TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission: I. Program description and sample characterization

Eppel F, Kadler M, Hea-Dörfer J, Benke P, Debbrecht L, Eich J, Gokus A, Hämmerich S, Kirchner D, Paraschos GF, Rösch F, Schulga W, Sinapius J, Weber P, Bach U, Dorner D, Edwards PG, Giroletti M, Kraus A, Hervet O, Koyama S, Krichbaum TP, Mannheim K, Ros E, Zacharias M, Zensus JA (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Astronomy & Astrophysics EDP Sciences

Book Volume: 684

Article Number: A11

DOI: 10.1051/0004-6361/202348262

Abstract

Aims. We introduce the TELAMON program which is using the Effelsberg 100-m telescope to monitor the radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, specifically TeV blazars and candidate neutrino-associated AGN. Here, we present and characterize our main sample of TeV-detected blazars. Methods. We analyzed the data sample from the first a2.5 yr of observations between August 2020 and February 2023 in the range from 14 GHz to 45 GHz. During this pilot phase, we observed all 59 TeV-detected blazars in the Northern Hemisphere (i.e., Deca- >a- 0) known at the time of observation. We discuss the basic data reduction and calibration procedures used for all TELAMON data and introduce a sub-band averaging method used to calculate average light curves for the sources in our sample. Results. The TeV-selected sources in our sample exhibit a median flux density of 0.12 Jy at 20 mm, 0.20 Jy at 14 mm, and 0.60 Jy at 7 mm. The spectrum for most of the sources is consistent with a flat radio spectrum and we found a median spectral index (S(ν)a- να) of αa- =a- a- 0.11. Our results on flux density and spectral index are consistent with previous studies of TeV-selected blazars. Compared to the GeV-selected F-GAMMA sample, TELAMON sources are significantly fainter in the radio band. This is consistent with the double-humped spectrum of blazars being shifted towards higher frequencies for TeV-emitters (in particular for high-synchrotron peaked BL Lac type objects), which results in a lower radio flux density. The spectral index distribution of our TeV-selected blazar sample is not significantly different from the GeV-selected F-GAMMA sample. Moreover, we present a strategy to track the light curve evolution of sources in our sample for future variability and correlation analysis.

Authors with CRIS profile

Steven Hämmerich Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut

Involved external institutions

Fraunhofer-Institut für Biomedizinische Technik (IBMT) / Fraunhofer Institute for Biomedical Engineering DE Germany (DE) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy DE Germany (DE) Commonwealth Scientific and Industrial Research Organisation (CSIRO) AU Australia (AU) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) Santa Cruz Institute for Particle Physics US United States (USA) (US) Niigata University / 新潟大学 JP Japan (JP) Ruprecht-Karls-Universität Heidelberg DE Germany (DE) Deutsches Elektronen-Synchrotron DESY DE Germany (DE)

How to cite

APA:

Eppel, F., Kadler, M., Hea-Dörfer, J., Benke, P., Debbrecht, L., Eich, J.,... Zensus, J.A. (2024). TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission: I. Program description and sample characterization. Astronomy & Astrophysics, 684. https://dx.doi.org/10.1051/0004-6361/202348262

MLA:

Eppel, F., et al. "TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission: I. Program description and sample characterization." Astronomy & Astrophysics 684 (2024).

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