Hard Extended X-ray Source in the IC 443 SNR Resolved by Chandra: A Fast Ejecta Fragment or a New Pulsar Wind Nebula?

Abstract

A Chandra observation of the isolated hard X-ray source XMMU J061804.3+222732, located in the region of apparent interaction of the supernova remnant IC 443 with a molecular cloud, resolved the complex structure of the source in a few bright clumps embedded in an extended emission of a ~ 30 arcsec size. The X-ray spectra of the clumps and the extended emission are dominated by a hard power-law component with a photon index of 1.2--1.4. In addition, we see some indications of an optically thin thermal plasma of a ~ 0.3 keV temperature. The observed X-ray morphology and spectra are consistent with those expected for an isolated supernova ejecta fragment interacting with a dense ambient medium. A possible alternative interpretation is a pulsar wind nebula associated with either IC 443 or another SNR, G189.6+3.3.

Accepted for publication in The Astrophysical Journal Letters High resolution Images of Fig.1 are appended

References in corpus (1)

• Faint Hard X-ray Sources in the Galactic Center Region: Supernova Ejecta Fragments Population

Cited by in corpus (9)

• Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope
• XMM-Newton observations of the supernova remnant IC 443: II. evidence of stellar ejecta in the inner regions
• MAGIC J0616+225 as delayed TeV emission of cosmic-rays diffusing from SNR IC 443
• Isolated X-ray -- infrared sources in the region of interaction of the supernova remnant IC 443 with a molecular cloud
• A population of isolated hard X-ray sources near the supernova remnant Kes 69
• NuSTAR Detection of a Hard X-ray Source in the Supernova Remnant - Molecular Cloud Interaction Site of IC 443
• NuSTAR Hard X-ray Observation of the Gamma-ray Binary Candidate HESS J1832-093
• Chandra X-Ray Observatory Observations of Neutron Stars: An Overview
• Six Years of Chandra Observations of Supernova Remnants