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Related papers: Effelsberg HI Survey of Compact High-Velocity Clou…

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We have mapped 11 compact high-velocity clouds (CHVCs) in the 21-cm line emission of neutral, atomic hydrogen, using the Effelsberg 100-m radio telescope. The aim of our observations was to study the overall distribution of the warm neutral…

Astrophysics · Physics 2009-11-10 T. Westmeier , C. Bruens , J. Kerp

We have observed 11 compact high-velocity clouds in the 21-cm line of neutral hydrogen with the 100-m telescope in Effelsberg. Our observations show that most of the clouds have a rather complex morphology. Head-tail structures and…

Astrophysics · Physics 2007-05-23 T. Westmeier , C. Bruens , J. Kerp

We present deep HI observations of three compact high-velocity clouds (CHVCs). The main goal is to study their diffuse warm gas and compact cold cores. We use both low- and high-resolution data obtained with the 100 m Effelsberg telescope…

Astrophysics of Galaxies · Physics 2015-06-18 Shahram Faridani , Lars Flöer , Jürgen Kerp , Tobias Westmeier

We have identified a class of high-velocity clouds which are compact and apparently isolated. The clouds are compact in that they have angular sizes less than 2 degrees FWHM. They are isolated in that they are separated from neighboring…

Astrophysics · Physics 2007-05-23 R. Braun , W. B. Burton

Compact high-velocity clouds (CHVCs) are the most distant of the HVCs in the Local Group model and would have HI volume densities of order 0.0003/cm^3. Clouds with these volume densities and the observed neutral hydrogen column densities…

Astrophysics · Physics 2009-11-07 Philip R. Maloney , Mary E. Putman

High-velocity clouds (HVCs) are clouds of HI seen around the Milky Way with velocities inconsistent with Galactic rotation, have unknown distances and masses and controversial origins. One possibility is that HVCs are associated with the…

Growing evidence supports the suggestion that the compact high-velocity clouds of HI (CHVCs) are located throughout the Local Group and continue to fuel galactic evolution. Recent distance estimates to individual objects lie in the range…

Astrophysics · Physics 2009-10-31 Robert Braun , W. Butler Burton

We present HI observations of the compact high-velocity cloud HVC289+33+251 that was discovered by Putman et al. (2002). Observations with the 100-m Effelsberg telescope demonstrate that this cloud is still unresolved by the 9' beam of the…

Astrophysics · Physics 2011-08-23 C. Bruens , T. Westmeier

We consider here the class of compact, isolated, high-velocity HI clouds, CHVCs, which are sharply bounded in angular extent down to a limiting column density of 1.5x10^18 cm^-2. We describe our automated search algorithm and it's…

Astrophysics · Physics 2007-05-23 W. B. Burton , R. Braun , V. de Heij

We present deep HI observations of the compact high-velocity cloud HVC125+41-207 using the 100-m Effelsberg telescope. Our goal was in particular to study the warm neutral medium (WNM) in detail. The Effelsberg data reveal a two phase…

Astrophysics · Physics 2009-11-06 C. Bruens , J. Kerp , A. Pagels

We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs) extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have median flux densities of 1.34 Jy km/s, median angular diameters of 10', and median…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-18 Elizabeth A. K. Adams , Riccardo Giovanelli , Martha P. Haynes

We combine the catalogs of compact high-velocity HI clouds extracted from the LDS and HIPASS surveys and analyze the all-sky properties of the ensemble. Five principal observables are defined for the CHVC population: (1) the spatial…

Astrophysics · Physics 2009-11-07 V. de Heij , R. Braun , W. B. Burton

We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with HI column density was…

Astrophysics of Galaxies · Physics 2012-03-06 Rik J. Williams , Smita Mathur , Shawn Poindexter , Martin Elvis , Fabrizio Nicastro

Six examples of the compact, isolated high-velocity clouds catalogued by Braun & Burton (1999) and identified with a dynamically cold ensemble of primitive objects falling towards the barycenter of the Local Group have been imaged with the…

Astrophysics · Physics 2016-01-27 W. B. Burton , Robert Braun

We have conducted an HI 21 cm emission-line survey using the Parkes 20cm multibeam instrument and the Australia Telescope Compact Array (ATCA) of six loose groups of galaxies chosen to be analogs to the Local Group. The goal of this survey…

Astrophysics · Physics 2011-02-11 D. J. Pisano , D. G. Barnes , B. K. Gibson , L. Staveley-Smith , K. Freeman , V. A. Kilborn

High-velocity clouds (HVC), fast-moving ionized and neutral gas clouds found at high galactic latitudes, may play an important role in the evolution of the Milky Way. The extent of this role depends sensitively on their distances and total…

Astrophysics of Galaxies · Physics 2015-06-04 N. Lehner , J. C. Howk , C. Thom , A. J. Fox , J. Tumlinson , T. M. Tripp , J. D. Meiring

A catalog of Southern anomalous-velocity HI clouds at Decl. < +2 deg is presented, based on data from the HI Parkes All-Sky Survey (HIPASS). The improved sensitivity (5sigma: T_B = 0.04 K) and resolution (15.5') of the HIPASS data results…

A distinct sub-class of anomalous velocity HI emission features has emerged from recent high quality surveys of the Local Group environment, namely the compact high velocity clouds (CHVCs). A program of high-resolution imaging with the…

Astrophysics · Physics 2007-05-23 Robert Braun , W. Butler Burton

We present deep Halpha spectroscopy towards several high-velocity clouds (HVCs) which vary in structure from compact (CHVCs) to the Magellanic Stream. The clouds range from being bright (~640 mR) to having upper limits on the order of 30 to…

Astrophysics · Physics 2009-11-10 M. E. Putman , J. Bland-Hawthorn , S. Veilleux , B. K. Gibson , K. C. Freeman , P. R. Maloney

Using Milky Way data of the new Effelsberg-Bonn HI Survey (EBHIS) and the Galactic All-Sky Survey (GASS), we present a revised picture of the high-velocity cloud (HVC) complex Galactic Center Negative (GCN). Owing to the higher angular…

Astrophysics of Galaxies · Physics 2015-05-28 Benjamin Winkel , Nadya Ben Bekhti , Verena Darmstädter , Lars Flöer , Jürgen Kerp , Philipp Richter
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