Search Publications
Measuring the black hole masses of high-redshift quasars
McLure, R. J.; Jarvis, M. J.
A new technique is presented for determining the black hole masses of high-redshift quasars from optical spectroscopy. The new method utilizes the full-width at half-maximum (FWHM) of the low-ionization MgII emission line and the correlation between the broad-line region (BLR) radius and the continuum luminosity at 3000 Å. Using archival ultraviol…
Far-Infrared Galaxies in the Far-Ultraviolet
Sanders, D. B.; Steidel, Charles C.; Heckman, Timothy M. +4 more
In an effort to better understand the UV properties of ultraluminous infrared galaxies (ULIGs), and compare them to the rest-frame UV properties of high redshift submillimeter and Lyman-break galaxies, we have obtained far- and near-UV imaging observations (λeff=1457 and 2364 Å, respectively) of two luminous infrared galaxies (LIGs-VV 1…
Revised Stellar Temperatures for Magellanic Cloud O Supergiants from Far Ultraviolet Spectroscopic Explorer and Very Large Telescope UV-Visual Echelle Spectrograph Spectroscopy
Hillier, D. J.; Crowther, P. A.; Willis, A. J. +3 more
We have undertaken quantitative analysis of four LMC and SMC O4-9.7 extreme supergiants using far-ultraviolet FUSE, ultraviolet IUE/Hubble Space Telescope, and optical Very Large Telescope UV-Visual Echelle Spectrograph spectroscopy. Extended, non-LTE model atmospheres that allow for the consistent treatment of line blanketing, developed by Hillie…
Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XVI. A 13 Year Study of Spectral Variability in NGC 5548
Filippenko, A. V.; Shapovalova, A. I.; Chavushyan, V. H. +38 more
We present the final installment of an intensive 13 year study of variations of the optical continuum and broad Hβ emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 Hβ measurements. The Hβ variations follow the continuum variations closely, with a typical time delay of about 20 da…
Stellar and wind properties of LMC WC4 stars. A metallicity dependence for Wolf-Rayet mass-loss rates
Hillier, D. J.; Crowther, P. A.; Fullerton, A. W. +2 more
We use ultraviolet space-based (FUSE, HST) and optical/IR ground-based (2.3 m MSSSO, NTT) spectroscopy to determine the physical parameters of six WC4-type Wolf-Rayet stars in the Large Magellanic Cloud. Stellar parameters are revised significantly relative to Gräfener et al. (\cite{Grafener1998}) based on improved observations and more sophistica…
Global Far-Ultraviolet (912-1800 Å) Properties of Star-forming Galaxies
Heckman, Timothy M.; Calzetti, Daniela; Leitherer, Claus +1 more
We present the results of an archival study of the Hopkins Ultraviolet Telescope (HUT) Astro-2 database. Nineteen spectra of star-forming regions and starburst galaxies were retrieved, reprocessed, and analyzed. The spectra cover the wavelength region 912-1800 Å, providing access to the domain of peak luminosity from a young stellar population. We…
Physical parameters of the high-mass X-ray binary 4U1700-37
Kaper, L.; Crowther, P. A.; Goodwin, S. P. +4 more
We present the results of a detailed non-LTE analysis of the ultraviolet and optical spectrum of the O6.5 Iaf+ star
Abundances of Deuterium, Nitrogen, and Oxygen in the Local Interstellar Medium: Overview of First Results from the FUSE Mission
Kruk, J. W.; Savage, B. D.; Shull, J. M. +33 more
Observations obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) have been used to determine the column densities of D I, N I, and O I along seven sight lines that probe the local interstellar medium (LISM) at distances from 37 to 179 pc. Five of the sight lines are within the Local Bubble, and two penetrate the surrounding H I wall. R…
An empirical calibration of star formation rate estimators
Terlevich, Roberto; Terlevich, Elena; Rosa-González, Daniel
The observational determination of the behaviour of the star formation rate (SFR) with look-back time or redshift has two main weaknesses: (i) the large uncertainty of the dust/extinction corrections, and (ii) that systematic errors may be introduced by the fact that the SFR is estimated using different methods at different redshifts. Most frequen…
The Mass of the Central Black Hole in the Seyfert Galaxy NGC 3783
Peterson, Bradley M.; Onken, Christopher A.
Improved analysis of ultraviolet and optical monitoring data on the Seyfert 1 galaxy NGC 3783 provides evidence for the existence of a supermassive, (8.7+/-1.1)×106Msolar, black hole in this galaxy. By using recalibrated spectra from the International Ultraviolet Explorer satellite and ground-based optical data, as well as re…