Dwarf nova oscillations and quasi-periodic oscillations in cataclysmic variables -- VI. Spin rates, propellering, and coherence
arXiv:0710.5057 · doi:10.1111/j.1365-2966.2007.12645.x
Abstract
We examine published observations of dwarf nova oscillations (DNOs) on the rise and decline of outbursts and show that their rates of change are in reasonable agreement with those predicted from the magnetic accretion model. We find evidence for propellering in the late stages of outburst of several dwarf novae, as shown by reductions in EUVE fluxes and from rapid increases of the DNO periods. Reanalysis of DNOs observed in TY PsA, which had particularly large amplitudes, shows that the apparent loss of coherence during late decline is better described as a regular switching between two nearby periods. It is partly this and the rapid deceleration in some systems that make the DNOs harder to detect. We suggest that the 28.95 s periodicity in WZ Sge, which has long been a puzzle, is caused by heated regions in the disc, just beyond the corotation radius, which are a consequence of magnetic coupling between the primary and gas in the accretion disc. This leads to a possible new interpretation of the `longer period DNOs' (lpDNOs) commonly observed in dwarf novae and nova-like variables.
arXiv comment9 pages, 3 figure, accepted for publication in MNRAS
References in corpus (14)
- Rapid Oscillations in Cataclysmic Variables
- Dwarf Nova Oscillations and Quasi-Periodic Oscillations in Cataclysmic Variables: II. A Low Inertia Magnetic Accretor Model
- Dwarf Nova Oscillations and Quasi-Periodic Oscillations in Cataclysmic Variables: III. A New Kind of Dwarf Nova Oscillation, and Further Examples of the Similarities to X-Ray Binaries
- Dwarf Nova Oscillations and Quasi-Periodic Oscillations in Cataclysmic Variables: I. Observations of VW Hyi
- WZ Sagittae as a DQ Herculis star
- Dwarf nova oscillations and quasi-periodic oscillations in cataclysmic variables -- V. Results from an extensive survey
- Solving the kilo-second QPO problem of the intermediate polar GK Persei
- On the magnetic accretor GK Persei in outburst
- Magnetically moderated outbursts of WZ Sagittae
- Time-Resolved Photometry of GK Per during the 1996 Outburst
- First Simultaneous Optical and EUV Observations of the Quasi-Coherent Oscillations of SS Cygni
- Dwarf Nova Oscillations and Quasi-Periodic Oscillations in Cataclysmic Variables, IV. Observations of Frequency Doubling and Tripling in VW Hyi
- Discovery of 15-second oscillations in Hubble Space Telescope observations of WZ Sagittae following the 2001 outburst
- Hubble Space Telescope Observations of UV Oscillations in WZ Sagittae During the Decline from Outburst
Cited by in corpus (13)
- WZ Sge-Type Dwarf Novae
- 57 second oscillations in Nova Centauri 1986 (V842 Cen)
- CC Sculptoris: A superhumping intermediate polar
- Secular changes in the quiescence of WZ Sge: the development of a cavity in the inner disk
- Is there evidence for field restructuring or decay in accreting magnetic white dwarfs?
- The Magnetospheric Boundary in Cataclysmic Variables
- Modeling the EUV spectra of optically thick boundary layers of dwarf novae in outburst
- High Cadence Time-Series Photometry of V1647 Orionis
- CC Sculptoris: Eclipsing SU UMa-Type Intermediate Polar
- Dwarf Nova Oscillations and Quasi-Periodic Oscillations in Cataclysmic Variables - VIII. VW Hyi in outburst observed with the Southern African Large Telescope
- Wavelets with Ridges: A High-Resolution Representation of Cataclysmic Variable Time-Series
- Dwarf nova oscillations and quasi-periodic oscillations in cataclysmic variables - VII. OY Carinae and oscillations in dwarf novae in quiescence
- Long-term photometric behavior of the eclipsing cataclysmic variable V729 Sgr