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Related papers: High-Velocity Clouds in M 83 and M 51

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Studies of the Milky Way's disk-halo interface have historically identified inflowing and outflowing gas incompatible with disk rotation on the basis of radial velocity, leading to the well-known categories of intermediate-velocity clouds…

Cosmological galaxy formation models predict the existence of dark matter minihalos surrounding galaxies and in filaments connecting groups of galaxies. The more massive of these minihalos are predicted to host HI gas that should be…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Katie M. Chynoweth , Glen I. Langston , Kelly Holley-Bockelmann

For about two decades, a population of relative small and nearby molecular clouds has been known to exist at high Galactic latitudes. Lying more than 10$^\circ$ from the Galactic plane, these clouds have typical distances of $\sim$150 pc,…

Astrophysics · Physics 2009-11-10 Diego F. Torres , T. M. Dame , Seth W. Digel

This is the third paper in a series in which we attempt to put constraints on the flattening of dark halos in disk galaxies. For this purpose we need to analyse the observed XV diagrams in edge-on galaxies to accurately measure the radial…

Astrophysics of Galaxies · Physics 2015-05-18 J. C. O'Brien , K. C. Freeman , P. C. van der Kruit

We present BIMA observations of a 2$\arcmin$ field in the northeastern spiral arm of M31. In this region we find six giant molecular clouds that have a mean diameter of 57$\pm$13 pc, a mean velocity width of 6.5$\pm$1.2 \kms, and a mean…

Astrophysics · Physics 2009-11-13 Kartik Sheth , Stuart N. Vogel , Christine D. Wilson , T. M. Dame

In a hierarchical merging scenario, the outer parts of a galaxy are a fossil record of the galaxy's early history. Observations of the outer disks and halos of galaxies thus provide a tool to study individual galaxy histories and test…

Astrophysics · Physics 2015-05-13 Anil Seth , Roelof de Jong , David Radburn-Smith , Henry Ferguson

As galactic halos are not directly visible, there are many ambiguities regarding their composition and rotational velocity. Though most of the dark matter is non-baryonic, {\it some fraction is}, and it can be used to trace the halo…

Astrophysics of Galaxies · Physics 2023-01-10 Noraiz Tahir , Francesco De Paolis , Asghar Qadir , Achille A. Nucita

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

We show that a string of HI clouds that form part of the high-velocity cloud complex known as GCN is a probable gaseous stream extending over more than 50 deg in the Galactic halo. The radial velocity gradient along the stream is used to…

Astrophysics of Galaxies · Physics 2015-05-19 Shoko Jin

An analysis of large-area CO J=3-2 maps from the James Clerk Maxwell Telescope for 12 nearby spiral galaxies reveals low velocity dispersions in the molecular component of the interstellar medium. The three lowest luminosity galaxies show a…

We consider global HI and optical properties of about three hundred nearby galaxies with V$_0 < 500$ km/s. The majority of them have individual photometric distance estimates. The galaxy sample parameters, e.g. their linear diameters, their…

Astrophysics · Physics 2023-04-19 I. D. Karachentsev , D. I. Makarov , W. K. Huchtmeier

Most detected neutral atomic hydrogen (HI) at low redshift is associated with optically bright galaxies. However, a handful of HI clouds are known which appear to be optically dark and have no nearby potential progenitor galaxies, making…

Astrophysics of Galaxies · Physics 2018-05-23 Rhys Taylor , Richard Wünsch , Jan Palouš

A summary of the current knowledge on hypervelocity stars (HVSs). HVSs are fascinating because their properties are linked to Sgr A* and the stellar environment of the Galactic Center. Observing the distribution of HVSs can address: 1) the…

Astrophysics · Physics 2008-11-05 Warren R. Brown

Hypervelocity stars (HVSs) ejected by the massive black hole at the Galactic center have unique kinematic properties compared to other halo stars. Their trajectories will deviate from being exactly radial because of the asymmetry of the…

Astrophysics · Physics 2009-06-23 Qingjuan Yu , Piero Madau

We study the interaction of galactic wind with hot halo gas using hydrodynamical simulations. We find that the outcome of this interaction depends crucially on the wind injection density and velocity. Various phases of the extraplanar media…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Mahavir Sharma , Biman B. Nath , Indranil Chattopadhyay , Yuri Shchekinov

Neutral hydrogen mapping of several small, very low column density High Velocity Clouds (HVC), using the Arecibo telescope, is reported. Some were found serendipitously superimposed at distinct velocities on largerHVCs; others were found to…

Astrophysics · Physics 2009-11-10 G. Lyle Hoffman , E. E. Salpeter , Ajay Hirani

The properties of galaxies follow scaling relations related to the physics that govern galaxy evolution. Based on these, we can identify galaxies undergoing specific evolutionary processes such as HI-excess galaxies, which have relatively…

Astrophysics of Galaxies · Physics 2024-12-12 H. Denes , V. A. Capa

We present 12CO(1->0) observations of 45 giant molecular clouds in M33 made with the BIMA array. The observations have a linear resolution of 20 pc, sufficient to measure the sizes of most GMCs in the sample. We place upper limits on the…

Astrophysics · Physics 2009-11-10 Erik Rosolowsky , Greg Engargiola , Richard Plambeck , Leo Blitz

We examine the vertical structure and equilibrium of the molecular gas layer in the galactic disk, measuring its scale height and velocity dispersion as a function of Galactic radius by modeling the CO emission at the tangent points. The…

Astrophysics · Physics 2009-10-22 Sangeeta Malhotra