Search Publications
HST UV Imaging of the Starburst Regions in the Wolf-Rayet Galaxy He 2-10: Newly Formed Globular Clusters?
Vacca, William D.; Conti, Peter S.
We have obtained an ultraviolet image of the Wolf-Rayet galaxy He 2-10 using the Faint Object Camera aboard the Hubble Space Telescope and a filter centered at 2200 A. From previous analysis of optical spectra of He 2-10, it is known that O-type and Wolf-Rayet stars are present in large numbers in the nuclear starburst region. In the ultraviolet r…
The X-Ray and Ultraviolet Absorbing Outflow in 3C 351
Elvis, Martin; Fiore, Fabrizio; Mathur, Smita +1 more
3C 351 (z = 0.371), an X-ray-"quiet" quasar, is one of the few quasars showing signs of a "warm absorber" in its X-ray spectrum; i.e., partially ionized absorbing material in the line of sight whose opacity depends on its ionization structure. The main feature in the X-ray spectrum is a K- edge due to O VII or O VIII. 3C 351 also shows unusually s…
Luminosity Effects and the Emission-Line Properties of Quasars with 0 < Z < 3.8
Green, Richard F.; Osmer, Patrick S.; Porter, Alain C.
We present data and a spectral atlas for 76 quasars with 2.97 < z < 3.80 and for 33 quasars with z ~ 2, together with measures of 73 quasars from the IUE archives that mostly have z < 1. The quasars provide a sampling of the luminosity-redshift plane at constant luminosity for 0 < z < 3.8, a range of a factor of 40 in luminosity for…
The Morphology of Faint Galaxies in Medium Deep Survey Images Using WFPC2
Glazebrook, K.; Illingworth, G. D.; Koo, D. C. +12 more
First results from HST Medium Deep Survey images taken with WFPC2 demonstrate that galaxy classifications can be reliably performed to magnitudes I_814_ <~ 22.0 in the F815W band. Published spectroscopic surveys to this depth indicate a mean redshift of z^bar^ ~ 0.5. We have classified over 200 galaxies in nine WFPC2 fields according to a basic…
HST/FOC Imaging of the Narrow-Line Region of NGC 1068
Boksenberg, A.; Capetti, A.; Sparks, W. B. +2 more
We present imaging observations of NGC 1068 taken with the COSTAR- corrected (Corrective-Optics Space Telescope Axial Replacement) Faint Object Camera on board the Hubble Space Telescope in the UV and optical continuum and [O III] emission lines. From these observations the structure of the nuclear region of NGC 1068 is shown to be very complex. B…
New Images of the Distant, Rich Cluster CL 0939+4713 with WFPC2
Lucas, Ray A.; Sparks, William B.; Dressler, Alan +1 more
New images of the distant cluster of galaxies CL 0939+4713 at z = 0.41 have been taken with the WFPC2 on the HST. The images go deeper and show considerably more detail than the aberrated images from WFPC1. We confirm that for this cluster the Butcher-Oemler effect results from a surprisingly large population of late-type spiral and irregular gala…
HST Eclipse Mapping of Dwarf Nova OY Carinae in Quiescence: an ``Fe II Curtain'' with Mach 6 Velocity Dispersion Veils the White Dwarf
Horne, Keith; Marsh, T. R.; Hubeny, Ivan +2 more
Hubble Space Telescope (HST) observations of the eclipsing dwarf nova OY Car in its quiescent state are used to isolate the ultraviolet spectrum (1150-2500 A at 9.2 A Full Width at Half Maximum (FWHM) resolution) of the white dwarf, the accretion disk, and the bright spot. The white dwarf spectrum has a Stark-broadened photospheric L(alpha) absorp…
Charged-Particle Motion in Multidimensional Magnetic Field Turbulence
Giacalone, J.; Jokipii, J. R.
We present a new analysis of the fundamental physics of charged-particle motion in a turbulent magnetic field using a numerical simulation. The magnetic field fluctuations are taken to be static and to have a power spectrum which is Kolmogorov. The charged particles are treated as test particles. It is shown that when the field turbulence is indep…
The Cepheid Distance to NGC 5253: Calibration of M(max) for the Type I Supernovae SN 1972E and SN 1895B
Panagia, N.; Saha, A.; Labhardt, Lukas +4 more
The apparent V distance modulus of NGC 5253, parent galaxy to the Type Ia supernovae SN 1972E and SN 1895B, is (m - M)_AV_ = 28.06+/-0.06 mag (internal error) determined from 11 Cepheid variables discovered with the Hubble Space Telescope. The internal differential absorption between the Cepheids and the two SNs is taken to be zero based on four i…
Interstellar Carbon Monoxide toward zeta Ophiuchi
Gilliland, Ronald L.; Federman, S. R.; Lambert, David L. +1 more
Interstellar CO A-X bands in the spectrum of zeta Oph were recorded at high Sound-to-Noise (S/N) with grating G160M of the Goddard High Resolution Spectrograph on the Hubble Space Telescope. Isotopic fractionation of CO is severe: CO-12/CO-13 = 167, C(16)O/C(18)O approximately equal to 1550 and C(16)O/C(17)O is greater than 5900 are found where C-…