Dynamic Accretion Disk-Corona Connection and Broad Fe K alpha Variability in Mrk 766 Revealed by Time-Resolved High Resolution X-Ray Spectroscopic Analysis

We present a multi-epoch, primarily X-ray study of the narrow-line Seyfert 1 (NLSy1) galaxy Mrk 766 by combining archival XMM-Newton observations spanning nearly two decades together with a XRISM observation obtained during its Performance Verification Phase. We analyzed the absorption and emission features in the soft X-ray spectra from RGS and EPIC-pn data, revealing a stratified multi-phase potentially ionised absorber with a column density varying at a timescale of about 1 day. The covering fraction shows positive correlation with the continuum flux, however with significant intrinsic scatter, between the epochs. Mrk 766 exhibits a multi-component Fe,K α emission line as revealed by fits to the XRISM data. A quasi-phenomenological model comprising a torus and a broad diskline component distinguishes the two components and constrains the inner radius of the potential broad line emitting disk substructure between R in=40-60,r g. Analysis of multiple epochs of the Fe K α complex across XMM-Newton observations reveals that the broad component tracks the continuum flux closely and effectively reflects the trend with respect to the continuum. The narrow component is consistent with a distant emitter, potentially the torus. Quasi-simultaneous monitoring with Swift-XRT and UVOT further indicates UV emission lagging the X-rays by 5.9+4.1-5.7 hours, consistent with disk reprocessing of coronal X-ray fluctuations, and corresponds to a light travel distance of up to 10 cubed,r g. Overall, our analysis maps the extent of the dynamically evolving absorber, the iron line emitter, and the accretion disk in this highly accreting NLSy1 system.