Early results from ChanPLaNS: Mystery of hard X-ray emitting CSPNe†

Montez, Rodolfo; Kastner, J. H.; Balick, B.; Behar, E.; Blackman, E.; Bujarrabal, V.; Chu, Y.-H.; Corradi, R. L. M.; De Marco, O.; Frank, A.; Frew, D.; Guerrero, M.; Kwok, S.; Lopez, J. A.; Miszalski, B.; Nordhaus, J.; Parker, Q.; Sahai, R.; Sandin, C.; Schoenberner, D.; Soker, N.; Sokoloski, J.; Steffen, W.; Ueta, T.; Villaver, E.; Zijlstra, A.
Bibliographical reference

Planetary Nebulae: An Eye to the Future, Proceedings of the International Astronomical Union, IAU Symposium, Volume 283, p. 450-451

Advertised on:
8
2012
Number of authors
26
IAC number of authors
1
Citations
0
Refereed citations
0
Description
We are presently using the Chandra X-ray Observatory to conduct the first systematic X-ray survey of planetary nebulae (PNe) in the solar neighborhood. The Chandra Planetary Nebula Survey (ChanPlaNS) is a 570 ks Chandra Cycle 12 Large Program targeting 21 high-excitation PNe within ~1.5 kpc of Earth. When complete, this survey will provide a suite of new X-ray diagnostics that will inform the study of late stellar evolution, binary star astrophysics, and wind interactions. Among the early results of ChanPlaNS (when combined with archival Chandra data) is a surprisingly high detection rate of relatively hard X-ray emission from CSPNe. Specifically, X-ray point sources are clearly detected in roughly half of the ~30 high-excitation PNe observed thus far by Chandra, and all but one of these X-ray-emitting CSPNe display evidence for a hard (few MK) component in their Chandra spectra. Only the central star of the Dumbbell appears to display ``pure'' hot blackbody emission from a ~200 kK hot white dwarf photosphere in the X-ray band. Potential explanations for the``excess'' hard X-ray emission detected from the other CSPNe include late-type companions (heretofore undetected, in most cases) whose coronae have been rejuvenated by recent interactions with the mass-losing WD progenitor, non-LTE effects in hot white dwarf photospheres, self-shocking variable winds from the central star, and slow (re-)accretion of previously ejected red giant envelope mass.