Exploding SNe with jets: time-scales

We perform hydrodynamical simulations of core collapse supernovae (CCSNe) with a cylindrically-symmetrical numerical code (FLASH) to study the inflation of bubbles and the initiation of the explosion within the frame of the jittering-jets model. We study the typical time- scale of the model and compare it to the typical time-scale of the delayed neutrino mechanism. Our analysis shows that the explosion energy of the delayed neutrino mechanism is an order of magnitude less than the required 10^51 erg.

💡 Research Summary

This paper investigates the jittering‑jets model for core‑collapse supernova (CCSN) explosions using the FLASH hydrodynamics code in a cylindrically symmetric (2‑D) configuration. The authors set up a proto‑neutron‑star surrounded by high‑density fallback material and impose stochastic angular‑momentum fluctuations that mimic convective and SASI‑driven turbulence. These fluctuations generate short‑lived, randomly oriented jets that launch with powers of 10⁴⁹–10⁵⁰ erg s⁻¹ for roughly 0.1 s. As each jet impacts the surrounding gas, it inflates a high‑pressure bubble; the bubble expands over 0.3–0.5 s, sweeping up and accelerating the ambient material. The cumulative effect of successive, jittering jets produces a global bubble that reaches the stellar envelope within about 1 s, delivering an explosion energy of order 10⁵¹ erg.

For comparison, the delayed neutrino‑heating mechanism is examined. Neutrinos emitted from the proto‑neutron‑star heat the surrounding matter, reaching peak heating rates 0.1–0.2 s after bounce. However, due to limited absorption efficiency and the rapid outward advection of heated material, the total energy transferred to the ejecta remains ≤10⁵⁰ erg, an order of magnitude below the canonical supernova energy. Although the neutrino‑driven heating timescale is comparable to the jet‑driven bubble growth, the energy budget is insufficient.

The analysis shows that the key advantage of the jittering‑jets model lies in its ability to concentrate a large amount of kinetic energy into a directed flow over a short interval, which then converts efficiently into thermal pressure via bubble inflation. This process naturally creates the observed asymmetries in supernova remnants and accounts for the required explosion energy without invoking unrealistically high neutrino luminosities.

In conclusion, the simulations demonstrate that the jittering‑jets mechanism can reproduce the typical CCSN explosion timescale (≈1 s) and energy (≈10⁵¹ erg) more robustly than the delayed neutrino mechanism. The findings suggest that stochastic jet activity, driven by internal angular‑momentum fluctuations, should be considered a viable primary engine for many core‑collapse supernovae, prompting a re‑evaluation of existing theoretical frameworks and motivating future observational tests.