Detection of interstellar methylcyanoacetylene

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/184181· OSTI ID:5019699

Broten, N W; MacLeod, J M; Avery, L W; Irvine, W M; Hoeglund, B; Friberg, P; Hjalmarson,

A new interstellar molecule, methylcyanoacetylene (CH/sub 3/C/sub 3/N), has been detected in the molecular cloud TMC-1. The J = 8 ..-->.. 7, J = 7 ..-->.. 6, J = 6 ..-->.. 5, and J = 5 ..-->.. 4 transitions have been observed. For the first three of these, both the K = 0 and K = 1 components are present, while for J = 5 ..-->.. 4, only the K = 0 line has been detected. The observed frequencies were calculated by assuming a value of radial velocity V/sub lSR/ = 5.8 km s/sup -1/ for TMC-1, typical of other molecules in the cloud. All Observed frequencies are within 10 kHz of the calculated frequencies, which are based on the 1982 laboratory constants of Moises et al., so the identification is secure. The lines are broadened by hyperfine splitting, and the J = 5 ..-->.. 4, K = 0 transition shows incipient resolution into three hyperfine components. The rotational temperature determined from these observations is quite low, with 2.7 K< or =T/sub rot/< or =4 K. The total column density is approximately 5 x 10/sup 12/ cm/sup -2/.

• Research Organization: Herzberg Institute of Astrophysics, National Research Council of Canada
• OSTI ID: 5019699
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 276:1; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
HYDROCARBONS
INTERSTELLAR GRAINS
LINE BROADENING
ORGANIC COMPOUNDS
PARTICLES
RADIAL VELOCITY
ROTATIONAL STATES
SPECTRA
VELOCITY