Front-row Seat of the Recent R Aqr Periastron Passage: X-Ray Multiepoch Spectral and Spatial Analysis

Andrea Sacchi, Margarita Karovska, John Raymond, Vinay Kashyap, Terrance J. Gaetz, Warren Hack, Jamie Kennea, Nicholas Lee, Amy J. Mioduszewski, Mark J. Claussen

Research output: Contribution to journalArticlepeer-review

Abstract

We report on the X-ray spectral and spatial evolution of the symbiotic star R Aqr. Through a multiepoch 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 toward 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 disk 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.

Original languageEnglish (US)
Article number12
JournalAstrophysical Journal
Volume961
Issue number1
DOIs
StatePublished - Jan 1 2024

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

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