Related papers: High-Velocity Clouds in M 83 and M 51
Using Milky Way data of the new Effelsberg-Bonn HI Survey (EBHIS) and the Galactic All-Sky Survey (GASS), we present a revised picture of the high-velocity cloud (HVC) complex Galactic Center Negative (GCN). Owing to the higher angular…
The extended ultraviolet (XUV) disk galaxies are one of the most interesting objects studied in the last few years. The UV emission, revealed by GALEX, extends well beyond the optical disk, after the drop of H$\alpha$ emission, the usual…
High-velocity particles ( $v>v_\mathrm{esc}$) in the Milky Way are rare but nonetheless important to characterize due to their impact on dark matter (DM) direct detection experiments. We select halos similar in mass to the Milky Way in a…
The extra-planar H I in the inner parts of the Milky Way has been discovered to contain numerous cloud-like structures when observed in the 21cm line with the Green Bank Telescope (GBT). These halo clouds have motions consistent with…
The observed flaring of HI disk in the outer region of galaxies has been used in the past to determine the shape of the dark matter halo. Previous studies based on this concept suggest a slightly oblate halo (axis ratio ~ 0.8) for our…
We present a percent-level accurate model of the line-of-sight velocity distribution of galaxies around dark matter halos as a function of projected radius and halo mass. The model is developed and tested using synthetic galaxy catalogs…
Spiral galaxies must acquire gas to maintain their observed level of star formation beyond the next few billion years (Leroy et al. 2008). A source of this material may be the gas that resides between galaxies, but our understanding of the…
Molecular clouds at very high latitudes ($b > 60^o$) away from the Galactic plane are considered rare and not conventional sites of star formation. Contrary to this, the recent discovery of high latitude embedded Clusters can possibly…
To date, all of the reported high velocity stars (HVSs), which are believed to be ejected from the Galactic center, are blue and therefore almost certainly young. Old-population HVSs could be much more numerous than the young ones that have…
Within the cosmological concordance model, Cold Dark Matter (CDM) subhalos form the building blocks which merge hierarchically to more massive galaxies. Since intergalactic gas is accreted by massive galaxies, observable e.g. as high-…
We review the various techniques used to constrain the Galactic halo mass profile for radii > 20 kpc with particular emphasis on identifying a self-consistent halo model and resolving the apparent discrepancies present in the literature on…
The origin of the deficiency in neutral Hydrogen of 13 spiral galaxies lying in the outskirts of the Virgo cluster is reassessed. If these galaxies have passed through the core of the cluster, their interstellar gas should have been lost…
It is widely accepted that cosmic rays (CRs) up to at least PeV energies are Galactic in origin. Accelerated particles are injected into the interstellar medium where they propagate to the farthest reaches of the Milky Way, including a…
The high- and intermediate-velocity interstellar clouds (HVCs/IVCs) are tracers of energetic processes in and around the Milky Way. Clouds with near-solar metallicity about one kpc above the disk trace the circulation of material between…
We consider how the gravity of the Galactic disk and the Large Magellanic Cloud (LMC) modifies the radial motions of hypervelocity stars (HVSs) ejected from the Galactic Center. For typical HVSs ejected towards low (high) Galactic…
Aperture synthesis observations of two HI cloud complexes located in the periphery of the Virgo galaxy cluster are presented. These low HI-mass clouds ($M_{HI}<$ 10$^{9}$) are seen projected on the M region of the western Virgo cluster,…
Neutral atomic hydrogen (HI) gas in interstellar space is largely organized into filaments, loops, and shells, the most prominent of which are "supershells". These gigantic structures requiring $\gtrsim 3 \times 10^{52}$ erg to form are…
We model the fastest moving (v_tot > 300 km/s) local (D < 3 kpc) halo stars using cosmological simulations and 6-dimensional Gaia data. Our approach is to use our knowledge of the assembly history and phase-space distribution of halo stars…
We have imaged the extended HI environment of M31 with an unprecedented combination of high resolution and sensitivity. We detect a number of distinct High Velocity Cloud components associated with M31. A sub-set of the features within 30…
We report results from a survey of high velocity clouds and the Magellanic Stream for faint, diffuse optical recombination emission lines. We detect H-alpha emission with surface brightness from 41 to 1680 milli-Rayleighs (mR) from HVCs,…