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Related papers: Summary of Recent Progress in Understanding HVCs

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We present Far Ultraviolet Spectroscopic Explorer observations of the atomic and molecular absorption in high velocity cloud HVC 287.5+22.5+240, which lies in front of the ultraviolet-bright nucleus of the Seyfert 1 galaxy NGC 3783. We…

Various scenarios have been proposed to explain the origin of the Galactic high-velocity clouds, predicting different distances and implying widely varying properties for the Galaxy's gaseous halo. To eliminate the difficulties of studying…

Astrophysics · Physics 2007-05-23 Eric D. Miller , Joel N. Bregman

Recent proper motion measurements of the Large and Small Magellanic Clouds (LMC and SMC, respectively) by Kallivayalil et al (2006a,b) suggest that the 3D velocities of the Clouds are substantially higher (~100 km/s) than previously…

The high-velocity cloud (HVC) Complex A is a probe of the physical conditions in the Galactic halo. The kinematics, morphology, distance, and metallicity of Complex A indicate that it represents new material that is accreting onto the…

Astrophysics of Galaxies · Physics 2013-08-06 Kathleen A. Barger , Lawrence M. Haffner , Bart P. Wakker , Alex S. Hill , Greg J. Madsen , Allison K. Duncan

Intermediate- and high-velocity clouds (IVCs, HVCs) are a potential source of fuel for star formation in the Milky Way (MW), but their origins and fates depend sensitively on their distances. We search for IVC and HVC in HST high-resolution…

Astrophysics of Galaxies · Physics 2022-04-20 N. Lehner , J. C. Howk , A. Marasco , F. Fraternali

We employ CaII K and NaI D interstellar absorption-line spectroscopy of early-type stars in the Large and Small Magellanic Clouds to investigate the large- and small-scale structure in foreground Intermediate and High Velocity Clouds…

Astrophysics of Galaxies · Physics 2015-11-11 J. V. Smoker , A. J. Fox , F. P. Keenan

We present the germ of a new model for High Velocity Clouds, derived from the idea that the dark matter halo of our Galaxy is in the form of cold, planetary-mass gas clouds. In this picture HVCs arise as a result of disruptive collisions…

Astrophysics · Physics 2007-05-23 Mark Walker , Mark Wardle

With the onset of the HI Parkes All-Sky Survey, a new view of the high-velocity cloud (HVC) distribution in the southern sky is being revealed. The dense spatial sampling and unbiased coverage of HIPASS gives it multiple advantages over…

Astrophysics · Physics 2015-06-24 M. E. Putman , B. K Gibson

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

A set of HI sources extracted from the north Galactic polar region by the ongoing ALFALFA survey has properties that are consistent with the interpretation that they are associated with isolated minihalos in the outskirts of the Local Group…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Riccardo Giovanelli , Martha P. Haynes , Brian R. Kent , Elizabeth K. Adams

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 model the kinematics of the high- and intermediate- velocity clouds (HVCs and IVCs) observed in absorption towards a sample of 55 Galactic halo stars with accurate distance measurements. We employ a simple model of a thick disc whose…

Astrophysics of Galaxies · Physics 2022-05-25 A. Marasco , F. Fraternali , N. Lehner , J. C. Howk

We discovered two small high-velocity compact clouds (HVCCs) in HCN $J=4-3$ and $J=3-2$ maps of the central 20 pc of our Galaxy. Both HVCCs have broad velocity widths ($\Delta V \gtrsim 40$ km s$^{-1}$) and compact sizes ($d\sim 1$ pc), and…

Astrophysics of Galaxies · Physics 2017-07-19 Shunya Takekawa , Tomoharu Oka , Yuhei Iwata , Sekito Tokuyama , Mariko Nomura

In this paper, we limit the stellar content of 13 high-velocity clouds (HVCs; including 1 compact HVC) using the detection limits of a new survey for resolved Milky Way satellite galaxies in the Sloan Digital Sky Survey Early Data Release…

Given the current and past star-formation in the Milky Way in combination with the limited gas supply, the re-fuelling of the reservoir of cool gas is an important aspect of Galactic astrophysics. The infall of \ion{H}{i} halo clouds can,…

Astrophysics of Galaxies · Physics 2015-01-07 Daniel Lenz , Jürgen Kerp , Lars Flöer , Benjamin Winkel , François Boulanger , Guilaine Lagache

We present Arecibo L-band Feed Array 21-cm observations of a sub-complex of HVCs at the tip of the Anti-Center Complex. These observations show morphological details that point to interaction with the ambient halo medium and differential…

We explore the Magellanic Stream (MS) using a Gaussian decomposition of the HI velocity profiles in the Leiden-Argentine-Bonn (LAB) all-sky HI survey. This decomposition exposes the MS to be composed of two filaments distinct both spatially…

Astrophysics · Physics 2009-06-23 David L. Nidever , Steven R. Majewski , W. Butler Burton

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

Six examples of the compact, isolated high-velocity HI clouds (CHVCs) identified by Braun and Burton (1999) have been imaged with the WSRT. The 65 confirmed objects in this class define a dynamically cold system, with a global minimum for…

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

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