arXiv subjects

Giulia Illuminati

Publications and source records attributed to Giulia Illuminati.

6 recordsLinked to original sources

arXiv2025

KM3NeT/ARCA stacking search for high-energy neutrinos from blazars

Blazars are promising targets for neutrino astronomy, as highlighted by IceCube's identification of TXS 0506+056 as a cosmic neutrino source candidate. High-frequency-peaked BL Lacs (HBLs) stand out due to their characteristic electromagnetic high-energy emission properties, which makes them as well promising candidates for the production of high-energy neutrinos. Such neutrinos could be detected by KM3NeT/ARCA, a next-generation deep-sea Cherenkov detector under construction in the Mediterranean Sea. This contribution presents the results of a binned likelihood stacking analysis investigating high-energy neutrino emissions from a subset of HBLs. A total of 232 sources have been selected from the 3HSP catalogue and targeted in the analysis of KM3NeT/ARCA data taken with several detector configurations, specifically in the period in which from 6 to 21 detection units were deployed. The analysis is based on neutrino emission models of blazars developed using the LeHa-Paris numerical code, which simulates the spectral energy distribution of jetted active galactic nuclei.

astro-ph.HE↗

arXiv2025

3C403: a candidate neutrino-emitting radio galaxy

3C403 is a well-known FRII radio galaxy with jets extending up to kiloparsec scales. We report its identification as the second most significant candidate among more than 150 sources examined using the 15-year neutrino dataset from the ANTARES Collaboration, making it one of the most promising radio-galaxy candidates for high-energy neutrino emission. Motivated by previous associations between blazars and neutrino events, we investigated the jet properties of 3C403 and their possible role in neutrino production. Multi-scale radio observations, from parsec to kiloparsec scales, reveal a stable, two-sided jet lying close to the plane of the sky, with no evidence of strong Doppler boosting, while X-ray data indicate a dominant, heavily absorbed accretion-related component. We also examined the recently proposed correlation between neutrino and hard X-ray fluxes - originally identified in blazars and Seyfert galaxies - and find that 3C403 occupies an intermediate location in the $L_{\nu}$--$L_{\rm hX}$ plane between jet-dominated and corona-dominated systems. However, the current upper limit on its neutrino flux prevents a firm assessment of whether it follows the proposed relation. With radiatively efficient accretion ($\lambda_{\rm Edd}\sim10^{-2}$), strong hard X-ray emission, and a powerful but misaligned jet, 3C403 provides a physically motivated laboratory for exploring the interplay between coronal activity and jet environments in multimessenger scenarios of neutrino production in active galaxies.

astro-ph.HE↗

arXiv2025

Cryoscope: A Cryogenic Infrared Survey Telescope in Antarctica

We present Cryoscope--a new 50 deg$^2$ field-of-view, 1.2 m aperture, $K_{dark}$ survey telescope to be located at Dome C, Antarctica. Cryoscope has an innovative optical-thermal design wherein the entire telescope is cryogenically cooled. Cryoscope also explores new detector technology to cost-effectively tile the full focal plane. Leveraging the dark Antarctic sky and minimizing telescope thermal emission, Cryoscope achieves unprecedented deep, wide, fast and red observations, matching and exceeding volumetric survey speeds from the Ultraviolet Explorer, Vera Rubin Observatory, Nancy Grace Roman Space Telescope, SPHEREx, and NEO Surveyor. By providing coverage beyond wavelengths of 2 $\mu$m, we aim to create the most comprehensive dynamic movie of the most obscured reaches of the Universe. Cryoscope will be a dedicated discovery engine for electromagnetic emission from coalescing compact binaries, Earth-like exoplanets orbiting cold stars, and multiple facets of time-domain, stellar and solar system science. In this paper, we describe the scientific drivers and technical innovations for this new discovery engine operating in the $K_{dark}$ passband, why we choose to deploy it in Antarctica, and the status of a fifth-scale prototype designed as a Pathfinder to retire technological risks prior to full-scale implementation. We plan to deploy the Cryoscope Pathfinder to Dome C in December 2026 and the full-scale telescope by 2030.

astro-ph.IM↗

arXiv2022

High-Energy and Ultra-High-Energy Neutrinos

Astrophysical neutrinos are excellent probes of astroparticle physics and high-energy physics. With energies far beyond solar, supernovae, atmospheric, and accelerator neutrinos, high-energy and ultra-high-energy neutrinos probe fundamental physics from the TeV scale to the EeV scale and beyond. They are sensitive to physics both within and beyond the Standard Model through their production mechanisms and in their propagation over cosmological distances. They carry unique information about their extreme non-thermal sources by giving insight into regions that are opaque to electromagnetic radiation. This white paper describes the opportunities astrophysical neutrino observations offer for astrophysics and high-energy physics, today and in coming years.

hep-ph↗

arXiv2019

Searches for point-like sources of cosmic neutrinos with 11 years of ANTARES data

The main goal of the ANTARES neutrino telescope is the identification of neutrinos from cosmic accelerators. The good visibility towards the Southern sky for neutrino energies below 100 TeV and the good angular resolution for reconstructed events make the telescope excellent to test for the presence of point-like sources, especially of Galactic origin. The median angular resolution for track-like events (mainly from $ν_μ$ CC interactions) is $0.4^{\circ}$ while the median angular resolution for contained shower-like events (mainly from $ν_{e}$ CC and all-flavour NC interactions) is $3^{\circ}$. Recently the ANTARES Collaboration published the result of the search for cosmic point-like neutrino sources using track-like and shower-like events collected during nine years of data taking. In this contribution, an update to this analysis using eleven years of data recorded between early 2007 and the end of 2017, for a total livetime of 3136 days, is presented. Moreover, the results of a search for time and space correlation between the ANTARES events and 54 IceCube tracks and those of the searches for neutrino candidates associated with the IceCube-170922A event or from the direction of the TXS 0506+056 blazar are reported.

astro-ph.HE↗

arXiv2019

ANTARES and IceCube combined search for neutrino point-like and extended sources in the Southern Sky

The ANTARES neutrino telescope, located in the Mediterranean Sea, and the IceCube neutrino observatory, located at the geographic South Pole, both search for cosmic neutrino events with an instantaneous full-sky field of view. The different characteristics of the two telescopes, in particular the larger instrumented volume of IceCube and the better visibility towards the Southern Sky for neutrino energies below 100 TeV of ANTARES, are exploited in a combined search for point-like and extended sources. The sensitivity to neutrino sources located in the Southern Sky is improved by a factor of $\sim$2 compared to individual studies. The data samples used in this analysis correspond to all track-like and shower-like events from the direction of the Southern Sky which were included in the nine-year ANTARES point-source analysis, combined with the through-going track-like events used in the seven-year IceCube point-source search. In this analysis, the Southern Sky is scanned for possible excesses of neutrinos that might indicate the presence of a source, while the coordinates of predefined candidate neutrinos sources are also evaluated in order to limit the penalty of trials. In addition, special focus is given to the region around the Galactic Centre, treated as an extended neutrinos source, and to the location of the supernova remnant RXJ 1713.7-3946. The result of this combined search for galactic and extra-galactic neutrino sources in the Southern Sky is reported here. No significant evidence of cosmic neutrino sources is found and flux upper limits from the various searches are presented.

astro-ph.HE↗