A population of isolated hard X-ray sources near the supernova remnant Kes 69

TL;DR

This study reports the detection of 18 hard X-ray sources near supernova remnant Kes 69, potentially linked to ejecta fragments or cataclysmic variables, indicating complex interactions in the remnant environment.

Contribution

First deep XMM-Newton observation of Kes 69 revealing a population of hard X-ray sources associated with the remnant's molecular cloud interaction.

Findings

18 hard X-ray sources detected in Kes 69 field

Significant excess of sources correlated with CO emission

Spectral analysis suggests ejecta fragments or cataclysmic variables

Abstract

Recent X-ray observations of the supernova remnant IC443 interacting with molecular clouds have shown the presence of a new population of hard X-ray sources related to the remnant itself, which has been interpreted in terms of fast ejecta fragment propagating inside the dense environment. Prompted by these studies, we have obtained a deep {\sl XMM-Newton} observation of the supernova remnant (SNR) Kes 69, which also shows signs of shock-cloud interaction. We report on the detection of 18 hard X-ray sources in the field of Kes 69, a significant excess of the expected galactic source population in the field, spatially correlated with CO emission from the cloud in the remnant environment. The spectra of 3 of the 18 sources can be described as hard power laws with photon index <2 plus line emission associated to K-shell transitions. We discuss the two most promising scenarios for the interpretation of the sources, namely fast ejecta fragments (as in IC443) and cataclysmic variables. While most of the observational evidences are consistent with the former interpretation, we cannot rule out the latter.