New Observations of Accretion Phenomena in Magnetic Cataclysmic Variables

¹ South African Astronomical Observatory, PO Box 9, Observatory 7935, Cape Town, South Africa
² Southern African Large Telescope, Box 9, Observatory 7935, Cape Town, South Africa
³ Department of Astronomy, University of Cape Town, Rondebosch 7770, Cape Town, South Africa

^a Corresponding author: dibnob@saao.ac.za

Published online: 8 January 2014

Abstract

We present an overview of the ongoing observational, theoretical and modelling work on magnetically controlled accretion phenomena in magnetic cataclysmic variables. With SAAO's high speed polarimeter, HIPPO, we have discovered polarized Quasi-Periodic Oscillations, on a timescale of several minutes. We have investigated various scenarios in which such QPOs can be created, all of them requiring some interaction between the ballistic accretion flow and the magnetic field of the accreting white dwarf. With high speed photometry, including observations with SALT, we are investigating the nature of high frequency QPOs (~sub-few seconds) from the accretion shocks in mCVs. We also present some high speed photometric observations revealing the magnetic accretion spots on the accreting White Dwarfs. Developments in the use of Doppler tomography are also presented. Our new "inside-out" visualization gives an alternative way of calculating Doppler tomograms that can better emphasize the ballistic and magnetically confined accretion flows.