Latest News
Are gamma-ray flares really random?
In the paper, titled “Signatures of scale-free dynamics in blazar gamma-ray flares,” Dmitry Prokhorov, L. Pfeifer and Prof. Buson tackle the temporal properties of gamma-ray flares using Fermi-LAT light curves from a large sample of blazars. The results reveal scale-invariant patterns in flare durations and waiting times, offering new insights into the complex and seemingly unpredictable nature of blazar variability. The study also examines the gamma-ray activity of TXS 0506+056 in the context of the high-energy neutrino event IC170922A.
September 2026Lepto-hadronic modeling of candidate neutrino sources
A new paper by Leonard Pfeiffer, Margot Boughelilba, and collaborators, titled "Lepto-hadronic modeling of blazars associated with well-reconstructed high-energy neutrino events", has been accepted for publication in Astronomy & Astrophysics (A&A). The study investigates six blazars spatially associated with high-energy IceCube neutrino events using multifrequency observations and lepto-hadronic emission models. The results show that these blazars can plausibly be linked to individual high-energy neutrino events, providing further insights into the connection between active galaxies and high-energy neutrinos.
September 2026Prof. Buson presenting at NOW 2026
At the Neutrino Oscillation Workshop (NOW 2026), in Otranto, Italy, Prof. Buson gave the plenary talk “The Sky through Gamma Rays and Other Messengers.” As part of the session “Particle Physics from the Sky and the Cosmos,” her presentation highlighted the role of gamma-ray observations and multimessenger astronomy in exploring the high-energy Universe and advancing our understanding of its most energetic phenomena.
September 2026Prof. Buson's Lectures at Hel.A.S Summer School
Prof. Buson was invited as a lecturer at the 6th Hel.A.S. Astrophysics Summer School in Athens, held from 24–28 August 2026 and focused on multimessenger astronomy. She delivered lectures on high-energy astrophysics with GeV gamma rays and on neutrino–gamma-ray cross-correlation studies, complemented by hands-on practical sessions. Through these activities, she shared her expertise in high-energy and multimessenger astrophysics with graduate students and early-career researchers.
August 2026Leo's Best Poster Award at the 2026 ISCRA School!
Leo Pfeiffer attended the 2026 International School of Cosmic Ray Astrophysics (ISCRA) under the theme *“Particles and the Cosmos – Bridging the Infinitesimal and the Infinite.”* During the week-long school, he attended lectures by leading researchers covering a broad range of topics, from multimessenger and cosmic-ray astrophysics to dark matter physics. He also presented his work on lepto-hadronic modeling of blazars associated with high-energy neutrino events and received the Best Poster Award from the school’s Committee.
August 2026Würzburgs Day of Physics 2026
The Day of Physics
is one of the University of Würzburg’s largest outreach events.
Bringing together chairs and professors across the university, the event features more
than 20 interactive exhibition stands, talks, and live connections with research institutes
around the world. It celebrates Conrad Röntgen, the first Nobel Prize winner in Physics,
who discovered X-rays in Würzburg.
The MessMapp group contributed to the event with an interactive exhibition highlighting the Sun
as both a fascinating object of scientific research and a potential sustainable source of energy
for the future.
FRANCI Meeting 2026
The Franconian Astronomy Neighborhood Collaboration Incentive (FRANCI) brings together universities across Franconia to exchange recent research highlights, group activities, and ideas for future collaborations. At this year’s meeting, Leo Pfeiffer presented recent research developments and results from the MessMapp project since the previous meeting.
June 2026Another Bachelor Thesis!
David Hajatpour successfully defended his Bachelor Thesis tackling the correlation of X-ray blazars and IceCube high-energy neutrino alerts.
June 2026KM3NeT paper led by Massimiliano and Leo published!
The companion paper for the KM3NeT ultra-high-energy event, co-led by our group members Massimiliano Lincetto and Leonard Pfeiffer, is now published!
June 2026Sara Buson: Colloquium at INFN Tor Vergata University
Prof. Buson gave a colloquium at INFN Tor Vergata University, presenting recent developments in multimessenger astronomy and sharing insights from our group research on high-energy gamma rays and astrophysical neutrinos.
June 2026Can one source class dominate the astrophysical neutrino flux?
A new paper by Walter Winter, Damiano F. G. Fiorillo, and Sara Buson, “Single-source-class interpretation of the diffuse astrophysical neutrino flux,” has been published in Physical Review D. Read the paper
The study investigates whether the diffuse astrophysical neutrino flux could be dominated by a single class of sources. Using detailed models of high-energy particle interactions, the authors explore the physical conditions required to reproduce the observed neutrino spectrum. The results suggest that future measurements of neutrino properties could help distinguish between different source scenarios and point to active galactic nucleus cores as a possible origin of the diffuse neutrino emission.
June 2026The 37th Rencontres de Blois on "Particle Physics and Cosmology"
At the 37th edition of this annual international multidisciplinary conference, Prof. Buson delivered a highlight talk on recent advances in the search for extragalactic neutrino sources, including recent results from our group.
May 2026ACME grants awarded to our group’s PhD students"
Visiting Experts through the second ACME TNA Call to Centres of Expertise:
Leo Pfeiffer and Jose Maria Sanchez Zaballa undertook research visits
supported by ACME grants awarded for their work in multimessenger astrophysics.
Leo visited CPPM in Marseille, where he contributed to an astronomy module for
identifying promising electromagnetic counterparts to KM3NeT neutrino candidates,
which will become part of the KM3NeT real-time analysis framework.
Jose Maria visited APC in Paris to develop expertise in neutrino analysis methods, working on
likelihood-analysis codes, GammaPy, and KM3NeT/ARCA230 detector response functions,
and exploring the integration of IceCubePy into the online multimessenger analysis platform MMODA.
4th MuMeNTA Workshop: Multi-MEssenger Numerical Techniques in Astrophysics
The 4th MuMeNTA Workshop took place in Athens, Greece, at Harokopio University. The three-day workshop, co-organised by Prof. Buson, brought together the multi-messenger modeling community to discuss and advance numerical modeling tools and codes used across the field. Our PostDoc Margot Boughelilba presented a time-dependent lepto-hadronic study of the neutrino-blazar candidate 5BZQ J0808+4950. This jetted AGN is located close to the direction of a high-energy neutrino and hotspot identified in approximately nine years of IceCube data. The study investigates whether neutrinos could be produced in the jet near the supermassive black hole through efficient particle acceleration.
March 2026Bachelor Thesis defended!
Emelie Kobsar successfully defended her Bachelor Thesis. The work tackled a new parametrization of point spread functions for neutrino detectors using IceCube Observatory data.
January 2026PhD Thesis successfully defended!
Alessandra Azzollini successfully defended with magna cum laude her PhD thesis, “Blazars in a multi-messenger perspective”, on the physical properties of candidate neutrino-emitter blazar candidates using a multi-wavelength approach.
December 2025The changing look of the neutrino-emitter blazar candidate 5BZQ J1243+4043
A work led by PhD student Alessandra Azzollini, focused on a candidate neutrino-emitter blazar, 5BZQ J1243+4043, that has been reported as a “changing-look” blazar. This Letter to the Editor, published in Astronomy & Astrophysics, investigates the spectral properties of this source, inferring the characteristics of its radiation field and accretion regime across different epochs. More Details
November 2025MessMapp results presented at the HEPRO IX conference
Prof. Buson was invited for an overview talk of MessMapp project's results at the HIGH ENERGY PHENOMENA IN RELATIVISTIC OUTFLOWS IX conference, in Rio de Janeiro. The contribution included the latest developments of icecubepy, and the latest multimessenger and theoretical modeling results.
August 2025Candidate neutrino-emitter blazars: intense radiation fields, powerful jets and efficient accretion
A study published in the Astronomy & Astrophysics Journal focused on the multi-wavelength properties of candidate neutrino-emitter blazars. The work, led by PhD student Alessandra Azzollini, investigates the physical nature of a subset of blazars using radio, optical spectroscopic, and gamma-rays information. Using statistical techniques, it show that candidate neutrino-emitter blazars display a mild tendency toward hosting intense radiation fields, powerful jets and radiatively efficient accretion, in contrast to the general blazar population.
August 2025The X-ray band as probe of multimessenger emission in blazars
The X-ray band is a key tracer of hadronic processes in the blazar's SED, providing indirect evidence of neutrino production. In a new study published in The Astrophysical Journal, PhD student Jose Maria Sanchez Zaballa investigated the X-ray spectral properties of the blazar 5BZB J0630-2406, a candidate neutrino source, using multi-epoch observations from XMM-Newton, NuSTAR, Swift-XRT, and eROSITA. While blazars are typically dominated by jet emission, Jose Maria and collaborators discovered that during low-flux states, 5BZB J0630-2406 shows an unexpected hard X-ray component. The findings suggest that the blazar may switch from a jet-dominated regime to a more complex emission scenario, consistent with processes such as coronal emission or photoionized absorption usually found in obscured AGN. The work unravels possible similarities in the multimesseger (neutrino) emission of blazars with non-jetted sources, such as the Seyfert galaxy NGC 1068.
July 2025Icecubepy and KM3NeT results presented at ICRC 2025 - The Astroparticle Physics Conference
The 2025 International Cosmic Ray Conference took place in Geneva. Massimiliano Lincetto, postdoc in the MessMapp group,
presented the latest developments of icecubepy, an open source software for the analysis of public IceCube data,
fruit of an intense effort by our group. More info about icecubepy are available at
the public GitHub repository,
In another presentation, Massimiliano reported the findings on the search and characterisation of candidate blazar counterparts
of the KM3NeT ultra-high energy event. The study was co-lead by the MessMapp group, with the involvement of an international team of collaborations.
Pre-print available in arXiv:2502.08484!
Fermi-LAT Collaboration Meeting 2025
At the 2025 Fermi-LAT Collaboration meeting in Milan, PhD student Leonard Pfeiffer reported on ongoing efforts by our team on the study of IceCube and KM3NeT high-energy events. One contribution focused on the search for blazar counterparts to the KM3NeT ultra-high energy neutrino detection, building on the results reported in the pre-print available on arXiv. In a second contribution, he provided an overview of the progress on neutrino real-time follow-up program with the Fermi-LAT, showcasing how rapid response analyses are being developed to unravel the possible connection between high-energy neutrino alerts and gamma-ray observations.
March 2025Workshop on Numerical Multi-Messenger Modelling
This workshop took place at DESY Zeuthen,
bringing together the community working on numerical codes to simulate multi-messenger emission (photons, neutrinos, cosmic rays)
from astrophysical sources. The workshop was designed to foster discussion and co-working, with sessions dedicated to recent
code developments and comparisons, applications to prominent sources in the photon/neutrino sky, and strategies for
multi-messenger data fitting. A huge organizational effort by Margot Boughelilba made the event possible.
Our group contributed with several talks: Jose Maria Sanchez Zaballa presented results on X-ray spectral features and
neutrino production in blazar 5BZB J0630-2406; Leonard Pfeiffer reported on the lepto-hadronic modelling of the
neutrino-candidate blazar 5BZB J1150+2417; and Massimiliano Lincetto discussed the KM3NeT ultra-high-energy
neutrino and its possible blazar origin (see also the pre-print on arXiv).
To close, Sara Buson gave an overview of MessMapp activities and recent science highlights, placing the
presented studies in a broader context and outlining the group's future directions.
The Highest Energy Neutrino Ever Observed
The KM3NeT collaboration measured a neutrino of record breaking energies using their ARCA detector in the mediterranian sea. Our team contributed to this study, helping shedding light in the possible blazar counterparts to this ultra-high-energy neutrino. Read more about these in the article published in Nature and the companion paper lead by our team. For more information, see the news website of the Julius-Maximilians University Würzburg.
February 2025Bachelor Thesis defended!
Annette Bremer finished and defended her Bachelor thesis on the characterization of the performance of an unbinned likelihood analysis framework using public data from the IceCube neutrino observatory.
October 2024Bachelor and Master Thesis defended!
Kilian Fischer finished and defended his Bachelor thesis
on the orbital Doppler boosting hypothesis of super massive black hole binaries.
Continuing his work in the MessMapp group also Leonard Pfeiffer completed his research
on the leptonic modelling of a candidate neutrino emitter blazar and successfully defended
his Master thesis
at the Julius-Maximilians University of Würzburg.
A new member joining the group
We welcome: Dmitry Prokhorov, joining as a PostDoc. Dmitry is a researcher with experience in studying high energy data of AGN and supernovae. Now, his research will focus on variability studies of Fermi-LAT blazars.
May 2024Proposal for Nustar
...is accepted!
May 2024A new member joining the group
We welcome: Margot Boughelilba, joining as a PostDoc. Margot is a researcher with experience in studying radio galaxies. Currently, her research focuses on the SED modelling of the broad-band emission of blazars.
April 2024Proposal for Swift cycle 20
...is accepted!
February 2024Sub-GeV Gamma Rays from Nearby Seyfert Galaxies and Implications for Coronal Neutrino Emission
...is now published. It presents the results of recent observations of high-energy neutrinos by IceCube and gamma rays by the Fermi Large Area Telescope (LAT) and the MAGIC telescope, in which Sara Buson was involved.
February 2024The galactic bubbles of starburst galaxies \\ The influence of galactic large-scale magnetic fields
...is now published with contributions by Gaëtan. It presents the observations of the large-scale magnetic field, in which galactic winds expand, that can impact the structure and evolution of inflated bubbles.
February 2024Two new members joining the team
Josè Maria Sanchez Zaballa, joining as PhD student. Josè obtained his master degree
at the University of Padova, under the supervision of Prof. E. Bottaccini.
His thesis focused on the modelling of the spectral energy distribution of AGN.
Massimiliano Lincetto, joining as PostDoc. His experience in the high-energy multi-messenger
neutrino field is evidenced by substantial contributions made within the IceCube and KM3NeT collaborations.
The ICRC 2023
Prof. Sara Buson presented the previous work of the group at the astroparticle physics conference in Nagoya, Japan.
Vardan Baghmanyan also contributed with a talk about gamma-ray lightcurve variability of AGN. The group shared three posters summarizing the ambitous work of Alessandra, Eleonora and Gaetan.
The Galileo Galilei Science&Space Festival 2023
Prof. Sara Buson gave a speech at the Press Centre at ESOC in Darmstadt as part
of the Galileo Science&Space Festival 2023.
Her presentation delved into the fascinating realms of multi-messenger astronomy,
blazars and the possible origin of extragalactic neutrinos detected by IceCube.
For more details about the festival, see here .
Further results by the MessMapp team now accessable on ArXiv!
Extragalactic neutrino factories
Read the article.
Master Thesis defended!
After six months spent in our group through the Erasmus program, Margherita de Toma completed her research on a peculiar gamma-ray source: a gravitational lensed blazar. She successfully defended her Master thesis at the University of Pisa.
May 2023Two new members joining the team
We welcome two new team memers: Eleonora Barbano, joining as PhD student. Eleonora obtained her master degree at the University of Torino, under the supervison of Prof. R. Bonino. Her thesis focused on the study of cosmic rays with the Fermi Large Area Telescope. Gaetan Fichet de Clairfontaine, joining as a PostDoc. Gaetan got his PhD degree at the Observatory of Paris, under the supervison of Prof. A. Zech. His PhD thesis focused on the modeling of AGN relativistic jet.
October 2022Early results by the MessMapp team published in ApJL!
Beginning a journey across the Universe: the discovery of extragalactic neutrino factories.
Read the article in ApJL (Buson et al. 2022, ApJL , 933, 43; ArXiv link).
Erratum article in ApJL (Buson et al. 2022, ApJL , 934, 2).
A new member joining MessMapp
We welcome: Vardan Baghmanyan, joining as a PostDoc. Vardan is a researcher with experience in studying GeV/TeV gamma-rays emitted by galactic sources, including molecular clouds and pulsar wind nebulae (PWNe). Currently, his research focuses on investigating the variability of TeV emissions from blazars.
July 2022B.Sc. Leonard Pfeiffer
Leo defended his Bachelor thesis. His work focussed on the charactherization of a possible PeVatron blazar.
Available at:
Multiwavelength investigation of PKS 1814-63 as a candidate gamma-ray source.
A new member joining MessMapp
We welcome: Alessandra Azollini, joining as a PhD student. Alessandra did her
master in the
University of Pisa under the supervision of Prof. S. N. Shore,
focusing on multi-wavelength spectroscopy of shock phenomena propagation in
explosive outbursts of symbiotic-like Recurrent Novae.
B.Sc. Lenz Oswald
Lenz defended his Bachelor thesis. His work focussed on candidate counterparts to
IceCube events in the field of eRASS. Available at:
Analysis of Counterparts of the Neutrino IceCube-200615A in the eFEDS Field of eROSITA