Search Publications
Australia Telescope Compact Array Survey of Candidate Ultracompact and Buried H II Regions in the Magellanic Clouds
Johnson, Kelsey E.; Indebetouw, Rémy; Conti, Peter
We present a systematic survey for ultracompact (UC) H II regions in the Magellanic Clouds. Understanding the physics of massive star formation (MSF) is a critical astrophysical problem. The study of MSF began in our Galaxy with surveys of UC H II regions, but before now this has not been done for other galaxies. We selected candidates on the basi…
Optical nuclei of radio-loud AGN and the Fanaroff-Riley divide
Kharb, P.; Shastri, P.
We investigate the nature of the point-like optical nuclei that have been found in the centres of the host galaxies of a majority of radio galaxies by the Hubble Space Telescope. We examine the evidence that these optical nuclei are relativistically beamed, and look for differences in the behaviour of the nuclei found in radio galaxies of the two …
Emission Line Properties of Active Galactic Nuclei from a Post-COSTAR Hubble Space Telescope Faint Object Spectrograph Spectral Atlas
Green, Paul J.; Vestergaard, Marianne; Aldcroft, Tom L. +4 more
We present consistent emission-line measurements for active galactic nuclei (AGNs), useful for reliable statistical studies of emission line properties. This paper joins a series including similar measurements of 993 spectra from the Large Bright Quasar Survey and 174 spectra of AGNs obtained from the Faint Object Spectrograph (FOS) on the Hubble …
The Extinction Law in High-Redshift Galaxies
Kochanek, C. S.; Muñoz, J. A.; Falco, E. E. +2 more
We estimate the dust extinction laws in two intermediate-redshift galaxies. The dust in the lens galaxy of LBQS 1009-0252, which has an estimated lens redshift of zl~=0.88, appears to be similar to that of the SMC, with no significant feature at 2175 Å. Only if the lens galaxy is at a redshift of zl~=0.3, which is completely …
The Properties and Evolution of the Highly Ionized Gas in MR 2251-178
Kaspi, Shai; Nandra, Kirpal; Turner, T. J. +3 more
We present the first XMM-Newton observations of the radio-quiet quasar MR 2251-178 obtained in 2000 and 2002. The EPIC pn spectra show a power-law continuum with a slope of Γ=1.6 at high energies absorbed by at least two warm absorbers (WAs) intrinsic to the source. The underlying continuum in the earlier observation shows a ``soft excess'' at low…
The Radio Continuum of the Metal-deficient Blue Compact Dwarf Galaxy SBS 0335-052
Hunt, Leslie K.; Thuan, Trinh X.; Ulvestad, James S. +1 more
We present new Very Large Array observations at five frequencies, from 1.4 to 22 GHz, of the extremely low metallicity blue compact dwarf SBS 0335-052. The radio spectrum shows considerable absorption at 1.49 GHz and a composite thermal plus nonthermal slope. After fitting the data with a variety of models, we find the best-fitting geometry to be …
Multi-fluid simulations of Ganymede's magnetosphere
Paty, Carol; Winglee, Robert
Comparative studies of 3D multi-fluid simulations with Galileo magnetometer data are used to develop a quantitative model of the currents and fields within Ganymede's magnetosphere as well as its bulk plasma environment. The model includes contributions from Jupiter's magnetosphere and the flux of different ion species originating from Ganymede's …
An all-sky optical catalogue of radio/X-ray sources
Hardcastle, M. J.; Flesch, E.
We present an all-sky catalogue that aligns and overlays the ROSAT HRI, RASS, PSPC and WGA X-ray catalogues and the NVSS, FIRST and SUMSS radio catalogues onto the optical APM and USNO-A catalogues. Objects presented are those APM/USNO-A optical objects which are calculated with ≥ 40% confidence to be associated with radio/X-ray detections, or whi…
X-ray spectroscopy on Abell 478 with XMM-Newton
Kaastra, J. S.; de Plaa, J.; Pointecouteau, E. +3 more
We report the results from a spatially resolved spectroscopy study with XMM-Newton on the relaxed cluster of galaxies
Hα variability of the recurrent nova T Coronae Borealis
Marziani, P.; Zamanov, R.; Stanishev, V. +1 more
We analyze Hα observations of the recurrent nova