ALMA view of the C-12/C-13 isotopic ratio in starburst galaxies
Journal article, 2019
We derive molecular-gas-phase C-12/C-13 isotope ratios for the central few hundred parsecs of the three nearby starburst galaxies NGC 253, NGC 1068, and NGC 4945 making use of the lambda similar to 3 mm (CN)-C-12 and (CNN)-C-13= 1-0 lines in the ALMA Band 3. The C-12/C-13 isotopic ratios derived from the ratios of these lines range from 30 to 67 with an average of 41.6 +/- 0.2 in NGC 253, from 24 to 62 with an average of 38.3 +/- 0.4 in NGC 1068, and from 6 to 44 with an average of 16.9 +/- 0.3 in NGC 4945. The highest C-12/C-13 isotopic ratios are determined in some of the outskirts of the nuclear regions of the three starburst galaxies. The lowest ratios are associated with the northeastern and southwestern molecular peaks of NGC 253, the northeastern and southwestern edge of the mapped region in NGC 1068, and the very center of NGC 4945. In the case of NGC 1068, the measured ratios suggest inflow from the outer part of NGC 1068 into the circum-nuclear disk through both the halo and the bar. Low C-12/C-13 isotopic ratios in the central regions of these starburst galaxies indicate the presence of highly processed material.
galaxies: nuclei
galaxies: ISM
radio lines: ISM
galaxies: abundances
galaxies: starburst
Author
X. D. Tang
Max Planck Society
Chinese Academy of Sciences
C. Henkel
Chinese Academy of Sciences
King Abdulaziz University
Max Planck Society
K. M. Menten
Max Planck Society
Y. Gong
Max Planck Society
S. Martin
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
S. Muehle
University of Bonn
Susanne Aalto
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Sebastien Muller
Chalmers, Space, Earth and Environment, Onsala Space Observatory
S. Garcia-Burillo
OAN IGN
S. Levshakov
Russian Academy of Sciences
R. Aladro
Max Planck Society
M. Spaans
University of Groningen
S. Viti
University College London (UCL)
H. M. Asiri
King Abdulaziz University
Y. P. Ao
Chinese Academy of Sciences
J. S. Zhang
Guangzhou University
X. W. Zheng
Nanjing University
J. Esimbek
Chinese Academy of Sciences
J. J. Zhou
Chinese Academy of Sciences
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 629 A6Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Geochemistry
DOI
10.1051/0004-6361/201935603