gamma Cas stars are Oe/Be stars that display an intriguing bright and hard X-rayemission. The origin of this X-ray emission could be either accretion by acompact companion or an interaction between the Be star and its decretion disk.Evidence favouring the latter scenario was obtained over recent years. Thisincludes observations of a quasi-simultaneous decrease by a factor 10 of theX-ray emission of HD45314 as the disk of this star nearly dissipated in 2016. Weaim at further constraining the gamma Cas phenomenon by taking advantage of suchspectacular variations. For this purpose, we propose observing a gamma Cas starnext time that its disk undergoes either an outburst or in case it clears away.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2019-08-26T07:23:28Z/2022-01-18T17:13:48Z
Version
19.17_20220121_1250
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, 2023, 'The impact of Be disks on the X-ray emission of gamma Cas stars', 19.17_20220121_1250, European Space Agency, https://doi.org/10.57780/esa-98iea8k
