Journal Article

Interstellar C<sub>2</sub> in the Perseus molecular complex: excitation temperature and density of a molecular cloud with anomalous microwave emission

Susana Iglesias-Groth

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 411, issue 3, pages 1857-1862
Published in print March 2011 | ISSN: 0035-8711
Published online February 2011 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2010.17807.x
Interstellar C2 in the Perseus molecular complex: excitation temperature and density of a molecular cloud with anomalous microwave emission

Show Summary Details

Preview

Interstellar absorption lines up to J″= 10 in the (2, 0) band and up to J″= 6 in the (3, 0) band of the C2 A1ΠuX1Σ+g system are detected toward star Cernis 52 (BD +31°640) in the Perseus molecular complex. The star lies in a reddened line of sight where various experiments have detected anomalous microwave emission spatially correlated with dust thermal emission. The inferred total C2 column density of N(C2) = (10.5 ± 0.2) × 1013 cm−2 is well correlated with that of CH, as expected from theoretical models, and is among the highest reported for translucent clouds with similar extinction. The observed rotational C2 lines constrain the gas kinetic temperature T and the density n=n(H) +n(H2) of the intervening cloud to T= 40 ± 10 K and n= 250 ± 50 cm−3, respectively. This is the first determination of the gas kinetic temperature and particle density of a cloud with known anomalous microwave emission.

Keywords: ISM: abundances; ISM: clouds; ISM: lines and bands; ISM: molecules

Journal Article.  4814 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.