Understanding the light curves of the HST-1 knot in M87 with internal relativistic shock waves along its jet

TL;DR

This paper models the multi-wavelength light curves of the HST-1 knot in M87 using a semi-analytical approach that accounts for internal relativistic shock waves generated by oscillations at the jet's base.

Contribution

It applies a semi-analytical model with genetic algorithms to accurately fit the observed light curves of the HST-1 knot, revealing the role of internal shocks in jet emission.

Findings

Successfully explains HST-1 light curves with >2 sigma confidence

Identifies periodic oscillations as key to shock formation

Demonstrates effectiveness of semi-analytical modeling in astrophysical jets

Abstract

Knots or blobs observed in astrophysical jets are commonly interpreted as shock waves moving along them. Long time observations of the HST-1 knot inside the jet of the galaxy M87 have produced detailed multi-wavelength light curves. In this article, we model these light curves using the semi-analytical approach developed by Mendoza et al. (2009). This model was developed to account for the light curves of working surfaces moving along relativistic jets. These working surfaces are generated by periodic oscillations of the injected flow velocity and mass ejection rates at the base of the jet. Using genetic algorithms to fit the parameters of the model, we are able to explain the outbursts observed in the light curves of the HST-1 knot with an accuracy greater than a 2 sigma statistical confidence level.