Conducting High-Frequency Radio SETI Searches using ALMA

The search for extraterrestrial intelligence (SETI) has yet to detect evidence of intelligent life. Historically, the search for technosignatures has been restricted to the ‘water hole’ – 1.440 to 1.660 GHz – due to minimum sky brightness and the quantum limitations of radio telescopes. We aim to conduct radio SETI searches above 80GHz, utilising ALMA’s Archive and a commensal stellar bycatch approach. Interferometry is advantageous for SETI surveys over single-dish observations to filter earth-bound RFI. However, considerations must be made for smearing limitations and the drift rate of narrowband signals at high frequencies. To our knowledge, SETI searches have yet to be conducted at millimetre and submillimetre wavelengths (except for a surveys conducted around the positronium line at 203GHz) and we believe that ALMA is a promising telescope for SETI surveys, widening the search to unexploited wavelengths.