Agnieszka Janiuk

Agnieszka Janiuk (Professor, group leader)

Agnieszka Janiuk was born and grew up in Warsaw. She studied astronomy at the Physics Department of the Warsaw University, where she received her Master of Science degree in 1998, based on the thesis prepared under the supervision of prof. Bożena Czerny. After that, Agnieszka Janiuk continued her research via PhD program at Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences in Warsaw, and she worked with prof. Czerny on modeling and observations of the accretion processes in AGN and Galactic black hole X-ray binaries (XRBs). As a part of that PhD, she developed a new numerical code for simulating the global structure and time evolution of an unstable accretion disk, which is subject to radiation pressure driven thermal and viscous instabilities. The code is now publicly available under the name GLADIS.

In 2003 Agnieszka Janiuk was a fellow at Max Planck Institute for Astrophysics (MPA) in Garching, Germany. The second postdoctoral fellowship she spent under supervision of prof. Daniel Proga at the University of Nevada, Las Vegas, USA. In 2007, she was awarded a tenure-track contract at NCAC, but in 2010, she moved to join the faculty of the Center for Theoretical Physics of PAS. Since then, she leads her own research group, and has already supervised a number of post-docs, PhD and Master students. In January 2021, she was awarded the full professorship in natural sciences by the President of Poland.

Her current research is mostly devoted to the cosmic explosions named gamma ray bursts. These phenomena share some physical properties with other black hole systems, but they are much more violent and explosive in nature. They are launching ultra-relativistic jets on the cost of black hole rotation and accretion mediated by the strong magnetic fields. In addition, nuclear reactions that occur in the very hot and dense plasmas of their accretion disks, lead to copious emission of neutrinos. Finally, what is now known from gravitational wave observations and their electromagnetic counterparts, many GRBs originate from binary neutron star mergers, whose ejecta are the nucleosynthesis sites for the heaviest elements in the Universe. The theoretical research on GRB in which the CTP PAS group is involved, is based on fully General Relativistic multi-dimensional simulations of accretion and magnetized jet ejections. It also utilized nuclear physics and microphysical properties of the GRB engines, under extreme conditions of mass densities and temperatures.

Gerardo Urrutia Sanchez

Gerardo Urrutia Sanchez (Postdoc)

Gerardo is a Mexican astrophysicist. He enjoys exploring topics related to high-energy astrophysics, his work is focused on the study of gamma ray bursts by numerical simulations. He obtained his bachelor's degree in physics at the Faculty of Sciences of the University of Mexico (UNAM). Furthermore, he had participated as an instructor and assistant professor of courses at the physics department. Gerardo completed his master of sciences and PhD degree at the Institute of Nuclear Sciences in Mexico City, under the supervision of prof. Fabio De Colle. The topic of his thesis is Special Relativistic Hydrodynamics Simulations of gamma ray bursts, exploring the dynamics and radiation of different models of structured jets. In February 2023, he joined the Astrophysics Group supervised by prof. Agnieszka Janiuk at CTP PAS. Currently, Gerardo is participating in the project "Origin of Gamma Ray Bursts and their large-scale characteristics".

Out of astrophysics, Gerardo enjoys listening to music, playing the guitar, drinking coffee, eating delicious things, riding a bicycle, reading magical realism of Latin Americans, traveling, seeing beagles and cats.


Joseph Saji (PhD student)

Joseph is a passionate astrophysics PhD student with a Master's degree in Physics from Cochin University of Science and Technology, Kerala, India. Following his academic journey, he worked as a research assistant at the Indian Institute of Science Education and Research (IISER-TVM) under Prof. Shabnam Iyyani on observational Gamma Ray Burst (GRB) research for a year and half. His master's thesis focused on a comprehensive statistical study on the X-ray flares in the afterglow of GRBs. Joseph is working with CFT astrophysics group under the supervision of Prof. Agnieszka Janiuk since october 2023, focusing on the project "modeling of kilonova emission".

Joseph enjoys coding and data analysis outside of academia. His interests beyond physics includes a passion for travel, music, and reading.

Former Members:

Fatemeh Hossein-Nouri (Postdoc)

Fatemeh was born and grew up in Tehran, the capital city of Iran. She found her passion in life, astronomy, when she was ten years old. She received her bachelor of science in physics from K.N.T University of Technology in Tehran in 2007. During her undergraduate program, she was the active member of the Student Physics Association and organized several invited talks, outreach programs and field trips.

Fatemeh moved to the United States in 2009 and received her Master degree in 2012, and her PhD degree in 2016 under supervision of Professor Matt Duez at Washington State University. Her PhD thesis was focused on developing the GRMHD module in SpEC (Spectral Einstein code) code, and numerical studies of the magnetized accretion disk. She was also a member of the SXS (Extreme Spacetime Simulations) collaboration. After completing her PhD program, she moved to India and worked as a research scientist under supervision of Professor Sukanta Bose at the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, India. She worked on several projects including Numerical studies of neutron stars f-mode oscillations and Relativistic corrections of the mode-tide coupling instability in binary neutron star systems.

Fatemeh joined the Center of Theoretical Physics (CTP) in Warsaw in December 2020. She has been working as a postdoctoral researcher under supervision of Professor Agnieszka Janiuk since then. Her current research is focused on the microphysics code development and numerical simulation of the magnetized neutrino-cooled accretion disks aiming to explain the origin of the Gamma Ray Bursts (GRBs) and kilonova radiations.

Bestin James

Bestin James (PhD student)

Bestin James graduated (MSc) in physics from the Department of Physics of Central University of Kerala in 2015. Earlier he completed his bachelor’s degree (BSc) in physics from St. Thomas College, Pala. His MSc project was devoted to the studies of wave instabilities in dusty plasmas, and for the BSc project he wrote about classification of galaxies using Hubble sequence. He worked as a lecturer in physics at Maharaja’s College Ernakulam and St. Peter’s College Kolenchery, Kerala in India before joining the group.

In CTP PAS Astrophysics group, he works on the topic of accretion onto black holes and magnetized jet launching. He is interested in understanding the properties of jets from accreting black hole sources at different scales.

Bestin defended his PhD thesis in October 2023 and a doctoral degree was awarded to him by the CTP PAS scientific council in December 2023.

Przemysław Figura (Postdoc)

He graduated (MSc) in astronomy from Astronomical Observatory of University of Warsaw. During his master's thesis studies he focused on numerical simulations of star's simple convection zone and overshooting of test particles into adjacent layers. Then he worked as a computer programmer and later began his PhD studies at Space Research Centre of the PAS in Warsaw. He received PhD degree in 2018 and in his research he analysed theoretically plasma flows and magnetic fields using Euler potentials formalism.

After the studies he become a postdoctoral researcher in TEAM project held at Astronomical Observatory, University of Warsaw. He worked in the Virgo Collaboration on Newtonian noise and tiltmeter data analysis using time series and spectral data analysis methods.

In September 2021 he joined Center of Theoretical Physics Astrophysics group as a postdoctoral researcher and has been working under supervision of Professor Agnieszka Janiuk. His research in the group was focused on stellar evolutionary models of massive stars as well as on development of numerical simulations of collapsar objects eventually producing long gamma ray bursts.