Search Publications
Discovery of a BL Lacertae object (EXO 055625-3838.6) in the error box of H 0557-385.
Tagliaferri, G.; Beuermann, K.; Giommi, P. +3 more
We present X-ray and optical data of a new BL Lacertae type object (EXO 055625-3838.6) which has been serendipitously discovered in an EXOSAT CMA image and is located within the error box of HO557-385 (4U0557-38, 3A0557-383), a hard X-ray source previously identified with a seyfert 1 galaxy. Although the soft X-ray flux of the BL Lac is 1O times h…
High-resolution Hα spectroscopy of the bright RS CVn system HR 7275.
Eker, Zeki
HR 7275 is a bright, long-period (28 day), single-lined RS CVn binary. High-resolution (0.36 A) and good signal-to-noise ratio echelle spectra do not show any clear evidence of the secondary in the system on spectral lines. Also, absence of a continuum on a low-resolution UV spectrum (IUE merged log) and the known mass function imply a main-sequen…
Anomalously high intercombination line ratios in symbiotic stars; extreme Bowen pumping ?
Feibelman, W. A.; Bhatia, A. K.; Kastner, S. O.
International Ultraviolet Explorer observations of the ratio of the O III intercombination lines near 1660 A are assembled, showing that the observed ratios in symbiotic stars are significantly higher than the theoretically predicted optically thin limit of 2.5. The presence of an enhancing physical process is thereby indicated. It is suggested th…
EXOSAT observations of the remnant of SN 1006.
Jones, L. R.; Pye, J. P.
The remnant produced by the supernova explosion of AD 1006 has been studied in X-rays with the Exosat Observatory. Images in the energy range 0.1-2 keV with resolution sufficient to resolve the limbs, obtained through three different filters, reveal a limb-brightened nebula containing clumps of emission and displaying large spectral variations wit…
Ultraviolet spectra of a large sample of quasars. I. Data and data reduction.
Gondhalekar, P. M.
Ultraviolet spectrophotometric data on all quasars (Z_e_ > 0.1) obtained with IUE from 1978 to the end of 1986 have been retrieved from IUE archive and re-extracted directly from the photometrically corrected images. A spectrum extraction procedure was used to maximize the signal-to-noise ratio and discriminate against spurious events outside t…