FRB-Italy 2025

7 May 2025, 13:00 → 9 May 2025, 17:00 Europe/Rome

Aula 216 (Area Territoriale di Ricerca di Bologna)

Luciano Nicastro (Istituto Nazionale di Astrofisica (INAF)), Andrea Possenti (Istituto Nazionale di Astrofisica (INAF))

Primo workshop nazionale della comunità FRB

Questo primo workshop, aperto, mira a stabilire un punto di incontro per la comunità italiana coinvolta nelle osservazioni e nello studio degli FRB, che già conta oltre una settantina di interessati, e per chiunque voglia conoscere meglio questa classe di fenomeni. Il workshop avrà una cadenza biennale, con l'obiettivo di favorire collaborazioni e progetti per la prossima era di studi sugli FRB. Durante il ciclo di workshop ospiteremo relatori di punta su ognuno degli aspetti sia tecnici che scientifici summenzionati, nonché contributi da giovani ricercatrici e ricercatori, stimolando e sviluppando così la prossima generazione di astronome e astronomi che lavoreranno sul tema.

I Fast Radio Burst (FRB) sono un argomento di studio centrale dell’astrofisica contemporanea. Nonostante le decine di modelli teorici proposti, la loro natura intrinseca continua peraltro ad essere misteriosa. I ricercatori INAF sono coinvolti in studi tesi a: i) imporre vincoli forti sulla loro origine, tramite esperimenti di identificazione delle loro controparti attraverso l’intera banda elettromagnetica, effettuati utilizzando tutte le strutture accessibili, oltreché tramite l’esplorazione di dati di archivio; ii) validare (o respingere) l'associazione proposta tra le stelle note come magnetar e (almeno una sottoclasse) degli FRB; iii) utilizzare gli FRB come strumenti, a volte unici, per un'ampia varietà di applicazioni astrofisiche, cosmologiche e di fisica fondamentale.

 

Nota:

Chi si è già iscritto può procedere con il pagamento della quota di iscrizione, ed eventualmente della cena sociale, selezionando Fee e Cena Sociale dal menù.

locandina_FRBItaly2025.pdf

Wednesday 7 May

13:00 → 14:00 Badge collection

14:00 → 15:55 Magnetar link

Connessioni fenomenologiche e modellistica legate alle magnetar

14:00 FRB-magnetar link: solicited talk a due voci con Marta

In this talk we will review the main observational and theoretical evidences that point toward a magnetars as FRB progenitors.

Speakers: Dr Alice Borghese (ESA/ESAC), Marta Burgay (Istituto Nazionale di Astrofisica (INAF))

14:35 News on SGR 1935+2154: implications for the nature of FRBs

The galactic magnetar SGR 1935+2154 provided on April 28, 2020 the first observational evidence for a connection between magnetars and FRBs. Since then this magnetar has attracted much interest and several observational campaigns and detailed studies of its behavior have been performed.
This has also been facilitated by the fact that SGR 1935+2154 has been the most active magnetars in the last years. I will review these results discussing the relevance of SGR 1935+2154 and other galactic magnetars for our understanding of FRBs.

Speaker: Dr Sandro Mereghetti (Istituto Nazionale di Astrofisica (INAF))

14:55 Search for transient radio emission from Galactic magnetars

he radio emission from magnetars is poorly understood and characterized observationally, in particular for what concerns single pulses and sporadic events.
The interest in it was boosted by the recent detection of an extremely bright ms radio signal from the Galactic magnetar SGR 1935+2154, which occurred almost simultaneously with a typical magnetar short burst of X-rays.
As of now, this event remains the only Galactic radio pulse reminiscent of fast radio bursts (FRBs) and the only one with a sound association with a known progenitor.
We performed a long-term campaign of seven Galactic magnetars using the Northern Cross transient radio telescope searching for short timescales and dispersed radio pulses obtaining no detections in ∼480 hours of observation.
Furthermore, under some assumptions on the magnetars properties and energetic behavior, we found that our upper limits point towards the fact that the entire population of FRBs observed cannot be explained by bursts emitted by magnetars.

Speaker: Andrea Geminardi (Istituto Nazionale di Astrofisica (INAF))

15:15 The FRB-magnetar connection in nearby galaxies

During this presentation I will present recent advancements on the study of fast radio bursts (FRBs) – short, energetic radio flashes of extragalactic origin, with typical durations of a millisecond – through low frequency observations conducted with the Northern Cross radio telescope. In particular, I will show how long-term radio monitoring of a sample of nearby galaxies can help investigate the FRB–magnetar connection. In fact, although magnetars are the most invoked progenitors of FRBs, it is not clear which fraction of the FRB population can be linked to magnetars born through the, core-collapse supernova channel, i.e. similar to the ones observed in our galaxy.

Speaker: Davide Pelliciari (Istituto Nazionale di Astrofisica (INAF))

15:35 CTAO LST−1 observations of magnetar SGR 1935+2154: deep limits on sub-second bursts and persistent TeV emission

The first observational evidence linking magnetars and Fast Radio Bursts (FRBs) was the detection of simultaneous radio and X-ray bursts from the Galactic magnetar SGR 1935+2154 in 2020.
We analysed over 25 hours of observations from the Large-Sized Telescope prototype (LST-1) of the Cherenkov Telescope Array Observatory (CTAO) during periods of high-energy activity in 2021 and 2022, searching for a potential TeV counterpart to both persistent and millisecond-scale burst emission.
For bursting emission, we examined nine 0.1-second windows centered on known short X-ray bursts, targeting possible millisecond-scale TeV signals in a low-photon-statistics regime.
While no persistent or bursting TeV emission was detected, our results place upper limits on the TeV flux of short magnetar bursts and highlight the potential of magnetars and FRBs as promising candidates for future CTAO observations.

Speaker: Gabriele Panebianco (Istituto Nazionale di Astrofisica (INAF))

16:00 → 16:30 Coffe break

16:30 → 17:25 Origin: Origin & emission models

16:30 Understanding FRBs with strong gravitational self-lensing in neutron stars

Over 15 years after their discovery, the nature of fast radio burst (FRB) sources still eludes our understanding. To date their bright, coherent radio emission has no detected counterparts outside of the radio band, with the exception of the FRB-like flares emitted by the galactic magnetar SGR 1935+215. These lended support, among the countless proposed interpretations, to the idea that FRB sources may be related to a cosmic population of magnetars. I will summarize the main scenarios that have been devised for explaining the peculiarity of FRB emission, and then introduce our novel interpretation of FRB properties in terms of strong gravitational self-lensing of flares occurring in neutron star (NS) magnetospheres, i.e. flares being lensed by the gravitational field of the NS producing them. I show how this idea explains in a unified picture the large FRB luminosities, the co-existence of rare repeaters and more numerous one-off sources, and their overall energy budget, allowing at the same time to bridge the gap between the apparent paucity of FRBs in the local universe and their comparatively large all-sky rate. Moreover, this interpretation accounts for (a) the double-peaked energy distribution of individual FRBs observed in the most active repeaters, in terms of an emission geometry reminiscent of that typical of radio pulsars, and (b) the redshift (and fluence) distribution of FRBs in the first CHIME catalog, in terms of a dominant population – consistent with magnetars - following the cosmic star formation history.

Speaker: Simone Dall'Osso (Istituto Nazionale di Astrofisica (INAF))

17:05 Fast radio bursts as gravitationally lensed events in neutron star magnetospheres

Fast Radio Bursts (FRBs) have, since their first detection, ranked among the most puzzling events in the sky owing to the extreme energies involved and the presence of both repeating and non-repeating sources: 15 years and thousands of bursts later, their emission mechanism still eludes us. I will present a new unified model for FRBs as magnetospheric events from neutron stars which naturally accounts for both types of behaviours, and show the good agreement of the model with the expected energy/fluence and redshift distributions, both for the population at large and individual, well-studied sources.

Speaker: Riccardo La Placa (Istituto Nazionale di Astrofisica (INAF))

17:25 → 18:00 Make the radio transient science popular

17:25 FRB-Italy: Innovative Approaches to Outreach and Education

INAF has always been involved in the development of activities for astronomy outreach and education. The purpose is to exploit innovative teaching approaches to foster the development of scientific and critical thinking, which are fundamental skills in our society.
“Hunting for FRBs” is one of the activities developed so far that represents these aspects. This educational workshop aims to introduce high school students to the research world. Participants have to look for FRBs on a noisy data set, experiencing a process similar to the one that stands behind scientific research.
The activity is based on the student-centered approach, an educational method that focuses on the specific interests and learning styles of students. It encourages active participation, collaboration, and free experimentation, the basis for the development of scientific thinking.
In my talk, I will present in more detail the activity and its educational potential in the framework of FRB research.

Speaker: Rachele Toniolo (Istituto Nazionale di Astrofisica (INAF))

17:40 FRB-Italy: Strategies for Effective Science Communication

The first Italian workshop on FRBs aims to bring together the national scientific community interested in these enigmatic phenomena, fostering collaborations and new research projects. An essential aspect of the initiative’s success is effective communication, which helps engage both the scientific community and the broader public. This contribution will explore targeted communication strategies, including the creation of a dedicated website, the dissemination of press releases, and the strategic use of social media, with the goal of amplifying the workshop’s impact and making research findings more accessible to a wider audience.

Speaker: Dr Maura Sandri (Istituto Nazionale di Astrofisica (INAF))

Thursday 8 May

09:00 → 10:55 MWL counterparts

09:00 Looking for a multi-wavelength counterpart for FRBs

Emission outside the radio band is predicted for most models trying to explain the FRB phenomenon. Its nature, however, is still to be determined, with the exception of the possible example provided by the Galactic FRB20200428A, where X-ray emission was observed simultaneously with the radio emission, with an energy ratio E_X/E_radio = 10^5.
I will review the targeted attempts to search for the multi-wavelength counterpart of FRBs and I will highlight the results of four years of multi-wavelength campaigns targeting FRB20180916B in optical, X- and gamma-rays, simultaneously with high sensitivity radio observations. Through this campaign the deepest prompt upper limits were obtained in optical and X-rays in terms of E_MWL/E_radio.
I will discuss the challenges of such large scale campaigns and the physical implications of our findings.

Speaker: Maura Pilia (Istituto Nazionale di Astrofisica (INAF))

09:35 The contribution of Insight-HXMT to constraining the possible X/gamma emission of extragalactic FRB sources

The first Chinese X-ray mission, Insight Hard X-ray Modulation Telescope (Insight-HXMT), carries on board three collimator-based instruments, which altogether cover the range 1-250 keV. In addition, the High-Energy (HE) instrument works as an open-sky monitor in the 0.2-3 MeV. In this talk I report two main contributions of Insight-HXMT: a) thanks to the unique combination of large effective area and sub-ms resolution of HE, we constrained the possible simultaneous emission of 39 well localised FRBs, excluding associations with typical gamma-ray bursts; b) also in the context of coordinated multiwavelength campaigns, we constrained possible high-energy activity of periodic repeater FRB20180916B throughout the different phases of radio activity, excluding the possible occurrence of energetic magnetar giant flares.

Speaker: Prof. Cristiano Guidorzi (University of Ferrara)

09:55 Search for FRB repeater counterparts with INTEGRAL

Up to date, there is only one FRB counterpart observed in hard X-rays. Bursts from a peculiar magnetar SGR 1935+2154 associated with FRB 200428, detected by INTEGRAL. In this work, an extensive search for hard X-ray bursts below the automatic INTEGRAL ISGRI-IBIS detection threshold that would be spatially and temporally coincident with the activity of recently active FRB repeaters has been performed. Targets FRB20220912, FRB20240209A and FRB20240114A have been investigated.

Speaker: Martin Topinka (Istituto Nazionale di Astrofisica (INAF))

10:15 Optical monitoring of FRB20220912A and comparison with background/foreground events

Repeating FRBs are ideal targets for multi-wavelength observational campaigns aiming at potential counterparts. We are monitoring FRB 20220912A, one of the most active repeaters, using the fast optical photon counters Aqueye+ and Iqueye at the Asiago Observatory. We are trying to characterize foreground/background events by analyzing archival Aqueye+ data taken on other fields. To this purpose we studied the field of PSR J1023+0038, considering the source as a low-level sky background contaminant. We find that 90% of the statistically significant events detected above the average rate in the 1 ms binned light curve are present both in the on-source and on sky detector fields. This fact suggests that these events are linked to diffuse atmospheric phenomena. We will compare these events with those found in the field of FRB 20220912A.

Speaker: Alessia Spolon (Istituto Nazionale di Astrofisica (INAF))

10:35 Search for optical counterpart of FRBs with SiFAP2@TNG

High-time-resolution detectors are playing a crucial role in advancing our understanding of fast transient events enabling precise measurements of their properties. SiFAP2, a state-of-the-art high-speed optical photometer permanently mounted at the 3.6m INAF Telescopio Nazionale Galileo (TNG) paved the way for significant breakthroughs in optical observations, especially on neutron stars. This instrument is deeply involved in a multiwavelength campaign on repeating Fast Radio Bursts to search for their optical counterpart. In this talk, I will present the SiFAP2 photometer as well as the first results obtained. In particular, I will focus on transient events we called Fast Optical Bursts and their possible association to FRBs. Finally, I will also present the enhanced version of SiFAP2 – named eSiFAP – which is currently under development to perform simultaneous optical and nIR fast photometry, and to be installed at TNG in the next future.

Speaker: Filippo Ambrosino (Istituto Nazionale di Astrofisica (INAF))

10:55 → 11:10 The open questions

Cosa si prevede per il futuro vicino e prossimo grazie soprattutto ai nuovi strumenti di ricerca.

11:10 → 11:40 Coffe break

11:40 → 12:30 MWL counterparts

11:40 AGILE contribution to MW campaigns to search for High-Energy Counterparts of Fast Radio Burst sources

The AGILE space mission, with its unique features (two coaligned imaging X- and gamma-ray detectors, a non-imaging calorimeter, and
the observing capability to cover about 80% if the sky in 7 minutes), participated to all the recent campaign searches for electromagnetic
(e.m.) counterparts of multi messenger events (gravitational waves and neutrinos), but also to high-energy counterparts search of Fast Radio Burst sources (FRBs). Since 2019, when the important discoveries of the CHIME/FRB instrument were published, AGILE has started an activity to search for X- and gamma-ray counterpart of these sources either in the archive or in real time.
We dedicated our first archival work to two reapeter sources (R-FRBs), FRB20180916B and FRB20181030A, supposed to be the nearest in 2019, based on the DM_excess. No detection were found in AGILE archive but significant hard X-ray to MeV-GeV upper limits (ULs) were evaluated. After the discovery of the periodic activity cycle of the reapeter FRB20180916B we setup a MW campaign with the italian radio telescopes, Northern Cross and Sardinia Radio Telescopes, together with Swift observations, whose main goal was to acquire XRT data to evaluate at first the X-ray emission from the source improving the total
exposure, but mainly devoted to monitor the activity cycles for eventual soft X-ray emission during simultaneous radio observations.
Preliminary analysis of XRT data resulted in no emission during this very long campaign (~400ks), and 3sigma flux X-ray and gamma-ray ULs from XRT, MCAL and GRID data were extracted and partially reported in 2020, 2021 and 2024.
Moreover, we started other two campaigns with Swift and the italian radiotelescopes, targeting the very active R-FRBs FRB20220912A and FRB20240114A.
We will describe the results from the AGILE MW campaigns involving the Swift mission, in particular that on the periodic source, and the perspective to continue the new ones, after the AGILE operations end.

Speaker: Francesco Verrecchia (Istituto Nazionale di Astrofisica (INAF))

12:00 AGILE observations of a sample of repeating Fast Radio Burst sources

We report on a comprehensive search for X-ray and Gamma-ray counterparts to a selected sample of repeating FRBs using AGILE data. Focusing on events with an excess dispersion measure below 300 pc cm⁻³, our high-resolution analysis with the AGILE MiniCalorimiter (MCAL) did not reveal any significant X-ray emission, enabling us to set robust upper limits on the flux above 400 keV within a spectral magnetar model framework. We derived also flux upper limits in the 18–60 keV band using SuperAGILE data archive, and we examined GRID coverage in the 0.03–10 GeV range on timescales from 10 to 10³ s as well as over AGILE’s 17-year archival data. Using the well-known FRB 200428 as a benchmark, we extrapolated expected X-ray emissions from the sample of repeating FRBs and compared these with rescaled historical magnetar bursts. Our findings place significant constraints on the magnetar model for FRB emission, with MCAL limits representing the most stringent constraints in the 0.4–30 MeV range. We will discuss the methodology, challenges, and implications of these results for future high-energy FRB studies.

Speaker: Dr Claudio Casentini (Istituto Nazionale di Astrofisica (INAF))

12:20 Multifrequency study of the energy distribution of the Crab single pulses

Giant pulses (GPs) are very energetic and impulsive phenomena, with flux densities up to few MJy and pulse widths from ~100 ns to ~100 µs, as observed from the Crab pulsar. The GPs observed from the Crab pulsar can be used to study the energy distribution and their dynamic spectra can address the emission mechanisms of neutron stars. Some fast radio bursts (FRBs) models involve neutron stars as progenitors of such emission. In this poster, we present a multifrequency analysis of the Crab single pulses, conducted at 408 MHz with the Northern Cross telescope and between 1400 MHz and 1900 MHz with Noto and Green Bank telescopes, which aimed at characterizing their fluence and width distribution. Radio observations were simultaneous to optical observations and a future joint analysis will help shed light on the physics behind single (giant) pulses, and, potentially, behind FRBs.

Speaker: Luca Beduzzi (Istituto Nazionale di Astrofisica (INAF))

12:30 → 12:50 Multimessenger counterparts

12:30 Constraints on Fast Radio Burst emission in the aftermath of Gamma-Ray Bursts

The physical origin of Fast Radio Bursts (FRBs) is still unknown. Many models consider magnetars as possible FRB sources, supported by the observational association of FRBs with the galactic magnetar SGR 1935+2154. Magnetars are also thought to be the source of the power of a fraction of Gamma Ray Bursts (GRBs), opening the possibility that the two extreme phenomena have a common progenitor.
In this work we present a new, systematic search for GRB-FRB association, using the most updated catalog of FRBs observed with the Canadian Hydrogen Intensity Mapping Experiment (CHIME) instrument, and the sample of all GRBs detected by Swift so far. We also show, using a synthetic population of FRBs associated to Swift GRBs, how likely it is to have a joint detection with current and future radio facilities.
With our analysis we only recovered two, low significant, possible GRB-FRB associations already reported in literature; however the absence of any unambiguous association so far between Swift GRBs and FRBs cannot exclude that the two populations are connected, given the characteristics of current GRB and FRB detectors. In the next decade, with new generations of GRB and FRB detectors there will be a higher probability to detect joint GRB-FRB events, if any.

Speaker: Barbara Patricelli (Istituto Nazionale di Astrofisica (INAF))

12:50 → 14:00 Lunch break

14:00 → 15:00 Multimessenger counterparts

14:00 Exploring the connection between FRBs and neutron star mergers

Neutron star (NS) mergers, detected via gravitational wave (GW) signals by LIGO and Virgo, create extreme magnetized environments, providing optimal conditions for coherent radio emission observable as a fast radio burst (FRB). The temporal and spatial coincidences between GW events and FRBs offer a unique opportunity to directly identify FRB progenitors, test models of magnetar formation, and probe the behavior of ultra-dense matter. In particular, some NS mergers produce an intermediate-lived hypermassive neutron star (HMNS), which may power delayed FRB emission before collapsing into a black hole. However, confirming these associations remains challenging due to detection sensitivities, sky localization constraints, and uncertainties in the time delay between the merger and the FRB. In this talk, I will discuss possible connections between GW events, FRBs, and NS mergers, as well as the observational constraints that can help test this link.

Speaker: Eleonora Troja (Istituto Nazionale di Astrofisica (INAF))

14:20 Incidence of afterglow plateaus in GRBs associated with binary neutron star mergers

One of the most surprising Gamma Ray Burst (GRB) features discovered with the Swift X-ray telescope (XRT) is a plateau phase in the early X-ray afterglow lightcurves. These plateaus are observed in the majority of long GRBs, while their incidence in short GRBs is still uncertain due to their fainter X-ray afterglow luminosity with respect to long GRBs. An accurate estimate of the fraction of short GRBs with plateaus is of utmost relevance given the implications on the jet structure and possibly on the nature of the binary neutron star (BNS) merger remnant. This work presents the results of an extensive data analysis of the largest and most up-to-date sample of short GRBs observed with the XRT, and for which the redshift has been measured. We found a plateau incidence of 18-37% in short GRBs, a fraction significantly lower than the one measured in long GRBs (>50%). Although still debated, the plateau phase could be explained as energy injection from the spin-down power of a newly born magnetized neutron star (magnetar). We show that this scenario can nicely reproduce the observed short GRB plateaus, while at the same time providing a natural explanation for the different plateau fractions between short and long GRBs. In particular, our findings may imply that only a minority of BNS mergers generating short GRBs leave behind a stable neutron star (NS) or a long-lived NS, long enough to form a plateau, constraining the maximum NS mass to be in the range ∼ 2.3 − 2.35 M⊙

Speaker: Maria Giuliana Stratta (Istituto Nazionale di Astrofisica (INAF))

14:40 Exploring the multi-messenger nature of FRBs: insights from gamma-ray and gravitational wave searches

Fast Radio Bursts (FRBs) are a recently discovered class of GHz-band astrophysical transients with an unknown origin. Exploring their potential gamma-ray and gravitational wave (GW) counterparts is crucial for constraining their emission mechanisms. We present a search for GW signals from FRBs, focusing on the Galactic magnetar SGR 1935+2154, using the GEO600 detector, setting the strictest upper limits on concurrent GW emission from FRBs to date. For gamma-ray searches, we analyzed 13 years of Fermi-LAT data covering over 1000 FRBs—the largest sample ever studied. This represents the most extensive and sensitive search for gamma-ray emission from FRBs, setting the most stringent upper limits on short- and long-timescale emission, cumulative signals, and individual photon searches. These results provide critical constraints on the multi-messenger nature of FRBs and their underlying physics.

Speaker: Giacomo Principe (Istituto Nazionale di Astrofisica (INAF))

15:00 → 15:20 Tools (SW & HW) and prospects

15:00 ItaliaN Single-dish radio telescopes enhancement for studying Transients And GRAvitational Waves (INSTAGRAW)

INAF manages three single-dish radio telescopes: SRT, Medicina, Noto. The science of pulsars and Fast Radio Bursts constitutes key projects in radio astronomy. SRT already plays a key role in various projects, such as the EPTA, which uses radio pulsar data to search for gravitational waves. Currently-available instrumentation at SRT severely limits its possible scientific return. At Medicina and Noto, no specific system was ever installed that would allow them to be involved in those fields.
I would present the INAF techno grant recently funded with the aims to equip all three telescopes with a modern infrastructure that will allow them to excel in transient studies; both as a single antenna and as part of an Italian pulsar timing array.
Specifically, the goal of this techno grant is to design and build - for SRT, Medicina and Noto - a digital infrastructure based on the SKARAB FPGA-based board that is capable of dealing with a bandwidth of at least 512 MHz to be recorded and/or post-processed for every science transients related, among which the Fast Radio Bursts.

Speaker: Andrea Melis (Istituto Nazionale di Astrofisica (INAF))

15:20 → 15:40 The open questions

Cosa si prevede per il futuro vicino e prossimo grazie soprattutto ai nuovi strumenti di ricerca.

15:40 → 16:10 Coffe break

16:10 → 18:00 Tools (SW & HW) and prospects

16:10 Searching for four-leaf clovers in the Radio Transiet Sky

The discovery of fast radio bursts (FRBs) was a serendipitous process, much like the detection of the first pulsar by S. J. Bell. Since the first FRB was identified in 2007, both hardware and software technologies for detecting these enigmatic transients have advanced dramatically, enabling the discovery of increasingly exotic events. In this talk, I will review the current state of FRB searches, covering both algorithmic and instrumental developments, and discuss future prospects for refining our search strategies.

Speaker: Matteo Trudu (Istituto Nazionale di Astrofisica (INAF))

16:45 Searches for optical counterparts of Fast Radio Bursts: instrumentation and strategies

A number of models predict the existence of multiwavelength (MWL) counterparts of Fast Radio Bursts (FRBs) in the form of an afterglow or an impulsive event. An optical detection would provide critical information on the nature of the progenitor and would greatly enhance our understanding of the FRB phenomenon. Suitable instrumentation and/or strategies are required for sensitive searches of short-duration optical flashes down to or even below the millisecond time scale and for a suitable characterization of the potential populations of foreground events. Here we summarize some conclusions from the experience gained in the observing campaigns carried out in the last five years using our fast photon counting optical instruments.

Speaker: Luca Zampieri (Istituto Nazionale di Astrofisica (INAF))

17:20 A tricky statistical search for Fast Optical Bursts

The long unexplored fast optical sky is now accessible thanks to new large ground-based telescopes and new generation instruments. Studying it may lead to new discoveries, but it is also challenging due to optical pollution.
In this talk, I will present our preliminary results obtained from an automated search and characterisation of mysterious Fast (millisecond) Optical Bursts (FOBs) in over 300 hours of observation with the fast photometer SiFAP2 at the Telescopio Nazionale Galileo.
Using a Bayesian Blocks-based algorithm we developed, we found a surprisingly high rate of 2 FOBs per hour. Our analysis suggests that many of these bursts likely have a non-astrophysical origin. However, some bursts show marginally significant evidence to the contrary.

Speaker: Carlo Campa (Istituto Nazionale di Astrofisica (INAF))

17:40 Prospects for detection of extragalactic magnetar giant flares with future X- and gamma-ray satellites

Magnetar giant flares (MGFs) are the most extreme transient events observed from these magnetically-powered neutron stars. They consist of an initial peak lasting fractions of a second during which the luminosity in the X and soft $\gamma$ band can reach up to 10$^{47}$ erg s$^{-1}$, followed by a decaying X-ray tail lasting hundreds of seconds and showing periodic modulation.
The periodic tail, which makes MGFs easily distinguishable from other high-energy transients (short GRBs in particular), has been detected so far only from three magnetars in the Local Group and it is difficult to observe with current telescopes from farther sources. However, the very luminous initial peak can be detected even from sources at distances up to more than 10 Mpc.

Some candidate MGFs have been identified among short gamma-ray bursts, the most significant being GRB 231115A in M82, but the scarcity of such events suggests that some extragalactic MGFs were misclassified as other kinds of transients. Various works have examined the spatial correlation between short transients and the local galaxy population, in order to determine which of the former can be associated with local sources. This increasing sample including extragalactic MGFs, can give better estimates on the rate and energy distribution of the flares. This can in turn constrain the overall budget of magnetic energy and its evolution in magnetars.

With the most recent (e.g. Einstein Probe, SVOM) and future facilities (e.g. eXTP, THESEUS) equipped with sensitive wide-field high-energy instruments and with rapid-slewing capability, the sample of MGFs candidates will definitely increase. In this contribution we discuss the future advances in this field, based on realistic simulations which take into account the instrument responses and the most recent results on the MGFs rates. We also discuss how many still unidentified sources in large archives of X-ray data could be attributed to MGFs.

Speaker: Edoardo Arrigoni (Istituto Nazionale di Astrofisica (INAF))

Friday 9 May

09:00 → 11:00 FRB Environment (hosts & PRSs):: Host galaxies & environment

09:00 The quest for PRS and their link with nebulae

Deep investigation of the environment where the bursts occur is the most promising way to shed light on these mysterious phenomena. Observations of a handful of events indicated different progenitor channels, yielding to distinct location, local environment and host galaxy properties. The recent discovery of a persistent radio source associated with FRB 20201124A and 20240114A supports the nebular model for the continuum emission, circumscribing the progenitors to magnetars (favoured) or hyperaccreting X-ray binaries. In the near future, the advent of new dedicated radio facilities will deliver dozens of arcsec-level localized FRBs per year, improving the statistics on host galaxies and continuum counterparts. The talk aim at reviewing current developments and future prospects of PRS characterisation.

Speaker: Dr Gabriele Bruni (INAF - Istituto di Astrofisica e Planetologia Spaziali)

09:35 The quest for radio continuum counterparts of FRBs

A handful of repeating Fast Radio Bursts (FRBs) have been found to be spatially associated with a compact persistent radio source (PRS). Observational evidence suggests that the continuum emission of PRSs originates from a nebula embedding either a magnetar or a binary system of compact objects. Therefore, PRSs are crucial targets to investigate the progenitors of FRBs and their formation channel. We followed-up a sample of 18 well-localized repeaters and one-off FRBs with sensitive ($10 \; \mu Jy \; beam^{-1}$) and high-resolution ($\sim 2’’$) uGMRT observations to search for possible PRSs. I will present preliminary results from such observing campaign, focusing on the comparison of our detections and upper limits with the properties of known PRSs in the literature.

Speaker: Luca Bruno (Istituto Nazionale di Astrofisica (INAF))

09:55 Pinpointing FRBs with VLBI

One key aspect required to understand the origin of FRBs is to know the type of environment they are emitted in. Thus, not only the host galaxy of an FRB is of importance, but also the precise location within that host need to be determined to solve the FRB-puzzle. Such accurate measurements are only possible with Very Long Baseline Interferometry. I will review the cases of FRBs localised with milliarcsecond precision, describing the technique, the main results and their implications, and the future prospects.

Speaker: Marcello Giroletti (Istituto Nazionale di Astrofisica (INAF))

10:15 The host galaxies of fast radio bursts

Although FRBs are frequent events, the precise localization has only been achieved in a limited number of cases. However, this number has doubled in the past year. In this talk, we will present key properties of a sample of galaxies hosting these events, compiled from existing publications. Over 100 FRB host galaxies have been identified so far, with redshifts measured for most of them. The redshift interval is 0.0 < z < 1.35, with median and mean values of z = 0.224 and z = 0.259, respectively. Approximately three-quarters of the hosts are star-forming, and at least 40% are spiral galaxies. The median stellar mass is M = 10^10.2 M_sun, spanning the range 8.1 < log10(M/M_sun) < 11.4. Although the dataset continues to expand, these findings offer valuable insights into the possible progenitors of FRBs. The number of host galaxy detections is growing rapidly, and we expect new interferometric facilities to increase the number of well-localized events tenfold in the coming years.

Speaker: Sandra Savaglio (Università della Calabria)

10:35 The FRB host galaxies catalogue

The number of FRB host galaxies is constantly increasing thanks to the precise localization of new interferometric facilities. With the aim of keeping track of and making the observed and derived FRB parameters accessible to the entire community, we are implementing a new catalogue. It will be fed by user data and made publicly accessible both programmatically and via a web interface.
The catalogue will replace and be made available through the existing frb-hosts.org website.
I will illustrate the content of the catalogue, how the data is collected and managed, and how it can be consulted and retrieved.

Speaker: Luciano Nicastro (Istituto Nazionale di Astrofisica (INAF))

11:00 → 11:30 Coffe break

11:30 → 12:05 FRB Environment (hosts & PRSs):

11:30 Cosmology with FRBs

Because of their extragalactic origin, FRBs can serve as very unique probes to explore our Universe. With nearly 150 localised FRBs with redshifts up to z=1.35, by use of the Macquart relation alone it is possible to study different cosmological aspects and even address some open issues in cosmology such as the missing baryon problem or the Hubble tension.
In my talk I will give a general overview on how to use FRBs to study the Universe. I will review some recent results in the literature, and I will discuss their possible future applications both in the short and in the long term.

Speaker: Matteo Cinus (Istituto Nazionale di Astrofisica (INAF))

12:05 → 12:40 Tools (SW & HW) and prospects

12:05 The Northern Cross Fast Radio Burst project: status update and future perspectives

The Northern Cross is a T-shaped radio interferometer located at the Medicina station, near Bologna, operating at 408 MHz. It has been undergoing a significant refurbishment/restoration over the last few years, allowing observations of fast radio bursts (FRBs, a project named "Northern Cross FRB project"). In this talk I will review the status of the project (past and current observing campaigns and their results) and describe the current readiness of the project and the future telescope upgrades, particularly in the light of the Next Generation Croce del Nord programme.

Speaker: Gianni Bernardi (Istituto Nazionale di Astrofisica (INAF))

12:40 → 13:00 Guest time (TBD)

13:00 → 14:00 Lunch break

14:00 → 15:00 The open questions

Cosa si prevede per il futuro vicino e prossimo grazie soprattutto ai nuovi strumenti di ricerca.

14:00 News from CHORD

A short report on the progress of the CHORD project (British Columbia - Canada).

Speaker: Andrea Possenti (Istituto Nazionale di Astrofisica (INAF))

14:15 General discussion

15:00 → 16:00 FRB-Italy: discussion and planning