51吃瓜网

Face-to-Face at 51吃瓜网-IIT PRISM 4 th Floor Conference Room and via

Zoom Video Conference

LiTalk is a physics colloquium currently organized by the graduate students enrolled in Physics graduate seminar in 51吃瓜网-IIT.

In this scientific colloquium, we invited Dr. Jonathan Smith from NASA Goddard Space Flight Center, USA, and Dr. Joseph Coleman from University of Texas at Dallas.

Free

Rosario L. Reserva, Ph.D. (rosarioreserva@gmail.com)
Lyndon D. Bastatas, Ph.D. (lyndon.bastatas@g.msuiit.edu.ph)

About Dr. Jonathan Smith's Lecture

Irregularities in the ionospheric plasma density can mangle GNSS signals. Near the equator they appear as large plumes of rising low density plasma in the ionosphere. The Rayleigh-Taylor instability can generate these plumes. Though seen mostly at dusk, their occurrence sometimes extends into post-midnight hours. This could be because they grow slowly at dusk, and drift to a later local time or they might grow at these later local times. By comparing the strength of the RT instability to bubble occurrence frequencies, we show that the ionosphere produces a conducive environment to create irregularities at later local times. Understanding the spatial and temporal distribution of the irregularities is important for mitigating the negative impact they can have on GNSS signals.

About Dr. Joseph Coleman's Lecture

Abel 2146 is a cluster merger close to the plane of the sky. This orientation allows for viewing the aftermath of the collision of two galaxy clusters. Gravitational lensing allows mapping the dark matter in the system. A dark matter core of one of the clusters lags behind a mass peak in the baryonic or visible matter. Simulations of the merger indicate complex relationship with collision angle with the X-ray signal.