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FUSE Observation of the Narrow-Line Seyfert 1 Galaxy RE 1034+39: Dependence of Broad Emission Line Strengths on the Shape of the Photoionizing Spectrum
Baron, E.; Leighly, Karen M.; Casebeer, Darrin A.
We present an analysis from simultaneous FUSE, ASCA, and EUVE observations, as well as a reanalysis of archival HST spectra, from the extreme narrow-line Seyfert 1 Galaxy RE 1034+39 (KUG 1031+398). RE 1034+39 has an unusually hard spectral energy distribution (SED) that peaks in the soft X-rays. Its emission lines are unusual in that they can all …
Optical Counterparts of Ultraluminous X-Ray Sources Identified from Archival HST WFPC2 Images
van der Marel, Roeland P.; Colbert, Ed; Ptak, Andrew +3 more
We present a systematic analysis of archival HST WFPC2 ``Association'' data sets that correlate with the Chandra positions of a set of 44 ultraluminous X-ray sources (ULXs) of nearby galaxies. The main motivation is to address the nature of ULXs by searching for optical counterparts. Sixteen of the ULXs are found in early-type galaxies (RC3 Hubble…
No signature of clear CO2 ice from the `cryptic' regions in Mars' south seasonal polar cap
Forget, F.; Bibring, Jean-Pierre; Langevin, Yves +5 more
The seasonal polar ice caps of Mars are composed mainly of CO2 ice. A region of low (< 30%) albedo has been observed within the south seasonal cap during early to mid-spring. The low temperature of this `cryptic region' has been attributed to a clear slab of nearly pure CO2 ice, with the low albedo resulting from absorptio…
A high-resolution spectroscopy survey of β Cephei pulsations in bright stars
Uytterhoeven, K.; De Ridder, J.; Aerts, C. +4 more
We present a study of absorption line-profile variations in early-B type near-main-sequence stars without emission lines. We have surveyed a total of 171 bright stars using the Nordic Optical Telescope (NOTSA), William Herschel Telescope (ING) and Coudé Auxiliary Telescope (ESO). Our sample contains 75% of all O9.5-B2.5 III-V non-emission-line sta…
Waves and horizontal structures in Titan's thermosphere
Waite, J. H.; Yelle, R. V.; Müller-Wodarg, I. C. F. +1 more
The Ion Neutral Mass Spectrometer (INMS) on board the Cassini spacecraft carried out in situ measurements of neutral gas composition above 1025 km altitude in Titan's atmosphere during its flybys in October 2004 (TA) and April 2005 (T5). Strong perturbations are present in the N2 and CH4 densities which we interpret as vertic…
A Strong X-Ray Flux Ratio Anomaly in the Quadruply Lensed Quasar PG 1115+080
Schechter, Paul L.; Fong, Wen-fai; Pooley, David +2 more
PG 1115+080 is a quadruply lensed quasar at z=1.72 whose image positions are well fit by simple models of the lens galaxy (at z=0.31). At optical wavelengths, the bright close pair of images exhibits a modest flux ratio anomaly (factors of ~1.2-1.4 over the past 22 yr) with respect to these same models. We show here that as observed in X-rays with…
Dynamical Mass Estimates for Incomplete Orbits: Young Multiple Stars in Taurus and Ophiuchus
Nelan, E.; Prato, L.; Schaefer, G. H. +2 more
We present recent measurements of the orbital motion in the binaries DF Tau and ZZ Tau and in the triples Elias 12, T Tau, and V853 Oph. We observed these systems with the Fine Guidance Sensors on the Hubble Space Telescope and with adaptive optics imaging at the W. M. Keck and Gemini North Observatories. Based on our measurements and those presen…
Coronal activity cycles in 61 Cygni
Schmitt, J. H. M. M.; Robrade, J.; Favata, F. +3 more
Context: .While the existence of stellar analogues of the 11 years solar activity cycle is proven for dozens of stars from optical observations of chromospheric activity, the observation of clearly cyclical coronal activity is still in its infancy.
Aims: .In this paper, long-term X-ray monitoring of the binary 61 Cygni is used to investigate p…
Probing the Dust Responsible for Small Magellanic Cloud Extinction
Gordon, Karl D.; Sofia, Ulysses J.; Clayton, Geoffrey C. +4 more
We explore the abundances and depletion levels of elements important to dust composition in four Small Magellanic Cloud (SMC) sight lines observed with the Hubble Space Telescope. The apparent optical depth method is used to interpret the high-resolution ultraviolet absorption data toward AzV 18, AzV 456, Sk 108, and Sk 155; the latter two sight l…
An Asymmetric Outflow from the Herbig Ae Star HD 163296
Bruhweiler, F. C.; Grady, C. A.; Kimble, R. A. +2 more
We present an observational picture of the HH 409 bipolar outflow including the detection of six previously unreported Herbig-Haro knots from the Herbig Ae star HD 163296. This study combines seven years of data from ground-based Fabry-Pérot and HST coronagraphic imagery, as well as HST long-slit spectral imagery. The redshifted counterjet include…