27–31 Aug 2018
LVH, Luisenstraße 58, 10117 Berlin
Europe/Berlin timezone

The many surprises from high-energy gamma-ray observations from the Sun

28 Aug 2018, 14:20
15m
-1- Lecture hall

-1- Lecture hall

Talk Gamma-rays Gamma Rays

Speaker

Dr Ng Kenny Chun Yu (Weizmann Institute of Science)

Description

I will discuss recent results on gamma-ray observations of the Sun with Fermi, which revealed many interesting and surprising features. These gamma rays are expected to be produced by hadronic interactions between cosmic rays and the solar atmosphere. The high flux of gamma rays observed from the Sun requires a large boost of gamma-ray production by some mechanism, which is likely related to solar magnetic fields. Our new results include the first resolved image of the Sun and a mysterious dip in the spectrum between 30-50 GeV. In particular, we also find that the solar gamma-ray spectrum during solar minimum is hard (~$E^{-2.1}$) and reaches at least 200 GeV. This suggests that ground based experiments like HAWC and LHAASO will be important for probing the Sun at TeV regime. Understanding solar gamma rays is crucial for predicting the solar atmospheric neutrino flux, which can realistically be detected by IceCube/KM3NeT, and is important for solar dark matter searches.

Primary author

Dr Ng Kenny Chun Yu (Weizmann Institute of Science)

Co-authors

Dr Annika Peter (Ohio State University) Mr Bei Zhou (Ohio State University) Dr John Beacom (Ohio State University) Dr Qing-wen Tang (Nanchang University) Dr Tim Linden (The Ohio State University)

Presentation materials