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Planetary Nebulae Research: Past, Present, and Future
被引:1
|作者:
Kwok, Sun
[1
,2
]
机构:
[1] Univ British Columbia, Dept Earth Ocean & Atmospher Sci, Vancouver, BC V6T 1Z4, Canada
[2] Univ Hong Kong, Fac Sci, Lab Space Res, Hong Kong, Peoples R China
来源:
基金:
加拿大自然科学与工程研究理事会;
关键词:
planetary nebulae;
stellar evolution;
asymptotic giant branch stars;
stellar winds;
mass loss;
nucleosynthesis;
molecules;
cataclysmic variables;
novae;
symbiotic stars;
STELLAR WIND PALEONTOLOGY;
TELESCOPE SNAPSHOT SURVEY;
MULTIPLE COAXIAL RINGS;
BIPOLAR NEBULA;
CENTRAL STARS;
PROTOPLANETARY NEBULAE;
HYDRODYNAMICAL MODELS;
RADIATION-GASDYNAMICS;
IONIZATION STRUCTURE;
OPTICAL THICKNESSES;
D O I:
10.3390/galaxies12040039
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
We review the evolution of our understanding of the planetary nebulae phenomenon and their place in the scheme of stellar evolution. The historical steps leading to our current understanding of central star evolution and nebular formation are discussed. Recent optical imaging, X-ray, ultraviolet, infrared, millimeter wave, and radio observations have led to a much more complex picture of the structure of planetary nebulae. The optically bright regions have multiple shell structures (rims, shells, crowns, and haloes), which can be understood within the interacting winds framework. However, the physical mechanism responsible for bipolar and multipolar structures that emerged during the proto-planetary nebulae phase is yet to be identified. Our morphological classifications of planetary nebulae are hampered by the effects of sensitivity, orientation, and field-of-view coverage, and the fraction of bipolar or multipolar nebulae may be much higher than commonly assumed. The optically bright bipolar lobes may represent low-density, ionization-bounded cavities carved out of a neutral envelope by collimated fast winds. Planetary nebulae are sites of active synthesis of complex organic compounds, suggesting that planetary nebulae play a major role in the chemical enrichment of the Galaxy. Possible avenues of future advancement are discussed.
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页数:19
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