Spectral observation of the composite supernova remnant G 29.7-0.3

Abstract

The X-ray properties of the supernova remnant G 29.7-0.3 are discussed based on spectral data from the EXOSAT satellite. In the 2 to 10 keV range a featureless power-law spectrum is obtained, the best-fit parameters being: energy spectral index α=-0.77, hydrogen column density on the line of sight N_H=2.3.10²² cm^-2. The incident X-ray flux from the source is (3.6±0.1) 10¹¹ erg cm^-2 s^-1 in the 2 to 10 keV range corresponding to an intrinsic luminosity of about 2. 10³⁶ erg s^-1 for a distance of 19 kpc. The source was not seen with the imaging instrument thus constraining the hydrogen column density to be N_H=(3.3 ±0.3) 10²² cm^-2 and the energy spectral index α=1.0±0.15. This new observation is consistent with emission by a synchroton nebula presumably fed by an active pulsar. An upper limit of ∼ 1.5% for the pulsed fraction in the range of periods 32ms to 10⁴ s has been obtained.