Hitomi-HXT deconvolution imaging of the Crab Nebula dazzled by the Crab pulsar

Abstract

We develop a new deconvolution method to improve the angular resolution of the Crab Nebula image taken by the Hitomi HXT. Here, we extend the Richardson-Lucy method by introducing two components for the nebula and the Crab pulsar with regularization for smoothness and flux, respectively, and deconvolving multi-pulse-phase images simultaneously. The deconvolved nebular image at the lowest energy band of 3.6--15 keV looks consistent with the Chandra X-ray image. Above 15 keV, we confirm that the NuSTAR's findings that the nebula size decreases in higher energy bands. We find that the north-east side of the nebula becomes dark in higher energy bands. Our deconvolution method can be applicable for any telescope images of faint diffuse objects containing a bright point source.

17 pages, 8 figures, This article has been accepted for publication in PASJ. Published by Oxford University Press. This is author's original version at the submission, containing some errors. Some figures are misaligned