Probing BH mass and accretion through X-ray variability in the CDFS

TL;DR

This study applies X-ray variability analysis to high-redshift AGNs in the CDFS to estimate black hole masses and accretion rates, revealing a wide range of SMBH properties at significant cosmic distances.

Contribution

It extends the variability-luminosity relation methodology to high-redshift AGNs using XMM-Newton data, incorporating Monte Carlo simulations for bias correction.

Findings

Black hole masses range from 10^5 to 10^9 solar masses.

Accretion rates vary from 10^-3 to above Eddington limit.

Results suggest diverse SMBH growth states at high redshift.

Abstract

Recent work on nearby AGNs has shown that X-ray variability is correlated with the mass and accretion rate onto the central SMBH. Here we present the application of the variability-luminosity relation to high redshift AGNs in the CDFS, making use of XMM-Newton observations. We use Monte Carlo simulations in order to properly account for bias and uncertainties introduced by the sparse sampling and the very low statistics. Our preliminary results indicate that BH masses span over the range from 10^5 to 10^9 solar mass while accretion rates range from 10^-3 up to values greater than 1, in unit of Eddington accretion rate.