منابع مشابه
Properties of Proto–Planetary Nebulae
This review describes some general properites of proto-planetary nebulae with particular emphasis on the recent work of morpholgical studies. The weight of observational evidence shows that proto-planetary nebulae (PPNe) are most certainly axisymmetric like planetary nebulae. Recent work suggests two subclasses of PPNe optical morphology, DUst-Prominent Longitudinally-EXtended (DUPLEX) and Star...
متن کاملMolecules in bipolar proto - planetary nebulae ⋆
Two bipolar proto-planetary nebulae, IRAS16594-4656 and IRAS17150-3224, have been detected in various molecular lines, namely CO, 13CO, HCN and CN, and remain undetected in several other species. CO(J=2-1) and CO(J=3-2) line profiles are compared to new spectra of similar PPN candidates, previously undetected in CO(J=2-1): CPD-53◦5736, IRAS17106-3046, IRAS17245-3951 and IRAS17441-2411. CO(J=2-1...
متن کاملMolecular Line Observations of Proto-planetary Nebulae
We present our recent results on mm-wave CO observations of proto-planetary nebulae. These include high-resolution interferometric maps of various CO lines in three well known bipolar PPNe: M 1–92, M 2–56 and OH 231.8+4.2. The global properties of the high velocity molecular emission in post-AGB sources have been also studied, by means of high-sensitivity single dish observations of the J=1–0 a...
متن کاملHST NICMOS Observation of Proto-Planetary Nebulae
We report NICMOS wide-band and polarimetric observations of four proto-planetary nebulae. Molecular hydrogen emission is detected near the ends of the bipolar lobes of IRAS 17150-3224, which is evidence for the interaction of a fast, collimated outflow with the remnant of the asymptotic giant branch wind.
متن کاملJets and Tori in Proto-Planetary Nebulae
We investigate the time sequence for the appearance of jets and molecular tori in the transition of stars from the Asymptotic Giant Branch to the planetary nebula phase. Jets and tori are prominent features of this evolution, but their origins are uncertain. Using optical and millimeter line kinematics, we determine the ejection history in a sample of well-observed cases. We find that jets and ...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1978
ISSN: 0074-1809
DOI: 10.1017/s0074180900143220