Related papers: What perturbs NGC 2188?

(abridged) Here we present HI line and 20-cm radio continuum data of the nearby galaxy pair NGC1512/1510 as obtained with the Australia Telescope Compact Array. These are complemented by GALEX UV-, SINGG Halpha- and Spitzer mid-infrared…

Our Galaxy is thought to have undergone an active evolutionary history dominated by star formation, the accretion of cold gas, and, in particular, mergers up to 10 gigayear ago. The stellar halo reveals rich fossil evidence of these…

Dwarf irregular galaxies with extended HI disk distributions, such as DDO 154, allow measurement of rotation curves, hence deduction of dark matter halo properties to large radial distances, up to several times the optical radius. These…

We have detected extremely wide (1100 km/s) CO(1-0) emission from NGC 1144, an interacting, luminous infrared galaxy that is the dominant component of the Arp 118 system. The observations show that NGC 1144 is one of the most CO luminous…

We present new multi-wavelength data for the NGC 4410 galaxy group. This group contains the peculiar radio galaxy NGC 4410A, which has a distorted double-lobed radio structure. NGC 4410A is strongly interacting with three nearby galaxies,…

We present radio interferometric observations of two irregular galaxies that were candidates for having unusually extended HI emission. The galaxies, UGC 199 and DDO 26, otherwise appeared to be normal, low-luminosity systems with modest…

Cold and cool gas (T $\leq 10^4$ K) in the circumgalactic medium (CGM) and its interaction with galaxies remain poorly understood. Simulations predict that cold gas flows into galaxies through cosmic filaments, determining the disk…

HST WFPC2 images are presented that span the inner 19 kpc diameter of the edge-on spiral galaxy NGC 3079; they are combined with ground-based Halpha+[N II] Fabry-Perot spectra and VLA images of radio polarization vectors and rotation…

We present new observations of the strongly-barred galaxy NGC 1365, including new photometric images and Fabry-Perot spectroscopy, as well as a detailed re-analysis of the neutral hydrogen observations from the VLA archive. We find the…

We present Australia Telescope Compact Array (ATCA) observations of a galaxy-sized intergalactic HI cloud (the Vela Cloud) in the NGC 3256 galaxy group. The group contains the prominent merging galaxy NGC 3256, which is surrounded by a…

High velocity gas that does not conform to Galactic rotation is observed throughout the Galaxy's halo. One component of this gas, HI high velocity clouds (HVCs), have attracted attention since their discovery in the 1960s and remain…

Star formation in interacting systems may take place in various locations, from the dust--enshrouded core of Ultraluminous Infrared Galaxies to more unusual places such as the debris of colliding galaxies expelled into the intergalactic…

We present matched-resolution maps of HI and CO emission in the Virgo Cluster spiral NGC 4647. The galaxy shows a mild kinematic disturbance in which one side of the rotation curve flattens but the other side continues to rise. This…

Recent HI observations reveal that the discs of spiral galaxies are surrounded by extended gaseous haloes. This extra-planar gas reaches large distances (several kpc) from the disc and shows peculiar kinematics (low rotation and inflow). We…

We present interferometric observations of CO J=1-0 emission in the central regions of the edge-on galaxy NGC 4631, known for its extended gaseous halo and its tidal interactions. Previous single-dish observations revealed that almost all…

To investigate the star-forming process in nearby dwarf galaxies, we present Integral Field Units (IFU) observation of the star-forming dwarf galaxy, NGC 1522, with the Very Large Telescope (VLT)/Multi Unit Spectroscopic Explorer (MUSE) as…

We report the discovery of an extended halo (40' in diameter) around the planetary nebula NGC7293 (the Helix Nebula) observed in 12micron band from the Wide-field Infrared Survey Explorer all-sky survey. The mid-infrared halo has an…

We have used dedicated 0.7m telescopes in California and Israel to image the halos of ~200 galaxies in the Local Volume to 29 mag/sq arcsec, the sample mainly drawn from the 2MASS Large Galaxy Atlas (LGA). We supplement the LGA sample with…

We present new multi-configuration HI aperture synthesis imaging of the nearby dwarf starburst galaxy NGC 625 obtained with the Australia Telescope Compact Array. Total HI column density images show gas well-aligned with the optical major…

We have examined star formation in two very luminous (M_V=-22 to -23) Sc-type spiral galaxies, NGC 801 and UGC 2885, using ultra-deep Halpha images. We combine these with UBV and 2MASS JHK images and HI maps to explore the star formation…