Modeling the radio outbursts in AE Aquarii

Abstract

AbstractIn this paper we model the non-thermal radio to infra-red flares from AE Aqr. In our model the non-thermal flares originate in highly magnetized (Bblob ≥ 2000 G) blobs that may be among the propeller ejected outflow. It was shown that the condition ß ≤ 1 constrains the frozen-in magnetic field in these blobs to Bblob ≥ 2000 G, which is of the same order of magnitude as the inferred polar field of the secondary. As these magnetized blobs encounter the violent mhd-propeller, processes such as reconnection, magnetic pumping, and shocks will result in continuous acceleration of electrons from (γ = 2 → 30; δ = 2.8 → 2.6) with resultant synchrotron emission. The total radio to infra-red flare spectrum was modelled in terms of such expanding magnetized synchrotron emitting blobs in various stages of their evolution from ρ = (r/r°) = 1 → 400. In terms of our model, the total integrated flux during outbursts, over the wide frequency range from 1 GHz is the result of several (~ 20) synchrotron emitting blobs observed in different stages of their evolution, resulting in a spectrum showing a peak flux of Sv ~ 148 mJy at v ~ 1805 GHz (~ 166 microns), where the spectrum changes from a typical self-absorbed Sv ∝ vα spectrum to Sv ∝ v-(δ-1)/2 spectrum, i.e. where the blobs are combined optically thin.