An X-ray study of the Monoceros supernova remnant

Abstract

Twelve Einstein IPC exposures within the region of the Monoceros supernova remnant are combined into a 0.2−4 keV X-ray map with 80 arcsec resolution. The X-ray bright regions correlate well with the bright optical filaments. From the IPC pulse height spectra, the bright regions are found to have a 2−6 keV high-temperature component, while all regions show a fainter 0.2−0.3 keV temperature component. A model with the supernova shock wave expanding into a three-component interstellar medium with a low-density (0.003 cm⁻³) hot component can fit the observed properties of Monoceros. Preferred values for the distance and age are 1500 pc and 3×10⁴ yr. The overall observed expansion of 50 km s⁻¹ can be explained by outward moving clouds interior to the shock front.