Abstract
We present results from the most recent set of observations obtained as part
of the Chandra X-ray observatory Planetary Nebula Survey (ChanPlaNS), the first
comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood
(i.e., within \~1.5 kpc of the Sun). The survey is designed to place constraints
on the frequency of appearance and range of X-ray spectral characteristics of
X-ray-emitting PN central stars and the evolutionary timescales of
wind-shock-heated bubbles within PNe. ChanPlaNS began with a combined Cycle 12
and archive Chandra survey of 35 PNe. ChanPlaNS continued via a Chandra Cycle
14 Large Program which targeted all (24) remaining known compact (R\_neb <\~ 0.4
pc), young PNe that lie within \~1.5 kpc. Results from these Cycle 14
observations include first-time X-ray detections of hot bubbles within NGC
1501, 3918, 6153, and 6369, and point sources in HbDs 1, NGC 6337, and Sp 1.
The addition of the Cycle 14 results brings the overall ChanPlaNS diffuse X-ray
detection rate to \~27\% and the point source detection rate to \~36\%. It has
become clearer that diffuse X-ray emission is associated with young (<\~5x10^3
yr), and likewise compact (R\_neb<\~0.15 pc), PNe with closed structures and high
central electron densities (n\_e>\~1000 cm^-3), and rarely associated with PNe
that show H\_2 emission and/or pronounced butterfly structures. Hb 5 is one such
exception of a PN with a butterfly structure that hosts diffuse X-ray emission.
Additionally, of the five new diffuse X-ray detections, two host WR-type
CSPNe, NGC 1501 and NGC 6369, supporting the hypothesis that PNe with central
stars of WR-type are likely to display diffuse X-ray emission.
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