Dorottya Szécsi (Nicolaus Copernicus University, Toruń, Poland)

Does "I Zwicky 18" harbor GW progenitors? The story of a dwarf galaxy and what I learned in the past 12 years

Abstract: The metal-poor, irregular dwarf galaxy called I Zwicky 18 has been suggested to harbor (theorized) progenitors of Gravitational-Wave emitting mergers. The galaxy emits an unprecedented amount of hard ionizing radiation together with certain emission features in its spectrum. To explain this, a theorist like me has to put together a complex hypothesis based on reliable computer models of those stars, and compare its predictions to all available observations in the literature. Sounds easy, right? But what if she finds that the observations *themselves* actually contradict each other? Then she has no choice but go down the rabbit hole of learning how observational astronomers work, speak, and think – a scientific challenge in itself. In this talk, I share my curious story of the past 12 years tackling the case of I Zwicky 18, and my hunt for finding observational evidence for the existence of a certain type of GW progenitors, which have just come to an end.

Related publication: ui.adsabs.harvard.edu

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Dorottya Szécsi started her career in Hungary, obtaining BSc/MSc in Physics at the Eötvös University, Budapest. During her Masters, she joined a research group on Gamma-Ray Bursts and won 1st prize at the national competition for student researcher (OTDK). She left her country to build an international career, accepting a PhD position from world-renowned massive-star expert prof. Norbert Langer in Bonn, Germany. After defending her PhD in 2016 Magna Cum Laude, she joined the Astronomical Institute in the Czech town Ondřejov near Prague for a post-doctoral position, during which she was awarded the Jan Frič Prize of the Czech Academy of Sciences for her achievement in the field of hot stellar winds. Her interest turned to the topic of Gravitational Waves, binary stars, and population synthesis after that, and she moved to the United Kingdom as a post-doc at the University of Birmingham, where she started to develop her own individual research cases. Winning the prestigious Humboldt Fellowship, she moved back to Germany to spend two years at the University of Cologne working on the BoOST project, an ambitious, user-friendly library of massive-star models that, on top of being a useful tool in GW-research, also caters to the needs of the star-formation and galaxy communities. In 2020, she joined the faculty of the Nicolaus Copernicus University in Toruń, Poland. Winning the prestigious OPUS grant from the Polish National Center of Science allowed her to establish her own 5-people research group. In 2024, she obtained her habilitation degree, and since 2025, she is tenured as an Associate Professor (equivalent to "docens" in the Hungarian system).