A new measurement of the Galactic ${}^{12}$C/${}^{13}$C gradient from sensitive HCO${}^{+}$ absorption observations

Gan Luo, Laura Colzi, Tie Liu +4

We present a new constraint on the Galactic ${}^{12}$C/${}^{13}$C gradient with sensitive HCO${}^{+}$ absorption observations against strong continuum sources. The new measurements suffer…