At the present time, the X-ray measurements of AM CVn stars (systems where onewhite dwarf accretes from another white dwarf) are heavily biased toward shortperiod systems. We propose to recitfy the situation by observing all AM CVnstars which do not have XMM observations in the archives but do have knownperiods. In fact, the X-ray measurements are more important for the long periodsystems than the short period systems, since in the long period systems, theboundary layers are expected to be optically thin, and a much larger fraction ofthe bolometric luminosity is expected to come out in X-rays, meaning that usingthese systems to test our understanding of evolution of double white dwarfsdepends crucially on knowing their X-ray fluxes.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2016-10-10T14:55:46Z/2017-02-19T09:44:24Z
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, Prof Thomas Maccarone, 2018, 'A Comprehensive Survey of Accretion in Double White Dwarfs', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-yarc34z
