Herschel/HIFI observations of high-JCO transitions in the protoplanetary nebula CRL 618

Physical conditions in the Protoplanetary Nebula CRL 618 derived from observations of vibrationally excited HC 3

We used the Effelsberg 100 m and IRAM 30 m telescopes to observe vibra-tionally excited cyanoacetylene (HC 3 N) in several rotational transitions toward the proto-planetary nebula CRL 618. Lines from 9 different vibrationally excited states with energies ranging up to 1600 K above ground were detected. The lines show P Cygni profiles indicating that the HC 3 N emission originates from an expand...

The synthesis of benzene in the protoplanetary nebula CRL 618 Paul

Spectroscopy of the protoplanetary nebula AFGL 618

We report on new optical spectroscopic observations of the protoplanetary nebula AFGL 618. Compared to older observations we find a change in some emission line ratios indicating dynamical evolutionary processes during the last few years. Possible reasons for this behaviour are discussed.

Detection of HCN Direct l - Type Transitions Probing Hot Molecular Gas in the Proto - Planetary Nebula CRL 618

We report the detection of direct ℓ-type transitions towards the proto-planetary nebula CRL 618 during a study of vibrationally excited carbon chains. ∆J = 0 transitions of HCN in its first excited bending mode v 2 = 1 were detected in absorption against the continuum of the central H ii region making use of the Effelsberg 100 m telescope and the Very Large Array. Additionally, the J = 9 direct...

0 Fe b 20 09 Collimated Fast Wind in the Pre - Planetary Nebula CRL 618

Collimated fast winds (CFWs) have been proposed to operate during the post-AGB evolutionary phase (and even earlier during the late AGB phase), responsible for the shaping of pre-planetary nebulae (PPNs) and young planetary nebulae (PNs). This paper is a follow-up to our previous study of CFW models for the well-studied PPN CRL 618. Previously, we compared our CFW models with optical observatio...