Recent progress of hard X-ray studies of classical novae
Abstract
Classical novae (CNe) are explosions caused by a nuclear runaway on the surface of a while dwarf (WD) when the critical mass is reached for the matter accreted from its companion star. The defining characteristic of CNe is a sudden increase in the optical brightness by 10 mag, but CNe also show a variety of phenomena across wavelengths. In the X-rays, two types of emission after a CNe have been known for decades: super-soft emission from the heated WD surface and hard emission presumably caused in shocks by the CN ejecta. Unlike the super-soft emission, the hard emission has not been observed in a systematic manner for its transient and faint nature. The start of monitoring campaign by Swift for X-ray bright CNe drastically changed the situation, making timely pointing observations using X-ray observatories feasible. Many new discoveries were reported in the hard X-ray regime and in the higher energy bands, including the detection of non-thermal emission, Fe fluorescence from rekindled accretion, altered chemical composition in the plasma. We review the recent progress of hard X-ray observational studies mainly made with Suzaku, XMM, and Chandra and discuss utility of MAXI in this field.
- Publication:
-
The First Year of MAXI: Monitoring Variable X-ray Sources
- Pub Date:
- December 2010
- Bibcode:
- 2010fym..confE..16T