Infrared and X-ray Emission of PWN G21.5-0.9
Abstract
The broadband emission from pulsar wind nebula (PWN) provides important insight into the birth properties of neutron stars, their progenitor core-collapse supernovae, and the mechanism by which they accelerate leptons to extreme energies. We present a reanalysis of the archival infrared (Spitzer) and X-ray spectral data (Chandra, NuSTAR, Hitomi) of PWN G21.5-0.9. Spectra obtained by the two detectors onboard NuSTAR (FPMA and FPMB) are fit separately to account for their difference. In addition, when fitting the wide-band X-ray spectra from NuSTAR (3 - 45 keV) and Hitomi (0.8 - 80 keV), we fit a piecewise power law model over separate energy ranges instead of a single broken power law over the entire energy range. We believe the piecewise power law fit over separate energy ranges captures the features of the smoothly curving spectra better than the broken power law. While the results show clear spectral steepening for higher energy bands in both NuSTAR and Hitomi spectra, the extent of the change in the photon index differs between the instruments. We also found that when comparing the power law fit parameters in the overlapping energy range (3 - 8 keV) between Chandra, NuSTAR, and Hitomi, the photon index for NuSTAR and Hitomi was higher than that of Chandra. With these new fit parameters we present the preliminary results of modeling the PWN with a one-zone model that takes into account the radiative and dynamical emission of the system.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23526306H