# X-ray polarization in radio-quiet AGN: Insights from the wedge corona model using Monte Carlo simulations

## TL;DR

This paper models X-ray polarization in radio-quiet AGNs using Monte Carlo simulations of a wedge corona, comparing results with IXPE observations to constrain the system's geometry and physical parameters.

## Contribution

It introduces a novel wedge corona model for AGN X-ray polarization and applies detailed Monte Carlo simulations including relativistic effects.

## Key findings

- Predicted polarization signatures depend on corona geometry and black hole spin.
- Model results are consistent with IXPE observations of NGC 4151.
- Constraints on the corona's opening angle and inner disk radius are derived.

## Abstract

In this study, we present novel calculations of X-ray polarization from radio-quiet and unobscured active galactic nuclei (AGNs) using the Monte Carlo code MONK, which includes all general and special relativity effects. Our geometric model, referred to as the ``wedge corona'', features a homogeneous cloud of electrons characterized by an aspect ratio of h/r and a radius that extends down to the innermost stable circular orbit around the central black hole (BH). Adopting the physical parameters of the Seyfert galaxy NGC 4151 as a baseline, we investigated various geometric and physical configurations of the BH-corona-accretion disk (AD) system, such as the coronal opening angle, temperature, optical depth, BH spin, and the inner radius of the disk. Finally, we compared our calculations with results from the Imaging X-ray Polarimetry Explorer (IXPE) for NGC 4151, the only radio-quiet and unobscured AGN with significant polarization detected by IXPE, to constrain the system's geometric parameters within the framework of the wedge corona model.