# Astrophysics Seminar

### Multimessenger View of High-Energy Cosmic Neutrino Sources

The discovery of high-energy cosmic neutrinos opened a new window of astroparticle physics. Their origin is a new mystery in the field, which is tightly connected to the long-standing puzzle about the origin of cosmic rays. I will discuss...

### The fate of the merger remnant in GW170817 and its imprint on the jet structure

On August 17, 2017, LIGO/Virgo detected the first gravitational waves from merging neutron stars. This event, known as GW170817 was accompanied by observations all over the electromagnetic spectrum.  The peculiar gamma-ray burst that followed the...

### Black-hole astronomy as a probe of fundamental physics

Aaron Held

Current observations in black-hole astronomy could offer new pathways to constrain deviations from General Relativity. This includes tests of black-hole uniqueness, black-hole stability, and corrections at strong curvature.

• The uniqueness...

### Newborn super star clusters at Cosmic Noon seen through gravitational lensing

Super star clusters with masses > 1e6 Msun are thought to be progenitors of globular clusters (GCs). Their births however are seldomly seen in the local Universe. Given radiation and kinetic feedbacks that regulate star formation, contribution to...

### Polar Disks and Planets Around Eccentric Orbit Binaries

Misaligned disks in binaries were commonly thought to evolve to a coplanar
state. However, recent theory and observations have surprisingly shown that disks around
eccentric orbit binaries can evolve to a polar state in which the disk is...

### Towards an accurate cosmological measurements with optical clusters

Tomomi Sunayama

Galaxy clusters are the most massive gravitationally self-bound objects in the Universe. These clusters form at the rare high peaks of the primordial density fluctuations, and they subsequently trace the growth of structure in the Universe as they...

### Fireball in Fast Radio Bursts

Kunihito Ioka

Fast radio bursts (FRBs) are the brightest radio transients in the universe. Since the unexpected discovery in the 21st century, their extreme nature is one of the biggest mysteries of astrophysics. FRBs are also unique probes of the universe...

Astronomical observations indicate that coherent, dynamically important magnetic fields are ubiquitous in the Universe. However, neither the origin problem -- what are the physical mechanisms that generate the initial seed'' magnetic fields —- nor...