Universität zu Köln

Manigand, S., Coutens, A., Loison, J. -C., Wakelam, V., Calcutt, H., Mueller, H. S. P., Jorgensen, J. K., Taquet, V., Wampfler, S. F., Bourke, T. L., Kulterer, B. M., van Dishoeck, E. F., Drozdovskaya, M. N. and Ligterink, N. F. W. (2021). The ALMA-PILS survey: first detection of the unsaturated 3-carbon molecules Propenal (C2H3CHO) and Propylene (C3H6) towards IRAS 16293-2422 B. Astron. Astrophys., 645. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746

Full text not available from this repository.

Abstract

Context. Complex organic molecules with three carbon atoms are found in the earliest stages of star formation. In particular, propenal (C2H3CHO) is a species of interest due to its implication in the formation of more complex species and even biotic molecules. Aims. This study aims to search for the presence of C2H3CHO and other three-carbon species such as propylene (C3H6) in the hot corino region of the low-mass protostellar binary IRAS 16293-2422 to understand their formation pathways. Methods. We use ALMA observations in Band 6 and 7 from various surveys to search for the presence of C3H6 and C2H3CHO towards the protostar IRAS 16293-2422 B (IRAS 16293B). The identification of the species and the estimates of the column densities and excitation temperatures are carried out by modeling the observed spectrum under the assumption of local thermodynamical equilibrium. Results. We report the detection of both C3H6 and C2H3CHO towards IRAS 16293B, however, no unblended lines were found towards the other component of the binary system, IRAS 16293A. We derive column density upper limits for C3H8, HCCCHO, n-C3H7OH, i-C3H7OH, C3O, and cis-HC(O)CHO towards IRAS 16293B. We then use a three-phase chemical model to simulate the formation of these species in a typical prestellar environment followed by its hydrodynamical collapse until the birth of the central protostar. Different formation paths, such as successive hydrogenation and radical-radical additions on grain surfaces, are tested and compared to the observational results in a number of different simulations, to assess which are the dominant formation mechanisms in the most embedded region of the protostar. Conclusions. The simulations reproduce the abundances within one order of magnitude from those observed towards IRAS 16293B, with the best agreement found for a rate of 10(-12) cm(3) s(-1) for the gas-phase reaction C-3 + O -> C-2 + CO. Successive hydrogenations of C-3, HC(O)CHO, and CH3OCHO on grain surfaces are a major and crucial formation route of complex organics molecules, whereas both successive hydrogenation pathways and radical-radical addition reactions contribute to the formation of C2H5CHO.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Manigand, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Coutens, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Loison, J. -C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wakelam, V. UNSPECIFIED UNSPECIFIED UNSPECIFIED Calcutt, H. UNSPECIFIED UNSPECIFIED UNSPECIFIED Mueller, H. S. P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Jorgensen, J. K. UNSPECIFIED UNSPECIFIED UNSPECIFIED Taquet, V. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wampfler, S. F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Bourke, T. L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Kulterer, B. M. UNSPECIFIED UNSPECIFIED UNSPECIFIED van Dishoeck, E. F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Drozdovskaya, M. N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Ligterink, N. F. W. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-601049
DOI:	10.1051/0004-6361/202038113
Journal or Publication Title:	Astron. Astrophys.
Volume:	645
Date:	2021
Publisher:	EDP SCIENCES S A
Place of Publication:	LES ULIS CEDEX A
ISSN:	1432-0746
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language SUBMILLIMETER-WAVE SPECTRUM; MILLIMETER-WAVE; MICROWAVE-SPECTRUM; INTERNAL-ROTATION; ETHYLENE-GLYCOL; GROUND-STATE; INTERSTELLAR CHEMISTRY; POTENTIAL FUNCTION; ORGANIC-MOLECULES; COLOGNE DATABASE Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/60104