In recent years, evidence has accumulated that some high-energy cosmic neutrinos may be associated with blazars. The strongest evidence for an individual association was found in the case of the blazar TXS 0506+056 which exhibited a major multi-wavelength flare coinciding with an IceCube neutrino event in 2017. A major open question is the production site of neutrinos in blazar jets,...
HST-1 is a knot in the conical kiloparsec-scale M87 jet, observed for the first time by the Hubble Space Telescope. In the images, it is the first resolved feature near the jet's "core" on the arcsecond scale. HST-1 showed superluminal speeds up to 6c and significant flaring activity in optical and across all bands from radio to X-rays and even gamma-rays. From the perspective of VLBI, the M87...
We present an overview of a proposal for the next generation Space VLBI mission Black Hole Explorer (BHEX). Its main scientific goal is to detect the photon ring and directly measure the mass and spin of supermassive black holes in centers of M87 and the Milky Way. Other science cases include demographics on a dozen of additional near-horizon sources as well as studying accretion, formation,...
Radio galaxies often exhibit complex morphologies that are challenging to identify using traditional source finders, necessitating visual inspection of radio maps. The large data volumes of the current and next generation of radio continuum surveys makes such visual inspection impractical. The objective of my research is to develop a more efficient method to identify and classify complex radio...
The origin of high-energy cosmic neutrinos detected by the IceCube observatory is a hotly debated topic in astroparticle physics. There are multiple candidate source classes which can accelerate cosmic particles to the energies required to emit high-energy cosmic neutrinos and which have in common that they lead to variable/transient radio emissions. Recent observational results suggest that...
Giant radio galaxies are a spectacular and gargantuan form of AGN, often living in under-dense environments and hosting jets that have been switched on for extended periods. Many seem ancient, with estimated ages over 100 Myr, and/or exhibit complex characteristics, suggesting multiple epochs of activity over their lifetime. In particular, studying giant radio galaxies with signs of young,...
Relativistic jets from Active Galactic Nuclei (AGN) are suggested to originate from supermassive black holes at the center of galaxies, surrounded by their accretion disks. The properties of the disks are intrinsically linked to the characteristics of the launched jets, in what is known as disk-jet connection. When considering their magnetization, accretion disks fall into two main categories:...
Remnant radio galaxies (RRGs) are characterized with switched off AGN activity resulting relic lobes devoid of any supply of plasma from jets. Despite the cessation of AGN activity, lobes can be detected for a period of time before they fade away due to radiative and dynamical energy losses. The time-scale of the remnant phase and AGN duty cycle are vital to understanding the evolution of...
Firstly, I will present our work on linking the radio-AGN life-cycle with feedback on the ionized gas. By combining the LOFAR survey LoTSS with other large radio surveys like FIRST and VLASS, we identified a sample of 5,700 radio-AGN at various evolutionary stages and ~150 restarted AGN. We characterized the [OIII] kinematics of the sample and found a significant correlation between the...
