$ J = 1-0 absorption observations toward nine bright extragalactic millimeter wave continuum sources. The extragalactic sources are at high Galactic…

Astrophysics of Galaxies · Physics 2018-07-04 Geumsook Park , Bon-Chul Koo , Kee-Tae Kim , Do-Young Byun , Carl E. Heiles

Context. Radio frequency molecular absorption lines appear along sight lines with AV well below 1 mag, revealing the presence of H2 in diffuse gas even when 2.6mm CO emission is absent. Aims. We discuss absorption lines of HCO+, C2H, HCN,…

Astrophysics of Galaxies · Physics 2025-06-17 Harvey Liszt , Maryvonne Gerin

The Magellanic Stream, a tidal tail of diffuse gas falling onto the Milky Way, formed by interactions between the Small and Large Magellanic Clouds, is primarily composed of neutral atomic hydrogen (HI). The deficiency of dust and the…

We describe medium-resolution spectroscopic observations taken with the ESO Multi-Mode Instrument in the CaII K line (3933.661 Angstroms) towards 7 QSOs located in the line-of-sight to the Magellanic Bridge. At a spectral resolution R =…

Astrophysics · Physics 2009-11-11 J. V. Smoker , F. P. Keenan , H. M. A. Thompson , C. Bruns , E. Muller , N. Lehner , J. -K. Lee , I. Hunter

We present the first results from the Small Magellanic Cloud portion of a new Australia Telescope Compact Array (ATCA) HI absorption survey of both of the Magellanic Clouds, comprising over 800 hours of observations. Our new HI absorption…

The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected…

Astrophysics of Galaxies · Physics 2015-05-18 F. Wyrowski , K. M. Menten , R. Guesten , A. Belloche

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 acquired ALMA ground state absorption profiles of HCO+ and other molecules toward 33 extragalactic continuum sources seen toward the Galactic anticenter, deriving N(H2) = N(HCO+)/3x10^{-9}. We observed J=1-0 CO emission with the IRAM 30m…

Astrophysics of Galaxies · Physics 2023-07-19 Harvey Liszt , Maryvonne Gerin

We have detected faint, diffuse H$\alpha emission from several points along the Magellanic Stream, using the Rutgers Fabry--Perot Interferometer at the CTIO 1.5-m telescope. At points on the leading edges of the H I clouds MS II, MS III,…

Astrophysics · Physics 2008-11-26 Benjamin J. Weiner , T. B. Williams

We present the GASKAP-HI pilot absorption survey of neutral hydrogen (HI) in the Magellanic system. This survey provides 3219 sightlines across the Large (LMC) and Small Magellanic Clouds (SMC) and the Magellanic Bridge (MB) towards 1.4-GHz…

We present a new technique to identify associations of HI emission in the Magellanic Stream (MS) and ultraviolet (UV) absorbers from 92 QSO sight lines near the MS. We quantify the level of associations of individual HI elements to the main…

Astrophysics of Galaxies · Physics 2024-02-15 Doyeon A. Kim , Yong Zheng , Mary E. Putman

We report the first detection of DCO+ in a circumstellar disk. The DCO+ J=5-4 line at 360.169 GHz is observed with the 15m James Clerk Maxwell Telescope in the disk around the pre-main sequence star TW Hya. Together with measurements of the…

Astrophysics · Physics 2011-05-23 E. F. van Dishoeck , W. F. Thi , G. J. van Zadelhoff

We measured the extragalactic 0.7 keV X-ray background by observing the X-ray shadow of a neutral gas cloud in the Magellanic Bridge region. Two \rosat PSPC observations of total 104~ks were complemented by a detailed H I mapping of the…

Astrophysics · Physics 2009-10-28 Q. Daniel Wang , Taisheng Ye

We present high-resolution (R = 20000) spectroscopy of H3+ absorption toward the luminous Galactic center sources GCS 3-2 and GC IRS 3. With the efficient wavelength coverage afforded by Subaru IRCS, six absorption lines of H3+ have been…

Astrophysics · Physics 2015-06-24 M. Goto , B. J. McCall , T. R. Geballe , T. Usuda , N. Kobayashi , H. Terada , T. Oka
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