Speaker
Description
Jets from accreting black-hole X-ray binary systems (BH-XRBs) are powerful outflows that release a large fraction of the accretion energy and power to the surrounding environment, providing a feedback mechanism that may alter the properties of the interstellar medium (ISM). Studying accretion processes alongside their feedback on the environment is crucial, as it enables the estimate of the matter and energy input/output around accreting BHs.
Signatures of jet feedback from BH-XRBs have so far been confirmed in only a handful of sources. Recent MeerKAT observations of Cyg X-1, GRS 1915+105, and GRS 1758-258 have revealed jet–ISM interaction structures, enabling the distinction of synchrotron and thermal emission components and the estimation of the jet power deposited into the ISM using calorimetric models. The BH-XRB GRO J1655-40 is an excellent candidate for studying jet–ISM feedback, since its high-density environment provides favorable conditions for jet–ISM interactions.
In this poster I will present the results obtained from ~ 9hr of observations of GRO J1655-40, taken in 2024 in the L-band at 1.28 GHz using MeerKAT. We identified a bow-shock structure lying at ~ 2.5 arcminutes away from the binary position. Given its alignment with the jet direction, the structure is likely the result of an interaction between the jet and the surrounding ISM. We identified distinct sub-structures based on their morphology and brightness, and measured their in-band spectral indexes. We then constrained the jet power and the ages of the structures using a calorimetry-based model for the bremsstrahlung-emitting regions. For the synchrotron-emitting structures, we estimated the electron plasma density and energy, and the magnetic field strength. Finally, we investigate the possible connection between the radio structure and the gamma-ray structure detected by H.E.S.S., both of which are aligned with the known jet direction.