Universität zu Köln

Carlhoff, P., Luong, Q. Nguyen, Schilke, P., Motte, F., Schneider, N., Beuther, H., Bontemps, S., Heitsch, F., Hill, T., Kramer, C., Ossenkopf, V., Schuller, F., Simon, R. and Wyrowski, F. (2013). Large scale IRAM30 m CO-observations in the giant molecular cloud complex W43. Astron. Astrophys., 560. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746

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Abstract

We aim to fully describe the distribution and location of dense molecular clouds in the giant molecular cloud complex W43. It was previously identified as one of the most massive star-forming regions in our Galaxy. To trace the moderately dense molecular clouds in the W43 region, we initiated W43-HERO, a large program using the IRAM 30 m telescope, which covers a wide dynamic range of scales from 0.3 to 140 pc. We obtained on-the-fly-maps in (CO)-C-13 (2-1) and (CO)-O-18 (2-1) with a high spectral resolution of 0.1 km s(-1) and a spatial resolution of 12 ''. These maps cover an area of similar to 1.5 square degrees and include the two main clouds of W43 and the lower density gas surrounding them. A comparison to Galactic models and previous distance calculations confirms the location of W43 near the tangential point of the Scutum arm at approximately 6 kpc from the Sun. The resulting intensity cubes of the observed region are separated into subcubes, which are centered on single clouds and then analyzed in detail. The optical depth, excitation temperature, and H-2 column density maps are derived out of the (CO)-C-13 and (CO)-O-18 data. These results are then compared to those derived from Herschel dust maps. The mass of a typical cloud is several 10(4) M-circle dot while the total mass in the dense molecular gas (>10(2) cm(-3)) in W43 is found to be similar to 1.9x10(6) M-circle dot. Probability distribution functions obtained from column density maps derived from molecular line data and Herschel imaging show a log-normal distribution for low column densities and a power-law tail for high densities. A flatter slope for the molecular line data probability distribution function may imply that those selectively show the gravitationally collapsing gas.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Carlhoff, P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Luong, Q. Nguyen UNSPECIFIED UNSPECIFIED UNSPECIFIED Schilke, P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Motte, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schneider, N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Beuther, H. UNSPECIFIED UNSPECIFIED UNSPECIFIED Bontemps, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Heitsch, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hill, T. UNSPECIFIED UNSPECIFIED UNSPECIFIED Kramer, C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Ossenkopf, V. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schuller, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Simon, R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wyrowski, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-470524
DOI:	10.1051/0004-6361/201321592
Journal or Publication Title:	Astron. Astrophys.
Volume:	560
Date:	2013
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 STAR-FORMATION; GALACTIC PLANE; MILKY-WAY; HI-GAL; PROBABILITY-DISTRIBUTION; MASSIVE PROTOSTARS; COLUMN DENSITY; REGION; ABUNDANCES; RESOLUTION Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/47052