Tentative insight into the multiplicity of the persistent dust maker WR106 from X-ray observations

TL;DR

This study reports the first X-ray observation of WR106, a dust-producing Wolf-Rayet star, finding no X-ray emission and highlighting the need for multi-method approaches to understand the star's potential binary nature.

Contribution

It provides the first dedicated X-ray analysis of WR106 and discusses the implications of non-detection for understanding dust formation and star multiplicity.

Findings

No X-ray emission detected from WR106.

Upper limits on X-ray flux established.

Persistent dust makers are under-investigated in X-ray astronomy.

Abstract

This paper presents the results of the analysis of the very first dedicated X-ray observation with XMM-Newton of WR106. This carbon-rich WC9d Wolf-Rayet star belongs to the category of persistent dust makers (WCd stars). The issue of the multiplicity of these dust makers is pivotal to understand the dust formation process, and in this context X-ray observations may allow to reveal an X-ray emission attributable to colliding-winds in a binary system. The main result of this analysis is the lack of detection of X-rays coming from WR106. Upper limits on the X-ray flux are estimated, but the derived numbers are not sufficient to provide compelling constraints on the existence or not of a colliding-wind region. Detailed inspection of archive data bases reveals that persistent dust makers have been poorly investigated by the most sensitive X-ray observatories. Certainly, the combination of several approaches to indirectly constrain their multiplicity should be applied to lift a part of the veil on the nature of these persistent dust makers.