|Title||The X-ray emission of the sdO stars Feige 34 and BD+28 4211|
|Author||Mr Nicola La Palombara|
|Description||The XMM observation of HD49798, BD+37 442, and BD+37 1977 allowed us to characterize their spectral and timing properties, and to attribute the observed flux to wind accretion from the sdO star onto a WD or NS companion and-or to turbulence and shocks in the stellar wind of the sdO star itself. A Chandra survey of a complete flux-limited sample of sdO stars provided a clear detection also of the sdO stars BD+28 4211 and Feige 34. While the former subdwarfs are luminous and He-rich sdO stars, the latter ones are compact He-poor stars. They are the first stars of this type detected at X-rays; therefore, now we propose to observe with XMM also BD+28 4211 and Feige 34. This proposal was already accepted in priority C for the AO-14 and AO-15 observing periods, but no observation has been made to date.|
|Publication||No observations found associated with the current proposal|
|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, 2019-05-21T22:00:00Z, 080010, 17.56_20190403_1200. https://doi.org/10.5270/esa-o99lwld|