6th Hel.A.S. Astrophysics Summer School

Contribution List

10. Guide field effects on particle reconnection in relativistic plasmas

Despina Karavola (National and Kapodistrian University of Athens)

25/08/2026, 14:00

Oral

Student Talks

Magnetic reconnection is a key mechanism for particle acceleration in astrophysical plasmas and has been widely studied using Particle-In-Cell (PIC) simulations. Because of high computational cost, most studies are restricted to 2D geometries, which only capture dynamics within the reconnection plane. In contrast, fully 3D reconnection allows particles to escape the current sheet and...

9. Study on synchrotron cooling of pitch-angle anisotropic electrons in relativistic magnetic reconnection.

Giorgos Konstantis (National and Kapodistrian University of Athens (NKUA))

25/08/2026, 14:12

Oral

Student Talks

Synchrotron radiation is a ubiquitous mechanism linked to non-thermal emission across different bands of the electromagnetic spectrum from radio to x-rays and even γ-rays in a plethora of astro-physical sources ranging from supernova remnants to active galactic nuclei (AGN) and gamma-ray bursts (GRBs). A key physical parameter for the synchrotron emission of a single particle is the angle...

11. Impact of Magnetic Field Inclination on MRI Evolution in Pair-Plasma Accretion Disks

Konstantinos Xanthos Argyropoulos (KU Leuven)

25/08/2026, 14:24

Oral

Student Talks

In this project I investigate how the inclination of the initial magnetic field affects MRI development in astrophysical accretion disks, using an electron-positron pair plasma approach. Previous studies have mostly considered vertical fields, leaving the role of oblique or toroidal fields unexplored in 3D kinetic simulations. By varying the magnetic field inclination, I study how geometry...

5. Magnetized inner disks explain Changing-Look AGN

Marios Kouzis (CAMK PAN)

25/08/2026, 14:36

Oral

Student Talks

Accreting supermassive black holes that undergo Changing-look events on timescales of months to a few years cannot be explained by standard accretion-disk theory; the radiation-pressure instability sets on at Eddington ratios well above the observed transition band and the viscous timescales are much longer than the observed duration.

We show that a magnetically supported disk-corona model...

12. Modeling the Multi-Wavelength Signature of Sagittarius A*

Eleni Antonopoulou (Academy of Athens / National & Kapodistrian University of Athens)

25/08/2026, 14:48

Oral

Student Talks

SgrA* shows flaring events in the near-infrared and X-ray bands
several times a day, with multiple flares tracing an orbit around the
black hole. We model the relativistic motion of hot spots and provide a
direct correlation between the flux eruption events, characteristic of the
MAD accretion state, and the observed flaring activity in the Galactic
Center (GRAVITY). However, MAD models...

4. From Models to Measurements: A Unified Framework for Blazar Polarisation Detectability

Sara Capecchiacci (IA-FORTH)

26/08/2026, 14:00

Oral

Student Talks

Multiwavelength polarimetric studies are a powerful tool used to probe the structure and physics of blazar jets. In particular, high-energy polarisation measurements allow us to discriminate between hadronic and leptonic emission scenarios. However, current polarimetric instruments are limited in sensitivity, restricting such measurements to only the brightest sources and highest flux states....

8. Artificial Neural Network classification of the Fermi-LAT 4FGL-DR4 catalog blazars of unknown type and unidentified sources

Francesco Casini (Università degli Studi di Perugia)

26/08/2026, 14:12

Oral

Student Talks

The Fermi Large Area Telescope (LAT) detected more than 7000 𝛾-ray sources in 14 years of operation which are collected in the 4FGL-DR4 catalogue. About a third of these sources are still unassociated with counterparts in other wavelength and approximately one fifth are associated with blazar of unknown type, as their classification as either BL Lac type blazars or flat spectrum radio quasars...

1. Exploring black hole magnetospheres with neural networks: recent developments

Georgios Karydianakis (National and Kapodistrian University of Athens, Academy of Athens)

26/08/2026, 14:24

Oral

Student Talks

Physics Informed Neural Networks have recently begun to be employed for the study of compact objects' magnetospheres. Known for their flexibility and ability to handle non linear equations, these new methods prove themselves to be potentially more efficient than traditional numerical techniques. Their feats include the ability to smoothly cross multiple critical surfaces, unlike most...

13. Search for the diffuse astrophysical neutrino flux with KM3NeT/ARCA

Chrysovalantis Karagiannis (National Centre of Scientific Research "Demokritos")

26/08/2026, 14:36

Oral

Student Talks

KM3NeT/ARCA is an underwater neutrino telescope currently under
construction in the Mediterranean Sea, off the coast of Portopalo di
Capo Passero (Sicily, Italy), at a depth of approximately 3500 m. As the
detector expands and reconstruction techniques improve, the increased
detector livetime steadily enhances its sensitivity to high-energy
astrophysical neutrinos. In this...

2. Vacuum Geometry: The Weyl Tensor, Principal Null Directions, and the Petrov Classification Supervisor: Dr. Theocharis Apostolatos

Nikolaos Doulgerakis

28/08/2026, 12:12

Oral

Student Talks

The direct detection of gravitational waves has opened a new observational window into the Universe, making a rigorous mathematical description of gravitational radiation imperative. Within the framework of General Relativity, the Petrov classification of the Weyl tensor serves as a fundamental tool for the algebraic classification of spacetimes. The purpose of this thesis is to study the...

6. Secondary Pair Emission Effects on the 478 keV Line in Novae

Kamil Kasprzak (Jagiellonian University)

28/08/2026, 12:22

Oral

Student Talks

Novae are key sites of explosive nucleosynthesis, producing isotopes such as beryllium-7, which subsequently decays into lithium-7. This makes them strong candidates for explaining the observed Galactic lithium abundance, which exceeds theoretical predictions. In this work, I examine the potential impact of high-energy emission of secondary e+e- pairs produced along gamma-rays in hadronic...

3. Grain Alignment and Dust Evolution Physics with Polarisation (GRADE-POL) IV. Decomposition of the Dust Polarisation at Mid-Infrared Wavelengths

HARIZI Manel (MSc student in astronomy astrophysics and space technology)

28/08/2026, 12:34

Oral

Student Talks

Understanding dust polarisation at mid-infrared (mid-IR) wavelengths poses difficulties due to its potential dual composition: absorption and emission polarisation. The Aitken technique has been employed to separate the contributions of these two components, in
which the polarisation spectrum is optically thin and the absorption and emission polarisation profiles of the BN object in Orion...

7. KM3NeT Real-time Analysis System in the Era of Multi-Messenger Astronomy

Paul Deguire (Centre de Physique des Particules de Marseille)

Oral

Student Talks

Although the characterisation of the cosmic-ray flux has significantly improved over the last decades, reaching the EeV energy scale, many fundamental questions remain open. Among these, a complete model accounting for the acceleration of charged particles to extreme energies is still lacking. To this end, the KM3NeT observatory, deployed at two abyssal sites in the Mediterranean Sea, offers a...