Speaker:
Gregory Huxtable
Date:
Tuesday, September 29, 2020
Time:
4:00 pm
Location:
Zoom Seminar
Abstract:
I will present results from recent work done in assessing the validity of wakefield acceleration (WFA) producing ultra high energy (UHE) particles, which eventually become UHECRs (UHE cosmic rays), or generate UHE gamma rays and neutrinos, inside astrophysical jets. Fermi acceleration likely is the cause of lower energy emission signals from these jets, but we dispute the common belief that it too is the cause of UHECRs (>1019eV), because of massive synchrotron loss at high energies. We used observational data from a broad range of objects, with masses from 1 – 109 
(solar mass), and compared with theoretically predicted values. In all cases it was found that WFA explains both the global properties and details. Each object we studied exhibits signs of plasma jets and emits intense high energy gamma rays (>10 GeV). Many of these objects also emit spatially identifiable UHECRs. The physical system need only have a central compact object (engine), an accretion disk, and subsequently jets for the magneto-rotational instability (MRI) and WFA tandem to accelerate particles to the highest energies. The mass of the central engine only effects maximum values. Furthermore, we will show how this theory can naturally explain the spatial localization of these signals, as well as their temporal structure.
Host:
Toshiki Tajima