Correlated X-ray and Optical Variability in Mkn 509

TL;DR

This study monitors Markarian 509 over three years, revealing correlated optical and X-ray variability with optical leading X-ray by 15 days, and characterizes the X-ray power spectrum and lag as related to accretion disk dynamics.

Contribution

First long-term multi-wavelength monitoring of Mkn 509 showing correlated variability and detailed power spectrum analysis.

Findings

Optical flux leads X-ray flux by 15 days.

X-ray power spectrum has a steep slope of -2.0, breaking at 34 days.

Variability lag suggests inward propagating accretion disk fluctuations.

Abstract

We present results of a 3 year monitoring campaign of the Seyfert 1 galaxy Markarian 509, using X-ray data from the Rossi X-ray Timing Explorer (RXTE) and optical data taken by the SMARTS consortium. Both light curves show significant variations, and are strongly correlated with the optical flux leading the X-ray flux by 15 days. The X-ray power spectrum shows a steep high-frequency slope of -2.0, breaking to a slope of -1.0 at at timescale of 34 days. The lag from optical to X-ray emission is most likely caused by variations in the accretion disk propagating inward.