333 citations · 4.2k across the 122 of their papers we have counts for
128 papers
Delayed Radio Flares in Neutrino-associated Blazars: The Case of TXS 0506+056
S. I. Stathopoulos, C. Yuan, G. Vasilopoulos +4
Radio flares have been postulated to be associated with the production of astrophysical neutrinos. For example, TXS 0506+056 exhibits a 2-3 yr delay between the 2017 IceCube-170922…
Neutrinos and gamma rays from Seyfert galaxies constrain the properties of coronal turbulence
Federico Testagrossa, Damiano F. G. Fiorillo, Luca Comisso +3
The TeV neutrino signal observed by IceCube from the active galactic nucleus (AGN) NGC 1068 can probe its innermost coronal regions. If these neutrinos originate from hadrons accel…
The role of Bethe-Heitler pair production in reconnection-driven flares in M87*
Maria Petropoulou, Despina Karavola, Lorenzo Sironi
Rapid TeV flares have been observed from the core of the active galaxy M87. These have been attributed to inverse Compton scattering of disk photons by electrons and positrons acce…
Investigating Active Galactic Nuclei variability with the Cherenkov Telescope Array Observatory
G. Grolleron, J. Biteau, M. Cerruti +21
Blazars, a type of active galactic nuclei (AGN) with relativistic jets pointed at the observer, exhibit flux variability across the electromagnetic spectrum due to particle acceler…
Diffuse neutrino flux from relativistic reconnection in AGN coronae
D. Karavola, M. Petropoulou, D. F. G. Fiorillo +3
IceCube observations point to Active Galactic Nuclei (AGN) as promising contributors to the observed astrophysical neutrino flux. Close to the central black hole, protons can be ac…
Diffuse neutrino flux from coronal magnetospheric current sheets of accreting black holes
Despina Karavola, Maria Petropoulou, Damiano F. G. Fiorillo +2
Non-jetted AGN exhibit hard X-ray emission with a power law spectrum above 2 keV, which is thought to be produced through Comptonization of soft photons by electrons and posi…
Accelerating SED Modeling of Astrophysical Objects Using Neural Networks
Federico Testagrossa, Georgios Vasilopoulos, Despina Karavola +4
Interpreting the spectral energy distributions (SEDs) of astrophysical objects with physically motivated models is computationally expensive. These models require solving coupled d…
Time-Dependent Modeling of the Sub-Hour Spectral Evolution During the 2013 Outburst of Mrk 421
MAGIC Collaboration, K. Abe, S. Abe +192
In April 2013, the TeV blazar Markarian~421 underwent one of its most powerful emission outbursts to date. An extensive multi-instrument campaign featuring MAGIC, VERITAS, and \tex…
Black-hole mass estimation through accretion disk spectral fitting for high-redshift blazars
G. Kyriopoulos, M. Petropoulou, G. Vasilopoulos +1
High-redshift () blazars, with relativistic jets aligned toward us, probe the most powerful end of the active galactic nuclei (AGN) population. We aim at determining the black…
A generalized study of linear electromagnetic cascades in astrophysical sources
Damiano F. G. Fiorillo, Federico Testagrossa, Chengchao Yuan +2
High-energy gamma rays can trigger electromagnetic cascades via pair production on ambient photons, reprocessing their energy to lower frequencies. A classic example is the cascade…
Coupled Time-Dependent Proton Acceleration and Leptonic-Hadronic Radiation in Turbulent Supermassive Black Hole Coronae
Chengchao Yuan, Damiano F. G. Fiorillo, Maria Petropoulou +1
Turbulent coronae of supermassive black holes can accelerate non-thermal particles to high energies and produce observable radiation, but capturing this process is challenging due…
The role of dissipation distance on reconnection-driven multi-messenger signals from blazar jets
Stamatios Ilias Stathopoulos, Maria Petropoulou
Blazars are characterized by relativistic jets that are closely aligned with our line of sight. This results in relativistic beaming, making blazars among the most luminous extraga…
The contribution of turbulent AGN coronae to the diffuse neutrino flux
Damiano F. G. Fiorillo, Luca Comisso, Enrico Peretti +2
Active galactic nuclei (AGN) can accelerate protons to energies of 10-100 TeV, with secondary production of high-energy neutrinos. If the acceleration is driven by magnetized…
Can the neutrinos from TXS 0506+056 have a coronal origin?
Damiano F. G. Fiorillo, Federico Testagrossa, Maria Petropoulou +1
The blazar TXS 0506+056 has been the first astrophysical source associated with high-energy astrophysical neutrinos, and it has emerged as the second-most-prominent hotspot in the…
A Comprehensive Hadronic Code Comparison for Active Galactic Nuclei
Matteo Cerruti, Annika Rudolph, Maria Petropoulou +14
We perform the first dedicated comparison of five hadronic codes (AM, ATHEA, B13, LeHa-Paris, and LeHaMoC) that have been extensively used in modeling of the spectral energy…
Particle acceleration and multi-messenger radiation from Ultra-Luminous X-ray Sources: A new class of Galactic PeVatrons
Enrico Peretti, Maria Petropoulou, Georgios Vasilopoulos +1
Super-Eddington accretion onto stellar-mass compact objects powers fast outflows in ultra-luminous X-ray sources (ULXs). Such outflows, which can reach mildly relativistic velociti…
An acceleration-radiation model for nonthermal flares from Sgr A
Maria Petropoulou, Gabriele Ponti, Giovanni Stel +1
(Abridged) Sgr A is the electromagnetic counterpart of the accreting supermassive black hole in the Galactic center. Its emission is variable in the near-infrared (NIR) and…
Neutrino and pair creation in reconnection-powered coronae of accreting black holes
D. Karavola, M. Petropoulou, D. F. G. Fiorillo +2
A ubiquitous feature of accreting black hole systems is their hard X-ray emission which is thought to be produced through Comptonization of soft photons by electrons and positrons…
Flares from plasmoids and current sheets around Sgr A*
I. Dimitropoulos, A. Nathanail, M. Petropoulou +2
The supermassive black hole Sgr A* at the center of our galaxy produces repeating near-infrared flares that are observed by ground and space based instruments. This activity has be…
A magnetized strongly turbulent corona as the source of neutrinos from NGC 1068
Damiano F. G. Fiorillo, Luca Comisso, Enrico Peretti +2
The cores of active galactic nuclei (AGN) are potential accelerators of 10-100 TeV cosmic rays, in turn producing high-energy neutrinos. This picture was confirmed by the compellin…
The Spectra of IceCube Neutrino (SIN) candidate sources -- V. Modeling and interpretation of multiwavelength and neutrino data
Xavier Rodrigues, Martina Karl, Paolo Padovani +5
A correlation has been reported between the arrival directions of high-energy IceCube events and gamma-ray blazars classified as intermediate- and high-synchrotron-peaked BL Lacs.…
The role of magnetospheric current sheets in pair enrichment and ultra-high energy proton acceleration in M87*
S. I. Stathopoulos, M. Petropoulou, L. Sironi +1
Recent advances in numerical simulations of magnetically arrested accretion onto supermassive black holes have shed light on the formation and dynamics of magnetospheric current sh…
A closer look at the electromagnetic signatures of Bethe-Heitler pair production process in blazars
Despina Karavola, Maria Petropoulou
The ''twin birth'' of a positron and an electron by a photon in the presence of a nucleus, known as Bethe-Heitler pair production, is a key process in astroparticle physics. The Be…
Application of neural networks to synchro-Compton blazar emission models
A. Tzavellas, G. Vasilopoulos, M. Petropoulou +2
Jets from supermassive black holes in the centers of active galaxies are the most powerful persistent sources of electromagnetic radiation in the Universe. To infer the physical co…