PhD student fellowship in Warsaw

The Director of the Center for Theoretical Physics PAS invites applications for PhD student fellowship at the CTP PAS, financed from the project MAESTRO 15 “Dynamics of processes around compact stars“ funded by National Science Center (grant registration number: UMO– 2023/50/A/ST9/00527). PI of the project is Prof. dr hab. Agnieszka Janiuk.

The aim of the project is to study accretion flows around compact stars, such as black holes and neutron stars. Using numerical computer simulations, a model of the accretion disk instability driven by a dominant radiation pressure (RPI), will be studied. It has been shown that in RPI, a self–regulated process leads to cyclic oscillations of disk temperature, density and luminosity in the unstable parts, which can be modeled numerically . The development of the dynamical model specifically addressed to accreting stellar mass black holes (Janiuk et al. 2002) was motivated by discovery of the seminal source, microquasar GRS 1915+105. Later on, subsequently found other microquasars have proven to be subject to RPI (Sukova et al. 2016). In the context of supermassive black holes, statistical studies were used (Czerny et al. 2009) to shed light on the problem. Most recently, however, a new class of sources called changing–look (CL) AGN are observed, where the tentative timescales of their eruptions are suggesting the RPI in action (Miniutti et al. 2019). Most recently, neutron stars have been invoked in this context as well (Vincentelli et al. 2023).

The scope of work of the successful Candidate within the project will be on development of numerical simulations and analysis of observational data related to the radiation pressure instability driven flares in accreting compact stars.