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CTQ 414: A New Gravitational Lens
Dressler, Alan; Winn, Joshua N.; Morgan, Nicholas D. +2 more
We report the discovery and ground-based observations of the new gravitational lens CTQ 414. The source quasar lies at a redshift of z=1.29 with a B magnitude of 17.6. Ground-based optical imaging reveals two point sources separated by 1.2" with a magnitude difference of roughly 1 mag. Subtraction of two stellar point-spread functions from images …
NGC 3516: The Long-Term Variability of the Active Galactic Nucleus Emission-Line and Absorption-Line Regions
Koratkar, A. P.; Korista, K. T.; O'Brien, P. T. +3 more
NGC 3516 displays the strongest intrinsic blueshifted UV absorption lines of any Seyfert 1 galaxy. In this paper, we report on UV spectrophotometric monitoring data obtained over a period of 11 months using the Hubble Space Telescope Faint Object Spectrograph (HST/FOS). The observations were at ~2 Å resolution and covered the wavelength range 1150…
Geneva photometry of the open cluster NGC 2451 and its exceptional Be star HR 2968 satellite.}
Carrier, F.; Burki, G.; Richard, C.
During many years, several authors discussed whether
Multisite observations of surface structures on AB Doradus in 1994 November
Catala, C.; Collier Cameron, A.; Janot-Pacheco, E. +15 more
We present time-resolved optical spectroscopy and broad-band photometry of the rapidly rotating southern K0 dwarf star AB Doradus, obtained during 1994 November. The data were obtained as part of a collaboration dedicated to MUlti-SIte COntinuous Spectroscopy (MUSICOS), and entailed coordinated observations on three continents to obtain the fulles…
Detection of Surface Brightness Fluctuations in NGC 4373 Using the Hubble Space Telescope
Casertano, Stefano; Ballester, Gilda E.; Dressler, Alan +16 more
Surface brightness fluctuations (SBF) have been detected for three elliptical galaxies--NGC 3379 in the Leo group, NGC 4406 in the Virgo cluster, and NGC 4373 in the Hydra-Centaurus supercluster--using marginally sampled, deep images taken with the Planetary Camera of the WFPC2 instrument on the Hubble Space Telescope (HST). The power spectrum of …
A Photometric Investigation of the GRB 970228 Afterglow and the Associated Nebulosity
Castander, Francisco J.; Lamb, Donald Q.
We carefully analyze the WFPC2 and STIS images of GRB 970228. We measure magnitudes for the GRB 970228 point-source component in the WFPC2 images of (V=26.20+0.14-0.13, Ic=23.94+0.10-0.09) and (V=26.52+0.16-0.18, Ic=24.31+0.15-0.11) on Mar…
The Radio-Optical Jet in NGC 3862 from Parsec to Subkiloparsec Scales
Venturi, T.; O'Dea, C. P.; Giovannini, G. +4 more
We have observed the radio source in NGC 3862 (3C 264) simultaneously with the European VLBI network and the MERLIN arrays, obtaining detailed images of its radio structure from parsec to subkiloparsec scales. 3C 264 shows a one-sided jet with evident variations in its morphological properties with distance. We have analyzed Hubble Space Telescope…
Ion-cyclotron wave dissipation channel for Alfvén waves
Kaghashvili, Edisher Kh.
The effect of inhomogeneous velocity flow on Alfvén wave dynamics in the solar wind is investigated. Unlike existing studies in this field that model energy deposition from high-frequency waves to solar wind particles, we consider here the possibility of obtaining high-frequency waves (in this case fast magnetosonic waves) from the ordinary Alfvén…
Ulysses measurements of variations in the solar wind-interstellar hydrogen charge exchange rate
McComas, D. J.; Gosling, J. T.; Pryor, W. R. +1 more
Charge exchange with solar wind protons is the primary ionization process for interstellar hydrogen traveling through the heliosphere. In this study we use Ulysses solar wind observations to examine and quantify variations in charge exchange. We find that these variations are largest within stream interaction regions where the charge exchange rate…
NICMOS Observations of the Pre-Main-Sequence Planetary Debris System HD 98800
Schneider, Glenn; Hines, Dean C.; Low, Frank J.
Spectral energy distributions (SEDs) from 0.4 to 4.7 µm are presented for the two principal stellar components of HD 98800, A and B. The third major component, an extensive planetary debris system (PDS), emits greater than 20% of the luminosity of star B in a blackbody SED at 164+/-5 K extending from mid-IR to millimeter wavelengths. At 0.95…