Search Publications
The physical parameters of the evolving population of faint galaxies
Ellis, Richard; Glazebrook, Karl; Abraham, Roberto +2 more
The excess number of blue galaxies at faint magnitudes is a subject of much controversy. Recent Hubble Space Telescope results have revealed a plethora of galaxies with peculiar morphologies tentatively identified as the evolving population. We report the results of optical spectroscopy and near-infrared photometry of a sample of faint HST galaxie…
The ultraviolet spectrum of the narrow-line Seyfert 1 galaxy RE J1034+396
Siemiginowska, A.; Mason, K. O.; Puchnarewicz, E. M.
RE J1034+396 has one of the hottest big blue bumps of any Seyfert 1 (kT_BB~120 eV) and thus provides a valuable insight into the physics in the nuclei of active galaxies. In this paper, we present UV spectroscopy of RE J1034+396, taken with the Faint Object Spectrograph on the Hubble Space Telescope. With a spectral resolution of ~1-2 Angstroms FW…
The Ultraviolet-Optical Albedo of Broad Emission Line Clouds
Korista, Kirk; Ferland, Gary
We explore the effective UV-optical albedos of a variety of types of broad emission line clouds, as well as their possible effects on the observed spectra of active galactic nuclei (AGNs). An important albedo source in moderately ionized ionization-bounded clouds is that which is due to neutral hydrogen: Rayleigh scattering of continuum photons of…
O5+ in High Speed Solar Wind Streams: SWICS/Ulysses Results
Wimmer-Schweingruber, Robert F.; Gloeckler, George; Geiss, Johannes +3 more
Recent observations with UVCS on SOHO of high outflow velocities of O5+ at low coronal heights have spurred much discussion about the dynamics of solar wind acceleration. On the other hand, O6+ is the most abundant oxygen charge state in the solar wind, but is not observed by UVCS or by SUMER because this helium-like ion has …
The PL relation of galactic carbon LPVs. The distance modulus to LMC
Bergeat, J.; Knapik, A.; Rutily, B.
We present a period-luminosity (PL) diagram of 115 galactic carbon-rich long period variables (LPVs) observed by the HIPPARCOS satellite, in the form of the (MK,log P) relation. Our plot is compared to the diagram of carbon variables observed in the Large Magellanic Cloud (LMC). Both diagrams are found very similar and three samples are…
Below the Lyman Edge: Ultraviolet Polarimetry of Quasars
Antonucci, Robert; Koratkar, Anuradha; Storrs, Alex +1 more
The Lyman edge at 912 Å is an important diagnostic region for studying quasi-stellar objects (QSOs). In particular, it reveals a great deal about the physical conditions within the atmospheres of accretion disks, a ubiquitous component of QSO theories. A robust prediction of accretion disk models is a significant polarization due to electron scatt…
Wind-Ulysses source location of radio emissions associated with the January 1997 coronal mass ejection
Maksimovic, M.; Kaiser, M. L.; Bougeret, J. -L. +2 more
We investigate the 3-D source location of interplanetary type Il-like radio bursts from observations involving two spacecraft. Uncommon type II radio emissions were observed simultaneously on 8 January 1997 by the Wind and Ulysses spacecraft and are believed to be associated with the Interplanetary Coronal Mass Ejection detected on 6-7 January by …
A radio-jet-galaxy interaction in 3C 441
Rawlings, Steve; Lacy, Mark; Ridgway, Susan E. +1 more
Multiwavelength imaging and spectroscopy of the z=0.708 radio galaxy 3C 441 and a red aligned optical/infrared component are used to show that the most striking aspect of the radio-optical `alignment effect' in this object is due to the interaction of the radio jet with a companion galaxy in the same group or cluster. The stellar population of the…
Deep Spectroscopy in the Field of 3C 212
Stockton, Alan; Ridgway, Susan E.
We present the results of long-slit and multiaperture spectroscopy of faint galaxies in the field of the z = 1.049 quasar 3C 212. We show that an apparently aligned optical feature beyond the northwest radio lobe has a redshift z = 0.928, and a similarly aligned feature just beyond the southeast radio lobe has a redshift z = 1.053, quite close to …
Modelling the 10-image lensed system B1933+503
Nair, S.
A gravitational lens model is presented for the newly discovered 10-image system B1933+503. The underlying object, revealed by modelling, is a triple radio source on the scale of a couple of hundred mas that is well-aligned along the line of sight with a foreground and somewhat flattened lensing galaxy, the orientation and location of which match …