Discovery of a Candidate Central Compact Object in the Galactic Nonthermal SNR G330.2+1.0

Abstract

We report on the discovery of a pointlike source (CXOU J160103.1$-$513353) at the center of a Galactic supernova remnant (SNR) G330.2+1.0 with {\it Chandra X-Ray Observatory}. The X-ray spectrum fits a black-body (BB) model with $kT$ $\sim$ 0.49 keV, implying a small emission region of $R$ $\sim$ 0.4 km at the distance of 5 kpc. The estimated X-ray luminosity is $L_X$ $\sim$ 1 $\times$ 10$^{33}$ ergs s$^{-1}$ in the 1 $-$ 10 keV band. A power law model may also fit the observed spectrum, but the fit results in a very large photon index, $Γ$ $\sim$ 5. We find no counterparts at other wavelengths. The X-ray emission was steady over the $\sim$13 hr observation period, showing no variability. While we find marginal evidence for X-ray pulsations ($P$ $\approx$ 7.5 s), the presence of a pulsar at the position of this object is not conclusive with the current data, requiring an independent confirmation. These results are generally consistent with an interpretation of this object as a Central Compact Object associated with SNR G330.2+1.0.