Recent observations of PKS 2155-304 with MAGIC and LST-1 in a multi-wavelength context
PKS 2155-304 is a well-known high-frequency peaked BL Lac (HBL) at redshift z=0.116, which has been extensively studied across the electromagnetic spectrum due to its rapid and large-amplitude variability. Several violent outbursts in X-rays and 𝛾-rays have been observed in the past, with intra-night variability in very-high-energy 𝛾-rays (VHE; E > 100 GeV) detected down to the minute timescale. The alternation of quiescent and enhanced states, observed with a tentative quasi-periodicity of 1.74 ± 0.13 years in high-energy (HE; 100 MeV < E < 100 GeV) 𝛾-rays, makes this source a key target also for ground-based 𝛾-ray instruments and in particular for the Imaging Atmospheric Cherenkov Telescopes. Its brightness, proximity, and well-determined redshift make this 𝛾-ray source a prime target for fundamental physics studies, including tests of Lorentz Invariance Violation (LIV), searches for axion-like particles (ALPs), and constraints on the distribution of the extragalactic background light (EBL). In the last two years, PKS 2155-304 has been independently monitored by the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes and the first Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array Observatory (CTAO) located at the Roque de Los Muchachos Observatory (La Palma, Spain). The observations were carried out at large zenith angles (LZA; ZA > 55°), and the VHE data have been complemented with simultaneous observations in HE 𝛾-rays (Fermi-LAT), X-rays (Swift-XRT) and optical wavelengths (ASAS-SN).
Authors
- F. Podobnik (ORCID: https://orcid.org/0000-0001-6125-9487)
- Jorge Otero-Santos (ORCID: https://orcid.org/0000-0002-4241-5875)
- I. Agudo (ORCID: https://orcid.org/0000-0002-3777-6182)
- G. Verna (ORCID: https://orcid.org/0000-0001-5916-9028)
- G. Bonnoli (ORCID: https://orcid.org/0000-0003-2464-9077)
- Gabriella Silvestri (ORCID: https://orcid.org/0000-0002-1950-1468)
- Davide Cerasole (ORCID: https://orcid.org/0000-0003-2033-756X)
- Francesco Schiavone
- Marina Manganaro
- Lisa Nikolić
Publication Details
- Published
- 2025-09-24
- DOI
- https://doi.org/10.22323/1.501.0783
- Primary Topic
- Geophysics and Gravity Measurements
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- Sveučilište u Zagrebu
- Comunidad de Madrid
- Ministerio de Ciencia, Innovación y Universidades
- Centres de Recerca de Catalunya
- European Commission
- Deutsche Forschungsgemeinschaft
- Ministry of Education, Culture, Sports, Science and Technology
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Ministerstvo Školství, Mládeže a Tělovýchovy
- Bundesministerium für Bildung und Forschung
- Generalitat de Catalunya
- Conselho Nacional de Desenvolvimento Científico e Tecnológico
- Max-Planck-Gesellschaft
- Narodowe Centrum Nauki
- Hrvatska Zaklada za Znanost
- Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
- Fundação Araucária
- Centre National de la Recherche Scientifique
- Ministerio de Ciencia e Innovación
- Istituto Nazionale di Astrofisica
- Sveučilište Josipa Jurja Strossmayera u Osijeku
- Junta de Andalucía
- Ministério da Ciência, Tecnologia, Inovações e Comunicações
- Istituto Nazionale di Fisica Nucleare
- Instituto de Astrofísica de Canarias
- Japan Society for the Promotion of Science
- Consejo Superior de Investigaciones Científicas
- Staatssekretariat für Bildung, Forschung und Innovation
- European Regional Development Fund
- Agencia Estatal de Investigación
- Institut National de Physique Nucléaire et de Physique des Particules
- Institute for Cosmic Ray Research, University of Tokyo