# Black holes, disks and jets following binary mergers and stellar collapse: The narrow range of EM luminosities and accretion rates

## TL;DR

This study uses general relativistic magnetohydrodynamic simulations to show that diverse binary mergers and stellar collapses produce jets with remarkably similar luminosities and accretion rates, aligning with observed gamma-ray burst distributions.

## Contribution

It reveals a universal range of jet luminosities and accretion rates across different astrophysical scenarios, supported by a simple explanatory model.

## Key findings

- Jet Poynting luminosities are narrowly distributed around 10^{52} erg/s.
- Accretion rates at jet launch are consistently between 0.1 and 10 solar masses per second.
- Results support binary mergers as progenitors of short GRBs and stellar collapses for long GRBs.

## Abstract

We have performed magnetohydrodynamic simulations in general relativity of binary neutron star and binary black hole-neutron star mergers, as well as the magnetorotational collapse of supermassive stars. In many cases the outcome is a spinnng black hole (BH) immersed in a magnetized disk, with a jet emanating from the poles of the BH. While their formation scenarios differ and their BH masses, as well as their disk masses, densities, and magnetic field strengths, vary by orders of magnitude, these features conspire to generate jet Poynting luminosities that all lie in the same, narrow range of $\sim 10^{52\pm1}~{\rm erg ~s^{-1}}$. A similar result applies to their BH accretion rates upon jet launch, which is $\sim 0.1-10~{\rm M_{\odot}~s^{-1}}$. We provide a simple model that explains these unanticipated findings. Interestingly, these luminosities reside in the same narrow range characterizing the observed luminosity distributions of over 400 short and long GRBs with distances inferred from spectroscopic redshifts or host galaxies. This result, together with the GRB lifetimes predicted by the model, supports the belief that a compact binary merger is the progenitor of an SGRB, while a massive, stellar magnetorotational collapse is the progenitor of an LGRB.