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


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, Observation Support

S. Garcia-Burillo


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 A6

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics




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