Abstract

Contributed Talk - Splinter Multimessenger

Friday, 13 September 2024, 14:50   (S25)

Short-Wavelength Radio Monitoring of Blazars with Very-High-Energy Emission in Total and Polarized Intensity

Jonas Heßdörfer on behalf of the TELAMON team
Julius-Maximilians-Universität Würzburg, MPIfR

We present recent results of the TELAMON program, which is a key-science program on the Effelsberg 100-m telescope to monitor the radio spectra of AGN under scrutiny in astroparticle physics, namely TeV blazars and neutrino-associated AGN. Here, we give an update of the program after ~4 years of observations. Recent results support the association between AGN and ultrahigh-energy cosmic-ray and neutrino emission, where the latter might be characteristically associated with radio flares in blazars. In this context, the Effelsberg telescope yields superior radio data compared to other monitoring programs in the low flux density regime due to its large dish aperture and sensitive instrumentation. This is particularly important as TeV-emitting blazars are often comparatively faint radio sources. Our sample includes all known northern TeV-emitting blazars as well as blazars positionally coincident with IceCube neutrino alerts. In order to compile a unique radio-defined sample of likely neutrino-associated AGN, we follow up on new IceCube alerts and include relevant sources into our monitoring sample. We recover total intensity as well as polarization information at high radio frequencies up to 44GHz. Coordinated and triggered mm-VLBI observations of selected TELAMON sources help to get a better understanding of the physical processes in parsec-scale jets related to high-energy astrophysics.