Isotopologues of dense gas tracers in nearby infrared bright galaxies

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 Millimétrique 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, N...