Searching for flickering statistics in T CrB

TL;DR

This study models the flickering variability in T CrB by simulating turbulent elements in its accretion disc, revealing that most flickering originates from the inner disc regions.

Contribution

It introduces a new method linking angular momentum transport to flickering statistics, estimating the inner disc radius and viscosity parameter from observational data.

Findings

Inner disc radius approximately 4 x 10^9 cm

Viscosity parameter α approximately 0.9

Flickering mainly from inner disc regions

Abstract

We analyze $V$-band photometry of the aperiodic variability in T CrB. By applying a simple idea of angular momentum transport in the accretion disc, we have developed a method to simulate the statistical distribution of flare durations with the assumption that the aperiodic variability is produced by turbulent elements in the disc. Both cumulative histograms with Kolmogorov-Smirnov tests, and power density spectra are used to compare the observed data and simulations. The input parameters of the model $R_{\rm in}$ and $\alpha$ are correlated on a certain interval and the most probable values are an inner disc radius of $R_{\rm in} \simeq 4 \times 10^9$ cm and a viscosity of $\alpha \simeq 0.9$. The disc is then weakly truncated. We find that the majority of turbulent events producing flickering activity are concentrated in the inner parts of the accretion disc.