We propose to observe the O star HD148937 for 30 ksec to measure both the X-rayhalo formed by dust scattering, as well as the spectrum of the star itself. TheX-ray halo measures the size and composition of large dust grains, which havemost of the mass that is in dust, but are difficult to observe at other wave-lengths. HD148937, unlike most halo sources, has emission lines, and we can usethese to image the halo in narrow energy bands. The spectrum of HD148937 will bemeasured by the XMM RGS with over 6000 counts, enough to detect absorption anddoppler shifts of strong lines. HD148937 is an unusual O star, 20 times brighterthan the average O star with a harder spectrum. This will test current models ofO star winds, which have difficulty creating even the average luminosity.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2001-02-25T10:29:18Z/2001-02-25T22:07:08Z
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, Dr Randall Smith, 2002, 'The X-ray Halo and Spectrum of the Unusual O Star HD148937', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-bx9u9g9
