Molecular Abundances in CRL 618

Molecular Line Survey of Crl 618 from 80 to 276 Ghz and Complete Model

We present the complete data set, model and line identification of a survey of the emission from the C-rich protoplanetary nebula CRL 618 performed with the IRAM-30m telescope in the following frequency ranges: 80.25-115.75 GHz, 131.25-179.25 GHz, and 204.25-275.250 GHz. A selection of lines from different species has been used in previous works to derive the structure of the source, its physic...

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...

A SEARCH FOR ortho - BENZYNE ( o - C 6 H 4 ) IN CRL 618 Susanna

Polycyclic aromatic hydrocarbons (PAHs) have been proposed as potential carriers of the unidentified infrared bands (UIRs) and the diffuse interstellar bands (DIBs). PAHs are not likely to form by gas-phase or solid-state interstellar chemistry, but rather might be produced in the outflows of carbon-rich evolved stars. PAHs could form from acetylene addition to the phenyl radical (C6H5), which ...

The synthesis of benzene in the protoplanetary nebula CRL 618 Paul

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...