The Astronomical Journal (Jan 2023)

A Simultaneous Dual-site Technosignature Search Using International LOFAR Stations

  • Owen A. Johnson,
  • Vishal Gajjar,
  • Evan F. Keane,
  • David J. McKenna,
  • Charles Giese,
  • Ben McKeon,
  • Tobia D. Carozzi,
  • Cloe Alcaria,
  • Aoife Brennan,
  • Bryan Brzycki,
  • Steve Croft,
  • Jamie Drew,
  • Richard Elkins,
  • Peter T. Gallagher,
  • Ruth Kelly,
  • Matt Lebofsky,
  • Dave H. E. MacMahon,
  • Joseph McCauley,
  • Imke de Pater,
  • Shauna Rose Raeside,
  • Andrew P. V. Siemion,
  • S. Pete Worden

DOI
https://doi.org/10.3847/1538-3881/acf9f5
Journal volume & issue
Vol. 166, no. 5
p. 193

Abstract

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The Search for Extraterrestrial Intelligence aims to find evidence of technosignatures, which can point toward the possible existence of technologically advanced extraterrestrial life. Radio signals similar to those engineered on Earth may be transmitted by other civilizations, motivating technosignature searches across the entire radio spectrum. In this endeavor, the low-frequency radio band has remained largely unexplored; with prior radio searches primarily above 1 GHz. In this survey at 110–190 MHz, observations of 1,631,198 targets from TESS and Gaia are reported. Observations took place simultaneously with two international stations (noninterferometric) of the Low Frequency Array in Ireland and Sweden. We can reject the presence of any Doppler drifting narrowband transmissions in the barycentric frame of reference, with equivalent isotropic radiated power of 10 ^17 W, for 0.4 million (or 1.3 million) stellar systems at 110 (or 190) MHz. This work demonstrates the effectiveness of using multisite simultaneous observations for rejecting anthropogenic signals in the search for technosignatures.

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