A Search for Technosignatures toward the Galactic Centre at 150 MHz

TL;DR

This study conducted a low-frequency search for extraterrestrial technosignatures at 150 MHz near the Galactic Centre using the Murchison Widefield Array, analyzing data from 144 exoplanetary systems and over 3 million stars, but found no evidence of technosignatures.

Contribution

First technosignature search at 155 MHz toward the Galactic Centre with high angular resolution and extensive star coverage, setting new power limits.

Findings

No technosignatures detected in the surveyed data.

Established an isotropic power limit of <1.1×10^19 W.

Performed the first search at this frequency toward the Galactic Centre.

Abstract

This paper is the fourth in a series of low-frequency searches for technosignatures. Using the Murchison Widefield Array over two nights we integrate 7 hours of data toward the Galactic Centre (centred on the position of Sagittarius A*) with a total field-of-view of 200 deg^2. We present a targeted search toward 144 exoplanetary systems, at our best yet angular resolution (75 arc seconds). This is the first technosignature search at a frequency of 155 MHz toward the Galactic Centre (our previous central frequencies have been lower). A blind search toward in excess of 3 million stars toward the Galactic Centre and Galactic bulge is also completed, placing an equivalent isotropic power limit <1.1X10^19W at the distance to the Galactic Centre. No plausible technosignatures are detected.