International Summer Student Internships (ISSI)

Projects proposed for the summer 2026

1. Investigating the evolution of the compact binary stars - the origin of sources for present and future gravitational waves detectors
   Mentor: Dr. Iwona Kotko

   The compact binaries are the binaries in which one of the components is a white dwarf (WD), a neutron star (NS), or a black hole (BH). Such binaries are the possible progenitors of the double compact objects which are the sources of gravitational waves detectable by present (LIGO/VIRGO/KAGRA) and future (e.g. LISA) gravitational waves detectors. Investigating the isolated binary evolution of the compact binaries may not only help us understand the origin of the mering binary black holes but also may shed light on still not well understood aspects of the binary evolution theory.
   
   The aim of the project is to investigate how the uncertain parameters of the binary evolution shape the statistical properties of three compact binary populations: double compact objects (NS-NS,NS-BH,BH-BH), X-ray binaries (star-NS/BH) and ultracompact binaries with WDs. The parameters for the study will be selected at the beginning of the project, and the results will be compared both with the observational data and with the existing theoretical predictions. During the project the student will be learning the basics of binary stars evolution and will get familiar with the population synthesis calculations. The knowledge of such numerical tools gives the opportunity to learn the stellar and binary evolution in the "laboratory", by studying how each single system in the population changes in each timestep depending on the parameters that one can control. 
   
   Requirement: programming and computer skills.

2. Lepton acceleration by the electromagnetic turbulence at the shock waves in cosmic plasma
   Mentor: Dr. Oleh Kobzar

   Energy spectra of Galactic cosmic rays (CR) are important for understanding the physics of their sources, as well as for constraining the Galaxy structure. They are close to the simple power-law distribution with maximum energies of ~ 2 PeV for hadronic and ~ 1 TeV for leptonic components. The measured energy distributions of the CR leptons are found to deviate from the typical simple power law, with excesses for the electrons at 0.1 – 1 TeV, and much harder positron spectra at 20 – 200 GeV. Besides, recent studies using numerical simulations indicate the more efficient positron acceleration compared to electrons, assuming the possibility of the charge-dependent acceleration processes. Our preliminary numerical experiments with use of the Particle-In-Cell (PIC) simulations confirm this assumption and show, that electromagnetic turbulence acting in the vicinity of supernova remnant (SNR) shock may be responsible for the observed effects.
   
   Objectives: Modelling of the CR lepton acceleration and interaction with electromagnetic turbulence acting at the SNR shock with use of PIC-simulations method. Investigations of the microphysics of charge-dependent acceleration.
   
   An aim of the student program is to become familiar with:
   - selected topics of the high energy astrophysics;
   - parallel computing with use of supercomputer clusters;
   - analysis and visualisation of data.
   Requirements:
   - programming skills in any language is essential (Fortran is welcome);
   - good knowledge in physics, mathematics, astronomy or related field;
   - verbal and written communication skills in English.

3. Probing the Origin of Radio Emission in Compact Radio Galaxies
   Mentor: Dr. Anna Wójtowicz

   Results from large radio surveys show that the number of galaxies with extended radio jets is significantly smaller than expected compared to the large population of compact, host-confined radio galaxies. If compact radio sources simply represented an early evolutionary stage in which jets later expand to large scales, a much larger number of extended systems would be observed.
   
   This discrepancy suggests several possible explanations. The radio emission in compact galaxies may not always originate from jets, the jet activity may be episodic rather than continuous, or the radio emission may be confined by a dense surrounding medium.
   
   In this context, one possible explanation for episodic activity in some compact radio galaxies is that the radio emission is triggered by stars that become tidally disrupted in the vicinity of the central black hole.
   
   In this project, the student will use archival data from Very Long Baseline Interferometry (VLBI) observations to study the extent and morphology of compact radio galaxies. The goal will be to distinguish between the proposed mechanisms responsible for their radio emission. In particular, the student will investigate whether any of the studied objects show radio properties consistent with emission triggered by a tidally disrupted star.
   
   Through this work, the student will:
   - gain practical experience working with archival interferometric data;
   - develop skills in analyzing radio observations and characterizing the properties of radio galaxies and their host environments using multi-wavelength archival data;
   

4. SDRAGNs can do it too – studies of large-scale radio structures associated with spiral galaxies
   Mentor: Dr hab., prof. UJ Marek Jamrozy
   Co-Mentor: Weronika Kiełpińska

   Radio galaxies have been known for seven decades. The generally accepted mechanism of their formation involves a rotating supermassive black hole (SMBH) surrounded by a disk of accreting matter and magnetic field. From those relatively small objects, called active galactic nuclei (AGNs), matter, energy, and magnetic field can be transferred in the form of narrow relativistic jets of charged plasma to very large distances, much exceeding the very size of a given galaxy.
   
   With the increasing number of interferometers and the new, sensitive, high-resolution data they provide, new types of radio galaxies are being discovered. Most of the thousands radio galaxies are associated with elliptical galaxies. Only a few dozen are known to emanate from the centers of spiral galaxies. These objects are known as spiral double radio AGNs (SDRAGNs). The reason why there are so few recognized objects with spiral hosts is unknown. Astronomers suspect a significant rôle for the dense interstellar medium, which may inhibit the formation of large-scale relativistic jets. Different parameters of the central SMBHs found in early- or late-type galaxies may also be important. Modeling the generation and outflow of large amounts of energy from the centers of some galaxies must be verified with observational data based on numerous, uniform samples of radio galaxies. However, only a few dozen radio sources associated with spiral galaxies have been identified so far.
   
   The goal of this project is to search for radio galaxies associated with spiral hosts based on the latest radio sky surveys. In this way, we expect to significantly increase the sample size of the SDRAGNs. Additionally, the student will select SDRAGNs for detailed multifrequency radio analysis.

5. Against all odds: investigating the one-sided extended radio sources from the ROGUE I catalog
   Mentor: Dr hab. Arti Goyal

   The theory of the formation of classical (double-lobed) radio sources with sizes ranging from parsec to mega-parsec scales mandates the presence of radio lobes on both sides of the optical host galaxy. The Radio sources associated with Optical Galaxies and having Unresolved and Extended morphologies I (ROGUE I) catalog lists the optical and radio morphologies of 32,616 radio sources classified through visual identification. This catalog is the largest of its kind that uses the Sloan Digital Sky Survey (SDSS) optical maps, Faint Images of Radio Sky at Twenty cm (FIRST), and NRAO Sky Survey (NVSS) radio maps to ascertain the respective morphologies. In this study, approximately 2,500 sources are found to have extended radio morphologies. Surprisingly, about 500 of them have extended radio-emitting lobe ONLY on one side of the optical host galaxy. This project aims to explore the nature of these sources.
   
   In this project, we will use more sensitive and better angular resolution LOFAR maps at 150 MHz, and the recently released VLA Sky Survey (VLASS) maps at 3 GHz to confirm the single-sided lobe of these sources. In addition, we will use optical emission-line diagnostics to measure the black hole mass, disk luminosity, etc. Finally, these quantities will be compared with similar size classical double radio sources.
   
   Within the scope of this project, the student will learn:
   - strengths and weaknesses of sky survey programs conducted at different wavebands and how to use them to our advantage;
   - cross-matching techniques to identify sources from different survey catalogs;
   - understanding the fundamental physics of radio source formation and evolution.
   
   More information about the ROGUE project is available at http://rogue.oa.uj.edu.pl. 

6. Tracing Star Formation in Galaxies with Powerful Radio Jets
   Mentor: Dr hab. Arti Goyal
   Co-Mentor: Subhrata Dey

   Radio galaxies host powerful jets launched from supermassive black holes that can extend far beyond their host galaxies and potentially influence their evolution. In this internship project, students will work with a sample of extended radio galaxies from the ROGUE I survey developed by researchers at Jagiellonian University. Using multi-wavelength observations and spectral energy distribution modeling with CIGALE, the project will focus on estimating key astrophysical properties such as AGN properties, stellar mass, dust attenuation, and star formation rates on different timescales. Students will explore how star formation activity relates to the presence and size of radio jets, providing insight into the role of active galactic nuclei in regulating galaxy evolution.
   
   Through this project, students will gain hands-on experience in modern astrophysical research, including multi-wavelength data analysis, SED modeling, and statistical interpretation of galaxy properties. They will develop practical skills in computational data analysis and scientific interpretation while learning about the physical processes linking black hole activity, radio jets, and star formation in galaxies. The internship offers an opportunity to contribute to an active research topic in extragalactic astrophysics while building valuable research and data science skills.

7. Teaching Machines to Recognize Radio Galaxies: Machine Learning for the Next Generation of Radio Surveys
   Mentor: Dr hab. Arti Goyal
   Co-Mentor: Subhrata Dey

   Radio galaxies display a remarkable diversity of shapes and sizes, reflecting the complex physics of supermassive black holes and their interaction with the surrounding environment. Their radio morphologies—such as Fanaroff–Riley type I and II, X-shaped, Z-shaped, and double–double radio galaxies—provide important clues about jet power, galaxy environment, and the life cycles of active galactic nuclei. Identifying and classifying these structures is therefore crucial for understanding galaxy evolution. In this project, students will use the largest human-classified sample of radio galaxies from the ROGUE survey, developed by researchers at Jagiellonian University, as a high-quality training dataset to develop machine learning models capable of automatically recognizing radio galaxy morphologies.
   
   Students will train and test machine learning algorithms on the ROGUE I dataset and then apply the trained models to radio images from modern surveys such as LOFAR Two-Metre Sky Survey and MeerKAT radio telescope. The goal is to automate the classification of radio galaxy morphologies in large datasets, enabling efficient analysis of thousands to millions of sources. This work will contribute directly to the challenges posed by next-generation facilities such as the Square Kilometre Array, which will produce unprecedented volumes of radio data. Through this project, students will gain hands-on experience in machine learning, astronomical image analysis, and big-data science while contributing to the development of tools essential for the future of radio astronomy.