Estimating the black hole mass of NGC1313 X-1 based on the spectral and timing properties

TL;DR

This paper estimates the black hole mass of NGC 1313 X-1 using spectral and timing data, confirming it as an intermediate-mass black hole with a mass between 2524 and 6811 solar masses.

Contribution

It introduces a combined spectral and timing modeling approach based on the epicyclic resonance and disk-corona models with magnetic fields to estimate black hole mass.

Findings

Black hole mass estimated between 2524 and 6811 solar masses.

Black hole spin likely higher than 0.3.

Supports the IMBH nature of NGC 1313 X-1.

Abstract

The discovery of 3:2 quasi-periodic oscillations (QPOs) in the ultraluminous X-ray source NGC 1313 X-1 suggests it harbors an intermediate-mass black hole (IMBH). We test this numerically by modelling the 3:2 QPOs and the associated X-ray spectrum based on the epicyclic resonance model and a disk-corona model with large-scale magnetic fields generated by the Cosmic Battery mechanism. The combined QPO-frequency and spectral fitting indicates that the BH mass ranges from 2524M_sun to 6811M_sun confirming its IMBH nature, and the BH spin is probably higher than ~0.3.