The highly luminous (>=10e37 erg/s) supersoft X-ray sources (SSS) are believed to be super-Eddington limited accreting white dwarfs undergoing surface hydrogenburning. The current paradigm for SSS (van den Heuvel et al. 1992) involves thermally unstable mass transfer from a 1-2 Msun companion. But this model hasnever been directly confirmed and yet is crucial for the evolution of cataclys-mic variables in general, and for the establishment of SSS as progenitors oftype Ia supernovae in particular. The key SSS is RXJ0513.9-6951 which hasrecurrent X-ray outbursts every 100-150d (lasting virgul30d) during which the opticaldeclines by 1 mag. We request TOO status to be triggered by optical monitoringso as to follow directly the predicted expansion of the white dwarf photosphere.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2004-04-28T17:52:12Z/2004-05-28T10:58:24Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Katherine McGowan, 2005, 'The Nature of the Luminous Supersoft X-ray Sources', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-5uf63pe
