首页 | 本学科首页   官方微博 | 高级检索  
     检索      


X-ray observations of 4 Draconis: symbiotic binary or cataclysmic triple?
Authors:Peter J Wheatley  Koji Mukai †  Domitilla de Martino
Institution:Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH;Laboratory for High Energy Astrophysics, NASA/GSFC, Code 662, Greenbelt, MD 20771, USA;INAF–Osservatorio Astronomico di Capodimonte, via Moiariello n. 16, I-80131 Napoli, Italy
Abstract:We present the first X-ray observations of the 4 Draconis system, consisting of an M3 III giant with a hot ultraviolet companion. It has been claimed that the companion is itself an AM Her-type binary system, an identification that places strong constraints on the evolution of cataclysmic variables. We find that the X-ray properties of 4 Draconis are consistent with the presence of an accreting white dwarf, but not consistent with the presence of an AM Her system. We conclude that 4 Draconis is therefore most likely a symbiotic binary containing a white dwarf accreting material from the wind of the red giant.
The X-ray spectrum of 4 Draconis is sometimes dominated by partially ionized photoelectric absorption, presumably due to the wind of the red giant. We note that X-ray monitoring of such systems would provide a powerful probe of the wind and mass-loss rate of the giant, and would allow a detailed test of wind accretion models.
Keywords:accretion  accretion discs  binaries: close  stars: individual: 4 Draconis  novae  cataclysmic variables  white dwarfs  X-rays: stars
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号