• 3HSP J095507.9+355101: A flaring extreme blazar coincident in space and time with IceCube-200107A 

      Giommi, P.; Padovani, P.; Oikonomou, Foteini; Glauch, T.; Paiano, S.; Resconi, E. (Peer reviewed; Journal article, 2020)
      The uncertainty region of the highly energetic neutrino IceCube200107A includes 3HSP J095507.9+355101 (z = 0.557), an extreme blazar, which was detected in a high, very hard, and variable X-ray state shortly after the ...
    • Comprehensive Multimessenger Modeling of the Extreme Blazar 3HSP J095507.9+355101 and Predictions for IceCube 

      Petropoulou, Maria; Oikonomou, Foteini; Giommi, Paolo (Peer reviewed; Journal article, 2020)
      3HSP J095507.9+355101 is an extreme blazar that has been possibly associated with a high-energy neutrino (IceCube-200107A) detected 1 day before the blazar was found to undergo a hard X-ray flare. We perform a comprehensive ...
    • Curious case of the maximum rigidity distribution of cosmic-ray accelerators 

      Ehlert, Domenik; Oikonomou, Foteini; Unger, Michael (Peer reviewed; Journal article, 2023)
      In many models, the sources of ultra-high-energy cosmic rays (UHECRs) are assumed to accelerate particles to the same maximum energy. Motivated by the fact that candidate astrophysical accelerators exhibit a vast diversity ...
    • Gamma-ray counterparts of 2WHSP high-synchrotron-peaked BL Lac objects as possible signatures of ultra-high-energy cosmic ray emission 

      Toomey, Michael; Oikonomou, Foteini; Murase, Kohta (Peer reviewed; Journal article, 2020)
      We present a search for high-energy γ-ray emission from 566 Active Galactic Nuclei at redshift z > 0.2, from the 2WHSP catalogue of high-synchrotron peaked BL Lac objects with 8 yr of Fermi-LAT data. We focus on a redshift ...
    • High-Energy Neutrino and Gamma-Ray Emission from Tidal Disruption Events 

      Murase, Kohta; Kimura, Shigeo; Zhang, Bing; Oikonomou, Foteini; Petropoulou, Maria (Peer reviewed; Journal article, 2020)
      Tidal disruption events (TDE) have been considered as cosmic-ray and neutrino sources for a decade. We suggest two classes of new scenarios for high-energy multi-messenger emission from TDEs that do not have to harbor ...
    • High-energy neutrino emission from blazars 

      Oikonomou, Foteini (Peer reviewed; Journal article, 2022)
      Active galactic nuclei (AGN) with relativistic jets are the most powerful persistent astrophysical sources of electromagnetic radiation in the Universe. Blazars are the most extreme subclass of AGN with jets directed along ...
    • Multi-Messenger Modelling of Active Galactic Nuclei 

      Sevle, Per Arne (Master thesis, 2023)
      Aktive galaktiske kjerner (AGN) er de kraftigste, kontinuerlige kildene i Universet. For å oppnå en dypere forståelse for disse intrikate objektene hele deres multi-messenger emissivitet utforskes. Denne avhandlingen ...
    • Multi-messenger modelling of FR0 galaxies 

      Paulsen, Therese (Master thesis, 2022)
      FR0-galakser er en nyoppdaget klasse av radiogalakser, som, i motsetning til FRI- og FRII-klassene, kan karakteriseres av deres begrensede jetstruktur og at de er tallrike i det lokale universet. Målet med denne masteroppgaven ...
    • A Neutral Beam Model for High-Energy Neutrino Emission from the Blazar TXS 0506+056 

      Zhang, Bing; Petropoulou, Maria; Murase, Kohta; Oikonomou, Foteini (Peer reviewed; Journal article, 2020)
      The IceCube collaboration reported an ~3.5σ excess of 13 ± 5 neutrino events in the direction of the blazar TXS 0506+056 during an ~6 month period in 2014–2015, as well as the (~3σ) detection of a high-energy muon neutrino ...
    • Quantum gravity phenomenology at the dawn of the multi-messenger era—A review 

      Addazi, A.; Alvarez-Muniz, J.; Alves Batista, Batista; Amelino-Camelia, G.; Antonelli, V.; Arzano, M.; Asorey, M.; Atteia, J.-L.; Bahamonde, S.; Bajardi, F.; Ballesteros, A.; Baret, B.; Barreiros, D.M.; Basilakos, S.; Benisty, D.; Birnholtz, O.; Blanco-Pillado, J.J.; Blas, D.; Bolmont, J.; Boncioli, D.; Bosso, P.; Calcagni, G.; Capozziello, S.; Carmona, J.M.; Cerci, S.; Chernyakova, M.; Clesse, S.; Coelho, J.A.B.; Colak, S.M.; Cortes, J.L.; Das, S.; D'Esposito, V.; Demirci, M.; Di Luca, Luca; di Matteo, Matteo; Dimitrijevic, D.; Djordjevic, G.; Prester, D. Dominis; Eichhorn, A.; Ellis, J.; Escamilla-Rivera, C.; Fabiano, G.; Franchino-Viñas, S.A.; Frassino, A.M.; Frattulillo, D.; Funk, S.; Fuster, A.; Gamboa, J.; Gent, A.; Gergely, L.A.; Giammarchi, M.; Giesel, K.; Glicenstein, J.-F.; Gracia-Bondía, J.; Gracia-Ruiz, R.; Gubitosi, G.; Guendelman, E.I.; Gutierrez-Sagredo, I.; Haegel, L.; Heefer, S.; Held, A.; Herranz, F.J.; Hinderer, T.; Illana, J.I.; Ioannisian, A.; Jetzer, P.; Joaquim, F.R.; Kampert, K.-H.; Uysal, A. Karasu; Katori, T.; Kazarian, N.; Kerszberg, D.; Kowalski-Glikman, J.; Kuroyanagi, S.; Lämmerzahl, C.; Said, J. Levi; Liberati, S.; Lim, E.; Lobo, I.P.; López-Moya, M.; Luciano, G.G.; Manganaro, M.; Marcianò, A.; Martín-Moruno, P.; Martinez, Manel; Martinez, Mario; Martínez-Huerta, H.; Martínez-Miravé, P.; Masip, M.; Mattingly, D.; Mavromatos, N.; Mazumdar, A.; Méndez, F.; Mercati, F.; Micanovic, S.; Mielczarek, J.; Miller, A.L.; Milosevic, M.; Minic, D.; Miramonti, L.; Mitsou, V.A.; Moniz, P.; Mukherjee, S.; Nardini, Germano; Navas, S.; Niechciol, M.; Nielsen, A.B.; Obers, N.A.; Oikonomou, Foteini; Oriti, D.; Paganini, C.F.; Palomares-Ruiz, S.; Pasechnik, R.; Pasic, V.; Pérez de los Heros, de; Pfeifer, C.; Pieroni, M.; Piran, T.; Platania, A.; Rastgoo, S.; Relancio, J.J.; Reyes, M.A.; Ricciardone, Angelo; Risse, M.; Frias, M.D. Rodriguez; Rosati, G.; Rubiera-Garcia, D.; Sahlmann, H.; Sakellariadou, M.; Salamida, F.; Saridakis, E.N.; Satunin, P.; Schiffer, M.; Schüssler, F.; Sigl, G.; Sitarek, J.; Peracaula, J. Solà; Sopuerta, C.F.; Sotiriou, T.P.; Spurio, M.; Staicova, D.; Stergioulas, N.; Stoica, S.; Strišković, J.; Stuttard, T.; Cerci, D. Sunar; Tavakoli, Y.; Ternes, C.A.; Terzić, T.; Thiemann, T.; Tinyakov, P.; Torri, M.D.C.; Tórtola, M.; Trimarelli, C.; Trześniewski, T.; Tureanu, A.; Urban, Federico; Vagenas, E.C.; Vernieri, D.; Vitagliano, V.; Wallet, J.-C.; Zornoza, J.D. (Peer reviewed; Journal article, 2022)
      The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection ...
    • Solving the Multimessenger Puzzle of the AGN-starburst Composite Galaxy NGC 1068 

      Eichmann, Björn; Oikonomou, Foteini; Salvatore, Silvia; Dettmar, Ralf-Jürgen; Tjus, Julia Becker (Peer reviewed; Journal article, 2022)
      Multiwavelength observations indicate that some starburst galaxies show a dominant nonthermal contribution from their central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both ...
    • Studying the arrival directions of ultra-high energy cosmic rays with deep neural networks 

      Quinton, Finley Alexander (Master thesis, 2023)
      Opprinnelsen til ultra-høye energi kosmiske stråler (UHECRs) er et over 100 år gammelt mysterium, og jakten på deres kilder er en av de største pågående utfordringene innen astropartikkelfysikk. Siden UHECRs er ladde ...