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相关论文: Reconstructing Deconstruction: High-Velocity Cloud…

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Optical emission lines have now been detected from about 20 high velocity clouds. These emission lines -- primarily H-alpha, secondarily [N II] and [S II] -- are very faint and diffuse, spread over the surfaces of the clouds. We compile…

天体物理学 · 物理学 2007-05-23 Benjamin J. Weiner , Stuart N. Vogel , T. B. Williams

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…

星系天体物理 · 物理学 2023-05-10 Allison Smith , D. Anish Roshi

Because isolated high-velocity clouds (HVCs) are found at great distances from the Galactic radiation field and because they have subsolar metallicities, there have been no detections of dust in these structures. A key problem in this…

星系天体物理 · 物理学 2016-02-10 Daniel Lenz , Lars Flöer , Jürgen Kerp

A recent discovery of two stellar clusters associated with the diffuse high-latitude cloud HRK 81.4-77.8 has important implications for star formation in the Galactic halo. We derive a plausible distance estimate to HRK 81.4-77.8 primarily…

星系天体物理 · 物理学 2016-05-04 J. Kerp , D. Lenz , T. Roehser

We present hydrodynamic simulations of high-velocity clouds (HVCs) traveling through the hot, tenuous medium in the Galactic halo. A suite of models was created using the FLASH hydrodynamics code, sampling various cloud sizes, densities,…

星系天体物理 · 物理学 2015-05-28 Kyujin Kwak , David B. Henley , Robin L. Shelton

We present new observational results on high-velocity clouds (HVCs) based on an analysis of the Leiden/Dwingeloo HI survey. We cataloged all HVCs with NHI > 1 10^19 cm^-2 and found 252 clouds that form a representative flux limited sample.…

天体物理学 · 物理学 2007-05-23 C. Bruens , J. Kerp , P. M. W. Kalberla , U. Mebold

Throughout the passage within the Galactic halo, high-velocity clouds (HVCs) sweep up ambient magnetic fields and form stretched and draped configurations of magnetic fields around them. Many earlier numerical studies adopt spherically…

星系天体物理 · 物理学 2023-05-03 Seoyoung Lyla Jung , Asger Grønnow , Naomi McClure-Griffiths

Green Bank Telescope (GBT) 21cm observations have revealed a faint, yet extensive HI cloud population surrounding the Andromeda Galaxy (M31). The newfound objects are likely analogs to the high-velocity HI clouds (HVCs) seen around the…

High-velocity clouds (HVCs) are multi-phase gas structures whose velocities (|v_LSR|>100 km/s) are too high to be explained by Galactic disk rotation. While large HVCs are well characterized, compact and small HVCs (with HI angular sizes of…

In the J, H, and Ks bands survey of the the Galactic Center region over an area of 2deg x 5deg, we have found many dark clouds, among which a distinguished chain of dark clouds can be identified with a quiescent CO cloud. The distances of…

We present the first set of distance limits from the David Dunlap Observatory Intermediate Velocity Cloud (DDO IVC) distance project. Such distance measures are crucial to understanding the origins and dynamics of IVCs, as the distances set…

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…

天体物理学 · 物理学 2011-08-23 C. Bruens , T. Westmeier

The study of high-velocity clouds has progressed much since the appearance of the review article by Wakker & van Woerden (1997), less than two years ago. Much of this progress is described in these workshop proceedings. Here we update the…

天体物理学 · 物理学 2007-05-23 Bart P. Wakker , Hugo van Woerden , Brad K. Gibson

The discovery of an HI cloud with peculiar properties at equatorial coordinates (J2000) ra=07h49m, dec=04d30m is presented. The HI object was detected at 21cm using the 300-m NAIC Arecibo telescope. Subsequent follow-up high-resolution…

天体物理学 · 物理学 2009-11-13 L. Dedes , C. Dedes , P. W. M Kalberla

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…

宇宙学与河外天体物理 · 物理学 2015-05-14 Riccardo Giovanelli , Martha P. Haynes , Brian R. Kent , Elizabeth K. Adams

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…

天体物理学 · 物理学 2009-11-07 V. de Heij , R. Braun , W. B. Burton

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…

天体物理学 · 物理学 2010-11-23 Leo Blitz , David N. Spergel , Peter J. Teuben , Dap Hartmann , W. Butler Burton

We decomposed the G333 complex and the G331 giant molecular cloud into multi-scale hub-filament systems (HFs) using the high-resolution $^{13}$CO (3$-$2) data from LAsMA observations. We employed the filfinder algorithm to identify and…

星系天体物理 · 物理学 2025-06-23 J. W. Zhou , J. S. Urquhart , F. Wyrowski , S. Neupane , T. Liu , M. Juvela

High-velocity clouds (HVCs), which are gas clouds moving at high velocity relative to the galactic disk, may play a critical role in galaxy evolution, potentially supplying gas to the disk and triggering star formation. In this study, we…

星系天体物理 · 物理学 2025-07-02 Maki Nagata , Fumi Egusa , Fumiya Maeda , Kazuki Tokuda , Kotaro Kohno , Kana Morokuma-Matsui , Jin Koda

We report the first determination of a distance bracket for the high-velocity cloud (HVC) complex C. Combined with previous measurements showing that this cloud has a metallicity of 0.15 times solar, these results provide ample evidence…