Modelling absorption and emission profiles from accretion disc winds with WINE

TL;DR

This paper introduces WINE, a spectroscopic model for AGN disc winds that combines photoionisation, radiative transfer, and relativistic effects, enabling detailed simulation and analysis of wind spectral features for current and future X-ray observatories.

Contribution

The paper presents WINE, a novel 3D spectroscopic model for AGN disc winds that improves the interpretation of wind properties from X-ray spectra.

Findings

Resolve and X-IFU can accurately constrain wind properties.

Spectral features depend on wind kinematics and ionisation.

SED shape significantly affects gas opacity.

Abstract

Fast, massive winds are ubiquitously observed in the UV and X-ray spectra of Active Galactic Nuclei (AGN) and other accreting sources. Theoretical and observational evidences suggest they are launched at accretion disc scales, carrying significant mass and angular momentum. Thanks to such high energy output, they may play an important role in transferring the accretion energy to the surrounding environment. In the case of AGNs, this process can help setting the so-called coevolution between the AGN and its host galaxy. To precisely assess the effective role of these winds, it is necessary to accurately measure their properties, including mass and energy rates. We aim to maximise the scientific return of current and future observations by improving the theoretical modelling of these winds through our Winds in the Ionised Nuclear Environment (WINE) model. WINE is a spectroscopic model designed for disc winds in AGNs and compact accreting sources, which couples photoionisation and radiative transfer with special relativistic effects and a three-dimensional model of the emission profiles. We explore with WINE the main spectral features associated to AGN disc winds, with particular emphasis on the detectability of the wind emission. We simulate observations with the X-ray microcalorimeters Resolve on board the XRISM satellite and the future Athena's X-IFU for the typical properties and exposure times of the sources in the XRISM Performance Verification phase. The wind kinematic, geometry, ionisation and column density deeply affect shape and strength of the spectral features. Thanks to this, both Resolve and X-IFU will be able to accurately constrain the main properties of disc winds in a broad range of parameters. We also find a dramatic difference in the gas opacity when using a soft, Narrow Line Seyfert 1-like SED compared to a canonical powerlaw SED with spectral index Gamma=2.