Nordic-Baltic Astronomy Days 2026

Session

28-B2: AGN

Th-08B

28 May 2026, 15:00

Room B

Description

Chair: Joni Tammi

332. Shocks, polarisation, and high-energy emission: Probing black hole jets from VLBI to IXPE

Georgios Filippos Paraschos (Finnish Centre for Astronomy with ESO)

28/05/2026, 15:00

Oral

Jets launched by accreting supermassive black holes (SMBHs) are key to understanding how energy is extracted from compact objects and fed into their environments. How these jets form and where high-energy $\gamma$-rays are produced, in the so-called blazar zone, remain open questions. Competing scenarios place the $\gamma$-ray emission either close to the SMBH, within the broad-line region, or...

333. 3C273 at the Highest Resolution

Britton Jeter (Finnish Centre for Astronomy with ESO)

28/05/2026, 15:15

Oral

Relativistic Jets from AGN are prime sources for cosmic neutrinos and other high energy particles, and likely act as a main force to regulate star formation and evolution in their host galaxies. The precise details of the jet launching mechanism, particle content, and energetics of the emitting electrons are still poorly understood. These questions can be tackled by investigating the...

334. Variable and non-variable blazars at very high energies; comparison of fractional variability and SED peak properties

Emma Johtela (University of Turku)

28/05/2026, 15:30

Oral

Blazars, which are active galactic nuclei with relativistic jets pointing towards us, are among the most energetic phenomena in the universe. The radiation observed from blazars covers the entire electromagnetic spectrum, sometimes all the way up to the very-high-energy (VHE) gamma-rays, with energies over 100 GeV. Their VHE gamma-ray flux can vary by orders of magnitude on timescales as...

335. Cold gas feels the shove, not the heat: how the M-sigma relation emerges in multiphase bulges

Matas Tartėnas (Center for Physical Sciences and Technology)

28/05/2026, 15:45

Oral

It has long been known that supermassive black hole (SMBH) mass correlates with host galaxy properties; the most fundamental of these is the M-sigma relation between SMBH mass and bulge velocity dispersion. In the framework of active galactic nucleus (AGN) wind-driven feedback, AGN luminosity is communicated to the surrounding gas via a quasi-relativistic wind emanating from the accretion...

336. Tracing the hot gas budget at the outskirts of galaxy groups with eROSITA

Hossam Khalil (University of Helsinki)

28/05/2026, 16:00

Oral

X-ray emission from the hot gaseous atmospheres of galaxy groups and clusters is a sensitive tracer of the non-gravitational processes that redistribute the matter within and around dark matter halos. In particular, energetic processes associated with accreting matter onto supermassive black holes, known as active galactic nuclei (AGN) feedback, are currently the favoured scenario for ejecting...