2020MNRAS.494.1095L -
Mon. Not. R. Astron. Soc., 494, 1095-1113 (2020/May-1)
Isotopologues of dense gas tracers in nearby infrared bright galaxies.
LI F., WANG J., FANG M., LI S., ZHANG Z.-Y., GAO Y. and KONG M.
Abstract (from CDS):
We present 1 and 3 mm observations of the 13C- and 15N-bearing isotopologues of dense gas tracers towards eight nearby infrared-bright galaxies. With the Institut de Radioastronomie Millimetrique 30-m telescope, we observed the J = 1-0 transitions of H13CN, HC15N, H13CO+, HN13C, and H15NC towards M 82, NGC 3079, IC 694, Mrk 231, and NGC 6240. The J = 3-2 transition of H13CN was obtained in M 82, NGC 3079, NGC 3504, NGC 4418, NGC 6240, and NGC 6946, using the 10-m Submillimeter Telescope (SMT). We report the first detections of HN13C J = 1-0 and H13CN J = 3-2 in M 82, and H13CN J = 3-2 in NGC 6240 and NGC 3079. We find different line profiles between the J = 1-0 and 3-2 transitions of H13CN in both M 82 and NGC 3079. The optical depths of HCN show significant variations among the sample, indicating that dense gas masses estimated from the line luminosities of HCN J = 1-0 and 3-2 should be treated with caution for individual galaxies. Optical depth of HCN J = 3-2 is found to be higher than that of HCN J = 1-0 in M 82, NGC 3079, NGC 4418, and NGC 6240, which indicates that ground state transitions of dense gas tracers might better trace the star-forming gas than the high-J transitions. Based on the H13CN/HC15N line ratios, with the double-isotopic method, low 14N/15N abundance ratios of 120 and 140 are found in NGC 3079 and Mrk 231, respectively.
Abstract Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
Journal keyword(s):
galaxies: individual: M 82 - NGC 3079 - NGC 3504 - IC 694 - NGC 4418 - MrK 231 - NGC 6946 - NGC 6240
Simbad objects:
17
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2020MNRAS.494.1095L and select 'bookmark this link' or equivalent in the popup menu