ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- IV. Radio Recombination Lines and evolution of star formation efficiencies

C. Zhang, Neal J. Evans, T. Liu +11

We report detection of radio recombination line (RRL) H${}_{40\alpha }$ toward 75 sources, with data obtained from ACA observations in the ATOMS survey of 146 active Galactic star forming…