Related papers: Supersoft X-ray Sources. Basic Parameters
We present new photometric and spectroscopic observations of the transient supersoft X-ray source RX J0537.7-7034 and find a periodicity of approximately 3.5 hrs. This establishes RX J0537.7-7034 as the supersoft X-ray source with the…
We report the identification of seven transient X-ray sources in the nearby Magellanic-type galaxy NGC 4449 using the archival multi-epoch X-ray observations conducted with {\it Chandra}, {\it XMM-Newton} and {\it Swift} telescopes over…
We present a comprehensive study of the soft X-ray properties of the BeppoSAX High-Energy Large Area Survey (HELLAS) sources. A large fraction (about 2/3) of the hard X-ray selected sources is detected by ROSAT. The soft X-ray colors for…
We report the identification of the ROSAT all-sky survey source 1RXS J154814.5-452845as new intermediate polar and present the results from follow-up optical and X-ray observations. The source shows pulsations with a period of 693 s both in…
We present a 100 yr optical lightcurve of the recently discovered supersoft X-ray source RX~J0019.8+2156 as deduced from photographic plates of Harvard and Sonneberg Observatory. Apart from the periodic orbital variations two different…
We study populations of soft and super-soft X-ray sources in nearby galaxies of various morphological types with the special emphasis on characterizing populations of stable nuclear burning accreting WDs. Analysing the content of Chandra…
We present ultraviolet observations of the supersoft X-ray source RXJ0439.8-6809 obtained with the Hubble Space Telescope Imaging Spectrograph. The ultraviolet spectrum is a very blue continuum overlayed with interstellar absorption lines.…
We report the discovery of a transient jet in the supersoft X-ray source RX J0925-4758 . The jet was observed in the Halpha line during a single night in June 1997 and had disappeared one day later. RX J0925-4758 is the third supersoft…
This catalog comprises an up-to-date list of luminous (>10^36 erg/s) supersoft X-ray sources. We include in this catalog accreting binary sources of high luminosity which are thought to be in a state of (steady or recurrent) hydrogen…
We analyse the spectral energy distribution (SED) of the eclipsing supersoft X-ray source CAL 87 covering wavelengths from X-rays to the near-infrared. Our study incorporates 26 data points across ultraviolet to near-infrared, sourced from…
Radiation of supersoft X-ray sources (SSS) dominates both the supersof X-ray and the far-UV domain. A fraction of their radiation can be reprocessed into the thermal nebular emission, seen in the spectrum from the near-UV to longer…
We obtained an optical spectrum of a star we identify as the optical counterpart of the M31 Chandra source CXO J004318.8+412016, because of prominent emission lines of the Balmer series, of neutral helium, and a He II line at 4686 Angstrom.…
We present a non-LTE model atmosphere analysis of Chandra HRC-S/LETG and XMM-Newton RGS spectroscopy of the prototypical supersoft source CAL 83 in the Large Magellanic Cloud. Taken with a 16-month interval, the Chandra and XMM-Newton…
Assuming that soft X-ray sources in symbiotic stars result from strong thermonuclear runaways, and supersoft X-ray sources from weak thermonuclear runaways or steady hydrogen burning symbiotic stars, we investigate the Galactic soft and…
Context. We report the discovery of a new luminous supersoft source, XMMU J005455.0-374117, in the nearby spiral galaxy NGC 300, in XMM-Newton observations performed on 2005 May 22 and on 2005 November 25. The source is not present in ROSAT…
We present the results of a systematic search for point-like and moderately extended soft (0.1-2.4 keV) X-ray sources in a raster of nine pointings covering a field of 8.95 deg^2 and performed with the ROSAT PSPC between October 1991 and…
The nearby Andromeda galaxy (M31) has been observed with the ROSAT PSPC in a mosaic of 6 pointings with 25 ksec each. In the paper describing the results on the total sample of detected sources, Supper et al. (1996) also report the…
Context. Close binary supersoft X-ray sources (CBSS) are binary systems that contain a white dwarf with stable nuclear burning on its surface. These sources, first discovered in the Magellanic Clouds, have high accretion rates and…
We report on very soft X-ray sources (VSSs) in M31. In a survey which was most sensitive to soft sources in four 8'x8' regions covered by Chandra's ACIS-S S3 CCD, we find 33 VSSs that appear to belong to M31. Fifteen VSSs have spectral…
In a recent ROSAT observation, taken during its optical low state, we found that the VY Scl star V751 Cyg was a highly luminous source of soft X-rays. The ROSAT HRI count rate of V751 Cyg was a factor of 10-20 higher than upper limits…