AD 775 Pulse of Cosmogenic Radionuclides Production as Imprint of a Galactic Gamma-Ray Burst

TL;DR

This paper proposes that the sudden increase in radiocarbon around AD 775 was caused by a galactic gamma-ray burst, which uniquely affected certain cosmogenic nuclides, providing a new explanation for this historical event.

Contribution

It introduces the hypothesis that a galactic gamma-ray burst caused the AD 775 radiocarbon spike, distinguishing it from cosmic ray events based on nuclide production patterns.

Findings

Radiocarbon increase in AD 775 possibly caused by gamma-ray burst.

Gamma-ray burst affects 14C and 36Cl production differently than cosmic rays.

Discriminates between gamma-ray burst and proton events using nuclide signatures.

Abstract

We suggest an explanation of a sharp increase in the abundance of cosmogenic radiocarbon found in tree rings dated AD 775. The increase could originate from high-energy irradiation of the atmosphere by a galactic gamma-ray burst. We argue that, unlike a cosmic ray event, a gamma-ray burst does not necessarily result in a substantial increase in long-lived 10Be atmospheric production. At the same time, the 36Cl nuclide would be generated in the amounts detectable in the corresponding ice core samples from Greenland and Antarctica. These peculiar features allow experimental discrimination of nuclide effects caused by gamma-ray bursts and by powerful proton events.