Bibcode
Freeman, M.; Montez, R., Jr.; Kastner, J. H.; Balick, B.; Frew, D. J.; Jones, D.; Miszalski, B.; Sahai, R.; Blackman, E.; Chu, Y.-H.; De Marco, O.; Frank, A.; Guerrero, M. A.; Lopez, J. A.; Zijlstra, A.; Bujarrabal, V.; Corradi, R. L. M.; Nordhaus, J.; Parker, Q. A.; Sandin, C.; Schönberner, D.; Soker, N.; Sokoloski, J. L.; Steffen, M.; Toalá, J. A.; Ueta, T.; Villaver, E.
Referencia bibliográfica
The Astrophysical Journal, Volume 794, Issue 2, article id. 99, 13 pp. (2014).
Fecha de publicación:
10
2014
Revista
Número de citas
51
Número de citas referidas
40
Descripción
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 (lsim 5 ×
103 yr), and likewise compact (R neb <~ 0.15
pc), PNe with closed structures and high central electron densities
(ne >~ 1000 cm-3), and is rarely
associated with PNe that show H2 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, two
of the five new diffuse X-ray detections (NGC 1501 and NGC 6369) host
[WR]-type central stars, supporting the hypothesis that PNe with central
stars of [WR]-type are likely to display diffuse X-ray emission.
Proyectos relacionados
Nebulosas Bipolares
Nuestro proyecto persigue tres objetivos principales: 1) Determinar las condiciones físico-químicas de las nebulosas planetarias con geometría bipolar y de las nebulosas alrededor de estrellas simbióticas. El fin es entender el origen de la bipolaridad y poner a prueba los modelos teóricos que intentan explicar la morfología y la cinemática nebular
Antonio
Mampaso Recio