Student Seminars: Astronomy and Astrophysics

jueves 2 mar. 2023 15:00 → 18:30 Europe/Madrid

Faculty of Physics, Room 4205 (Building D, second floor) (Campus Burjassot)

The programme is the following (please, note that the schedule is approximate; we kindly ask you to come to the full session if at all possible, since some flexibility in the schedule is unavoidable):

15:00: The impact of magnetic fields in stellar evolution

by Adam Griffiths

Abstract: Magnetic fields play a role in almost all astrophyiscal phenomena. However, due to the added complexity they bring they are often the last to be considered when developping a model to explain a phenomenon. In the field of stellar evolution the inclusion of magnetic fields in models has become more systematic in recent years. I will explain why magnetic fields are an important factor for stellar evolution and how theorists deal with them in this context.


15:30: A sub-grid model for magneto-hydrodynamical turbulence

by Miquel Miravet-Tenés

Abstract: Insufficient numerical resolution of grid-based, direct numerical simulations (DNS) hampers the development of instability-driven turbulence at small (unresolved) scales. As an alternative to DNS, sub-grid models can potentially reproduce the effects of turbulence at small scales in terms of the resolved scales, and hence can capture physical effects with less computational resources. In this talk I will present the MHD-instability-induced-turbulence (MInIT) mean-field model, which is based on the evolution of the turbulent kinetic energy density. 


16:00: Thermal effects in Binary Neutron Stars merger with full-tabulated EOS

by Davide Guerra

Abstract: The state of the matter inside the most astrophysical compact object known as "neutron star" (NS) is still a mystery. Through the gravitational wave observations joint with the electromagnetic ones, there would be the possibility to unveil the properties of the Equation of State (EOS) that describes the inner part of NS. During this seminar, I will present our preliminary results from numerical relativity simulations introducing a more realistic finite-temperature tabulated EOS. In this way, we could analyze the imprinting of a new micro-physical treatment in the gravitational wave emission. 

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17:00: A GW classification pipeline based on Machine Learning algorithms

by Miquel Llorens-Monteagudo

Abstract: Nowadays, it is well known that the detection of gravitational waves (GW) has opened a new window to understanding our Universe. Many efforts are being carried away to improve our ability to tell apart astrophysical signals between them and from all the intrinsic noise of the GW detectors, at both hardware and software level. Recently, state-of-the-art Machine Learning algorithms have made a strong appearance in the later, proving their worth at the same —sometimes higher— level of standard algorithms. In this seminar I will provide a brief introduction to the general workflow of a machine-learning oriented pipeline for signal classification, and show an example using Dictionary Learning algorithms.


17:30: Physical interpretation of the perfect fluid solutions to the Einstein equations

by Salvador Mengual

Abstract: Many formal perfect fluid solutions to the Einstein field equations have been obtained, usually by imposing geometric constraints that simplify the integration of the field equations. However, very few such solutions have been interpreted as physically realistic fluids. In this seminar, we will see what "physically interpreting a perfect fluid solution" means and how to do it.

18:00: Looking for Lyman-alpha emitting sources

by Alberto Torralba

Abstract: Among the nebular-emission lines of galaxies in the rest-frame UV, Lyman-alpha is intrinsically one of the most luminous. I will give an overview about how we can find Lyman-alpha emitting sources, and the insights they provide about the high-redshift Universe (z>2).