Related papers: Galactic Small Scale Structure Revealed by the GAL…

We present results from multi-epoch neutral hydrogen (HI) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10--150 AU/yr, these pulsars have…

It is well known that both the star formation rate and the cold gas content of a galaxy depend on the local density out to distances of a few Megaparsecs. In this paper, we compare the environmental density dependence of the atomic gas mass…

An isolated HI cloud with peculiar properties has recently been discovered by Dedes, Dedes, & Kalberla (2008, A&A, 491, L45) with the 300-m Arecibo telescope, and subsequently imaged with the VLA. It has an angular size of ~6', and the HI…

Growing evidence supports the suggestion that the compact high-velocity clouds of HI (CHVCs) are located throughout the Local Group and continue to fuel galactic evolution. Recent distance estimates to individual objects lie in the range…

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…

We present a 93' by 93' map of the area near the Local Group dwarf galaxy LGS 3, centered on an HI cloud 30' away from the galaxy. Previous authors associated this cloud with LGS 3 but relied on observations made with a 36' beam. Our…

The abundance of neutral hydrogen (HI) in satellite galaxies in the Local Group is important for studying the formation history of our Local Group. In this work, we generated mock HI satellite galaxies in the Local Group using the high mass…

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…

High sensitivity 21-cm HI line observations, with an rms noise level of \sim 0.5 mJy, were made of 35 spiral galaxies in the Coma Supercluster, using the refurbished Arecibo telescope, which resulted in the detection of 25 objects. These…

A survey of 329 nearby galaxies (redshift z < 0.045) has been conducted to study the distribution of mass and light within spiral galaxies over a range of environments. The 18 observed clusters and groups span a range of richness, density,…

The high-latitude Galactic H I cloud toward the extragalactic radio source 3C 225 is characterized by very narrow 21 cm emission and absorption indicative of a very low H I spin temperature of about 20 K. Through high-resolution optical…

We present first results from the "Survey of HI in Extremely Low-mass Dwarfs" (SHIELD), a multi-configuration EVLA study of the neutral gas contents and dynamics of galaxies with HI masses in the 10^6-10^7 Solar mass range detected by the…

We present findings of 3D filamentary structures in the Smith Cloud, a high-velocity cloud (HVC) located at $l=38^{\circ}$, $b=-13^{\circ}$. We use data from the Galactic Arecibo L-Band Feed Array \ion{H}{i} (GALFA-\ion{H}{i}) along with…

Context. The Galactic ASKAP collaboration (GASKAP) is undertaking an HI emission survey of the 21cm line to map the Magellanic system and the Galactic plane with the Australian Square Kilometre Array Pathfinder (ASKAP). One of the first…

We present a catalog of 59 ultra-compact high velocity clouds (UCHVCs) extracted from the 40% complete ALFALFA HI-line survey. The ALFALFA UCHVCs have median flux densities of 1.34 Jy km/s, median angular diameters of 10', and median…

We present the catalog of HI sources extracted from the ongoing Arecibo Legacy Fast ALFA (ALFALFA) extragalactic HI line survey, found within the sky region bounded by 9h36m < RA < 11h36m and +08deg < DEC < +12deg. The HI catalog presented…

We map the Hi distribution of galaxies in a $\sim 1.5^\circ \times 2.5^\circ$ region located at the virial radius south of the Virgo cluster using the KAT$-$7 and the WSRT interferometers. Because of the different beam sizes of the two…

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…

Imaging of galaxies to study the interstellar medium on scales of a few pc is difficult. However, for the Milky Way galaxy two major Galactic all sky HI 21-cm line surveys will become available soon with unprecedented quality. We present…

Aims: we studied the global distribution and kinematics of the extra-planar neutral gas in the Milky Way. Methods: we built 3D models for a series of Galactic HI layers, projected them for an inside view, and compared them with the…