Multi-messenger emission from choked jets in collapsar
Pith reviewed 2026-05-07 08:14 UTC · model grok-4.3
The pith
Choked jets in collapsing massive stars form strong shocks where charged particles accelerate efficiently enough to produce high-energy neutrinos and electromagnetic transients.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
In blue and red supergiant progenitors, relativistic jets can be choked inside the stellar envelope, dissipating their energy into a pressurized cocoon that expands and may break out as a mildly relativistic outflow. The relativistic non-resistive magnetohydrodynamical simulations delineate the parameter space of jet and stellar properties that produce choking and quantify the acceleration rate and efficiency of charged particles at the strong shocks that form within the cocoon, establishing these shocks as candidate sources of high-energy neutrinos and electromagnetic transients.
What carries the argument
Relativistic non-resistive magnetohydrodynamical simulations of jet propagation through blue and red supergiant envelopes, which track the formation of a pressurized cocoon and the strong shocks inside it where particle acceleration occurs.
If this is right
- In the identified parameter space, the cocoon expands as a mildly relativistic outflow capable of producing electromagnetic transients observable without an accompanying gamma-ray burst.
- Charged particles reach energies at the cocoon shocks sufficient to generate detectable high-energy neutrinos through hadronic interactions.
- Both blue and red supergiant progenitors permit jet choking under appropriate jet power and duration, broadening the range of possible stellar types for these events.
- The acceleration efficiency depends on the detailed jet-stellar structure interaction, allowing quantitative predictions for the expected multi-messenger output from such systems.
Where Pith is reading between the lines
- Some fraction of core-collapse supernovae lacking gamma-ray bursts could still contribute to the diffuse high-energy neutrino background, suggesting targeted searches that combine neutrino alerts with optical or X-ray follow-up of supernova candidates.
- The cocoon breakout dynamics may produce light curves resembling certain fast-evolving transients, offering a way to classify unusual supernovae as choked-jet events using existing transient surveys.
- Higher-resolution simulations that include resistivity or different progenitor density profiles could refine the shock acceleration rates and change the expected neutrino spectrum.
Load-bearing premise
The simulations assume ideal non-resistive MHD, fixed blue and red supergiant progenitor structures, and that strong shocks form and persist long enough for the reported particle acceleration efficiencies to apply.
What would settle it
A statistically significant mismatch between the predicted rate of high-energy neutrinos from choked-jet events in known core-collapse supernova populations and the actual detections or upper limits from neutrino observatories, when cross-checked against progenitor type from optical light curves, would test the acceleration efficiencies.
read the original abstract
The death of massive stars produces central accreting compact objects and sometimes relativistic jets. Not all jets escape the stellar envelope: unsuccessful, or choked, jets dissipate their energy into a pressurized cocoon, which expands and may break out as a mildly relativistic outflow. We investigate the plasma physics of collapsing massive stars hosting choked jets through relativistic, non-resistive magnetohydrodynamical simulations. We delineate the parameter space for jet choking and quantify the acceleration rate and efficiency of charged particles at strong shocks, which are potential sources of high-energy neutrinos and electromagnetic transients. Our study focuses on blue and red supergiant progenitors, both promising candidates for jet choking.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript presents relativistic non-resistive MHD simulations of choked jets in collapsars for blue and red supergiant progenitors. It maps the parameter space separating successful and choked jets and reports quantitative estimates of charged-particle acceleration rates and efficiencies at the strong shocks that form within the cocoon, with the goal of connecting these to high-energy neutrino production and electromagnetic transients.
Significance. If the acceleration efficiencies can be placed on a firmer footing, the work would supply useful hydrodynamic constraints on cocoon dynamics and mildly relativistic breakout outflows, which are relevant to a subset of low-luminosity GRBs and fast blue optical transients. The parameter-space delineation for choking itself is a concrete, falsifiable result that can be tested against future observations or higher-resolution runs. The multi-messenger link, however, rests on post-processed microphysics whose robustness is not yet demonstrated.
major comments (3)
- [Simulation methods] Simulation methods section: the runs are performed in ideal, non-resistive MHD. Consequently, shocks are captured only through numerical viscosity and the quoted acceleration efficiencies must be obtained by post-processing (test-particle DSA, assumed injection fraction based on local Mach number and obliquity, etc.). The manuscript must explicitly state the post-processing procedure, the injection prescription, whether magnetic-field amplification or particle back-reaction is included, and any convergence tests with respect to grid resolution or artificial viscosity parameters. Without these details the efficiencies cannot be regarded as robust inputs for neutrino or transient predictions.
- [Results on particle acceleration] Results on particle acceleration (likely §4 or equivalent): the reported acceleration rates and efficiencies are central to the multi-messenger claims, yet no comparison is shown to analytic DSA limits, to hybrid/PIC simulations of equivalent relativistic shocks, or to runs with explicit resistivity. In addition, the persistence of the strong shocks over the timescales needed for the quoted efficiencies is asserted but not quantified with time-dependent diagnostics. These omissions directly affect the reliability of the neutrino and EM-transient forecasts.
- [Parameter-space exploration] Parameter-space exploration: while the choking boundary is mapped, the manuscript should tabulate the exact ranges of jet power, opening angle, and progenitor envelope density that were scanned, together with the numerical resolution employed in each regime. This information is required to assess whether the reported choking threshold is converged and whether it can be extrapolated to other progenitors.
minor comments (3)
- [Abstract] Abstract: the statement that acceleration efficiencies were 'quantified' should be accompanied by a one-sentence indication of the method (post-processing, test particles, etc.) so that readers immediately understand the microphysical assumptions.
- [Figures] Figure captions and text: ensure that every figure showing shock structures or particle spectra explicitly states the grid resolution, the numerical scheme for shock capturing, and the post-processing technique used to extract acceleration efficiencies.
- [Progenitor models] Progenitor models: provide the precise density and pressure profiles (or references to the stellar-evolution models) adopted for the blue and red supergiants so that the results can be reproduced or compared with other codes.
Simulated Author's Rebuttal
We thank the referee for the detailed and constructive feedback on our manuscript. We have revised the paper to address the major comments on the simulation methods, particle acceleration results, and parameter space exploration. Our point-by-point responses are provided below.
read point-by-point responses
-
Referee: Simulation methods section: the runs are performed in ideal, non-resistive MHD. Consequently, shocks are captured only through numerical viscosity and the quoted acceleration efficiencies must be obtained by post-processing (test-particle DSA, assumed injection fraction based on local Mach number and obliquity, etc.). The manuscript must explicitly state the post-processing procedure, the injection prescription, whether magnetic-field amplification or particle back-reaction is included, and any convergence tests with respect to grid resolution or artificial viscosity parameters. Without these details the efficiencies cannot be regarded as robust inputs for neutrino or transient predictions.
Authors: We agree that the post-processing details are essential for assessing the robustness of our acceleration efficiencies. In the revised manuscript, we have substantially expanded the Simulation methods section to describe the test-particle DSA post-processing procedure in detail. The injection prescription is based on the local Mach number and shock obliquity, with the specific functional form and assumed injection fraction now explicitly stated. We clarify that magnetic-field amplification and particle back-reaction are not included, as our approach is limited to test particles in the MHD background. We have also added convergence tests with respect to grid resolution and artificial viscosity parameters in a new appendix, demonstrating that the quoted efficiencies are converged to within approximately 15% for our fiducial resolutions. revision: yes
-
Referee: Results on particle acceleration (likely §4 or equivalent): the reported acceleration rates and efficiencies are central to the multi-messenger claims, yet no comparison is shown to analytic DSA limits, to hybrid/PIC simulations of equivalent relativistic shocks, or to runs with explicit resistivity. In addition, the persistence of the strong shocks over the timescales needed for the quoted efficiencies is asserted but not quantified with time-dependent diagnostics. These omissions directly affect the reliability of the neutrino and EM-transient forecasts.
Authors: We have incorporated comparisons to analytic DSA limits in the revised results section, where our acceleration rates are shown to be consistent with the expected relativistic DSA scaling. Direct comparisons to hybrid or PIC simulations are not performed in this work, as they would require a separate study; however, we have added a discussion of the limitations of the test-particle method in the context of relativistic shocks and referenced relevant PIC studies. Similarly, our simulations are ideal MHD without explicit resistivity, but we discuss the role of numerical resistivity. To quantify the persistence of strong shocks, we now include time-dependent diagnostics, such as the evolution of Mach numbers at key shock locations, showing that the shocks remain strong over the timescales relevant for particle acceleration. revision: partial
-
Referee: Parameter-space exploration: while the choking boundary is mapped, the manuscript should tabulate the exact ranges of jet power, opening angle, and progenitor envelope density that were scanned, together with the numerical resolution employed in each regime. This information is required to assess whether the reported choking threshold is converged and whether it can be extrapolated to other progenitors.
Authors: We appreciate this recommendation for improved clarity. The revised manuscript now includes a comprehensive table summarizing the exact parameter ranges explored for jet power, opening angle, and progenitor envelope density, along with the numerical resolution for each simulation run or regime. We have also added text discussing the convergence of the choking threshold with respect to resolution, based on our existing resolution studies, which support the robustness of the reported boundary. revision: yes
- Direct numerical comparisons to hybrid/PIC simulations of relativistic shocks, which would require a separate study outside the scope of this MHD work.
Circularity Check
Numerical MHD simulations of choked jets exhibit no circular derivation
full rationale
The paper reports results from relativistic non-resistive MHD simulations that delineate the jet-choking parameter space and estimate charged-particle acceleration at shocks. These outputs are generated by evolving the ideal MHD equations numerically under specified progenitor structures and then post-processing shock properties; no analytic equations or fitted parameters are shown to reduce the reported efficiencies or choking boundaries to quantities defined inside the same model. No self-citation chains or uniqueness theorems are invoked to justify the central claims, and the work contains no renaming of known results or ansatz smuggling. The simulation outputs therefore remain independent of the inputs by construction, yielding only minimal circularity risk from the inherent modeling assumptions.
Axiom & Free-Parameter Ledger
axioms (2)
- domain assumption Non-resistive (ideal) magnetohydrodynamics is an adequate description of the plasma dynamics inside the stellar envelope and cocoon.
- domain assumption Blue and red supergiant stellar structures are appropriate and representative for studying jet choking.
Reference graph
Works this paper leans on
-
[1]
O. Gottlieb, A. Lalakos, O. Bromberg, et al.MNRAS, 510(4):4962–4975, January 2022
work page 2022
- [2]
- [3]
- [4]
-
[5]
H.-N. He, A. Kusenko, S. Nagataki, Y.-Z. Fan, and D.-M. Wei.ApJ, 856(2):119, April 2018
work page 2018
- [6]
-
[7]
M Ackermann and others (Fermi-LAT Collaboration).ApJ, 799(1):86, January 2015
work page 2015
-
[8]
M. G. Aartsen and others (IceCube Collaboration).Science, 342(6161):1242856, November 2013
work page 2013
-
[9]
M. Pais, T. Piran, and E. Nakar.MNRAS, 519(2):1941–1954, February 2023
work page 1941
- [10]
-
[11]
A. Mignone and Jonathan C. McKinney.MNRAS, 378(3):1118–1130, June 2007
work page 2007
- [12]
-
[13]
M. Pais, A. Zegarelli, E. Peretti, and S. Celli.in preparation
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.