KONSTANTINOS MIGKAS
Astrophysicist
X-ray Oort postdoctoral fellow
Leiden University, the Netherlands
A few words about me...
I am an X-ray Oort postdoctoral fellow at Leiden Observatory since April 2023. My passion is studying the Universe with galaxy clusters. My main focus is probing the isotropy of cosmic expansion and quantifying bulk flows in the local Universe. X-ray analysis of clusters, the physics driving their behavior, and the filaments that connect them are also a big part of my research life.
I grew up in Greece, in a small town called Filyro, right outside Thessaloniki. As an undergrad, I studied Physics at Aristotle University in Thessaloniki. In my 4th year, I chose the Astronomy stream, and I realized what I want to do with my professional life from then on. After that, I was awarded a full scholarship to study Astrophysics in the 2-year MSc program at the University of Bonn. A PhD followed in the group of Prof. Thomas Reiprich at the Argelander Institute for Astronomy in Bonn, under a full scholarship by the International Max-Planck Research School of Astronomy & Astrophysics. I was awarded the Best Thesis award in Physics and Astronomy by the University of Bonn. Bonn had become my home at that point and I stayed for another 2 years as a postdoc working with Dr. Florian Pacaud and Dr. Tim Schrabback. Then, it was time for Leiden. I love it so much there. Both the city and, mostly, the institute. You'll find me there (at least) until 2026.
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On a more personal note; I am a proud husband to the most remarkable person I know, my wife Eftychia, with whom I'm spending my whole life's journey from the 1st year of our BSc degrees to this day. I am also the happiest dad on earth to our beautiful son Alexandros. Music, literature, basketball, video games, and travelling, fill the rest of my life.
Highlighted Publications
Probing cosmic isotropy with a new X-ray cluster sample
We introduce a novel powerfil technique to examine in-depth the directionality of cosmological parameters using galaxy cluster scaling relations. We apply the methodology to 2 completely independent cluster samples detecting a 3σ variation of the Hubble constant
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We introduced the largest X-ray cluster sample with self-consistent temperature measurements at that time. We used it, combined with other independent cluster samples, to show that the X-ray luminosity-temperature relation of clusters exhibit a 4σ angular variation that can be interpreted as a 10% variation of the Hubble constant.
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We use 10 galaxy cluster scaling relations combining X-ray, microwave (SZ), and infrared data to robustly detect a 9% sky variation in the Hubble constant at a 5.4σ level. This could alternatively explained by a 900 km/s bulk flow extending up to 500 Mpc. Both results strongly contradict the standard cosmological model.
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