HD149404 is an O7.5If + ON9.7I binary that has experienced a Case A Roche lobeoverflow episode. Although the system has been studied intensively in theoptical and UV, the orbital inclination as well as the wind parameters remainpoorly constrained. The X-ray emission from the wind-wind interaction betweenthe stars should be modulated by a changing wind column density as the starsrevolve around each other. We propose three observations, of 25 ks each: twoscheduled at conjunction phases, and one observation near quadrature. Usingthese three spectra, it is possible to establish the variations of the absorbingcolumn density and hence to constrain the orbital inclination, the wind momentumratio and the radial extent of the wind interaction zone.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2018-08-16T05:23:42Z/2018-08-28T22:29:35Z
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, 2019, 'Constraining the properties of the post-RLOF massive binary HD149404', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-z6eq6b1
