Indications of magnetic accretion in Swift J0826.2-7033

TL;DR

This study presents the first detailed X-ray analysis of Swift J0826.2-7033, indicating magnetic accretion with specific periodicities, spectral characteristics, and evidence of a complex accretion process involving disc-overflow and evolved donor features.

Contribution

It provides the first long X-ray observation revealing magnetic accretion signatures and detailed spectral analysis of Swift J0826.2-7033, suggesting a unique accretion mechanism and evolutionary state.

Findings

Detection of long orbital period (~7.8 h) and short timescale variabilities.

Energy-independent modulations indicating non-absorption related variability.

Spectral evidence of a multi-temperature post-shock region with ~43 keV maximum temperature.

Abstract

We present our findings from the first long X-ray observation of the hard X-ray source Swift J0826.2-7033 with XMM-Newton, which has shown characteristics of magnetic accretion. The system appears to have a long orbital period (~7.8 h) accompanied by short timescale variabilities, which we tentatively interpret as the spin and beat periods of an intermediate polar. These short- and long-timescale modulations are energy-independent, suggesting that photoelectric absorption does not play any role in producing the variabilities. If our suspected spin and beat periods are true, then Swift J0826.2-7033 accretes via disc-overflow with an equal fraction of accretion taking place via disc and stream. The XMM-Newton and Swift-BAT spectral analysis reveals that the post-shock region in Swift J0826.2-7033 has a multi-temperature structure with a maximum temperature of ~43 keV, which is absorbed by a material with an average equivalent hydrogen column density of ~1.6$\times$10$^{22}$ cm$^{-2}$ that partially covers ~27% of the X-ray source. The suprasolar abundances, with hints of an evolved donor, collectively make Swift J0826.2-7033 an interesting target, which likely underwent a thermal timescale mass transfer phase.