Universität zu Köln

Coutens, A., Ligterink, N. F. W., Loison, J-C, Wakelam, V, Calcutt, H., Drozdovskaya, M. N., Jorgensen, J. K., Mueller, H. S. P., van Dishoeck, E. F. and Wampfler, S. F. (2019). The ALMA-PILS survey: First detection of nitrous acid (HONO) in the interstellar medium. Astron. Astrophys., 623. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746

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Abstract

Nitrogen oxides are thought to play a significant role as a nitrogen reservoir and to potentially participate in the formation of more complex species. Until now, only NO, N2O, and HNO have been detected in the interstellar medium. We report the first interstellar detection of nitrous acid (HONO). Twelve lines were identified towards component B of the low-mass protostellar binary IRAS 16293-2422 with the Atacama Large Millimeter/submillimeter Array, at the position where NO and N2O have previously been seen. A local thermodynamic equilibrium model was used to derive the column density (similar to 9 x 10(14) cm(2) in a 0.'' 5 beam) and excitation temperature (similar to 100 K) of this molecule. HNO, NO2, NO+, and HNO3 were also searched for in the data, but not detected. We simulated the HONO formation using an updated version of the chemical code Nautilus and compared the results with the observations. The chemical model is able to reproduce satisfactorily the HONO, N2O, and NO2 abundances, but not the NO, HNO, and NH2OH abundances. This could be due to some thermal desorption mechanisms being destructive and therefore limiting the amount of HNO and NH2OH present in the gas phase. Other options are UV photodestruction of these species in ices or missing reactions potentially relevant at protostellar temperatures.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Coutens, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Ligterink, N. F. W. UNSPECIFIED UNSPECIFIED UNSPECIFIED Loison, J-C UNSPECIFIED UNSPECIFIED UNSPECIFIED Wakelam, V UNSPECIFIED UNSPECIFIED UNSPECIFIED Calcutt, H. UNSPECIFIED UNSPECIFIED UNSPECIFIED Drozdovskaya, M. N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Jorgensen, J. K. UNSPECIFIED UNSPECIFIED UNSPECIFIED Mueller, H. S. P. UNSPECIFIED UNSPECIFIED UNSPECIFIED van Dishoeck, E. F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wampfler, S. F. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-153415
DOI:	10.1051/0004-6361/201935040
Journal or Publication Title:	Astron. Astrophys.
Volume:	623
Date:	2019
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 DISSOCIATIVE RECOMBINATION; ROVIBRATIONAL PARAMETERS; MOLECULAR-SPECTROSCOPY; RATE COEFFICIENTS; COLOGNE DATABASE; STAR-FORMATION; RATE CONSTANTS; NITRIC-OXIDE; AB-INITIO; HNO Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/15341