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Related papers: CHVCs: Galactic Building Blocks at z = 0

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High sensitivity H I observations of the nearby spiral galaxy NGC 2403 obtained with the VLA are presented and discussed. The properties of the extended, differentially rotating H I layer with its H I holes, spiral structure and outer warp…

Astrophysics · Physics 2009-11-07 Filippo Fraternali , Gustaaf van Moorsel , Renzo Sancisi , Tom Oosterloo

To gain insight into four highly ionized high-velocity clouds (HVCs) discovered by Sembach et al. (1999), we have analyzed data from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) for the PKS 2155-304 and…

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

We notice that nearby galaxies having high negative peculiar velocities are distributed over the sky very inhomogeneously. A part of this anisotropy is caused by the "Local Velocity Anomaly", i.e. by the bulk motion of nearby galaxies away…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Igor D. Karachentsev , Olga G. Nasonova , Helene M. Courtois

The high- and intermediate-velocity interstellar clouds (HVCs/IVCs) are tracers of energetic processes in and around the Milky Way. Clouds with near-solar metallicity about one kpc above the disk trace the circulation of material between…

Astrophysics · Physics 2009-06-23 B. P. Wakker , D. G. York , R. Wilhelm , J. C. Barentine , P. Richter , T. C. Beers , Z. Ivezic , J. C. Howk

The distributions of peculiar velocities of rich clusters and of groups of galaxies are investigated for different cosmological models and are compared with observations. Four cosmological models are studied: standard ($\Omega=1$) CDM,…

Astrophysics · Physics 2009-10-22 Neta A. Bahcall , Mirt Gramann , Renyue Cen

Aims. We aim to investigate the ionisation conditions and distances of Galactic high-velocity clouds (HVCs) in the Galactic halo and beyond in the direction of the Local Group (LG) barycentre and anti-barycentre, by studying spectral data…

Astrophysics of Galaxies · Physics 2019-06-26 Sietske J. D. Bouma , Philipp Richter , Cora Fechner

We have detected over 400 HI clouds in the lower halo of the Galaxy within the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth quadrant that spans 18 degrees in longitude, 40 degrees in latitude and is centered on…

We present search results of 22 high latitude (b > 25 deg.) sightlines for OH 18-cm emission using the 305-m radio telescope at the Arecibo Observatory. These sightlines appear in neutral hydrogen emission at intermediate velocities (V_lsr…

Astrophysics of Galaxies · Physics 2023-05-10 Allison Smith , D. Anish Roshi

We present HI imaging of GBT 1355+5439 performed with the Westerbork Synthesis Radio Telescope. This is a dark HI object recently discovered close to the nearby galaxy M101. We find GBT 1355+5439 to be an HI cloud 5x3 arcmin in size. The…

Astrophysics of Galaxies · Physics 2015-06-16 T. A. Oosterloo , G. H. Heald , W. J. G. de Blok

We discuss new, high sensitivity HI observations of the spiral galaxy NGC2403 which show extended emission at anomalous velocities with respect to the `cold' disk. This `anomalous' gas component (~1/10 of the total HI mass) is probably…

Astrophysics · Physics 2009-11-07 Filippo Fraternali , Tom Oosterloo , Renzo Sancisi , Gustaaf van Moorsel

The neutral hydrogen structure of high-velocity cloud A0 (at about -180 km/s) has been mapped with a 9.1 arcmin resolution. Gaussian decomposition of the profiles is used to separately map families of components defined by similarities in…

Astrophysics of Galaxies · Physics 2015-06-15 Gerrit L. Verschuur

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

We collected data on radial velocities and distances of galaxies to elucidate structure and kinematics of the filament attached to the Virgo cluster from south. In the region RA = [12.5 - 13.5]h, Dec = [-20 - 0]deg there are 171 galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Igor D. Karachentsev , Olga G. Nasonova

We report the detection of a largely ionized very-high velocity cloud (VHVC; $v_{\rm LSR}\sim-350$ km/s) toward M33 with the Hubble Space Telescope/Cosmic Origin Spectrograph. The VHVC is detected in OI, CII, SiII, and SiIII absorption…

Astrophysics of Galaxies · Physics 2017-11-02 Y. Zheng , J. K. Werk , J. E. G. Peek , M. E. Putman

We present the current distance estimates to 11 intermediate velocity clouds (IVCs) which are part of the David Dunlap Observatory Intermediate Velocity Cloud (DDO IVC) Distance Project (Clarke et al. 1999). We briefly discuss constraints…

Astrophysics · Physics 2007-05-23 T. E. Clarke , M. Gladders , G. Mallen-Ornelas

We have compiled a new sample of 240 halo objects with accurate distance and radial velocity measurements, including globular clusters, satellite galaxies, field blue horizontal branch stars and red giant stars from the Spaghetti survey.…

We have observed six `dark' neutral hydrogen (HI) clouds discovered in the Virgo cluster by the Arecibo Galaxy Environment Survey (AGES) with the Karl G. Jansky Very Large Array (VLA), giving higher angular and velocity resolution than the…

Astrophysics of Galaxies · Physics 2026-01-28 Robert Minchin , Rhys Taylor , Emmanuel Momjian , Boris Deshev , Vojtěch Partík

CO--0.40--0.22 is a peculiar molecular cloud that is compact and has an extraordinary broad velocity width. It is found in the central molecular zone of our Galaxy. In this direction, there is another cloud with an H$_2$O maser spot at a…

Astrophysics of Galaxies · Physics 2017-05-10 Yuhei Iwata , Haruka Kato , Daisuke Sakai , Tomoharu Oka

We report the discovery of eleven high-velocity HI clouds at Galactic latitudes of 25-30 degrees, likely embedded in the Milky Way's nuclear wind. The clouds are detected with deep Green Bank Telescope 21 cm observations of a $3.2^\circ…

Astrophysics of Galaxies · Physics 2025-07-08 Rongmon Bordoloi , Andrew J. Fox , Felix J. Lockman

The Owens Valley Radio Observatory (OVRO) millimeter array was used to make observations of the CS(2-1) line (at 97.981 GHz) arising from the G0.07+0.04 region of the ``-30 km/s'' molecular cloud near the Galactic center with a spatial…

Astrophysics · Physics 2009-11-07 Cornelia C. Lang , W. M. Goss , Mark Morris