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The Infrared Continuum Spectrum of VY Canis Majoris
Decin, Leen; Feuchtgruber, Helmut; Melnick, Gary J. +3 more
We combine spectra of VY CMa obtained with the short- and long-wavelength spectrometers, SWS and LWS, on the Infrared Space Observatory3 to provide a first detailed continuum spectrum of this highly luminous star. The circumstellar dust cloud through which the star is observed is partially self-absorbing, which makes for complex computational mode…
The European Large-Area Infrared Space Observatory Survey V: A BeppoSAX Hard X-Ray Survey of the S1 Region
Danese, L.; Alexander, D. M.; Perola, G. C. +18 more
We present BeppoSAX observations of the southern S1 region in the European Large-Area Infrared Space Observatory (ISO) Survey (ELAIS). These observations cover an area of ~1.7 deg2 and reach an on-axis (~0.7 deg2) 2-10 keV (hard X-ray, or HX) sensitivity of ~10-13 ergs s-1 cm-2. This is the fi…
Analysis of Type IIn SN 1998S: Effects of Circumstellar Interaction on Observed Spectra
Filippenko, Alexei V.; Kirshner, R. P.; McCray, R. +20 more
We present spectral analysis of early observations of the Type IIn supernova 1998S using the general non-local thermodynamic equilibrium atmosphere code PHOENIX. We model both the underlying supernova spectrum and the overlying circumstellar interaction region and produce spectra in good agreement with observations. The early spectra are well fitt…
Kinematics of 1200 Kilometer per Second Jets in HE 3-1475
Borkowski, Kazimierz J.; Harrington, J. Patrick
Spectroscopic observations of a proto-planetary nebula He 3-1475 with the Space Telescope Imaging Spectrograph reveal the kinematics of its high-velocity (1200 km s-1) jets. The jets are formed at a large (0.15 pc) distance from its central star by collimation of an asymmetric stellar wind in a pair of conical shocks seen in Wide Field …
Observations of the Interstellar Medium in the Magellanic Bridge
Sembach, K. R.; Dufton, P. L.; Keenan, F. P. +2 more
We present ultraviolet and optical spectra of DI 1388, a young star in the Magellanic Bridge, a region of gas between the Small and Large Magellanic Clouds. The data have signal-to-noise ratios of 20-45 and a spectral resolution of 6.5 km s-1. Interstellar absorption by the Magellanic Bridge at vLSR~200 km s-1 is v…
Deep Near-Infrared Luminosity Function of a Cluster of Galaxies at Z=0.3
Andreon, S.
The deep near-infrared luminosity function of AC 118, a cluster of galaxies at z=0.3, is presented. AC 118 is a bimodal cluster, as evidenced both by our near-infrared images of lensed galaxies, by public X-ray ROSAT images, and by the spatial distribution of bright galaxies. Taking advantage of the extension and depth of our data, which sample an…
Variable Interstellar Absorption toward the Halo Star HD 219188: Implications for Small-Scale Interstellar Structure
Fitzpatrick, Edward L.; Welty, Daniel E.
Within the last 10 yr, strong, narrow Na I absorption has appeared at vsolar~-38 km s-1 toward the halo star HD 219188; that absorption has continued to strengthen, by a factor of 2-3, over the past 3 yr. The line of sight appears to be moving into/through a relatively cold, quiescent intermediate-velocity (IV) cloud, because…
The Large-Scale Ionized Outflow of CH Cygni
Livio, Mario; Corradi, Romano L. M.; Gonçalves, Denise R. +3 more
Hubble Space Telescope (HST) and ground-based [O II] and [N II] images obtained in the period 1996-1999 reveal a complex, ionized optical nebula around the symbiotic binary CH Cyg extending out to 18" or 5000 AU from the central stars. The observed velocity range of the nebula, derived from long-slit echelle spectra, is 130 km s-1. In s…
Coronal Inflows and the Sun's Nonaxisymmetric Open Flux
Sheeley, N. R., Jr.; Wang, Y. -M.; Knudson, T. N.
Wang et al. recently described white-light coronagraph observations of faint coronal features moving inward toward the Sun at heliocentric distances of 2-6 Rsolar. In a study of these inflows during 1996-2000, we have found that they occur along bends of the coronal streamer belt and are especially common when the magnetic field has a f…
Double Loop Configuration of a Flaring Region from Microwave, Extreme-Ultraviolet, and X-Ray Imaging Data
Kundu, M. R.; White, S. M.; Grechnev, V. V. +1 more
We use extensive multiwavelength data to study a flare belonging to the interacting-loop class of events identified by Hanaoka. The class of flares is identified morphologically from the presence of two well-separated radio sources in 17 GHz images (in this event, 160" apart), with only one source showing soft X-ray emission. This event shows many…