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Far-Ultraviolet and Optical Spectrophotometry of X-Ray Selected Seyfert Galaxies
Grewing, M.; Bowyer, S.; Clarke, J. T.
Five X-ray selected Seyfert galaxies were examined via near-simultaneous far-ultraviolet and optical spectrophotometry in an effort to test models for excitation of emission lines by X-ray and ultraviolet continuum photoionization. The observed Ly-alpha/H-beta ratio in the present sample averages 22, with an increase found toward the high-velocity…
The Extinction Law in the Open Cluster NGC 457 and the Intrinsic Energy Distribution of phi Cassiopeiae (F0 Ia)
Morrison, N. D.; Rosenzweig, P.
Five early B-type stars near the main-sequence turnoff in NGC 457 have been observed at low dispersion with the short-wavelength prime and the long-wavelength redundant cameras of the IUE satellite. The equivalent widths of spectral features that are particularly strong and sensitive to temperature and luminosity were computed in the cluster stars…
The Orbit and Properties of the HD 149162 System
Mayor, M.; Johnson, Hugh M.
HD 149162 is classified photometrically single and SB1 except for H-alpha emission that departs widely from the radial velocity of the K0 dwarf. Ca II H and K and Mg II h and k also show emission components at low dispersion. The system is X-ray luminous although ostensibly old disk and a slow K dwarf rotator. The orbit and other observations lead…