A Comparison of the X-ray Polarimetric Properties of Stellar and Supermassive Black Holes

TL;DR

This study compares X-ray polarization properties of stellar and supermassive black holes, finding similar characteristics especially in the hard state, suggesting a shared coronal geometry across different black hole masses.

Contribution

It provides the first comprehensive comparison of X-ray polarimetric properties across black hole types, supporting a unified accretion geometry model.

Findings

Polarization properties are very similar in stellar and supermassive black holes.

Similarity is especially pronounced in the hard state.

Supports the idea of a common coronal geometry across black hole classes.

Abstract

X-ray polarization provides a new way to probe accretion geometry in black hole systems. If the accretion geometry of black holes is similar regardless of mass, we should expect the same to be true of their polarization properties. We compare the polarimetric properties of all non-blazar black holes observed with IXPE. We find that their polarization properties are very similar, particularly in the hard state, where the corona dominates. This tentatively supports the idea that stellar and supermassive black holes share a common coronal geometry.