Search Publications
The Morphologies of Distant Galaxies. II. Classifications from the Hubble Space Telescope Medium Deep Survey
Glazebrook, Karl; Ellis, Richard S.; Abraham, Roberto G. +4 more
The morphological properties of high-redshift galaxies are investigated using a sample of 507 objects (I < 22.0 mag) from the Hubble Space Telescope (HST) Medium Deep Survey. Independent visual morphological classifications for each galaxy are used to quantify the statistical uncertainties in the galaxy classifications. Visual classifications a…
Comparative Analysis of the High- and Low-Ionization Lines in the Broad-Line Region of Active Galactic Nuclei
Marziani, P.; Moles, M.; Sulentic, J. W. +2 more
We present the first comparative study of high- and low-ionization lines in a large sample of active galactic nuclei (AGNs). We report measurements of C IV λ1549, HeII λ1640, and O III] λ1663 paired to measurements of Hβ, HeII λ4686, and Fe II_opt_ in 52 low-redshift AGNs (z <~0.8). Ultraviolet archival spectra covering the region of C IV λ1549…
HST Snapshot Survey of 3CR Radio Source Counterparts. I. Intermediate Redshifts
Baum, Stefi A.; Sparks, William B.; Miley, George K. +5 more
We have obtained images of 267 3CR radio galaxies and quasars by conducting a snapshot survey with HST's WFPC2 through a broadband red (F702W) filter. This is the first in a series of papers resulting from this survey, describing and presenting the basic data. Here we focus on the 77 radio galaxies within the redshift range 0.1 <z < 0.5 (91%…
Combined Ultraviolet and Optical Spectra of 48 Low-Redshift QSOs and the Relation of the Continuum and Emission-Line Properties
Corbin, Michael R.; Boroson, Todd A.
We present combined ultraviolet and optical spectra of 48 QSOs and Seyfert 1 galaxies in the redshift range 0.034-0.774. The UV spectra were obtained non-simultaneously with the optical and are derived from archival Hubble Space Telescope (HST) Faint Object Spectrograph and International Ultraviolet Explorer (IUE) observations. The sample consists…
A Multiwavelength Catalog of Seyfert 2 Galaxies Observed in the 2--10 keV Energy Band
Malaguti, G.; Bassani, L.; Polletta, M. +2 more
This paper is a catalog of Seyfert 2 galaxies observed in the 2-10 keV band (339 flux entries). In total, it contains data on 150 objects; for 76 objects, a positive detection is reported, while for the remaining sources, 2 σ upper limits to the X-ray emission are given. Most of the data have been collected from the literature over a period starti…
Ultra--Steep-Spectrum Radio Sources. II. Radio, Infrared, Optical, and HST Imaging of High-Redshift 4C Objects
Huang, J. -S.; Chambers, K. C.; Miley, G. K. +3 more
We present radio, infrared, optical, and HST imaging data on eight high-redshift (z > 2) ultra-steep-spectrum 4C radio sources. The radio polarization morphologies are highly asymmetric, indicating large rotation measures across the objects. The optical morphologies are all aligned with the radio axis. The multicolor images show strong asymmetr…
An Atlas of Hubble Space Telescope Ultraviolet Images of Nearby Galaxies
Filippenko, Alexei V.; Ho, Luis C.; Maoz, Dan +3 more
We present an atlas of UV (~2300 A) images, obtained with the Hubble Space Telescope (HST) Faint Object Camera, of the central 22" x 22" of 110 galaxies. The observed galaxies are an unbiased selection constituting about one-half of a complete sample of all large (D > 6') and nearby (V < 2000 km s^-1^) galaxies. This is the first extensive U…
Cepheid Calibration of the Peak Brightness of Type IA Supernovae. VI. SN 1960F in NGC 4496A
Panagia, N.; Saha, A.; Labhardt, Lukas +3 more
Cepheid variables have been found in the SBcII galaxy NGC 4496A, parent to the Type Ia supernova 1960F. Of the 130 variables discovered with the Hubble Space Telescope (HST) over a 70 day observing internal from 1994 June to August, comprising 17 epochs in the F555W band and four epochs in the F814W band, 95 are bona fide Cepheids. The periods ran…
Hubble Space Telescope Observations of Planetary Nebulae in the Magellanic Clouds. III. Ultraviolet Spectroscopy Using the Faint Object Spectrograph
Ford, H. C.; Harrington, J. P.; Wood, P. R. +6 more
Ultraviolet grating spectra (λλ1150-2300) of planetary nebulae in the Magellanic Clouds, obtained with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST), are used to identify and measure nebular emission lines and continua, and in one case to detect the stellar wind of the central star. Eight nebulae are observed in the Large…
Correlation of Ultraviolet and Radio Flux in Three Active Galactic Nuclei
Shukla, Hemant; Stoner, Ronald E.
We report the results of a search for correlations between the time- variable ultraviolet (UV) and the radio flux in three AGNs, viz., 3C 273, 3C 120, and PKS 2155-304. Data from 1984 to present were used. UV data from the short-wave IUE camera were downloaded from the IUE Regional Data Analysis Facility and the National Space Science Data Center …