Journal Club



08.06.2020

"JAGB (J-region Asymptotic Giant Branch) stars as primary distance indicators"

Piotr Wielgorski (CAMK, Warsaw)

The talk will be based on: https://arxiv.org/abs/2005.10792 and https://arxiv.org/abs/2005.10793


15.06.2020

"Bringing General Relativity into the Laboratory"

Jonas Pereira (CAMK, Warsaw)

I will explain how some aspects of, e.g., astrophysics, cosmology and quantum field theory in curved spacetimes could be effectively reproduced and probed with the use of metamaterials (man-made media with controllable dielectric coefficients). In addition, I'll try to quickly elaborate on how experimental efforts into this direction might also help advance important technologies.


22.06.2020

"Astronomical signatures at the world’s first temple: Göbekli tepe"

Filiz Kahraman (CAMK, Warsaw)

Göbekli Tepe ("Potbelly Hill") is an archaeological site in the Southeastern Anatolia Region of Turkey approximately 12 km (7 mi) northeast of the city of Şanlıurfa. Dr. Kahraman will tell us about the astronomical knowledge of the first inhabitants of this UNESCO site.


29.06.2020

"Rotating neutron stars with non-barotropic thermal profile"

Giovanni Camelio (CAMK, Warsaw)

Being able to determine the stationary structure of a neutron star allows to study its properties, like the parameter space of the equation of state, the mass-radius diagram, and the gravitational wave emission. Moreover, this stationary configuration can be used as initial condition for a much more resource demanding hydrodynamical simulation. A key approximation made for computing the stationary structure of hot and rotating neutron stars is that of barotropicity, namely that all thermodynamical quantities are in a one-to-one relationship, which in turn implies that the specific angular momentum of a fluid element is in a one-to-one relationship with its angular velocity. However, this is a poor approximation for the compact remnant of a core-collapse supernova or of a binary neutron star merger. In this talk I describe how, for the first time, we determine the structure of stationary, hot, rotating neutron stars without the barotropic approximation. To do so, we introduce a potential formulation for the Euler equation, which is a novel technique even in the context of Newtonian stars. Coauthors: Tim Dietrich, Miguel Marques, Stephan Rosswog Paper: arXiv:1908.11258 - Camelio, Dietrich, Marques & Rosswog, PRD 100:123001 (2019).