Thermal and Nonthermal Emission from the Extragalactic Microquasar S26

FLORENCIA RIZZO; LEANDRO ABAROA; GUSTAVO E. ROMERO; GIULIO MANCUSO

Congreso; Reunión Anual de la Asociación Argentina de Astronomía; 2023

Asociación Argentina de Astronomía

S26 is a unique microquasar that exhibits the most powerful jetsobserved in accreting binaries, with a kinetic luminosity of Ljet≈ 1040-1erg s . According to the jet-disk symbiosis model, this implies thatthe accretion luminosity onto the stellar black hole should behighly super-Eddington, of the order of Lacc≈ Ljet, to power the jet.However, the observed X-ray luminosity of this system, asmeasured by Chandra and XMM-Newton telescopes, indicates anapparent very sub-Eddington accretion luminosity with Lacc≈ 1036-1erg s , not enough to explain the jet power. In this contribution, wepresent a study of the thermal and nonthermal radiation of S26 and we explore the relation between the jet and disk in this source. We analyze X-ray observations of the system obtained with XMM-Newton and we develop a jet model to explain the emission. We investigate particle acceleration and radiative processes that occur in adiabatic shocks generated at the base of the jet. An schematic picture of the system is shown in the right-hand figure.