gamma Cas objects are Be stars presenting an unusually intense and hard X-rayemission. Currently, only about a dozen such objects are known and it is wellpossible that additional cases, even bright ones, remain undetected. To improvethe situation, we propose to observe a set of well-chosen Be stars withsnapshots to search for the characteristic gamma Cas signatures.
Publications
Three discoveries of \\u03b3 Cas analogues from dedicated XMM-Newton observations of Be stars |Naz\\u00e9, Ya\\u00ebl, Motch, Christian, et al. | MNRAS | 493-2511 | 2020 | 2020MNRAS.493.2511N | http://ui.adsabs.harvard.edu/#abs/2020MNRAS.493.2511N
A possible nonthermal X-ray emission from \\u03b3 Cas analogues stars |Ryspaeva, Elizaveta B., Kholtygin, Alexander F., | OAst | 30-132 | 2021 | 2021OAst...30..132R | http://ui.adsabs.harvard.edu/#abs/2021OAst...30..132R
X-ray emission from Ae/Be Herbig stars due to disc-stellar magnetosphere interaction |Ryspaeva, Elizaveta, Kholtygin, Alexander, | MNRAS | 521-2427 | 2023 | 2023MNRAS.521.2427R | http://ui.adsabs.harvard.edu/#abs/2023MNRAS.521.2427R
Analysis of X-Ray Emission from OB Stars. IV. About X-Ray Emission from Inhomogeneous Winds of OB Stars |Ryspaeva, Elizaveta, Kholtygin, Alexander, | RAA | 23-105016 | 2023 | 2023RAA....23j5016R | http://ui.adsabs.harvard.edu/#abs/2023RAA....23j5016R
The XMM-Newton Line Emission Analysis Program (X-LEAP). I. Emission-line Survey of O VII, O VIII, and Fe L-shell Transitions |Pan, Zeyang, Qu, Zhijie, et al. | ApJS | 271-62 | 2024 | 2024ApJS..271...62P | http://ui.adsabs.harvard.edu/#abs/2024ApJS..271...62P
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 Yael Naze, 2020, 'Hunting for gamma Cas objects', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-97lizme
