Investigating the low-flux states in six Intermediate Polars

TL;DR

This study analyzes optical photometry of six intermediate polars during low-flux states, revealing changes in periodicities and accretion properties in some systems, while others show stable variability patterns.

Contribution

It provides new timing analysis of six intermediate polars during low-flux states, highlighting how accretion dynamics change or remain stable across different systems.

Findings

DW Cnc and V515 And show changing dominant periodicities during flux decrease.

V1223 Sgr's variability is quenched at low flux without changing accretion geometry.

RX J2133.7+5107 exhibits enhanced accretion and increased beat frequency variability.

Abstract

We present optical photometry of six intermediate polars that exhibit transitions to a low-flux state. For four of these systems, DW Cnc, V515 And, V1223 Sgr and RX J2133.7+5107, we are able to perform timing analysis in and out of the low states. We find that, for DW Cnc and V515 And, the dominant periodicities in the light curves change as the flux decreases, indicating a change in the sources' accretion properties as they transition to the low state. For V1223 Sgr we find that the variability is almost completely quenched at the lowest flux, but do not find evidence for a changing accretion geometry. For RX J2133.7+5107, the temporal properties do not change in the low state, but we do see a period of enhanced accretion that is coincident with increased variability on the beat frequency, which we do not associate with a change in the accretion mechanisms in the system.