A study of the long-term activity of five intermediate polars with accretion discs

0549281 - ASÚ 2022 RIV GB eng J - Článek v odborném periodiku
Šimon, Vojtěch
A study of the long-term activity of five intermediate polars with accretion discs.
Monthly Notices of the Royal Astronomical Society. Roč. 505, č. 1 (2021), s. 161-171. ISSN 0035-8711. E-ISSN 1365-2966
Institucionální podpora: RVO:67985815
Klíčová slova: accretion discs * magnetic fields * radiation mechanisms
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.235, rok: 2021
Způsob publikování: Omezený přístup
https://doi.org/10.1093/mnras/stab739

Intermediate polars (IPs) are cataclysmic variables with mildly magnetized white dwarfs (WDs). This analysis of the long-term optical activity of five examples of IPs with accretion discs used data from the Catalina Real-time Transient Survey, Digital Access to a Sky Century @ Harvard (DASCH) and the American Association of Variable Star Observers (AAVSO). It is shown that each of these IPs had their most preferred value of absolute magnitude M-opt, even if it significantly varied on the superorbital time-scale. The values of M-opt of these IPs were in the zone of thermal-viscous instability (TVI) of the disc most of the time. The properties of a series of outbursts of V426Oph can be explained by an intermittently operating TVI. The activity of TVCol and DWCnc is interpreted as caused by a gradually variable mass inflow rate from the secondary to a cool disc. The mass transfer rate from the secondary varied on a well-determined time-scale. It is shown that M-opt of EIUMa, close to the peaks of outbursts of non-magnetic dwarf novae, fluctuated on the time-scale of days, it also produced short flares, ascribed to the bursts of matter from the donor. HYLeo, with a presumably cool disc, fluctuated between its high and low states. A temporary brightening from an extended low state is ascribed to a short, intense burst of matter from the donor to the remaining cool disc or torus.
Trvalý link: http://hdl.handle.net/11104/0325305