Multimessenger Prospects for Low-Luminosity Gamma-Ray Bursts: Joint Neutrino and X-Ray Observations

TL;DR

This work tackles the multimessenger prospects for LLGRBs by developing a dynamical model of a relativistic jet propagating through dense extended material and computing the resulting high-energy neutrino production via $pp$ and $p\gamma$ processes, including detailed cooling and suppression effects. It contrasts non-magnetized ($\sigma \ll 1$) and magnetized ($\sigma=10$) jets, classifies jet outcomes into choked, HLGRB, and LLGRB regimes, and connects the theory to observables by computing joint X-ray and neutrino detectability using current and next-generation instruments (e.g., IceCube-Gen2, Einstein Probe). Key findings include that single-event joint detections are feasible mainly for nearby or high-$L_{ m iso}$ LLGRBs in the non-magnetized case (e.g., $L_{ m iso}\sim10^{47}\ \mathrm{erg\,s^{-1}}$ out to $D_L\sim1.6\times10^{2}$ Mpc optimistic), while magnetized jets yield smaller accessible volumes; stacking ~100 magnetized LLGRBs dramatically improves reach (to $D_L\lesssim7.0\times10^{2}$ Mpc) and yields ~2 joint detections yr$^{-1}$ optimistic. The predicted diffuse neutrino flux from LLGRBs and choked jets in the magnetized scenario remains well below IceCube measurements, implying these sources are unlikely to dominate the diffuse neutrino background. Overall, the results underscore the value of next-generation neutrino telescopes and wide-field X-ray surveys for practical multimessenger LLGRB studies and jet-physics constraints.

Abstract

Low--luminosity gamma-ray bursts (LLGRBs) are promising candidates for high-energy neutrinos, yet no coincident neutrino events have been detected so far. Recent advances in X-ray time-domain astronomy, together with the development of next-generation neutrino telescopes, open new opportunities for joint X-ray and neutrino observations of these transients. We calculate the jet dynamical evolution and the associated neutrino production for both non-magnetized and magnetized outflows. For individual events, joint X-ray and neutrino detection is generally limited to nearby LLGRBs or sources with high luminosities. Thus, we consider a next-generation neutrino telescope with an effective area enhanced by a factor of $\sim30$ relative to IceCube. In the non-magnetized scenario, joint detection of individual events is enabled for sources with typical isotropic luminosities of $L_{\mathrm{iso}}\sim10^{47}\,\mathrm{erg\,s^{-1}}$ out to luminosity distances of $D_L\sim1.6\times10^{2}\,\mathrm{Mpc}$, corresponding to an expected detection rate of order $1$ per year. In contrast, for the magnetized scenario at the same luminosity, the accessible distance is significantly reduced, with joint observations confined to sources within $D_L\sim6.5\times10^{1}\,\mathrm{Mpc}$ and an expected detection rate of order $0.5$ per year. For stacked samples of $\sim100$ magnetized LLGRBs, stacking substantially enlarges the accessible distance range, enabling joint observations for sources with representative luminosities of $L_{\mathrm{iso}}\sim1\times10^{47}\,\mathrm{erg\,s^{-1}}$ out to $D_L\lesssim7.0\times10^{2}\,\mathrm{Mpc}$ and corresponding to an expected detection rate of order $2$ per year. These results demonstrate that joint X-ray and next-generation neutrino observations enable a practical multimessenger probe of LLGRBs.

Figures (7)

• Figure 1: Schematic illustration of the jet–extended-material interaction.
• Figure 2: Structure of the FS--RS system. Regions I--IV are separated by the FS, CD, and the RS.
• Figure 3: Jet head radius $R_{\mathrm{h}}$ at which the jet becomes choked as a function of the intrinsic luminosity $L_0$. The results are shown for different magnetization parameters.
• Figure 4: Neutrino energy spectrum for a GRB 060218–like event. The red and blue curves correspond to different jet magnetization parameters, $\sigma \ll 1$ and $\sigma = 10$, respectively. GRB 060218 has an observed redshift of $z=0.033$2006GCN..4792....1M, which is used in our calculations.
• Figure 5: Parameter space in the $L_{\mathrm{iso}}$–$D_L$ plane for individual LLGRBs. Variations in the extended-material density and the engine duration at the one-standard-deviation level give rise to a finite width in both the electromagnetic and neutrino sensitivities shown here. The light-orange shaded region indicates the sensitivity range of the Einstein Probe Wide-field X-ray Telescope, with the orange solid curve indicating the representative sensitivity (the median value). Hatched bands represent the corresponding $90\%$ neutrino detection limits. The band with left-slash hatching ($/$) corresponds to the IceCube sensitivity, while the band with right-slash hatching ($\backslash$) shows the sensitivity of a next-generation neutrino telescope with a sensitivity of $\sim30$ times that of IceCube. Sources located in the left-hand overlap region between the EP–WXT sensitivity range and a given neutrino band can be jointly detected.