DETECTIONS OF C{sub 2}H, CYCLIC-C{sub 3}H{sub 2}, AND H{sup 13}CN IN NGC 1068

Journal Article · Sun Feb 20 04:00:00 EST 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/728/2/L38· OSTI ID:21560479

Nakajima, T; Takano, S ^[1]; Kohno, K; Inoue, H ^[2]

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1. Nobeyama Radio Observatory, National Astronomical Observatory of Japan, 462-2 Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan)
2. Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)

We used the Nobeyama 45 m telescope to conduct a spectral line survey in the 3 mm band (85.1-98.4 GHz) toward one of the nearest galaxies with an active galactic nucleus (AGN), NGC 1068, and the prototypical starburst galaxy NGC 253. The beam size of this telescope is {approx} 18'', which was sufficient to spatially separate the nuclear molecular emission from the emission of the circumnuclear starburst region in NGC 1068. We detected rotational transitions of C{sub 2}H, cyclic-C{sub 3}H{sub 2}, and H{sup 13}CN in NGC 1068. These are detections of carbon-chain and carbon-ring molecules in NGC 1068. In addition, the C{sub 2}H N = 1-0 lines were detected in NGC 253. The column densities of C{sub 2}H were determined to be 3.4 x 10{sup 15} cm{sup -2} in NGC 1068 and 1.8 x 10{sup 15} cm{sup -2} in NGC 253. The column densities of cyclic-C{sub 3}H{sub 2} were determined to be 1.7 x 10{sup 13} cm{sup -2} in NGC 1068 and 4.4 x 10{sup 13} cm{sup -2} in NGC 253. We calculated the abundances of these molecules relative to CS for both NGC 1068 and NGC 253, and found that there were no significant differences in the abundances between the two galaxies. This result suggests that the basic carbon-containing molecules are either insusceptible to AGN or are tracing cold (T{sub rot} {approx} 10 K) molecular gas rather than X-ray irradiated hot gas.

• OSTI ID: 21560479
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 728; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CARBON
DETECTION
ELEMENTS
EMISSION
GALAXIES
GALAXY NUCLEI
MOLECULES
NONMETALS
TELESCOPES