A Multiwavelength Study of Dust Formation in Accreting White Dwarfs
Abstract
Cataclysmic Variables (CVs) are binary systems in which a white dwarf primary accretes matter from a low-mass secondary. Infrared (IR) observations show that a very small fraction of CVs form dust grains and molecules after an outburst. However, the formation process and the grains' subsequent evolution and dissipation remain a difficult problem; there are only a handful of hypotheses to explain the process, none of which are definitive, and there are relatively few high-resolution spectroscopic studies of dust-forming CVs. In order to address this lack, we conduct a survey of 3 dust-forming and 3 non-dust-forming CVs, using archival high-resolution optical/IR spectra from HST and X-ray spectra from XMM-Newton and Chandra. We model the photoionisation process with photoionisation spectral synthesis code CLOUDY and use standard models within the X-ray spectrum fitting code SPEX. Our analysis of both continuum and line features reveals the physical parameters of the systems, such as temperature, luminosity of central source, and the velocity and density distribution of the ejecta. We also estimate the chemical abundances of different elements in the presence and absence of circumstellar dust grains.
- Publication:
-
43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1615P