SIMBAD references

This paper examines the effect of secondary-star magnetic activity in AE Aquarii on the mass-transfer process. The results can be extrapolated to cataclysmic variables in general. Based upon the evolution of the system, the surface polar field of the secondary star has been constrained to values of the order of B_2,{cir}∼ 1000 G. This may indicate the presence of a global magnetic field on the star, making magnetic activity on the stellar surface at least plausible. We have shown that magnetic fields of the order of B≥ 300 G will effectively curtail the mass-transfer process through the L1 point, resulting in a fragmentation of the mass-transfer flow as it is forced through the magnetic obstruction, while magnetic fields with values B < 250 G will be advected along with the fluid through the L1 region. This scenario will result in the field being pinched off, resulting in an inhomogeneous or `blobby' magnetized mass flow towards the compact object. We show that magnetic flux conservation will result in these magnetic fields reaching values of B_blob∼ 3000 G close to the white dwarf, giving rise to the observed radio outbursts due to the violent encounter with the fast-rotating white-dwarf magnetosphere. Within this framework, optical flares can also be explained in terms of the collisional interaction between a spectrum of denser unmagnetized blobs in the fragmented flow after ejection from the system by the magnetospheric propeller. This may explain the apparent anticorrelation between the non-thermal radio and thermal optical flares seen in AE Aquarii. Supplementing the ideas above, it has been shown that extended prominences in the L1 region may also be instrumental in producing fragmented and magnetized mass transport. Compressed fragments of fluid will be released from these structures when the fluid pressure dominates the magnetic pressure inside. Reconnection at the foot points may initiate episodes of particle acceleration and non-thermal emission when these structures interact with the propeller, followed by enhanced mass transfer and optical brightening of the source when the mass transfer encounters the propeller, leading to the same anticorrelation between radio and optical outbursts.