Chandra View of DA 530: A Sub-Energetic Supernova Remnant with a Pulsar Wind Nebula?

TL;DR

This study uses Chandra X-ray observations to identify a potential pulsar wind nebula and analyze the thermal emission of the supernova remnant DA 530, revealing its low-energy explosion origin and possible core-collapse progenitor.

Contribution

First detection of a pulsar wind nebula candidate in DA 530 and detailed spectral analysis indicating a low-energy supernova origin.

Findings

Identification of an extended X-ray feature likely representing a pulsar wind nebula.

Spectral analysis shows thermal plasma with low temperature and high Si over-abundance.

Remnant likely resulted from a low-energy core-collapse supernova with a progenitor of 8-12 solar masses.

Abstract

Based on a Chandra ACIS observation, we report the detection of an extended X-ray feature close to the center of the remnant DA 530 with 5.3 sigma above the background within a circle of 20'' radius. This feature, characterized by a power-law with the photon index gamma=1.6+-0.8 and spatially coinciding with a nonthermal radiosource, most likely represents a pulsar wind nebula. We have further examined the spectrum of the diffuse X-ray emission from the remnant interior with a background-subtracted count rate of ~0.06 counts s^-1 in 0.3-3.5 keV. The spectrum of the emission can be described by a thermal plasma with a temperature of ~0.3-0.6 keV and a Si over-abundance of >~7 solar. These spectral characteristics, together with the extremely low X-ray luminosity, suggest that the remnant arises from a supernova with an anomalously low mechanical energy (<10^50 ergs). The centrally-filled thermal X-ray emission of the remnant may indicate an early thermalization of the SN ejecta by the circum-stellar medium. Our results suggest that the remnant is likely the product of a core-collapsed SN with a progenitor mass of 8-12 Msun. Similar remnants are probably common in the Galaxy, but have rarely been studied.