One of the latest scientific articles featuring Stephen M. Brincat and Charles Galdies (University of Malta) has recently been accepted as co-authors for publication by the renowned The Astrophysical Journal.
This multi-collaborative work is entitled: Investigating the low-flux states in six Intermediate Polars. Intermediate polars (IPs) are a subclass of cataclysmic variables in which a white dwarf accretes matter from a main sequence companion star. These types of stars are quite rare in the known universe. What is unique about them is that they consist of a binary orbiting star system, one of which is a white dwarf star with a magnetic field that significantly pushes out the inner accretion disk. This unique arrangement only allows material to fall down its magnetic poles. The white dwarf belonging to an IP is so close to the normal star that it strips away its outer atmosphere. As the white dwarf spins, the columns of infalling gas rotate with it.
An analysis of the timing of the light curves of IPS in both optical and X-ray wavelengths can reveal a lot about the dominant way of gas accretion within the system. This paper studies the temporal properties of V515 Andromedae, amongst other IP targets, and suggests that the observed decrease in optical flux is related to a transition between disk-fed, stream-fed and disk-overflow accretion geometries. This paper also publishes the timing analysis of 3 other IP targets – DW Cnc, V1223 Sgr and 1RXS J213344.1+510725.