We present the results of millimetre-wave spectroscopic and continuum observations of comet C/2020 F3 (NEOWISE) undertaken with the Institut de RadioAstronomie Millimetrique (IRAM) 30-m and the NOrthern Extended Millimeter Array (NOEMA) telescopes on 22, 25-27 July and 7 August 2020. Production rates of HCN, HNC, CH_3_OH, CS, H_2_CO, CH_3_CN, H_2_S, and CO were determined with upper limits on 6 others species. The comet shows abundances within the range observed in other comets. The CO abundance is low (3.2% relative to water) while H_2_S is relatively abundant (1.1% relative to water). The H_2_CO abundance shows a steep variation with heliocentric distance, possibly related to a distributed production from the dust or macro-molecular source. The CH_3_OH and H_2_S production rates show a slower decrease post-perihelion than water. Interferometric map of the continuum could not detect the nucleus point source contribution (implying a size r<4.7km) but yielded an estimate of the dust production rate, leading to a relatively low dust-to-gas ratio of 0.7+/-0.3 on 22.4 July 2020.

Cone search capability for table J/A+A/668/A171/list (List of spectra)