Search Publications
Detailed observations of NGC 4151 with the IUE - III. Variability of the strong emission lines from 1978 February to 1980 May.
Tanzi, E. G.; Tarenghi, M.; Perola, G. C. +8 more
Observations of the variability of the three strong ultraviolet emission lines in the Seyfert galaxy NGC 4151 (C IV, C III] and Mg II) are used to study the structure of the broad line region and the nuclear energy source of this active galaxy. Data on the line profile variations further permit the kinematic mapping of the broad line region throug…
Selective excitation of Fe II in the laboratory and late-type stellaratmospheres.
Jordan, C.; Johansson, S.
Low resolution spectra of cool giants and supergiants observed with the International Ultraviolet Explorer (IUE) satellite contain emission features for which it has been difficult to establish unambiguous identifications. High resolution spectra of RR Tel and Beta Gru (M 3 II) show lines which can be definitely attributed to Fe II. The presence o…
X-ray observations of a large sample of cataclysmic variable stars using the Einstein Observatory
Mason, K. O.; Cordova, F. A.
This paper presents the results of an X-ray survey of 31 known or suspected cataclysmic variables. Eighteen of these close binary systems are detected with inferred luminosities in the 0.1 - 4.0 keV band of between 1030 and 1032erg s-1. The majority have relatively hard X-ray spectra (kT > 2 keV) irrespective of…
The chromosphere and corona of T Tauri.
Jordan, C.; Brown, A.; de M. Ferraz, M. C.
Observations of the ultraviolet spectrum of the pre-main-sequence star T Tauri have been made using the International Ultraviolet Explorer (IUE) satellite. The fluxes of the emission lines are used to make models of the temperature and density structure of the chromosphere and transition region to the corona. Several models are discussed to cover …
Element depletions in interstellar gas - II. The density-dependence of calcium and sodium depletions.
Gondhalekar, P. M.; Pettini, M.; Phillips, A. P.
The behavior of Ca and Na depletions in interstellar gas is studied in view of complementary, high resolution optical and UV spectra for nine stars in the same region of sky. The optical absorption lines of Ca II and Na I are analyzed to determine their column densities in each line-of-sight, and the UV data are used to estimate H column densities…
K 648, the planetary nebula in the globular cluster M 15.
Howarth, I. D.; Seaton, M. J.; Walsh, J. R. +2 more
IUE observations of the planetary nebula K648 in the globular cluster M15 have been obtained, and the first determinations of the C abundance in the nebular envelope have been made. Improved measurements of fluxes in the optical nebular emission lines and in forbidden N II 6583 have been obtained. Semiforbidden C III 1908 and C II 2326 are strong …
Diffuse LY alpha emission around NGC 1275.
Fabian, A. C.; Nulsen, P. E. J.; Arnaud, K. A.
The authors report on short wavelength ultraviolet observations (1200 - 1900 Å) of NGC 1275 taken with the International Ultraviolet Explorer satellite. Diffuse Lyα radiation was discovered which is identified with the optical filaments surrounding the galaxy. The lack of a detected ultraviolet stellar continuum limits the number of massive young …
The pulsating extreme helium star BD +13 3224. II. Ultraviolet fluxesand effective temperature variations.
Heber, U.; Lynas-Gray, A. E.; Hill, P. W. +1 more
BD + 13 deg 3224 (V652 Her) is characterized on the basis of low-resolution spectra obtained with the short-wavelength prime camera of the IUE on July 5, 1980, and optical spectra obtained at integration time 200 s with the 3.9-m Anglo-Australian Telescope on May 24 and 25, 1980. The results are presented in tables and graphs and discussed. Static…
The remarkavle kinematics of the WR wind-blown bubble RCW 58.
Smith, L. J.; Pettini, M.; Hartquist, T. W. +1 more
High resolution, high signal-to-noise ratio, ultraviolet, and optical observations of HD 96548, a WN8 star surrounded by the nebula RCW 58 which consists of stellar ejecta enclosed in a wind-blown bubble, are presented. The spectra exhibit blueshifted absorption components in a number of interstellar lines arising from a variety of ions. The veloc…
Analysis of the three high-velocity B stars HD 125924, 165955 and CPD-72 1184.
Tobin, W.; Kaufmann, J. P.
Optical and IUE observations are analyzed for three high radial velocity stars, HD 125924 (+252 km/s), HD 165955 (-160 km/s), and CPD-72 deg 1184 (-217 km/s). On account of their high velocities and no evidence of abnormal carbon and nitrogen abundances, the stars cannot be subluminous members of an old disc population. Magnesium and silicon level…