Transient obscuration event captured in NGC 3227 III. Photoionization modeling of the X-ray obscuration event in 2019

Abstract

A growing number of transient X-ray obscuration events in type I AGN suggest that our line-of-sight to the central engine is not always free. Multiple X-ray obscuration events have been reported in the nearby Seyfert 1.5 galaxy NGC 3227 from 2000 to 2016. In late 2019, another X-ray obscuration event was identified with Swift. Two coordinated target-of-opportunity observations with XMM-Newton, NuSTAR, and HST/COS were triggered in Nov. and Dec. 2019 to study this obscuration event. For each observation, we analyze the time-averaged X-ray spectra. We perform photoionization modeling with the SPEX code, which allows us to constrain the intrinsic continuum simultaneously with various photoionized absorption and emission components. Similar to previous transient X-ray obscuration events in NGC 3227, the one caught in late 2019 is short-lived (less than five months). If the obscurer has only one photoionized component, the two X-ray observations in late 2019 cannot be explained by the same obscurer that responds to the varying ionizing continuum. Due to the unknown geometry of the obscurer, its number density and distance to the black hole cannot be well constrained. The inferred distance covers at least two orders of magnitude, from the BLR to the dusty torus. Unlike some other X-ray obscuration events in Seyfert galaxies like NGC 5548 and NGC 3783, no prominent blueshifted broad absorption troughs were found in the 2019 HST/COS spectra of NGC 3227 when compared with archival UV spectra. This might be explained if the X-ray obscurer does not intercept our line of sight to (a significant portion of) the UV emitting region. It is not straightforward to understand the variety of the observational differences in the X-ray obscuration events observed so far. Future observations with high-quality data are needed to unveil the nature of the X-ray obscuration events. [shortend for arXiv]

A&A accepted

References in corpus (22)

• Active Galactic Nuclei: what's in a name?
• The AGN Black Hole Mass Database
• Occultation measurement of the size of the X-ray emitting region in the Active Galactic Nucleus of NGC 1365
• A fast and long-lived outflow from the supermassive black hole in NGC 5548
• On the use of C-stat in testing models for X-ray spectra
• Ionized outflows from active galactic nuclei as the essential elements of feedback
• Space Telescope and Optical Reverberation Mapping Project. I. Ultraviolet Observations of the Seyfert 1 Galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope
• A characteristic optical variability timescale in astrophysical accretion disks
• Systematic comparison of photoionised plasma codes with application to spectroscopic studies of AGN in X-rays
• Chasing obscuration in type-I AGN: discovery of an eclipsing clumpy wind at the outer broad-line region of NGC 3783
• Anatomy of the AGN in NGC 5548: II. The Spatial, Temporal and Physical Nature of the Outflow from HST/COS Observations
• Timing the warm absorber in NGC 4051
• Density diagnostics of ionized outflows in active galactic nuclei: X-ray and UV absorption lines from metastable levels in Be-like to C-like ions
• Stratified disc wind models for the AGN broad-line region: ultraviolet, optical and X-ray properties
• The XMM-Newton/HST view of the obscuring outflow in the Seyfert Galaxy Mrk 335 observed at extremely low X-ray flux
• Incoherent fast variability of X-ray obscurers. The case of NGC 3783
• Eclipsing the X-ray emitting region in the active galaxy NGC 6814
• Variability of the coronal line region in NGC 4151
• Transient obscuration event captured in NGC 3227. I. Continuum model for the broadband spectral energy distribution
• The Inner Accretion Flow in the Resurgent Seyfert-1.2 AGN Mrk 817
• X-ray obscuration from a variable ionized absorber in PG 1114+445
• The X-Rays wind connection in PG 2112+059

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