DOI:10.1086/376961 - Corpus ID: 16129802
High-Velocity Cloud Complex H: A Satellite of the Milky Way in a Retrograde Orbit?
@article{Lockman2003HighVelocityCC, title={High-Velocity Cloud Complex H: A Satellite of the Milky Way in a Retrograde Orbit?}, author={Felix J. Lockman}, journal={The Astrophysical Journal Letters}, year={2003}, volume={591}, pages={L33 - L36}, url={https://api.semanticscholar.org/CorpusID:16129802}}- F. J. Lockman
- Published21 May 2003
- Environmental Science, Physics
- The Astrophysical Journal Letters
Observations with the Green Bank Telescope of 21 cm H I emission from the high-velocity cloud complex H suggest that it is interacting with the Milky Way. A model in which the cloud is a satellite of the Galaxy in an inclined, retrograde circular orbit reproduces both the cloud's average velocity and its velocity gradient with latitude. The model places complex H at R = 33 ± 9 kpc from the Galactic center on a retrograde orbit inclined ≈45° to the Galactic plane. At this location, it has a mass…
38 Citations
38 Citations
The Smith Cloud: A High-Velocity Cloud Colliding with the Milky Way
- F. J. LockmanR. BenjaminA J HerouxG. LangstonReceived Accepted
- 2008
Physics, Environmental Science
New 21 cm H I observations made with the Green Bank Telescope show that the high-velocity cloud known as the Smith Cloud has a striking cometary appearance and many indications of interaction with…
A Component of the Smith High-velocity Cloud Now Crossing the Galactic Plane
We have identified a new structure in the Milky Way: a leading component of the Smith high-velocity cloud that is now crossing the Galactic plane near longitude 25°. Using new 21 cm H i data from the…
HIGH-VELOCITY CLOUDS IN THE NEARBY SPIRAL GALAXY M 83
- E. MillerJ. BregmanB. Wakker
- 2009
Environmental Science, Physics
We present deep H i 21 cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity…
Where Are the High-Velocity Clouds in Local Group Analogs?
High-velocity clouds (HVCs) are clouds of H I seen around the Milky Way with velocities inconsistent with Galactic rotation; they have unknown distances and masses and controversial origins. One…
DISCOVERY OF STAR FORMATION IN THE EXTREME OUTER GALAXY POSSIBLY INDUCED BY A HIGH-VELOCITY CLOUD IMPACT
- Natsuko IzumiN. KobayashiC. YasuiA. TokunagaM. SaitoS. Hamano
- 2014
Physics, Environmental Science
We report the discovery of star formation activity in perhaps the most distant molecular cloud in the extreme outer galaxy. We performed deep near-infrared imaging with the Subaru 8.2 m telescope,…
An intermediate-velocity H i cloud falling to the galactic disk; Possible evidence for low-metallicity H i gas originating outside the galactic disk
- Y. FukuiMasako KogaM. Sasaki
- 2018
Physics
We found that an intermediate-velocity cloud (IVC), IVC 86−36, in H i 21 cm emission shows a head–tail distribution toward the Galactic plane with marked parallel filamentary streamers, which is…
ANOMALOUS H i IN NGC 2997
- K. HessD. PisanoE. WilcotsJ. Chengalur
- 2009
Physics
We present deep H i observations of the moderately inclined spiral galaxy, NGC 2997. The goal of these observations was to search for H i clouds in the vicinity of NGC 2997 analogous to the…
Hi Clouds Beyond the Galactic Disk
- F. J. Lockman
- 2003
Environmental Science, Physics
Recent observations in the 21cm line with the Green Bank Telescope have changed our view of the neutral interstellar medium (ISM) in several ways. The new data show that in the inner parts of the…
High-Velocity Clouds Merging with the Milky Way
- F. J. Lockman
- 2008
Physics, Environmental Science
HI observations with the Green Bank Telescope have now given us two clear examples of high-velocity HI clouds which are encountering the Milky Way disk and losing matter to it: Complex H, passing…
An Accurate Distance to High-Velocity Cloud Complex C
We report an accurate distance of d = 10 ± 2.5 kpc to the high-velocity cloud Complex C. Using high signal-to-noise ratio Keck HIRES spectra of two horizontal-branch stars, we have detected Ca II K…
26 References
Discovery of a Population of H I Clouds in the Galactic Halo
- F. J. Lockman
- 2002
Physics
A population of discrete H I clouds in the halo of the inner Galaxy has been discovered in 21 cm observations made with the Green Bank Telescope. The halo clouds are seen up to 1.5 kpc from the…
High-Velocity Clouds: Building Blocks of the Local Group
- L. BlitzD. SpergelLeiden University
- 1999
Physics
We suggest that the high-velocity clouds (HVCs) are large clouds, with typical diameters of 25 kpc, containing 3×107 M☉ of neutral gas and 3×108 M☉ of dark matter, falling onto the Local Group;…
A Lower Limit to the Distance of High-Velocity Cloud Complex H
We derive a lower limit for the distance of the high-velocity cloud (HVC) complex H, which is a structure covering 480 square degrees on the sky and is centered on l = 131°, b = 1°. Considering the…
Where Are the High-Velocity Clouds?
Recent observations of high-velocity clouds (HVCs) have revealed compression fronts and tail-shaped features of H I, suggesting that they are interacting with an external medium. We perform…
Infrared Search for Young Stars in H I High-Velocity Clouds
- Ž. IvezićD. Christodoulou
- 1997
Physics
We have searched the IRAS Point Source Catalog and HIRES maps for young stellar objects (YSOs) in the direction of five H I high-velocity clouds (HVCs). In agreement with optical searches in the…
Dynamical evolution of high velocity clouds in the intergalactic medium
- C. KonzC. BruensG. T. Birk
- 2002
Environmental Science, Physics
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…
On the Distance Determination and Ionization of the High-Velocity Clouds
- Andrea FerraraGeorge B. Field
- 1994
Physics
We present a study of the ionization and thermal structure of neutral hydrogen clouds located in the Galactic halo, immersed in the extragalactic background radiation field, and supposed to be in…
H I Fine Structure in Magellanic Tidal Debris
- B. WakkerT. OosterlooM. Putman
- 2002
Physics, Environmental Science
We report on H I observations with the Australia Telescope and the Parkes telescope of one of the cores of the high-velocity cloud (HVC) WW 187 (also known as HVC 287+23+240 and HVC 287.5+22.5+240).…
The Oldest Stars of the Extremely Metal-Poor Local Group Dwarf Irregular Galaxy Leo A
We present deep Hubble Space Telescope (HST) single-star photometry of Leo A in B, V, and I. Our new field of view is offset from the centrally located field observed by Tolstoy et al. in order to…
Related Papers
Showing 1 through 3 of 0 Related Papers