Related papers: Interacting Galactic Neutral Hydrogen Filaments an…
Context. The HI distribution at high Galactic latitudes is found to be filamentary and closely related to the far infrared (FIR) in caustics with coherent velocity structures. These structures trace the orientation of the magnetic field…
We present new neutral hydrogen (HI) observations of the nearby galaxy NGC 2403 to determine the nature of a low-column density cloud that was detected earlier by the Green Bank Telescope. We find that this cloud is the tip of a complex of…
Large-scale filaments ubiquitously exist in the Galactic interstellar medium, and their radial profiles offer insights into their formation mechanisms. We present a statistical analysis of molecular hydrogen column density ($\rm N(H_2)$)…
We study the properties of low-column density gas clumps in the halo of the Milky Way based on high-resolution 21-cm observations. Using interferometric data from the WSRT and the VLA we study HI emission at low-, intermediate- and high…
Recent radio surveys have revealed pulsars with dispersion and scattering delays induced by ionized gas that are larger than the rest of the observed pulsar population, in some cases with electron column densities (or dispersion measures;…
Context. HI filaments are closely related to dusty magnetized structures that are observable in the far infrared (FIR). Recently it was proposed that the coherence of oriented HI structures in velocity traces the line of sight magnetic…
Observations of intergalactic neutral hydrogen can provide a wealth of information about structure and galaxy formation, potentially tracing accretion and feedback processes on Mpc scales. Below a column density of NHI ~ 10^19 cm-2, the…
There is mounting evidence for an extra-planar gas layer around the Milky Way disk, similar to the anomalous HI gas detected in a few other galaxies. As much as 10% of the gas may be in this phase. We analyze HI clouds located in the…
We model the distribution of the observed profiles of 21 cm line emission from neutral hydrogen (HI) in central galaxies selected from a statistically representative mock catalog of the local Universe in the Lambda-cold dark matter…
Synchrotron emission pervades the Galactic plane at low radio frequencies, originating from cosmic ray electrons interacting with the Galactic magnetic field. Using a low-frequency radio telescope, the Murchison Widefield Array (MWA), we…
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…
We present the first full map of the H-alpha emission from the intermediate-velocity cloud Complex L. Kinematically resolved emission components from the ionized gas reveal a close spatial and velocity correspondence to that of the neutral…
We present a global study of HI spectral line mapping for 16 Hickson Compact Groups (HCGs) combining new and unpublished VLA data, plus the analysis of the HI content of individual galaxies. Sixty percent of the groups show morphological…
We investigate the nature of a Galactic center source, G0.17+0.15, lying along the northern extension of the Radio Arc near l~0.2deg. G0.17+0.15 is an HII region located toward the eastern edge of the radio bubble, embedded within the…
We investigate the physical properties of structures seen in channel map observations of 21-cm neutral hydrogen (HI) emission. HI intensity maps display prominent linear structures that are well aligned with the ambient magnetic field in…
High-spatial-resolution HI observations have led to the realisation that the nearby (within few hundreds of parsecs) Galactic atomic filamentary structures are aligned with the ambient magnetic field. Enabled by the high quality data from…
Traditionally IVC and HVC were defined to be concentrations of HI gas, with line-of-sight velocities that are inconsistent with data on the differential rotation of the Galaxy. We demonstrate that IVCs and HVCs can be identified from…
Using archival data from ATCA, WSRT, and the VLA, we have analyzed the HI emission of 22 tidal tail regions of the Mullan et al. sample of pairwise interacting galaxies. We have measured the column densities, line-of-sight velocity…
Context. Neutral atomic hydrogen (HI) absorption lines can be used to probe the cold neutral medium (CNM) at high Galactic latitudes. Cold HI with a significant optical depth from the GASKAP-HI survey is found to be located predominantly if…
Large HI shells, with diameters of hundreds of pc and expansion velocities of 10-20kms-1 are well observed features of local gas rich galaxies. These shells could well be predicted as a result of the impact of OB associations on the ISM,…