Dynamic Accretion Disk–Corona Connection and Broad Fe K α Variability in Mrk 766 Revealed by Time-resolved High-resolution X-Ray Spectroscopic Analysis
- 1University of Maryland Baltimore County
- 2Presidency University
- 3Inter-University Centre for Astronomy and Astrophysics (IUCAA)
Abstract
We present a multiepoch, primarily X-ray study of the narrow-line Seyfert 1 (NLSy1) galaxy Mrk 766 by combining archival XMM-Newton observations spanning nearly 2 decades together with an XRISM observation obtained during its Performance Verification Phase. We analyzed the absorption and emission features in the soft X-ray spectra from Reflection Grating Spectrometer and EPIC-pn data, revealing a stratified multiphase potentially ionized absorber with a column density varying at a timescale of ∼1 day. The covering fraction shows positive correlation with the continuum flux, however with significant intrinsic scatter, between the epochs. Mrk 766 exhibits a multicomponent Fe K α emission line as revealed by fits to the XRISM data. A quasi-phenomenological model comprising a torus and a broad disk-line 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 the Neil Gehrels Swift Observatory X-Ray Telescope and UVOT further indicates UV emission lagging the X-rays by 5 . 9 − 5.7 + 4.1 hr, consistent with disk reprocessing of coronal X-ray fluctuations, and corresponds to a light travel distance of up to 10 ³ 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.
Versions
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BibTeX
@article{mondal2026dynamic,
title = {{Dynamic Accretion Disk–Corona Connection and Broad Fe K α Variability in Mrk 766 Revealed by Time-resolved High-resolution X-Ray Spectroscopic Analysis}},
author = {Ayon Mondal and Tathagata Saha and Arijit Sar and Ritaban Chatterjee},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/aea83d},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea83d},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Dynamic Accretion Disk–Corona Connection and Broad Fe K α Variability in Mrk 766 Revealed by Time-resolved High-resolution X-Ray Spectroscopic Analysis
AU - Ayon Mondal
AU - Tathagata Saha
AU - Arijit Sar
AU - Ritaban Chatterjee
PY - 2026
DA - 2026/10/21
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aea83d
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aea83d
AB - We present a multiepoch, primarily X-ray study of the narrow-line Seyfert 1 (NLSy1) galaxy Mrk 766 by combining archival XMM-Newton observations spanning nearly 2 decades together with an XRISM observation obtained during its Performance Verification Phase. We analyzed the absorption and emission features in the soft X-ray spectra from Reflection Grating Spectrometer and EPIC-pn data, revealing a stratified multiphase potentially ionized absorber with a column density varying at a timescale of ∼1 day. The covering fraction shows positive correlation with the continuum flux, however with significant intrinsic scatter, between the epochs. Mrk 766 exhibits a multicomponent Fe K α emission line as revealed by fits to the XRISM data. A quasi-phenomenological model comprising a torus and a broad disk-line 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 the Neil Gehrels Swift Observatory X-Ray Telescope and UVOT further indicates UV emission lagging the X-rays by 5 . 9 − 5.7 + 4.1 hr, consistent with disk reprocessing of coronal X-ray fluctuations, and corresponds to a light travel distance of up to 10 ³ 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.
SN - 0004-637X
SN - 1538-4357
ER -