Discovery of Radial Spectral Hardening in the Hot Bubble of Planetary Nebula BD+30 3639 with Median Energy Imaging [SSA]

http://arxiv.org/abs/2305.04948


We introduce a new imaging analysis technique to study the spatial distribution of the X-ray emission from the hot bubble of planetary nebula BD+30 3639. Hot bubble emission is typically photon-starved, thus limiting the methods for spatial-spectral analysis, however, this new technique uses the statistics of photon energies across the nebula to identify spatial variations. Using the median energy value of the X-ray photons, we identified a rise in median energy values towards the projected edge of the nebula, which we refer to as radial spectral hardening. We explored the origin of this radial spectral hardening with X-ray spectral analysis of distinct regions of high- and low-median energy values. Given that the hot bubble is embedded within a young, dense, planetary nebula, we argue that the radial spectral hardening is due to an increased column density at the projected nebular edge. Median energy imaging provides a promising new methodology for exploring the spatial variations in faint extended X-ray sources.

Read this paper on arXiv…

R. Jr
Wed, 10 May 23
55/65

Comments: 10 pages, 6 figures, and one potentially embarrassing last minute revision. Submitted to ApJ