Agnieszka Janiuk (CFT PAN)
The observations of the gravitational wave source, the compact binary merger GW170817, revealed the presence of a short GRB, emitted by a relativistic jet, and a kilonova powered by heavy-element nucleosynthesis. A multi-component picture of the post-merger system is needed to explain the complex phenomenology of this source. I will present recent results of our GR MHD simulations, based on detailed microphysics, neutrino cooling, and radiative transfer, that are focused on the role of accretion disk winds. A related open question here is how the lifetime of a hypermassive neutron star, possibly formed after the merger and ultimately undergoing collapse to a black hole, shapes the ejecta. In the second part of the talk, I'll briefly discuss the hidden evolution of GRB jets that may be revealed by their GW signals. It can be shown that detections of GWs from nearby long GRBs and Type Ic SNe could help constrain the mechanisms operating in their central engines. Finally, I will highlight recent developments of numerical techniques by our group, related to self-gravitating collapsar models.
Federico Gonzalez (Universidad Nacional de San Juan)
Radek Poleski (OAUW)
Christian Ikechukwu Eze (CAMK PAN)
Leatitia Gibaud (University of Białystok)
Mikołaj Korzyński (CFT PAN)
Sebastian Trojanowski (Astrocent)
On October 6, 2026, the Nobel Prize in Physics was awarded to Francis Halzen "for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin". A particle theorist by training, Halzen has often remarked that he ended up leading a massive experimental collaboration at the South Pole "by accident", making this prize a tribute to the synergy between theory and experiment. Because TeV-PeV neutrinos are born in high-energy proton collisions and travel through dense matter without being absorbed or deflected, they allow us to pinpoint the cosmic accelerators where protons reach extreme energies. In this talk, I will discuss how a cubic kilometer of Antarctic ice was turned into a giant particle detector, and how IceCube simultaneously probes the environments around supermassive black holes and particle interactions at energies beyond terrestrial colliders.
Dorottya Szesci (Nicolaus Copernicus University, Toruń)
The metal-poor, irregular dwarf galaxy called I Zwicky 18 has been suggested to harbor (theorized) progenitors of Gravitational-Wave emitting mergers. The galaxy emits an unprecedented amount of hard ionizing radiation together with certain emission features in its spectrum. To explain this, a theorist like me has to put together a complex hypothesis based on reliable computer models of those stars, and compare its predictions to all available observations in the literature. Sounds easy, right? But what if she finds that the observations *themselves* actually contradict each other? Then she has no choice but go down the rabbit hole of learning how observational astronomers work, speak, and think – a scientific challenge in itself. In this talk, I share my curious story of the past 12 years tackling the case of I Zwicky 18, and my hunt for finding observational evidence for the existence of a certain type of GW progenitors, which have just come to an end. (Relevant paper: A&A 703 A131)
Parikshit Biswas (CAMK, Warsaw)
