Universität zu Köln

Potapov, A., Sanchez-Monge, A., Schilke, P., Graf, U. U., Moeller, Th. and Schlemmer, S. (2016). The CO-H-2 van der Waals complex and complex organic molecules in cold molecular clouds: A TMC-1C survey. Astron. Astrophys., 594. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746

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Abstract

Context. Almost 200 different species have been detected in the interstellar medium (ISM) during the last decades, revealing not only simple species but complex molecules with more than six atoms. Other exotic compounds, like the weakly-bound dimer (H-2)(2), have also been detected in astronomical sources like Jupiter. Aims. We aim to detect, for the first time, the CO-H-2 van der Waals complex in the ISM, which could be a sensitive indicator for low temperatures if detected. Methods. We used the IRAM 30 m telescope, located in Pico Veleta (Spain), to search for the CO-H-2 complex in a cold, dense core in TMC-1C (with a temperature of similar to 10 K). All the brightest CO-H-2 transitions in the 3 mm (80-110 GHz) band were observed with a spectral resolution of 0.5-0.7 km s(-1), reaching a rms noise level of similar to 2 mK. The simultaneous observation of a broad frequency band, 16 GHz, allowed us to conduct a serendipitous spectral line survey. Results. We did not detected any lines belonging to the CO-H2 complex. We set up a new, more stringent upper limit for its abundance to be [CO-H-2]/[CO] similar to 5 x 10(-6), while we expect the abundance of the complex to be in the range similar to 10(-8)-10(-3). The spectral line survey has allowed us to detect 75 lines associated with 41 different species (including isotopologues). We detect a number of complex organic species, for example methyl cyanide (CH3CN), methanol (CH3OH), propyne (CH3CCH), and ketene (CH2CO), associated with cold gas (excitation temperatures similar to 7 K), confirming the presence of these complex species not only in warm objects but also in cold regimes.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Potapov, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Sanchez-Monge, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schilke, P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Graf, U. U. UNSPECIFIED UNSPECIFIED UNSPECIFIED Moeller, Th. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schlemmer, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-258891
DOI:	10.1051/0004-6361/201628426
Journal or Publication Title:	Astron. Astrophys.
Volume:	594
Date:	2016
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 MASSIVE-STAR-FORMATION; WEAKLY-BOUND COMPLEX; SPECTRAL-LINE SURVEY; ROTATIONAL SPECTRUM; PRESTELLAR CORES; HOT CORE; SPECTROSCOPY; MILLIMETER; PHASE; DEUTERATION Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/25889