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NGC 3603 and Its Wolf-Rayet Stars: Galactic Clone of R136 at the Core of 30 Doradus, but without the Massive Surrounding Cluster Halo
Drissen, Laurent; Moffat, Anthony F. J.; Shara, Michael M.
HST/PC images of the dense stellar cluster at the center of the Galaxy's most massive visible H II region, NGC 3603, reveal remarkable similarity to the dense core R136 in the Local Group's most massive Giant H II region, 30 Dor. The projected star density for stars brighter than M_V_ = -5.0 in both objects increases inwards to the last data bin i…
The Ultraviolet Pulsations of the Cataclysmic Variable AE Aquarii as Observed with the Hubble Space Telescope
Eracleous, Michael; Horne, Keith; Wood, Janet H. +3 more
We present the results of high time resolution UV spectroscopy and simultaneous high-speed UBVR photometry of AE Aqr. The UV spectra were obtained with the Faint Object Spectrograph aboard the Hubble Space Telescope (HST), and the photometry was carried out with the 82 sec telescope at McDonald Observatory. Our study focuses on the coherent 33 sce…
The Hubble Space Telescope Medium Deep Survey with the Wide Field and Planetary Camera. I. Methodology and Results on the Field near 3C 273
Im, M.; Glazebrook, K.; Illingworth, G. D. +21 more
We present results from the Medium Deep Survey (MDS), a Key Project using the Hubble Space Telescope. Wide Field Camera images of random fields have been taken in "parallel mode" with an effective resolution of 0'2 FWHM in the V(F555W) and I(F785LP) filters. The exposures presented here were targeted on a field 6' away from 3C 273, and resulted in…
An X-Ray and Optical Study of the Supernova Remnant W44
Rho, Jeonghee; Hester, J. Jeff; Schlegel, Eric M. +1 more
We report the results of a 8000 s observation of the supernova remnant W44 using the ROSAT Position Sensitive Proportional Counter (PSPC). The image shows the same centrally peaked morphology observed by the Einstein IPC and contrasts with the shell-like radio morphology. The eastern limb shows a lack of X-ray emission within the radio shell, prob…
Galaxy Pairs in Deep HST Images: Evidence for Evolution in the Galaxy Merger Rate
Keel, William C.; Windhorst, Rogier A.; Burkey, Jordan M. +1 more
We use four deep serendipitous fields observed with the HST Wide-Field Camera to constrain the rate of galaxy merging between the current epoch and z~0.7. Since most mergers occur between members of bound pairs, the merger rate is given to a good approximation by (half) the rate of disappearance of galaxies in pairs. An objective criterion for pai…
Geometry and Physical Conditions in the Stellar Wind of AG Carinae
Drissen, Laurent; Robert, Carmelle; Leitherer, Claus +8 more
AG Carinae is one of the prototypes of the class of Luminous Blue Variables (LBVs). Since 1990 the star has continuously brightened in its visual continuum. We report on a multi-instrument and -wavelength observing campaign to monitor the current activity phase of AG Car. Ground-based photometry, polarimetry, spectroscopy, and space-ultraviolet sp…
The Hubble Space Telescope Quasar Absorption Line Key Project. VI. Properties of the Metal-rich Systems
Turnshek, David A.; Petitjean, Patrick; Schneider, Donald P. +10 more
We present an analysis of the properties of a sample of 18 metal-rich, low-redshift z_abs_ < z_em_ absorbers seen in low- and medium-resolution spectra obtained for the Quasar Absorption Line Key Project with the Hubble Space Telescope Faint Object Spectrograph. For most of the C IV and Lyman-limit systems, observations in the optical wavelengt…
HST Ultraviolet Spectropolarimetry of NGC 1068
Antonucci, Robert; Hurt, Todd; Miller, Joseph
We present multiaperture spectropolarimetric observations of the Seyfert 2 galaxy NGC 1068. The nuclear region of NGC 1068 was observed with three apertures 4.3" x 1.4", 1.0" and 0.3") by the Hubble Space Telescope. These ultraviolet data allow us to study the scattered, nuclear light without the complication of polarization dilution caused by str…
Detection of CO Cameron Band Emission in Comet P/Hartley 2 (1991 XV) with the Hubble Space Telescope
Feldman, P. D.; A'Hearn, M. F.; Weaver, H. A. +3 more
Ultraviolet (UV) spectra of comet P/Hartley 2 (1991 XV) taken with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST) in 1991 September reveal several bands of the Cameron system of CO (a 3 Pi-X 1 Sigma). These band are most likely due to 'prompt' emission from CO2 and, thus, provide a direct tracer of the CO2 abundance in the…
The Ultraviolet Emission Properties of Five Low-Redshift Active Galactic Nuclei at High Signal-to-Noise Ratio and Spectral Resolution
Laor, Ari; Schneider, Donald P.; Green, Richard F. +3 more
We analyze the ultraviolet (UV) emission line and continuum properties of five low-redshift active galactic nuclei (four luminous quasars: PKS 0405 - 123, H1821 +643, PG 0953+414, and 3C 273, and one bright Seyfert 1 galaxy: Mrk 205). The HST spectra have higher signal-to-noise ratios (typically ~60 per resolution element) and spectral resolution …