Evidence for weak maser action in interstellar cyanodiacetylene
1976; IOP Publishing; Volume: 209; Linguagem: Inglês
10.1086/182285
ISSN1538-4357
AutoresN. W. Broten, J. M. MacLeod, T. Oka, L. W. Avery, J. W. Brooks, R. X. McGee, L. M. Newton,
Tópico(s)Advanced Chemical Physics Studies
Resumoview Abstract Citations (32) References (9) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evidence for weak maser action in interstellar cyanodiacetylene. Broten, N. W. ; MacLeod, J. M. ; Oka, T. ; Avery, L. W. ; Brooks, J. W. ; McGee, R. X. ; Newton, L. M. Abstract The letter reports observations of the J = 1-0 and J = 8-7 rotational transitions of cyanodiacetylene (HC5N) at the respective frequencies of 2.663 GHz and 21.301 GHz in Sgr B2. A value of -4.12 + or 0.07 MHz for the HC5N quadrupole coupling constant is obtained from the resolved hyperfine splitting of the J = 1-0 transition. Assuming thermal equilibrium of the molecules at an excitation temperature of 30 K and an optical depth of much less than unity, a total column density of 1.5 by 10 to the 14th power per sq cm is computed for both the J = 8-7 transition and the previously observed J = 4-3 transition. An anomalously large intensity is found for the J = 1-0 transition in HC5N, suggesting maser action in this molecule. Additional theoretical evidence is cited in support of weak maser action in the J = 1-0 line of HC5N. Publication: The Astrophysical Journal Pub Date: November 1976 DOI: 10.1086/182285 Bibcode: 1976ApJ...209L.143B Keywords: Acetylene; Cyano Compounds; Interstellar Masers; Radio Astronomy; Interstellar Chemistry; Molecular Rotation; Thermodynamic Equilibrium; Astrophysics full text sources ADS |
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