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Related papers: HVCs probing a gaseous Galactic halo

200 papers

We report that neutral hydrogen (HI) gas clouds, resembling High Velocity Clouds (HVCs) observed in the Milky Way (MW), appear in MW-sized disk galaxies formed in high-resolution Lambda Cold Dark Matter (LCDM) cosmological simulations which…

Astrophysics · Physics 2007-05-23 Tim W. Connors , Daisuke Kawata , Jeremy Bailin , Jason Tumlinson , Brad K. Gibson

Previous HST and FUSE observations have revealed highly ionized high-velocity clouds (HVCs) or more generally low HI column HVCs along extragalactic sightlines over 70-90% of the sky. The distances of these HVCs have remained largely…

Astrophysics of Galaxies · Physics 2015-05-14 N. Lehner , J. C. Howk

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

Complex A is a high-velocity cloud that is traversing through the Galactic halo toward the Milky Way's disk. We combine both new and archival Green Bank Telescope observations to construct a spectroscopically resolved HI~21-cm map of this…

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…

The halo of our Galaxy is populated with a significant number of high-velocity clouds (HVCs) moving with a speed up to $500$ km/s. It is suggested that these HVCs might contain a non-negligible fraction of the missing baryons. The main aim…

Astrophysics of Galaxies · Physics 2024-12-03 Noraiz Tahir , Martin Lopez Corredoira , Francesco De Paolis

Searching the HI Parkes All-Sky Survey (HIPASS) and its northern extension, we detected a population of very compact high-velocity clouds (HVCs) with similar velocities in the Galactic standard-of-rest frame which appear to be arranged in…

Astrophysics · Physics 2009-11-13 T. Westmeier , B. S. Koribalski

In recent years several hypervelocity stars (HVSs) have been observed in the halo of our Galaxy. Such HVSs have possibly been ejected from the Galactic center and then propagated in the Galactic potential up to their current position. The…

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

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 explore the hypothesis that clouds detected in quasar absorption line systems are falling at a terminal velocity toward the center of high redshift gaseous galactic halos. Since both the ionization level and terminal velocity of halo…

Astrophysics · Physics 2007-05-23 Robert A. Benjamin

We investigate the convective stability of two popular types of model of the gas distribution in the hot Galactic halo. We first consider models in which the halo density and temperature decrease exponentially with height above the disk.…

Astrophysics of Galaxies · Physics 2015-06-18 David B. Henley , Robin L. Shelton

HI observations of high-velocity clouds (HVCs) indicate, that they are interacting with their ambient medium. Even clouds located in the very outer Galactic halo or the intergalactic space seem to interact with their ambient medium. In this…

Astrophysics · Physics 2016-08-30 C. Konz , C. Bruens , G. T. Birk

In the Galactic halo, metal-bearing Galactic halo material mixes into high velocity clouds (HVCs) as they hydrodynamically interact. This interaction begins long before the clouds completely dissipate and long before they slow to the…

Astrophysics of Galaxies · Physics 2014-11-19 Jeffrey A. Gritton , Robin L. Shelton , Kyujin Kwak

Using X-ray constrained beta-models for the radial distribution of gas in the outskirts of galaxies, we analyze the termination of galactic winds and the formation and evolution of halo clouds by thermal instability. At low mass-loss rates,…

Astrophysics of Galaxies · Physics 2020-10-15 Michael Shull , Jacob A. Moss

In this contribution the current state of knowledge about the high-velocity clouds (HVCs) is summarized. Recent progress has shown that the HVCs are a diverse phenomenon. The intermediate-velocity clouds (IVCs) are likely to be part of a…

Astrophysics · Physics 2007-05-23 B. P. Wakker

In the spectra of 139 early-type Large Magellanic Cloud (LMC) stars observed with FUSE and with deep radio Parkes HI 21-cm observations along those stars, we search for and analyze the absorption and emission from high-velocity gas at…

Astrophysics of Galaxies · Physics 2009-08-24 N. Lehner , L. Staveley-Smith , J. C. Howk

High-velocity atomic clouds in the Galactic center have attracted significant attention due to their enigmatic formation process, which is potentially linked to the starburst or supermassive black hole activities in the region. Further, the…

Astrophysics of Galaxies · Physics 2023-12-27 Mengfei Zhang , Miao Li

High-velocity clouds (HVCs) are composed of neutral hydrogen (HI) moving at velocities that deviate from the general rotational motion of the Milky Way. Currently, the origins of the HVCs remain poorly known due to the difficulty in…

Astrophysics of Galaxies · Physics 2025-04-15 Xiao-Lan Liu , Jin-Long Xu , Peng Jiang , Ming Zhu , Chuan-Peng Zhang , Naiping Yu , Ye Xu , Xin Guan , Jun-Jie Wang

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