Exploring the Central Compact Object in the RX J0852.0-4622 Supernova Remnant with XMM-Newton

TL;DR

This study analyzes XMM-Newton observations of the central compact object in SNR RX J0852.0-4622, supporting its identification as a neutron star with hot polar regions, but finds no pulsations or spectral lines.

Contribution

It provides new X-ray spectral analysis and constraints on the properties of the neutron star candidate in RX J0852.0-4622, clarifying its emission characteristics and ruling out previous spectral line claims.

Findings

No pulsations detected down to a 3-sigma upper limit.

Spectrum best described by double blackbody or blackbody plus power law.

No X-ray emission lines, including previously claimed features.

Abstract

The properties of the presumably young galactic supernova remnant (SNR) RX J0852.0-4622, discovered by ROSAT, are still uncertain. The data concerning the distance to the SNR, its age, and the presence of a compact remnant remain controversial. We report the results of several XMM-Newton observations of CXOU J085201.4-461753, the central compact source in RX J0852.0-4622. The currently prefered interpretation of CXOU J085201.4-461753 being a neutron star is in line with our analysis. The Chandra candidate pulsation periods are not confirmed; actually no period was found down to a 3-sigma upper limit for any pulsed fraction. The spectrum of CXOU J085201.4-461753 is best described by either a two blackbody spectrum or a single blackbody spectrum with a high energy power law tail. The two blackbody temperatures of 4 MK and 6.6 MK along with the small size of the emitting regions with radii of 0.36 and 0.06 km invalidate the interpretation that the thermal radiation is cooling emission from the entire neutron star surface. The double blackbody model suggests emission from the neutron star's hot polar regions. No X-ray lines, including the emission feature previously claimed to be present in Chandra data, were found.