Speaker
Description
In this talk, I'll present a new application of the Time-Evolving PhotoIonisation Device (TEPID) code to a time-resolved NuSTAR+XMM-Newton spectrum of NGC 4051 from 2018. This nearby Seyfert I AGN is an ideal laboratory of the innermost accretion scale thanks to its brightness and wealth of spectroscopic features, from the optical to the X-rays. It hosts three disk winds with increasing velocity, ionisation and density, routinely detected in all the X-ray observations over the last 20 years.
Thanks to our advanced modeling, we have been able to accurately derive the gas number densities $n_H$ for the first time. This is a fundamental quantity to accurately probe such winds, however it is totally degenerate when assuming time-equilibrium ionisation and is indeed poorly known in all kind of compact, optically unresolved sources. Together with the usual spectroscopic diagnostics - $N_H, \xi, v_{out}$ , ... - , the gas number density allows to accurately determine the wind geometry and energetics without a-priori assumptions.
This allows to locate such winds in the optical Broad Line Region (around 0.005 parsecs) and lead to a coherent picture of all the gravitational-bound and outflowing structures around the accretion disc, from cold (Fe K$\alpha$) reflection to optical and UV virialised emission, up to the X-ray outflows.
I'll also illustrate the foreseen improvement with the high-resolution instrument Resolve onboard XRISM and the upcoming X-IFU onboard NewAthena.