Prospects for Observing Astrophysical Transients with GeV Neutrinos

TL;DR

The paper addresses whether diverse astrophysical transients can emit GeV neutrinos detectable by IceCube-DeepCore and the upcoming IceCube Upgrade. It develops physically motivated models for GeV neutrino production in shock-powered transients, GRBs, and FRBs, incorporating proton acceleration, neutron decoupling, and $p\gamma$ interactions, and then computes time-integrated neutrino fluences using representative light-curve templates. By comparing these predicted fluences to analytic sensitivity estimates across 1–10 GeV and 10–1000 GeV, the study finds that most transients lie well below detection thresholds, though nondetections can constrain jet composition and environments; a Galactic event or future, more sensitive detectors could alter prospects. The work highlights the value of GeV neutrino observations in constraining transient physics and motivates coordinated optical/IR surveys and continued detector enhancements to probe the physics of shock acceleration and jet dynamics in diverse transient populations.

Abstract

Although Cherenkov detectors of high-energy neutrinos in ice and water are often optimized to detect TeV-PeV neutrinos, they may also be sensitive to transient neutrino sources in the 1-100~GeV energy range. A wide variety of transient sources have been predicted to emit GeV neutrinos. In light of the upcoming IceCube-Upgrade, which will extend the IceCube detector's sensitivity down to a few GeV, as well as improve its angular resolution, we survey a variety of transient source models and compare their predicted neutrino fluences to detector sensitivities, in particular those of IceCube-DeepCore and the IceCube Upgrade. We consider the ranges of neutrino fluence from transients powered by non-relativistic shocks, such as novae, supernovae, fast blue optical transients, and tidal disruption events. We also consider fast radio bursts and relativistic outflows of high- and low-luminosity gamma-ray bursts. Our study sheds light on the prospects of observing GeV transients with existing and upcoming neutrino facilities.

Figures (3)

• Figure 1: Flavor-summed $(\nu + \overline{\nu})$ effective area and angular resolution of GRECO and Upgrade. The GRECO dataset is optimized on 10 GeV - 1 TeV; Upgrade is intended to provide additional sensitivity to events on 1 - 10 GeV. We obtain GRECO Northern sky effective area and median angular resolution from GRECO_nova_erratum. We evaluate the expected Upgrade parameters using simulated data provided by Icecube_Upgrade_data. The effective area for GRECO is averaged over the northern sky, while the effective area for Upgrade is averaged over the full sky.
• Figure 2: $E^2 dN/dEdA$ of various transient sources. The spectra of four shock-powered transient source types are shown with spectral index $\alpha = 2.4$, and are normalized to the mean values shown in Table \ref{['transient_values']}. The FRB spectrum for thermal neutrino emission is evaluated using fiducial parameters $t_{\mathrm{FRB}} = 1$ ms and $\mathcal{E}_{\mathrm{radio}} = 10^{40}$ erg, and $d = 10$ kpc. In the case of a high-luminosity GRB, the spectra are shown separately for the decoupling and collision models; in the case of a low-luminosity GRB, the spectrum is shown for the decoupling model only. All GRB spectra are normalized using mean values from Table \ref{['transient_values']}.
• Figure 3: Predicted source fluences (time-integrated energy flux) and IceCube sensitivities integrated over 1-10 GeV (above) and 10 - 1000 GeV (below). Downward arrows indicate error bars with a lower value going to zero. The nearest distance of each transient type is estimated assuming ten years of IceCube observation. We show the estimate of FRB emission only on 10-1000 GeV as the FRB neutrino emission is negligible at lower energies. While we also show an estimate for the fluence of a Galactic core-collapse supernova occurring at a distance of 10 kpc, this does not reflect the true rate of Galactic supernovae, and it is unlikely that such a nearby event will occur in the next decade.