I am an astrophysicist and an engineer, currently an Assistant Professor at Hiroshima University. I like to work on merging galaxy clusters and the hot intracluster medium, with an interest in understanding these hot atmospheres using multiwavelength observations.
Galaxy clusters are the largest objects in the Universe, so not only does our research sit in the realm of observational cosmology and large scale structure formation, but it also lies as the intersect between theory, observation, and simulation. These objects can span several millions of light years across, and have temperatures in the millions of Kelvin despite having an extremely low particle density. My research in particular is focused on merging galaxy clusters and how the substructures formed during merging events can constrain the microphysics (conduction, diffusion, viscosity, etc.) of the intracluster medium (ICM). Galaxy cluster mergers are the most energetic events after the Big Bang. All this energy is released in the form of turbulence and shocks, which propagate through the ICM, dissociating the dark matter from the rest of the baryonic gas, and which often create some impressive radio signatures. Each of these different substructures give specific clues about the rich history of the cluster, and with the help of numerical simulations and multiwavelength data (X-ray, radio, Sunyaev Zeldovich, etc.), we are sometimes able to paint a convincing story about how it all came together.
Besides extragalactic astrophysics, I have also done some work in our local neighborhood. I've worked with the Heliophysics and Space Weather group at NASA Goddard, studied the effects of the solar wind on our radiation belts and the geomagnetic field with machine learning, modelled the bowshock using in-situ data, graviational lensing of the cosmic microwave background, many other projects. I am currently also working on some engineering work, where I am characterising the surface roughness of the magnetic diverter for the ESA Athena mission, to simulate the soft proton particle scattering background using Geant4. This is part of a second project I am working on which involves understanding the flaring, soft proton contamination, and instrument particle backgrounds on current X-ray observatories.
Before working in the space sector I worked in other scientific fields. My first contribution was doing field work in the Amazon rainforest. One project involved the modeling of biodiversity in extreme, black water swamps in central Amazonia, where I was responsible for collecting and identifying plants in these remote swamps for the local herbarium. Another project was a concervation project aiming to model the spread of disease both from cities into the jungle and vice versa, where we caught and sampled vectors of disease (bats, rats, marsupials, and primates). In the meantime I also collected many rare entomological specimens which I donated to the collection at the National Institute of Amazonian Research (INPA). Besides that, I've also worked on two geophysics projects using magnetometers on research vessels in both the North Sea and in the Skagerrak region.
I try to keep my entomology passion alive at home today. You can find more about my personal life here
I earned my B.Sc. in Earth and Space Sciences in 2015 specializing in Geophysics from Jacobs University Bremen (previously International University Bremen) followed by a MSc. Eng. in Earth and Space Physics and Engineering specializing in Astrophysics, Space Research, and Data Processing in Astrophysics from the Technical University of Denmark.
I completed my Ph.D. at Masaryk University working with Dr. Norbert Werner; specifically, my thesis title was, "Spatially resolved X-ray spectroscopy of dynamically active clusters and constraints on intra-cluster medium physics".
Click the Icon below for a CV (Updated Feb 2021).
The thermodynamic structure and large-scale structure filament in MACS J0717.5+3745 -- PDF
J. P. Breuer, N. Werner, F. Mernier, K. Umetsu, A. Simionescu, M. Devlin, L. Di Mascolo, T. Dibblee-Barkman, S. Dicker, B. S. Mason, T. Mroczkowski, C. Romero, C. L. Sarazin, J. Sievers
The infalling elliptical galaxy M89: The chemical composition of the AGN disturbed hot atmosphere -- PDF
Sinancan Kara ; Tomáš Plšek ; Klaudia Protušová ; Jean-Paul Breuer ; Norbert Werner ; François Mernier ; E. Nihal Ercan
Ram-pressure stripped radio tail and two ULXs in the spiral galaxy HCG 97b -- PDF
Hu D. ; Zajaček M. ; Werner N. ; Grossová R. ; Jáchym P. ; Roberts I. D. ; Ignesti A. ; Kenney J. D. P. ; Plšek T. ; Breuer J-P. ; Shimwell T. ; Tasse C.
Athena charged particle diverter simulations: effects of micro-roughness on proton scattering using Geant4 -- PDF
Breuer, Jean-Paul ; Galgóczi, Gábor ; Fioretti, Valentina ; Zlámal, Jakub ; Liška, Petr ; Werner, Norbert ; Santin, Giovanni ; Boudin, Nathalie ; Ferreira, Ivo ; Guainazzi, Matteo ; von Kienlin, Andreas ; Lotti, Simone ; Mineo, Teresa ; Molendi, Silvano ; Perinati, Emanuele
Geant4 simulation of the residual background in the ATHENA Wide Field Imager from protons deflected by the Charged Particle Diverter -- PDF
Galgóczi, Gábor ; Breuer, Jean-Paul ; Fioretti, Valentina ; Zlámal, Jakub ; Werner, Norbert ; Čalkovský, Vojtěch ; Boudin, Nathalie ; Ferreira, Ivo ; Guainazzi, Matteo ; von Kienlin, Andreas ; Lotti, Simone ; Mineo, Teresa ; Molendi, Silvano ; Perinati, Emanuele
The mergers in Abell 2256: displaced gas and its connection to the radio-emitting plasma -- PDF -- Supplement
Breuer, J. P.; Werner, N.; Mernier, F.; Mroczkowski, T.; Simionescu, A.; Clarke, T. E.; ZuHone, J. A.; Di Mascolo, L.
Space Radiation and Plasma Effects on Satellites and Aviation: Quantities and Metrics for Tracking Performance of Space Weather Environment Models -- Article (image credit)
Zheng, Y.; Ganushkina, N. Y.; Jiggens, P.; Jun, I.; Meier, M. M.; Minow, J. I.; O'Brien T. P.; Pitchford, D.; Shprits, Y. Y.; Tobiska, W. K.; Xapsos, M. A.; Guild, T. B.; Mazur, J. E.; Kunetsova, M. M.
Characterization of more than three years of in-orbit radiation damage of SiPMs on GRBAlpha and VZLUSAT-2 CubeSats -- PDF
Jakub Ripa, Marianna Dafcikova, Pavel Kosik, Filip Münz, Masanori Ohno, Gabor Galgoczi, Norbert Werner, Andras Pal, Laszlo Meszaros, Balazs Csak, Yasushi Fukazawa, Hiromitsu Takahashi, Tsunefumi Mizuno, Kazuhiro Nakazawa, Hirokazu Odaka, Yuto Ichinohe, Jakub Kapus, Jan Hudec, Marcel Frajt, Maksim Rezenov, Vladimir Daniel, Petr Svoboda, Juraj Dudas, Martin Sabol, Robert Laszlo, Martin Koleda, Michaela Duriskova, Lea Szakszonova, Martin Kolar, Nikola Husarikova, Jean-Paul Breuer, Filip Hroch, Tomas Vitek, Ivo Vertat, Tomas Urbanec, Ales Povalac, Miroslav Kasal, Peter Hanak, Miroslav smelko, Martin Topinka, Hsiang-Kuang Chang, Tsung-Che Liu, Chih-Hsun Lin, Chin-Ping Hu, Che-Chih Tsao
GRBAlpha: the smallest astrophysical space observatory - Part 1: Detector design, system description and satellite operations -- PDF
A. Pál, M. Ohno, L. Mészáros, N. Werner, J. Řípa, B. Csák, M. Dafčíková, M. Frajt, Y. Fukazawa, P. Hanák, J. Hudec, N. Husáriková, J. Kapuš, M. Kasal, M. Kolář, M. Koleda, R. Laszlo, P. Lipovský, T. Mizuno, F. Münz, K. Nakazawa, M. Rezenov, M. Šmelko, H. Takahashi, M. Topinka, T. Urbanec, J-P. Breuer, T. Bozóki, G. Dálya, T. Enoto, Z. Frei, G. Friss, G. Galgóczi, F. Hroch, Y. Ichinohe, K. Kapás, L. L. Kiss, H. Matake, H. Odaka, H. Poon, A. Povalač, J. Takátsy, K. Torigoe, N. Uchida, Y. Uchida
The peak-flux of GRB 221009A measured with GRBAlpha -- PDF
J. Řípa, H. Takahashi, Y. Fukazawa, N. Werner, F. Munz, A. Pal, M. Ohno, M. Dafcikova, L. Meszaros, B. Csak, N. Husarikova, M. Kolar, G. Galgoczi, J-P. Breuer, F. Hroch, J. Hudec, J. Kapus, M. Frajt, M. Rezenov, R. Laszlo, M. Koleda, M. Smelko, P. Hanak, P. Lipovsky, T. Urbanec, M. Kasal, A. Povalac, Y. Uchida, H. Poon, H. Matake, K. Nakazawa, N. Uchida, T. Bozoki, G. Dalya, T. Enoto, Z. Frei, G. Friss, Y. Ichinohe, K. Kapas, L. L. Kiss, T. Mizuno, H. Odaka, J. Takatsy, M. Topinka, K. Torigoe
Early results from GRBAlpha and VZLUSAT-2 -- PDF
Řípa, Jakub ; Pal, Andras ; Ohno, Masanori ; Werner, Norbert ; Meszaros, Laszlo ; Csak, Balazs ; Dafcikova, Marianna ; Daniel, Vladimir ; Dudas, Juraj ; Frajt, Marcel ; Hanak, Peter ; Hudec, Jan ; Junas, Milan ; Kapus, Jakub ; Kasal, Miroslav ; Koleda, Martin ; Laszlo, Robert ; Lipovsky, Pavol ; Munz, Filip ; Rezenov, Maksim ; smelko, Miroslav ; Svoboda, Petr ; Takahashi, Hiromitsu ; Topinka, Martin ; Urbanec, Tomas ; Breuer, Jean-Paul ; Enoto, Teruaki ; Frei, Zsolt ; Fukazawa, Yasushi ; Galgoczi, Gabor ; Hroch, Filip ; Ichinohe, Yuto ; Kiss, Laszlo ; Matake, Hiroto ; Mizuno, Tsunefumi ; Nakazawa, Kazuhiro ; Odaka, Hirokazu ; Poon, Helen ; Uchida, Nagomi ; Uchida, Yuusuke
Studentship at European Southern Observatory - Worked on developing a Bayesian joint forward modelling method for combining X-ray spatially resolved spectroscopic data and Sunyaev Zeldovich observations of galaxy clusters.
Internal Grant Agency of Masaryk University - Working on some particle simulation work for the magnetic diverter instrument in the upcoming Athena mission. The goal is to better understand the particle scattering, ionizing interactions, and related secondary background contribution.
Atacama Pathfinder Experiment (APEX) mm/sub-mm observation experience in Chile for two weeks.
IRAM 30 meter telescope mm/sub-mm observation experience in Spain for one week.