Stream-fed Accretion in Intermediate Polars

Abstract

I review the observational evidence for stream-fed accretion in intermediate polars. Recent work on the discless system V2400 Oph confirms the pole-flipping model of stream-fed accretion, but this applies only to a minority of the flow. The bulk of the flow is in the form of blobs circling the white dwarf, a state which might have been a precursor to disc formation in other IPs. I also discuss work on the systems with anomalously long spin periods, V1025 Cen and EX Hya. There are arguments both for and against stream-fed accretion in V1025 Cen, and further work is necessary before reaching a conclusion about this system.