Discovery of Recombining Plasma from a Magnetic Cataclysmic Variable, EX Hya with Suzaku
Abstract
A magnetic cataclysmic variable (mCV) is considered to be a primary contributor of the unresolved X-ray emission prevailing in the Galactic center region and also along the Galactic plane (GDXE). We investigated a mCV, EX HYA based on a detailed spectral analysis using Suzaku, and found significant residuals at 9-10 keV in the spectrum with a conventional thermal plasma model for mCVs. It is consistent with an Fe XXVI RRC feature. Since a collisional ionized equilibrium plasma cannot produce the observed flux of the RRC, the plasma should be in a recombining state. A possible scenario is photoionization; X-rays from high-temperature plasma in the accreting column ionize low-temperature plasma.
- Publication:
-
New Horizons in Galactic Center Astronomy and Beyond
- Pub Date:
- July 2021
- Bibcode:
- 2021ASPC..528..403S