|Title||X-ray emission as a probe of accretion in white dwarf - L dwarf binaries|
|Author||Dr Beate Stelzer|
|Description||Only a handful of short-period (~ 100 min) binary systems composed of white dwarf (WD) and L dwarf (WDLDs) are known. The detection of X-ray emission from such systems can be considered a clear sign for accretion because the coronal X-ray emission levels of L dwarfs are below the sensitivity limits of current instrumentation. Only one WDLD (SDSS J121209.31+013627.7) was detected with Swift as a relatively bright X-ray source (log(L_x) [erg-s] ~ 29.3). We propose to search for orbital modulation of the X-ray emission in SDSS J1212+0136 and another promising WDLD accretor candidate to confirm the presence of an accretion spot on the WD. These observations will yield the strongest constraints ever obtained for mass transfer rates in binaries with low-mass stars (~ 5 10^(-15) Msun-yr).|
|Publication||X-ray orbital modulation of a white dwarf accreting from an L dwarf. The system SDSS J121209.31+013627.7 . Stelzer, B., de Martino, D., et all. . A&A . 598-6 . 2017 . 2017A&A...598L...6S ,
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2016-06-23T22:00:00Z, 076044, 17.56_20190403_1200. https://doi.org/10.5270/esa-bjxo067|