Search Publications
Faint Submillimeter Galaxies: Hubble Space Telescope Morphologies and Colors
Kneib, J. -P.; Ivison, R. J.; Smail, Ian +1 more
We present deep optical imaging from the Hubble Space Telescope (HST) and from the ground for galaxies selected from the first submillimeter survey of the distant universe. Our survey comprises 850 µm continuum maps of seven massive lensing clusters and covers a total area of 0.01 deg2 to 1 σ noise levels of <=2 mJy beam-1…
On Quasar Masses and Quasar Host Galaxies
Laor, Ari
The mass of massive black holes in quasar cores can be deduced by using the typical velocities of Hβ-emitting clouds in the broad-line region and by the size of this region. However, this estimate depends on various assumptions and is susceptible to large systematic errors. The Hβ-deduced black hole mass in a sample of 14 bright quasars is found h…
Observations of Correlated White-Light and Extreme-Ultraviolet Jets from Polar Coronal Holes
Llebaria, A.; St. Cyr, O. C.; Michels, D. J. +7 more
Time-lapse sequences of white-light images recorded with the Large Angle Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric Observatory (SOHO) frequently show long, narrow structures moving outward over the Sun's polar regions at high apparent speeds. By comparing the LASCO observations with Fe XII λ195 spectroheliograms made with the…
The Gaseous Extent of Galaxies and the Origin of Lyα Absorption Systems. III. Hubble Space Telescope Imaging of Lyα-absorbing Galaxies at z < 1
Chen, Hsiao-Wen; Lanzetta, Kenneth M.; Webb, John K. +1 more
We present initial results of a program to obtain and analyze Hubble Space Telescope (HST) Wide Field Planetary Camera 2 images of galaxies identified in an imaging and spectroscopic survey of faint galaxies in fields of HST spectroscopic target QSOs. We measure properties of 87 galaxies, of which 33 are associated with corresponding Lyα absorptio…
The Effect of Temperature Anisotropy on Observations of Doppler Dimming and Pumping in the Inner Corona
Li, Xing; Habbal, Shadia Rifai; Kohl, John L. +1 more
Recent observations of the spectral line profiles and intensity ratio of the O VI λλ1032 and 1037.6 doublet by the Ultraviolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory (SOHO), made in coronal holes below 3.5 RS, provide evidence for Doppler dimming of the O VI λ1037.6 line and pumping by the chromospheri…
The O II Luminosity Density of the Universe
Hogg, David W.; Cohen, Judith G.; Blandford, Roger +1 more
Equivalent widths of [O II] 3727 Å lines are measured in 375 faint galaxy spectra taken as part of the Caltech Faint Galaxy Redshift Survey centered on the Hubble Deep Field. The sensitivity of the survey spectra to the [O II] line is computed as a function of magnitude, color, and redshift. The luminosity function of galaxies in the [O II] line, …
Infrared Space Observatory Measurements of a [C II] 158 Micron Line Deficit in Ultraluminous Infrared Galaxies
Wolfire, M. G.; Lord, S. D.; Stacey, G. J. +6 more
We report measurements of the [C II] 157.74 µm fine-structure line in a sample of seven ultraluminous infrared galaxies (ULIGs) (LIR>1012 Lsolar) with the Long Wavelength Spectrometer on the Infrared Space Observatory. The [C II] line is an important coolant in galaxies and arises in interstellar gas expos…
The Hubble Space Telescope Quasar Absorption Line Key Project. XIV. The Evolution of Lyα Absorption Lines in the Redshift Interval z = 0-1.5
Turnshek, David A.; Schneider, Donald P.; Savage, Blair D. +10 more
We present the results of an analysis of the rate of evolution of the Lyα absorption lines in the redshift interval 0.0 to ~1.5 based upon a sample of 987 Lyα absorption lines identified in the spectra of 63 QSOs obtained with the Faint Object Spectrograph (FOS) of the Hubble Space Telescope (HST). These spectra were obtained as part of the QSO Ab…
Measurements of Solar Magnetic Element Motion from High-Resolution Filtergrams
Berger, Thomas E.; Title, Alan M.; Löfdahl, Mats G. +1 more
Solar photospheric flowfield properties on sub-0.5" scales are measured using local correlation tracking (LCT) and object tracking of magnetic bright points (MBPs: photospheric bright points associated with magnetic elements). The dataset is a 70 minute time series of cospatial and cotemporal G-band 4305 Å and wideband 4686 Å filtergrams obtained …
Binary Stars in the Orion Trapezium Cluster Core
Beckwith, Steven V. W.; Petr, Monika G.; Coudé du Foresto, Vincent +2 more
We have obtained high angular resolution (0.13" FWHM) near-infrared images of the central ~40" × 40" of the Trapezium cluster, using a speckle holography technique that we describe in detail. A search for close binary systems was made in Ks (2.16 µm) and H (1.65 µm) mosaic images, in which 45 and 35 stars were detected, resp…