Detection of X-rays from the symbiotic star V1329 Cyg

TL;DR

This paper reports the first detection of X-ray emission from the symbiotic star V1329 Cyg, revealing a two-temperature plasma spectrum with unique absorption characteristics, suggesting shock-related origins possibly linked to jets or accretion processes.

Contribution

First X-ray detection of V1329 Cyg showing a two-temperature plasma spectrum with minimal absorption, indicating shock origins within jets or accretion regions.

Findings

Detected X-ray emission with two plasma temperatures (0.11 keV and 0.93 keV).

Soft X-ray component is only absorbed by interstellar material, unusual for symbiotic stars.

No significant X-ray or ultraviolet variability observed.

Abstract

We report the detection of X-ray emission from the symbiotic star V1329 Cyg with XMM-Newton. The spectrum from the EPIC pn, MOS1 and MOS2 instruments consists of a two-temperature plasma with k T = 0.11 keV and k T = 0.93 keV. Unlike the vast majority of symbiotic stars detected in X-rays, the soft component of the spectrum seems to be absorbed only by interstellar material. The shock velocities corresponding to the observed temperatures are about 300 km/s and about 900 km/s. We did not find either periodic or aperiodic X-ray variability, with upper limits on the amplitudes of such variations being 46 % and 16 % (rms), respectively. We also did not find any ultraviolet variability with an rms amplitude of more than approximately 1 %. The derived velocities and the unabsorbed nature of the soft component of the X-ray spectrum suggest that some portion of the high energy emission could originate in shocks within a jet and beyond the symbiotic nebula. The lower velocity is consistent with the expansion velocity of the extended structure present in HST observations. The higher velocity could be associated with an internal shock at the base of the jet or with shocks in the accretion region.