Day 1132

Tuesday.

1608.02308
Supernovae and single-year anomalies in the atmospheric radiocarbon record
Dee, Pope, Miles, Manning, Miyake

Single-year spikes in radiocarbon production are caused by intense bursts of radiation from space.  See emit both high-energy particle and EM radiation, but it is the latter that is most likely to strike the atmosphere all at once and cause a surge in 14C production.  In the 1990s, it was claimed that the SN in 1006 CE produced exactly this effect.  With the 14C spikes in the years 775 and 994 CE now attributed to extreme solar events, attention has returned to the question of whether historical SNe are indeed detectable using annual 14C measurements.  Here, combine new and existing measurements over 6 documented and putative SNe, and conclude that no such astrophysical event has yet left a distinct imprint on the past atmospheric 14C record.


1608.02408
The lunar Askaryan technique with the Square Kilometer Array
James, et al

The lunar Askaryan technique is a method to study the highest-energy cosmic rays, and their predicted counterparts, the ultra-high-energy neutrinos.  By observing the Moon with a radio telescope, and searching for the characteristic nanosecond-scale Askaryan pulses emitted when a high-energy particle interacts in the outer layers of the Moon, the visible lunar surface can be used as a detection area.  Several previous experiments, at Parkes, Goldstone, Kalyazin, Westerbork, and ATCA, Lovell, LOVAR, and the VLA, have developed the necessary techniques to search for these pulses, but existing instruments have lacked the necessary sensitivity to detect the know flux of cosmic rays from such a distance.  This will change with the advent of SKA.  SKA will be the world's most powerful radio telescope.  To be built in southern Africa, Australia and New Zealand during the next decade, it will have an unsurpassed sensitivity over the key 100 MHz to few-GHz band.  Introduce a planned experiment to use the SKA to observe the highest-energy CRs and, potentially, neutrons.  The estimated event rate will be presented, along with the predicted energy and directional resolution.  Prospects for directional studies with phase 1 of the SKA will be discussed, as well the major technical challenges to be overcome to make full use of this powerful instrument.  Finally, show how phase 2 of the SKA could provide a vast increase in the number of detected CRs at the highest energies, and this to provide new insight into their spectrum and origin.