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Hubble Space Telescope Medium Deep Survey. II. Deconvolution of Wide Field Camera Field Galaxy Images in the 13h+43degree Field
Gilmore, G.; Glazebrook, K.; Illingworth, G. D. +12 more
We present isophotal profiles of six faint field galaxies from some of the first deep images taken for the Hubble Space Telescope (HST) Medium Deep Survey (MDS). These have redshifts in the range z = 0.12-0.401. The images were taken with the Wide Field Camera (WFC) in "parallel mode" and deconvolved with the Lucy method using as the point-spread …
The distance to the Complex C of high-velocity halo clouds
Wakker, B. P.; Bomans, D. J.; de Boer, K. S. +5 more
High resolution IUE spectra of sdB and HBB stars in the direction of the concentration of neutral hydrogen gas at high-velocity named Complex C have been obtained. The interstellar absorption line profiles are compared with Effelsberg HI 21-cm emission profiles. Since the distances to the stars are known from spectroscopic investigations, firm low…
Conditions in the Z = 0.692 Absorber toward 3CR 286
Cohen, Ross D.; Junkkarinen, Vesa T.; Beaver, E. A. +3 more
We present HST/FOS^1^ ultraviolet and ground-based optical spectra of the z = 0.692 21 cm absorption system in the QSO 3CR 286. The strength of the damped Lyα absorption implies an H I column density, N(H I)~2 x 10^21^ cm^-2^. We derive a high spin temperature for the H I gas, T_s_~> 10^3^ K, as has been found for other high-redshift 21 cm abso…
The Orion Nebula: Structure, Dynamics, and Population
O'Dell, C. R.
The physical nature and evolution of the Orion Nebula has begun to be revealed by calibrated emission line images and high resolution spectroscopy. We review the evidence that the nebula is a thin wall of emission on the near side of the Orion Molecular Cloud and that its separation from the dominant ionizing star is about 0.3 pc. The density of t…
Gas Kinematics and Ionization along the Extended Sight Line to HD 116852
Sembach, Kenneth R.; Savage, Blair D.
We present Goddard High-Resolution Spectrograph intermediate observations of the interstellar medium toward HD 116852, a low halo star at a distance of 4.8 kpc (z = -1.3 kpc) in the direction l = 304. deg 9, b = 16.deg 1. The small science aperture observations have signal-to-noise ratios ranging from 30 to 90 and resolutions of 11 to 18 km/s (FWH…
Modeling the X-ray spectrum of Kepler's supernova remnant.
Ballet, J.; Decourchelle, A.
We introduce realistic initial conditions for the ejecta density profile (power law) and propose to explain the silicon, sulphur and iron excess seen in Kepler's supernova remnant as associated with shocked enriched ejecta. We assume the composition of the interstellar medium to be solar. We describe the hydrodynamic interaction between the ejecta…
A Weak Diffuse Interstellar Band in the Far-Ultraviolet Spectrum of zeta Ophiuchi
Savage, B. D.; Tripp, T. M.; Cardelli, J. A.
Goddard High Resolution Spectrograph (GHRS) observations at 3.5 km/s resolution reveal several new weak unidentified interstellar absorption lines in the ultraviolet spectrum of zeta Ophiuchi. The unidentified line at 1369.13 A has the appearance and characteristics of a weak diffuse interstellar band (DIB). The line has a smooth profile similar t…
He II lines from cataclysmic variable winds.
Hoare, M. G.
We present the first quantitative examination of the contribution of the stellar winds in high accretion rate, non-magnetic cataclysmic variables to the He II λ1640 and λ4686 lines. The line profiles are simulated with the Sobolev approximation using level populations taken from previous NLTE calculations which matched the observed strengths of th…
Proper motion study of the globular cluster M 3
Tucholke, H. -J.; Scholz, R. -D.; Brosche, P.
We present proper motions for stars in the field of the galactic globular cluster NGC 5272 (M 3). This study forms part of the Bonn programme of globular cluster proper motions. 14 plates were taken with the Bonn double refractor, spanning epoch differences of up to 85 years. Relative proper motions for all well-measurable stars in the 1.5deg x 1.…
N III Intercombination Lines in the IUE Spectra of Gaseous Nebulae
Feibelman, W. A.; Dufton, P. L.; Keenan, F. P. +3 more
Theoretical N III electron density-sensitive emission-line ratios involving intercombination transitions, derived using recent calculations of electron impact excitation rates and oscillator strengths, are presented for R1 = I(1754.0 Å)/I(1749.7 Å), R2 = I(1752.2 Å)/I(1749.7 Å), R3 = I(1748.6 Å)/I(1749.7 Å), and R<…