Molecular absorption lines toward the nucleus of Centaurus A

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169506· OSTI ID:6159288

Eckart, A; Cameron, M; Genzel, R; Jackson, J M; Rothermel, H ^[1]

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1. Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.)

Measurements of absorption in the lines of (C-12)O, (C-13)O, HCO(+), HCN, CN, and CS toward the nuclear continuum source in Centaurus A are reported. The spectra show a number of features which can be attributed to individual molecular clouds with properties similar to dense molecular clouds in the Galaxy. The deepest absorption at the systemic velocity of Cen A originates in quiescent molecular clouds that are cold, dense, and clumped, and happen to lie along the line of sight to the central compact continuum source. A (C-12)O fractional abundance is obtained which is in excellent agreement with typical values derived for the dense ISM in the Galaxy. For the central absorption feature, the (C-12)O and (C-13)O J = 2-1 to J = 1-0 line ratio and the limit on this ratio for CN indicate that the absorption occurs in very cold and/or subthermlly excited gas. 45 refs.

• OSTI ID: 6159288
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 365; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
ABUNDANCE
ACYL RADICALS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CONFIGURATION
COSMIC GASES
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
CYANIDES
CYANOGEN
ELEMENT ABUNDANCE
ELLIPTICAL CONFIGURATION
FLUIDS
FORMYL RADICALS
GALAXIES
GALAXY NUCLEI
GASES
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INTERSTELLAR SPACE
MOLECULES
OXIDES
OXYGEN COMPOUNDS
RADICALS
RADIO GALAXIES
SPACE
SPECTRA
SULFIDES
SULFUR COMPOUNDS