Launching, propagation and emission of relativistic jets from binary mergers and across mass scales

Relativistic jets are marvellous astrophysical phenomena and formidable tools in multi-messenger astronomy.

Revealed by uncountable examples, their existence has been the subject of observations for decades across a variety of length and timescales.

They are associated with some of the most energetic phenomena in the universe, such as gamma-ray bursts (GRBs), microquasars, and active galactic nuclei (AGNs).

As particle accelerators in GRBs, or as regulators of galaxy evolution in AGNs, relativistic jets represent a cornerstone in our understanding of the universe.

Yet, relativistic jets raise far more questions than answers: Do rotating black holes provide the enormous energy powering relativistic jets? How can jets propagate stably across huge scales when plagued by a number of instabilities? What produces their emission during propagation and at breakout?

Building on the first pioneering calculations in which I showed that merging magnetised neutron stars produce jet-like structures, and on the tremendous success in obtaining and interpreting the first image of a supermassive black hole, I am in a unique position to offer a complete set of answers to these long-standing questions.

JETSET proposes to construct a new and organic comprehension of the mechanisms behind the launching, propagation and emission of relativistic jets from merging binaries.

It will also clarify if the same physical processes are responsible for the jet phenomenology across eight orders of magnitude in the mass scale, going from stellar-mass to the largest supermassive black holes.

To achieve this goal, JETSET will combine a computational infrastructure employing the most advanced numerical methods with accurate observations from electromagnetic bands, neutrinos and gravitational waves.

In this way, a novel and comprehensive view will be built of one of the most fascinating and puzzling astrophysical phenomena, linking the deepest fabric of spacetime with the nonlinear dynamics of plasmas.