arXiv subjects

Stephen Sclafani

Publications and source records attributed to Stephen Sclafani.

3 recordsLinked to original sources

arXiv2025

Detecting Neutrino Emission from Supernova Remnants: A Theoretically Motivated Target Catalog

Galactic supernova remnants (SNRs) are thought to accelerate cosmic rays (CRs) to several PeV energies, but this has yet to be confirmed as general behavior. Although several sources show ~100 TeV gamma rays, their hadronic origin is uncertain; a matching neutrino signal would provide definitive evidence. Using insight from the theory of diffusive shock acceleration, we evaluate the spectra and environments of the sample of Galactic SNRs to identify those most likely to be hadronic, categorizing them into a tiered catalog depending on their likelihood to produce neutrinos detectable in the TeV-PeV range. We then calculate the estimated stacked sensitivity of IceCube for each tier using IceCube's ten-year public data. Our results suggest that this strategy of stacking SNRs and carefully excluding leptonic sources by using theoretical arguments may allow for a detection of this source class that would otherwise be impossible. A follow-up analysis of these catalogs using TeV-PeV sensitive neutrino data from IceCube (or similar telescopes like KM3NeT/ARCA) offers the most decisive, near-future test for the hadronic nature of these SNRs and the maximum energies of their CR spectra.

astro-ph.HE↗

arXiv2023

Observation of high-energy neutrinos from the Galactic plane

IceCube has discovered a flux of astrophysical neutrinos and presented evidence for the first neutrino sources, a flaring blazar known as TXS 0506+056 and the active galaxy NGC 1068. However, the sources responsible for the majority of the astrophysical neutrino flux remain elusive. In addition to hypothetical sources within our Galaxy, high energy neutrinos are produced when cosmic rays interact at their acceleration sites and during propagation through the interstellar medium. The Galactic plane has therefore long been hypothesized as a neutrino source. In this contribution, new results are presented for searches of neutrino sources utilizing a dataset that builds upon recent advances in deep-learning-based reconstruction methods for neutrino-induced cascades. This work presents the first observation of high-energy neutrinos from the Milky Way Galaxy, rejecting the background-only hypothesis at 4.5$σ$. The neutrino signal is consistent with diffuse emission from the Galactic plane, potentially in combination with emission by a population of sources.

astro-ph.HE↗

arXiv2019

Correlation of IceCube neutrinos with the 2MASS Redshift Survey

Since the detection of high energy astrophysical neutrinos in IceCube, there has been a search for their sources. Although recent evidence of neutrinos from a flaring blazar could explain some of the neutrino flux, sources for the remainder are still unknown. This analysis searches for neutrinos produced via interactions between diffuse intergalactic Ultra-High Energy Cosmic Rays (UHECR) and matter. In this work the local galaxy density serves as the target for cosmic ray interactions, thus neutrinos produced from these interactions are expected to trace the galaxies spatially. The spatial distribution of galaxies within the local universe (z < 0.10) as seen in the 2MASS Redshift Survey (2MRS) is anisotropic. Here we present an analysis that searches for the spatial correlation between the arrival directions of neutrinos observed at the IceCube neutrino observatory and the directions of high galaxy density in the local universe. No such correlation was found and this analysis presents limits on the flux of neutrinos from the local universe.

astro-ph.HE↗