Study of a new central compact object: The neutron star in the supernova remnant G15.9+0.2

TL;DR

This study analyzes the X-ray emission of a central compact object in supernova remnant G15.9+0.2, confirming it as a young, low-magnetized neutron star with spectral modeling supporting a carbon atmosphere consistent with Galactic distance.

Contribution

First detailed spectral analysis of the neutron star in G15.9+0.2 supporting its classification as a CCO with atmosphere models aligning with Galactic distance.

Findings

Supports the neutron star as a thermally emitting CCO.

Carbon atmosphere models fit the data with a Galactic distance.

Similar to other known CCOs like Cas A and HESS J1731-347.

Abstract

We present our study of the central point source CXOU J181852.0-150213 in the young Galactic supernova remnant (SNR) G15.9+0.2 based on the recent ~90 ks Chandra observations. The point source was discovered in 2005 in shorter Chandra observations and was hypothesized to be a neutron star associated with the SNR. Our X-ray spectral analysis strongly supports the hypothesis of a thermally emitting neutron star associated with G15.9+0.2. We conclude that the object belongs to the class of young cooling low-magnetized neutron stars referred to as central compact objects (CCOs). We modeled the spectrum of the neutron star with a blackbody spectral function and with our hydrogen and carbon neutron star atmosphere models, assuming that the radiation is uniformly emitted by the entire stellar surface. Under this assumption, only the carbon atmosphere models yield a distance that is compatible with a source located in the Galaxy. In this respect, CXOU J181852.0-150213 is similar to two other well-studied CCOs, the neutron stars in Cas A and in HESS J1731-347, for which carbon atmosphere models were used to reconcile their emission with the known or estimated distances.