Search Publications
Four spacecraft measurements of the quasiperpendicular terrestrial bow shock: Orientation and motion
Balogh, A.; Horbury, T. S.; Lucek, E. A. +5 more
Measurements of the magnetic field at the four Cluster spacecraft, typically separated by ~600 km, during bow shock crossings allow the orientation and motion of this structure to be estimated. Results from 48 clean and steady quasiperpendicular crossings during 2000 and 2001, covering local times from 0600 to 1700, reveal the bow shock normal to …
Faint Cataclysmic Variables in Quiescence: Globular Cluster and Field Surveys
Bildsten, Lars; Townsley, Dean M.
Current evolutionary models imply that most cataclysmic variables (CVs) have Porb<2 hr and are dwarf nova (DN) systems that are quiescent most of the time. Observations of nearby quiescent DNs find that the UV spectrum is dominated by the hot white dwarf (WD), indicating that it provides a significant fraction of the optical light in…
Deuterium and Oxygen toward Feige 110: Results from the FUSE Mission
Sembach, K. R.; Sonneborn, G.; Moos, H. W. +11 more
We present measurements of the column densities of interstellar D I and O I made with the Far Ultraviolet Spectroscopic Explorer (FUSE) and of H I made with the International Ultraviolet Explorer (IUE) toward the sdOB star Feige 110 [(l,b)=(74.09d,-59.07d) d=179+265-67 pc; z=-154+57-227 pc]. Our determin…
GRB 010921: Discovery of the First High Energy Transient Explorer Afterglow
Price, P. A.; Harrison, F. A.; Reichart, D. E. +16 more
We report the discovery of the optical and radio afterglow of GRB 010921, the first gamma-ray burst afterglow to be found from a localization by the High Energy Transient Explorer satellite. We present optical spectroscopy of the host galaxy, which we find to be a dusty and apparently normal star-forming galaxy at z=0.451. The unusually steep opti…
The effect of lensing on the identification of SCUBA galaxies
Ivison, R. J.; Smail, Ian; Blain, A. W. +1 more
Spectroscopic surveys of submillimetre(submm)-selected sources have uncovered optically bright galaxies at z<~ 1 close to the positions of several submm sources. Naive statistical analyses suggest that these galaxies are associated with the submm emission. However, in some cases, it is difficult to understand this association given the relative…
HST, VLT, and NTT imaging search for wide companions to bona-fide and candidate brown dwarfs in the Cha I dark cloud
Neuhäuser, R.; Comerón, F.; Brandner, W. +2 more
We present results from a deep imaging search for companions around the young bona-fide and candidate brown dwarfs Cha Hα 1 to 12 in the Cha I dark cloud, performed with HST WFPC2 (R, I, Hα ), VLT FORS1 (VRI), and NTT SofI (JHKs). We find 16 faint companion candidates around five primaries with separations between 1.5'' and 7…
High-Dispersion Spectroscopy of the X-Ray Transient RXTE J0421+560 (=CI Camelopardalis) during Outburst
Welsh, William F.; Ivans, Inese I.; Robinson, Edward L.
We obtained high-dispersion spectroscopy of CI Cam, the optical counterpart of XTE J0421+560, 2 weeks after the peak of its short outburst in 1998 April. The optical counterpart is a supergiant B[e] star that is emitting a two-component wind, a cool, low-velocity wind and a hot, high-velocity wind. The cool wind, which is the source of narrow emis…
A Three-dimensional Map of Titan's Tropospheric Haze Distribution Based on Hubble Space Telescope Imaging
McKay, Christopher P.; Griffith, Caitlin A.; Noll, Keith +2 more
We use Hubble Space Telescope (HST) images of Titan obtained in late 1996 to determine a three-dimensional map of haze optical depth in Titan's atmosphere. These images, taken at six wavelengths from 888 to 953 nm, probe Titan's atmosphere at various altitudes ranging from the surface to roughly 100 km. We solve for the total haze optical depths t…
Nobeyama Millimeter Array CO (J=1-0) Observations of the Hα/Radio Lobe Galaxy NGC 3079: Gas Dynamics in a Weak Bar Potential and Central Massive Core
Kohno, K.; Koda, J.; Sofue, Y. +4 more
We present 12CO (1-0) observations in the central 4.5 kpc (1') of the Hα/radio lobe galaxy NGC 3079 with the Nobeyama Millimeter Array. The molecular gas shows four components: a main disk, spiral arms, a nuclear disk, and a nuclear core. The main disk extends along the galaxy major axis. We detected its central 2 kpc radius, while its …
Hubble Space Telescope Expansion Parallaxes of the Planetary Nebulae NGC 6578, NGC 6884, NGC 6891, and IC 2448
Bond, Howard E.; Panagia, Nino; Balick, Bruce +3 more
We have combined two epochs of Hubble Space Telescope WFPC2 imaging data with ground-based expansion velocities to determine distances to three planetary nebulae (NGC 6578, NGC 6884, and IC 2448). We used two variants of the expansion parallax technique-a gradient method and a magnification method-to determine the distances. The results from the t…