Related papers: Classical radio source propagating into outer HI d…
We present sensitive aperture synthesis observations of the nearby, late-type spiral galaxy NGC 6503, and produce HI maps of considerably higher quality than previous observations by van Moorsel & Wells (1985). We find that the velocity…
Neutral atomic hydrogen (HI) constitutes a key phase of the cosmic baryon cycle, bridging the ionised circumgalactic medium and the star-forming molecular gas. Yet, nearly 75 years after its discovery, direct views of HI through its 21cm…
We analyse Herschel/SPIRE images of the edge-on spiral galaxy NGC 891 at 250, 350 and 500 micron. Using a 3D radiative transfer model we confirm that the dust has a radial fall-off similar to the stellar disk. The dust disk shows a break at…
The supermassive black holes (SMBHs) of narrow-line Seyfert 1 galaxies (NLS1s) are at the lowest end of mass function of active galactic nuclei (AGNs) and preferentially reside in late-type host galaxies with pseudobulges, which are thought…
In this paper the cosmic evolution of the space density of Fanaroff & Riley Class I (FRI) radio sources is investigated out to z ~ 1, in order to understand the origin of the differences between these and the more powerful FRIIs. High…
We present deep kpc- and pc-scale neutral atomic hydrogen (HI) absorption observations of a very young radio source (< 5000 yrs), 4C 31.04, using the WSRT and the Global VLBI array. Using $z=0.0598$, we detect a broad absorption feature…
We present centimeter and millimeter observations of the NGC 2071 star-forming region performed with the VLA and CARMA. We detected counterparts at 3.6 cm and 3 mm for the previously known sources IRS 1, IRS 2, IRS 3, and VLA 1. All these…
A mosaic of six HI line observations with the Australia Telescope Compact Array is used to search for intergalactic gas in the NGC 1808 group of galaxies. Within the field of view of about 1.4 deg x 1.2 deg, no emission from intergalactic…
Orion Source I (`SrcI') is the protostar at the center of the Kleinmann-Low Nebula. ALMA observations of SrcI with 0.2" angular resolution were made at 350 and 660 GHz to search for the H26alpha and H21alpha hydrogen recombination lines and…
We present imaging of the HI 21cm absorption line system seen toward the nuclear regions of Mrk 231 at z = 0.04217, and imaging of the radio continuum emission at 1.4 GHz, on scales ranging from a few parsecs to a few hundred parsecs. These…
We analyze the properties of a sample of X-shaped radio-sources (XRSs). These objects show, in addition to the main lobes, a pair of wings producing their peculiar radio morphology. We obtain our sample by selecting from the initial list of…
We present high spatial resolution ground-based broad-band imaging, H-alpha +[NII] narrow-band imaging and long-slit spectroscopy for the E4 radio galaxy NGC 7052, which has a nuclear dust disc. We detect ionized gas with a LINER spectrum,…
We present multi-frequency, radio-continuum and HI observations of NGC4438, the highly-disturbed, active galaxy in the Virgo cluster, with the VLA and the GMRT. High-resolution observations with the VLA at 4860 and 8460 MHz show the…
The nearby blue compact dwarf, NGC 2915, has its stellar disc embedded in a large, extended (~ 22 B-band scale-lengths) HI disc. New high-resolution HI synthesis observations of NGC 2915 have been obtained with the Australia Telescope…
We present our multiwavelength analysis of a prototype \HI-excess galaxy, GASS 3505, selected based on having a large gas content ($M_{\rm HI} = 10^{9.9}$ \msun) compared to its little associated star formation activity ($\sim$0.1 \msun\…
Deep and high resolution radio observations of the Hubble Deep Field and flanking fields have shown the presence of two distant edge-darkened FR I radio galaxies, allowing for the first time an estimate of their high redshift space density.…
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…
Tidal debris which are rich in HI gas, formed in interacting and merging systems, are suitable laboratories to study star formation outside galaxies. Recently, several such systems were observed, which contained many young star forming…
Using a self-similar model for the expansion of cocoons surrounding the jets in powerful extragalactic radio sources (type FRII), we investigate the influence of the properties of the gas surrounding these objects on their evolution. The…
We present a detailed study of PKS1814-637, a rare case of powerful radio source (P_5 GHz = 4.1 x 10^25 W/Hz) hosted by a disk galaxy. Optical images have been used to model the host galaxy morphology confirming it to be dominated by a…