An XMM-Newton view of the Symbiotic Stars HM Sge, NQ Gem, and PU Vul [SSA]

http://arxiv.org/abs/2301.08191


We present the analysis of archival XMM-Newton observations of the symbiotic stars (SySts) HM Sge, NQ Gem, and PU Vul. The EPIC-pn spectra reveal the presence of emission lines and spectral modeling reveal unprecedented characteristics. For instance, the best fit to the EPIC-pn spectrum of the $\beta$-type SySt PU Vul reveals the presence of two plasma components. We report the discovery of an extremely soft spectral component in the EPIC-pn spectrum of the $\beta$-type Syst HM Sge which we suggest is produced by periodic mass ejections such as jets. We suggest that a simple $\beta$-type classification no longer applies to HM Sge. Finally, the spectrum of the $\beta/\delta$-type SySt NQ Gem can not be fitted by a two-temperature plasma model as performed by previous authors. The model requires extra components to fit the 1.0–4.0 keV energy range. More sophisticated models to $\beta/\delta$-type SySt are needed in order to peer into the accretion process from such systems.

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J. Toalá, M. Botello and L. Sabin
Fri, 20 Jan 23
21/72

Comments: 6 pages, 2 Tables, 2 Figures; Submitted to ApJ