Related papers: An Evolutionary Sequence of Expanding Hydrogen She…

We have discovered a number of very small isolated HII regions 20-30 kpc from their nearest galaxy. The HII regions appear as tiny emission line dots (ELdots) in narrow band images obtained by the NOAO Survey for Ionization in Neutral Gas…

(Abbrev.) We present high-resolution spectroscopy of the oxygen K-shell interstellar absorption edge in 7 X-ray binaries using the HETGS onboard Chandra. Using the brightest sources as templates, we found a best-fit model of 2 absorption…

We present 21-cm HI line and optical R-band observations for a sample of 26 edge-on galaxies. The HI observations were obtained with the Westerbork Synthesis Radio Telescope, and are part of the WHISP database (Westerbork HI Survey of…

Massive galaxies display extended light profiles that can reach several hundreds of kilo parsecs. These stellar halos provide a fossil record of galaxy assembly histories. Using data that is both wide (~100 square degree) and deep (i>28.5…

We present a statistical study of the neutral atomic hydrogen (HI) gas extending into the circumgalactic medium perpendicular to the disk for 7 edge-on galaxies with inclinations above $85^{\circ}$ from the FEASTS program with a $3\sigma$…

We present 21-cm observations and models of the neutral hydrogen in NGC 4565, a nearby, edge-on spiral galaxy, as part of the Westerbork Hydrogen Accretion in LOcal GAlaxieS (HALOGAS) survey. These models provide insight concerning both the…

HI-Selected galaxies obey a linear relationship between their maximum detected radius Rmax and rotational velocity. This result covers measurements in the optical, ultraviolet, and HI emission in galaxies spanning a factor of 30 in size and…

We examine the global HI properties of galaxies in quarter-billion particle cosmological simulations using Gadget-2, focusing on how galactic outflows impact HI content. We consider four outflow models, including a new one (ezw) motivated…

(Abridged) We have used the VLA to search for neutral atomic hydrogen in the circumstellar envelopes of five AGB stars. We have detected HI 21-cm emission coincident in both position and velocity with the semi-regular variable RS Cnc. The…

The Serpens OB2 association (l ~ 18.5 deg, b ~ 1.9 deg, d = 1950 +/- 30 pc) is a large star-forming complex ~65 pc above the Galactic midplane, with a clumpy, elongated structure extending ~50 pc parallel to the plane. We analyse probable…

Conditions for the fragmentation of expanding shells due to gravitational instability are discussed. The self-similar analytical solution is compared with the results of 3-dimensional computer simulations for the expansion into homogeneous…

Modelling the distribution of neutral hydrogen (HI) in dark matter halos is important for studying galaxy evolution in the cosmological context. We use a novel approach to infer the HI-dark matter connection at the massive end ($m_{\rm HI}…

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…

(ABRIDGED) Gaseous halos of nine nearby galaxies (with redshifts cz < 6000 km/s) were probed at large galactocentric radii using background quasars observed with HST GHRS and STIS. The projected quasar-galaxy separations range from 55 to…

We present NOT optical observations of a clump (l = 127.9435 deg, b = +1.8298 deg), embedded in an extended, irregularly shaped, diffuse optical nebula. This condensation shows an emission-line spectrum typical of classic HII regions.…

We investigated the kinematics of ionized gas in an extended (20 degrees by 15 degrees) region containing the X-ray Superbubble in Cygnus with the aim of finding the shell swept up by a strong wind from Cyg OB2. H-alpha observations were…

A sample of 69 galaxies with radial velocities less than 2500 km/s was selected from the HI Parkes All Sky Survey (HIPASS) and imaged in broad band B and R and narrow band H-alpha to deduce details about star formation in nearby disk…

Galactic halo gas traces inflowing star formation fuel and feedback from a galaxy's disk and is therefore crucial to our understanding of galaxy evolution. In this review, we summarize the multi-wavelength observational properties and…

Stellar halos are the only major stellar component of disk galaxies that lack systematic observational characterization, yet they encode critical information about galaxy merger histories. We present the first systematic census of stellar…

New high resolution, high sensitivity WSRT HI synthesis observations of the spiral galaxy NGC 3631 are presented. In the total atomic hydrogen map, the spiral arms are well distinguished from the interarm regions, while the sensitivity…