Late-time electromagnetic luminosity transition

Determine whether the post-collapse electromagnetic luminosity of the simulated binary neutron-star merger remnants eventually increases toward the value predicted by the Blandford–Znajek mechanism after its observed initial decline.

Background

Both simulations show a decline in Poynting-flux luminosity approximately 5–10 ms after black-hole formation. Previous simulations reportedly found that the luminosity can later increase and approach the Blandford–Znajek prediction.

Because the present simulations do not cover a sufficiently long post-collapse interval, the authors leave unresolved whether the same late-time transition occurs for their equal-mass and unequal-mass systems.

References

Although our simulations do not extend sufficiently far into the post-collapse phase to determine whether a similar transition occurs, the equal-mass model exhibits several features consistent with the conditions required for activation of this mechanism.

— Binary Neutron Star Merger Simulations with Microphysical Equation of State using Spritz  (2608.23310 - Nouri et al., 24 Aug 2026) in Section 3.3.3, “Electromagnetic luminosity”

Furthermore, our simulations follow the post-collapse evolution for only a short time, preventing us from determining whether the formation of the highly magnetized funnel and observed polar outflow can ultimately lead to a successful Blandford-Znajek jet powered by the BH-disk system.

— Binary Neutron Star Merger Simulations with Microphysical Equation of State using Spritz  (2608.23310 - Nouri et al., 24 Aug 2026) in Section 4, “Conclusions”