We propose to probe the Lx/Lbol relation of O-type stars in the young opencluster IC 1805. This cluster hosts a very rare and extreme O4If^+ star (HD15570), i.e. a transition object between normal O-stars and evolved Wolf-Rayetstars. Theoretical models predict that such transition stars should have aweaker X-ray emission than less extreme O-star, with a log(Lx/Lbol) intermediatebetween the -7 value of O-stars and the much lower value obtained for Wolf-Rayetstars. IC 1805 offers the unique opportunity to test this scenario on ahomogeneous population of O-stars (same distance, same age, samemetallicity,.).
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2014-08-25T20:50:00Z/2014-08-26T10:43:20Z
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 Gregor Rauw, 2015, 'Probing the extremes of the Lx-Lbol relation of O-stars', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-1i69jji
