Galaxy Evolution using Graph Theory
by
B228
ΘΕΕ02
Abstract: In this talk we present a methodological framework for studying galaxy evolution by utilizing Graph Theory and network analysis tools and algorithms. More specifically, we showcase the development and implementation of a unified methodological framework for graph clustering, by analyzing mid-infrared spectra of local (z < 0.4) and distant (0.3 < z < 3.0) ultraluminous infrared galaxies (ULIRGs) and quasars, obtained by NASA's Spitzer space telescope. Ultraluminous infrared galaxies consist of multiple galaxies which interact gravitationally and eventually merge, forming one larger galaxy. This process results in a redistribution of gas, dust and stars across the galactic merger, leading to an increased rate of star formation and the activation of the supermassive black holes at the galactic centers, called active galactic nuclei (AGN). By investigating the distribution of physical features in these galaxies across relational diagrams (e.g. similarity graphs) of the constructed networks, we examine the evolution of their power sources, leading to an evolutionary paradigm for the merger scenario of galaxies.
About the speaker: Mr Orestis Pavlou has recently completed his PhD studies at European University Cyprus, with his PhD thesis titled: "Graph Theoretical Analysis of Galaxy Evolution". He is currently working as a Research Specialist and is participating in several European Space Agency funded research projects as a PhD Researcher and a member of the Aristarchus Research Center (ARC) research group at European University Cyprus. His doctoral research studies involved developing a Graph Theoretical framework using Python to analyze mid-infrared spectra of ultraluminous infrared galaxies and quasars from NASA’s Spitzer Space Telescope in order to generate an evolutionary paradigm for galaxies. He holds an MSc degree in Physics & Astronomy from the University of Amsterdam, as a member of the Gravitation AstroParticle Physics Amsterdam (GRAPPA) excellence program. He also holds a BSc & MSc diploma in Applied Mathematics and Physical Sciences from the National Technical University of Athens, where he focused on Theoretical & Computational Physics and Nuclear & Particle Physics.