The nebular spectra of Type Ia supernovae ($\gtrapprox$ 100 days after explosion) consist mainly emission lines from singly- and doubly-ionised Fe-group nuclei. However, theoretical models for many scenarios predict that non-thermal ionisation leads to multiply-ionised species whose recombination photons ionise deplete Fe$^{+}$ , resulting in negligible [Fe II] emission. We investigate a method...

We have used MERLIN at 408 MHz to image the central starburst region of M82 with a resolution of 0.5 arcsec. We detect 20 supernova remnants at this frequency which is a much smaller number than we detect at higher frequencies (50). We attribute this diierence to free-free absorption by ionised gas. We nd that 7 remnants show low-frequency turnovers in their spectra consistent with free-free ab...

We have carried out a radio-wavelength imaging survey of 45 bright-rimmed clouds (BRCs), using the Australia Telescope Compact Array to characterise the physical properties in their ionised boundary layers. We detected radio emission from a total of 25 clouds and using a combination of Digitised Sky Survey and mid-infrared MSX 8 μm images classified the emission into that associated with the io...

Based on an analysis of the interstellar highly ionised species C IV, Si IV, N V, and O VI observed in the FUSE and HST/STIS E140M spectra of four hot stars in the Large Magellanic Cloud (LMC), we find evidence for a hot LMC halo fed by energetic outflows from the LMC disk and even possibly an LMC galactic wind. Signatures for such outflows are the intermediate and high-velocity components (vLS...

We have carried out a radio-wavelength imaging survey of 45 bright-rimmed clouds (BRCs), using the Australia Telescope Compact Array to characterise the physical properties in their ionised boundary layers. We detected radio emission from a total of 25 clouds and using a combination of Digitised Sky Survey and mid-infrared MSX 8µm images classified the emission into that associated with the ion...

We report on the analysis of a short XMM-Newton observation of the reddened Type 1 QSO 2MASS 234449+1221 first identified in the Two Micron All-Sky Survey. The underlying X-ray continuum is found to be typical of a broad-line active galaxy, with photon index Γ∼1.9. Low energy absorption can be modelled by a column NH∼10 22 cm of moderately ionised gas or a smaller column of cold gas. Addition o...

Aims. To search for evidence of triggered star formation within four bright-rimmed clouds, SFO 58, SFO 68, SFO 75 and SFO 76. Methods. We present the results of radio continuum and molecular line observations conducted using the Mopra millimetre-wave telescope and Australia Telescope Compact Array. We use the J = 1−0 transitions of 12CO, 13CO and C18O to trace the distribution of molecular mate...

We present the results of deep Westerbork Synthesis Radio Telescope observations of neutral hydrogen in 12 nearby elliptical and lenticular galaxies. The selected objects come from a representative sample of nearby galaxies earlier studied at optical wavelengths with the integral-field spectrograph SAURON. They are field galaxies, or (in two cases) located in poor group environments. We detect ...