ITC Pizza Lunch


Wednesday, May 2, 2018, 11:00am to 12:00pm


Sofia Moschou

Title: Modeling Radio Loud Coronal Mass Ejections

Ground-based radio observations offer access to a diverse range of
physical processes, from thermal to eruptive ones, that take place in
the solar atmosphere. Radio waves have a strong dependence on the
refraction index and thus follow curved paths when they travel in
stratified media, such as the stellar coronae. The effect of
refraction is stronger for lower radio frequencies. Inspired by the
solar paradigm that has revealed a “1-1” relation between Type II
radio bursts and CME shock waves, stellar radio astronomers are
conducting surveys to incontrovertibly observe stellar CMEs. I will
present a newly developed radio synthetic imaging tool integrated in
state-of-the-art computational simulations of the solar corona and
wind. The tool calculates and visualizes the Bremsstrahlung radio
emission for both the quiescent corona and CMEs along the actual
curved paths of the radio rays. Our results are in good agreement with
high frequency observations of the solar corona.


Xiawei Wang

Title: Multi-messengers and star formation from AGN outflows

We study the hydrodynamics and non-thermal emission from the forward
outflow shock produced by an AGN-driven outflow. We show that AGN
outflows simultaneously account for all three messengers— gamma-rays,
neutrinos and ultra-high energy cosmic rays at their observed levels.
Furthermore, we study the star formation within outflows driven by AGN
outflows as a new source of hypervelocity stars (HVSs). We show that
shells swept up by AGN outflows are capable of cooling and
fragmentation into cold clumps via thermal instabilities and the
corresponding HVS production rate is ~ 4-5 orders of magnitude greater
than the Hills mechanism.
See also: Pizza Lunch, 2017-18