Role of UV processing in the chemistry of hydrocarbons and carbon dust in Protoplanetary Nebulae

Christine Joblin¹, P. Pilleri¹, J. Cernicharo², A. Castro-Carrizo³, N. Cox¹, G. Quintana-Lacaci², K. Demyk¹, M. Agundez², C. Sánchez Contreras⁴, J. Goicoechea², I. Sakon⁵, T. Onaka⁵ & J.-A. Martín-Gago²

¹IRAP, Univ. Toulouse/CNRS, France
²ICMM, CSIC, Spain
³IRAM, France
⁴CAB, CSIC, Spain
⁵Dept Astronomy, University of Tokyo, Japan

We aim at characterizing the role of UV-processing into the mechanisms that lead to the formation of complex hydrocarbons and carbon dust in evolved stars. Our study focuses on the two carbon-rich protoplanetary nebulae, CRL 618 and CRL 2688, which are characterized by a different temperature, hence UV field, of the central star. Benzene is only seen in CRL 618 whereas only CRL 2688 shows emission from mixed aromatic/aliphatic carbon dust. A photodissociation region is known to be present in CRL 618, which could be associated with the dense torus at scales of 0.2 to ~1". We are gathering information at infrared and millimetre wavelengths and at high spatial resolution to characterize the local physical conditions as well as the distribution of chemical species in these two objects. We will present the status of this work including recent data obtained with ALMA. The new questions that will be opened on gas and dust chemistry will motivate laboratory studies that will be carried out in the framework of the ERC Synergy Nanocosmos project.

Last update: