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Related papers: A Neutral Hydrogen Self-Absorption Cloud in the SG…

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We present the first results from a new carbon monoxide (CO) survey of the southern Galactic plane being conducted with the Mopra radio telescope in Australia. The 12CO, 13CO and C18O J=1-0 lines are being mapped over the l = 305-345 deg, b…

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 deep HI 21-cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity neutral gas is detected toward M 83, with…

Astrophysics · Physics 2011-02-11 Eric D. Miller , Joel N. Bregman , Bart P. Wakker

We report the detection of a peculiar molecular cloud, CO 0.02-0.02, lying about 5' Galactic-east from the center of the Galaxy. (12)CO images taken with NRO 45 m telescope showed that it is relatively compact (about 3x4 pc^2) as well as…

Astrophysics · Physics 2009-10-31 T. Oka , G. J. White , T. Hasegawa , F. Sato , M. Tsuboi , A. Miyazaki

We report the first evidence of molecular gas in two atomic hydrogen (HI) clouds associated with gas outflowing from the Small Magellanic Cloud (SMC). We used the Atacama Pathfinder Experiment (APEX) to detect and spatially resolve…

We present results of a blind search for Galactic HI 21-cm absorption lines toward 19130 radio sources, using 390 pointings of MALS, each pointing centered on a source brighter than 200 mJy. We detected 3640 HI absorption features. This…

We present an analysis of the HI and CO gas in conjunction with the Planck/IRAS submillimeter/far-infrared dust properties toward the most outstanding high latitude clouds MBM 53, 54, 55 and HLCG 92-35 at b = -30 deg to -45 deg. The CO…

The consortium for Galactic studies with the Arecibo L-band Feed Array (ALFA) is conducting a neutral hydrogen (HI) survey of the whole Arecibo sky (declination range from -1 to 38 degrees), with high angular (3.5') and velocity resolution…

We investigate the evolution of molecular clouds through the kinematics of their atomic hydrogen (HI) envelopes, using $^{12}\mathrm{CO}$ and 21-cm emission to trace the molecular and atomic gas, respectively. We measure the large-scale…

Astrophysics of Galaxies · Physics 2026-02-03 Thummim Mekuria , Nia Imara

We investigate the practice of assigning high spin temperatures to damped Lyman-alpha absorption systems (DLAs) not detected in HI 21-cm absorption. In particular, Kanekar & Chengaulr (2003) have attributed the mix of 21-cm detections and…

Astrophysics · Physics 2009-11-10 S. J. Curran , M. T. Murphy , Y. M. Pihlstroem , J. K. Webb , C. R. Purcell

At present neutral atomic hydrogen (HI) gas in galaxies at redshifts above $z \sim 0.3$ (the extent of 21-cm emission surveys in individual galaxies) and below $z \sim 1.7$ (where the Lyman-$\alpha$ line is not observable with ground-based…

We study the structure and kinematics of the OH-streamer and the +80 km/s cloud and their interactions with the circumnuclear disk (CND) and with other molecular clouds in the vicinity of the Galactic centre (GC), and we map OH absorption…

Astrophysics of Galaxies · Physics 2015-11-04 Roland Karlsson , Aage Sandqvist , Kambiz Fathi , Sergio Martín

We have made HI 21cm-line absorption measurements using the GMRT towards 15 directions in the Galaxy which are known to have high random velocity clouds as seen in the optical absorption lines of CaII and NaI. For the first time, in 6 out…

Astrophysics · Physics 2007-05-23 Rekhesh Mohan , K. S. Dwarakanath , G. Srinivasan , Jayaram N. Chengalur

We suggest that the high--velocity clouds (HVCs) are large clouds, with typical diameters of 25 kpc and containing 5e7 solar masses of neutral gas and 3e8 solar masses of dark matter, falling onto the Local Group; altogether the HVCs…

Astrophysics · Physics 2010-11-23 Leo Blitz , David N. Spergel , Peter J. Teuben , Dap Hartmann , W. Butler Burton

We map the Hi distribution of galaxies in a $\sim 1.5^\circ \times 2.5^\circ$ region located at the virial radius south of the Virgo cluster using the KAT$-$7 and the WSRT interferometers. Because of the different beam sizes of the two…

Astrophysics of Galaxies · Physics 2016-09-14 Amidou Sorgho , Kelley M. Hess , Claude Carignan , Tom A. Oosterloo

We use spectroscopic data from HST and FUSE to study the wide range of ionization states of the "highly ionized high-velocity clouds". Studied extensively in OVI absorption, these clouds are usually assumed to be infalling gas in the…

Astrophysics · Physics 2009-11-10 J. A. Collins , J. M. Shull , M. L. Giroux

We present a large-scale, interferometric survey of ammonia (1,1) and (2,2) toward the Galactic Center observed with the Australia Telescope Compact Array (ATCA). The survey covers Delta l ~1degree (~150pc) at an assumed distance of 8.5…

Astrophysics of Galaxies · Physics 2015-06-18 Juergen Ott , Axel Weiss , Lister Staveley-Smith , Christian Henkel , David S. Meier

We combine HI 21cm observations of the Milky Way, M31, and the local galaxy population with QSO absorption-line measurements to geometrically model the three-dimensional distribution of infalling neutral gas clouds (HVCs) in the extended…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Philipp Richter

UV absorption studies with FUSE have observed H2 molecular gas in translucent and diffuse clouds. Observations of the 158 micron [C II] fine structure line with Herschel also trace the same H2 molecular gas in emission. We present [C II]…

Astrophysics of Galaxies · Physics 2017-04-12 Thangasamy Velusamy , William Langer , Paul Goldsmith , Jorge L. Pineda

New HI images from the VLA Galactic Plane Survey (VGPS) show clear absorption features associated with the supernova remnant (SNR) G18.8+0.3. High-resolution $^{13}$CO images reveal that molecular clouds overlap the radio filaments of…

Astrophysics · Physics 2009-11-13 W. W. Tian , D. A. Leahy , Q. D. Wang