INFERRING THE TEMPERATURE AND DENSITY OF DIFFUSE INTERSTELLAR CLOUDS FROM C3 OBSERVATIONS

Koeppen, Nicole

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https://hdl.handle.net/2142/79478 Copy

Description

Title

INFERRING THE TEMPERATURE AND DENSITY OF DIFFUSE INTERSTELLAR CLOUDS FROM C3 OBSERVATIONS

Author(s)

Koeppen, Nicole

Contributor(s)

McCall, Benjamin J.

Issue Date

24-Jun-15

Keyword(s)

Astronomy

Abstract

Observations of carbon chain molecules are useful in determining the number densities and temperatures of diffuse interstellar clouds. In 2003, C$_{3}$ was observed towards ten different sightlines and the rotational distributions were determined using the oscillator strengths available at that time.footnote{Adamkovics et al. Ap.J., 595, 235 (2003)} The population of each rotational level was adjusted individually in order to obtain the best fit for all of the P, Q, and R branch lines. This past year, the effect of perturbing states on the C$_3$ spectrum was elucidated, and improved oscillator strengths determined.footnote{Schmidt et al. MNRAS, 441, 1134 (2014)} With these new values, we have redetermined the rotational distribution of C$_{3}$ in these ten sightlines, and used a rotational excitation model analogous to that of Roueff et al.footnote{Roueff et al. A&A, 384, 629 (2002)} and collisional cross sections from Smith et al.footnote{Smith et al. J. Phys. Chem. A, 118, 6351 (2014)} to infer the kinetic temperatures and number densities.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79478

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