The XMM observation of HD49798, BD+37 442, and BD+37 1977 allowed us tocharacterize their spectral and timing properties, and to attribute the observedflux to wind accretion from the sdO star onto a WD or NS companion and/or toturbulence and shocks in the stellar wind of the sdO star itself. A Chandrasurvey of a complete flux-limited sample of sdO stars provided a clear detectionalso of the sdO stars BD+28 4211 and Feige 34. While the former subdwarfs areluminous and He-rich sdO stars, the latter ones are compact He-poor stars. Theyare the first stars of this type detected at X-rays; therefore, now we proposeto observe with XMM also BD+28 4211 and Feige 34. This proposal was alreadyaccepted in priority C for the AO-14 and AO-15 observing periods, but no observation has been made to date.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2018-04-27T22:24:13Z/2018-04-28T14:14:13Z
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, Mr Nicola La Palombara, 2019, 'The X-ray emission of the sdO stars Feige 34 and BD+28 4211', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-o99lwld
