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arXiv · 2312.03055

Front-row seat of the recent R Aqr periastron passage: X-ray multi-epoch spectral and spatial analysis

A. Sacchi·M. Karovska·J. Raymond·V. Kashyap·T. J. Gaetz·W. Hack·J. Kennea·N. Lee·A. J Mioduszewski·M. J Claussen
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Abstract

We report on the X-ray spectral and spatial evolution of the Symbiotic star R Aqr. Through a multi-epoch observational campaign performed with Chandra between 2017 and 2022, we study the X-ray emission of this binary system, composed of an evolved red giant star and a white dwarf (WD). This analysis is particularly timely as the WD approached the periastron in late 2018/early 2019, thus mass transfer, jet emission and outburst phenomena are to be expected. Through detailed spectral analysis, we detect a significant rise in the soft X-ray (0.5-2 keV) emission of R Aqr, likely linked to jet emission, followed by a decay towards the previous quiescent state. The hard X-ray emission (5-8 keV), is not immediately affected by the periastron passage; the hard component, after maintaining the same flux level between 2017 and 2021, rapidly decays after 2022. Possible explanations for this are a change in the reflection properties of the medium surrounding the binary, obscuration of the central region by material ejected during the periastron passage, or even the partial/complete destruction of the inner regions of the accretion disc surrounding the WD. In addition to this activity in the central region, extended emission is also detected, likely linked to a hot spot in a pre-outburst-emitted jet, which can be observed moving away from the system's central region.

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A. Sacchi, M. Karovska, J. Raymond, V. Kashyap, T. J. Gaetz, W. Hack, J. Kennea, N. Lee, A. J Mioduszewski, M. J Claussen. 2023-12-05. Front-row seat of the recent R Aqr periastron passage: X-ray multi-epoch spectral and spatial analysis. https://arxiv.org/abs/2312.03055

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