Searching Signals in Chinese Ancient Records for the ${}^{14}$C Increases in AD 774-775 and in AD 992-993

Abstract

According to the analysis of the ${}^{14}$C content of two Japanese trees over a period of approximately 3000 years at high time resolution, Miyake (2012) found a rapid increase at AD 774-775 and later on at AD 992-993 (Miyake 2013). This corresponds to a high-energy event happened within one year that input $\gamma$-ray energy about 7$\times$10${}^{24}$erg to the Earth, leaving the origin a mystery. Such strong event should have an unusual optical counterpart, and have been recorded in historical literature. We searched Chinese historical materials around AD 744-775 and AD 992-993, but no remarkable event was found except a violent thunderstorm in AD 775. However, the possibility of a thunderstorm containing so much energy is still unlikely. We conclude the event caused the ${}^{14}$C increase is still unclear. This event most probably has no optical counterpart, and short gamma-ray burst, giant flare of a soft gamma-ray repeater and terrestrial $\gamma$-ray flash may all be the candidates.

8 pages, 3 figures

References in corpus (5)

• Self-organized criticality in X-ray flares of gamma-ray burst afterglows
• Causes of an AD 774-775 14C increase
• A Galactic short gamma-ray burst as cause for the 14C peak in AD 774/5
• Terrestrial effects of possible astrophysical sources of an AD 774-775 increase in 14C production
• Modeling atmospheric effects of the September 1859 Solar Flare

Cited by in corpus (2)

• A rapid cosmic-ray increase in BC 3372-3371 from ancient buried tree rings in China
• Consequences of Energetic Magnetar-Like Outbursts of Nearby Neutron Stars: ${}^{14}$C Events and the Cosmic Electron Spectrum