Absorption Variability of the Highly Obscured Active Galactic Nucleus NGC 4507

Abstract

We present a detailed study of the highly obscured active galaxy NGC 4507, performed using four Nuclear Spectroscopic Telescope Array (NuSTAR) observations carried out between May and August in 2015 (~ 130 ks in total). Using various phenomenological and physically motivated torus models, we explore the properties of the X-ray source and those of the obscuring material. The primary X-ray emission is found to be non-variable, indicating a stable accretion during the period of the observations. We find the equatorial column density of the obscuring materials to be ~ 2 x 10^24 cm^-2 while the line of sight column density to be ~ 7 - 8 x 10^23 cm^-22. The source is found to be deeply buried with the torus covering factor ~ 0.85. We observe variability in the line-of-sight column density on a timescale of < 35 days. The covering factor of the Compton-Thick material is found to be ~ 0.35, in agreement with the results of recent X-ray surveys. From the variability of the line-of-sight column density, we estimate that the variable absorbing material is likely located either in the BLR or in the torus.

arXiv comment20 pages, 15 figures, 8 tables, accepted for publication in MNRAS

References in corpus (49)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• HI4PI: A full-sky HI survey based on EBHIS and GASS
• On characterising the variability properties of X-ray light curves from active galaxies
• The Relationship Between Luminosity and Broad-Line Region Size in Active Galactic Nuclei
• AGN Dusty Tori: II. Observational Implications of Clumpiness
• AGN Dusty Tori: I. Handling of Clumpy Media
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• An X-ray Spectral Model for Compton-Thick Toroidal Reprocessors
• X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180
• Simultaneous X-ray/optical/UV snapshots of active galactic nuclei from XMM-Newton: spectral energy distributions for the reverberation mapped sample
• Ubiquitous variability of X-ray absorbing column densities in Seyfert 2 Galaxies
• The close environments of accreting massive black holes are shaped by radiative feedback
• BAT AGN Spectroscopic Survey I: Spectral Measurements, Derived Quantities, and AGN Demographics
• ASCA observations of Seyfert 1 galaxies: I. Data Analysis, Imaging and Timing
• Compton-thick Accretion in the local Universe
• Swift BAT Survey of AGN
• X-ray Spectral Properties of the BAT AGN Sample
• Changing look: from Compton-thick to Compton-thin, or the re-birth of fossil AGN
• Occultation measurement of the size of the X-ray emitting region in the Active Galactic Nucleus of NGC 1365
• First X-ray-Based Statistical Tests for Clumpy-Torus Models: Eclipse Events from 230 Years of Monitoring of Seyfert AGN
• New Spectral Model for Constraining Torus Covering Factors from Broadband X-ray Spectra of Active Galactic Nuclei
• The Nature of the Compton-thick X-ray Reprocessor in NGC 4945
• Suzaku Observations of Active Galactic Nuclei Detected in the Swift/BAT Survey: Discovery of "New Type" of Buried Supermassive Black Holes
• On the Unification of Active Galactic Nuclei
• BAT AGN Spectroscopic Survey -- XII. The relation between coronal properties of Active Galactic Nuclei and the Eddington ratio
• The BeppoSAX view of bright Compton-thin Seyfert 2 galaxies
• Rapid N_H changes in NGC 4151
• The Link Between the Hidden Broad Line Region and the Accretion Rate in Seyfert 2 Galaxies
• X-Ray Spectral Model from Clumpy Torus and Its Application to Circinus Galaxy
• IC 751: a new changing-look AGN discovered by NuSTAR
• Black hole mass and accretion rate of active galactic nuclei with double-peaked broad emission lines
• NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei: II. Median High-energy Cutoff in Seyfert II Hard X-ray Spectra
• The formerly X-ray reflection-dominated Seyfert~2 galaxy NGC6300
• Chandra monitoring of UGC 4203: the structure of the X-ray absorber
• The variability properties of X-ray steep and X-ray flat quasars
• On the size-luminosity relation of AGN dust tori in the mid-infrared
• RefleX: X-ray absorption and reflection in active galactic nuclei for arbitrary geometries
• The complex X-ray spectrum of NGC 4507
• A Compton-thin Solution for the Suzaku X-ray Spectrum of the Seyfert 2 Galaxy Mkn 3
• BAT AGN Spectroscopic Survey XXVII: Scattered X-Ray Radiation in Obscured Active Galactic Nuclei
• Application of X-Ray Clumpy Torus Model (XCLUMPY) to 10 Obscured Active Galactic Nuclei Observed with Suzaku and NuSTAR
• Monitoring the Violent Activity from the Inner Accretion Disk of the Seyfert 1.9 Galaxy NGC 2992 with RXTE
• Nature of Compton-thick Active Galactic Nuclei in "Non-merging'' Luminous Infrared Galaxies UGC 2608 and NGC 5135 Revealed with Broadband X-ray Spectroscopy
• Decoupling absorption and continuum variability in the Seyfert 2 NGC 4507
• On the nature of the X-ray absorption in the Seyfert 2 galaxy NGC 4507
• Probing Nuclear and Circumnuclear Properties of NGC 6300 using X-ray Observations
• X-ray absorption variability in NGC 4507

Cited by in corpus (3)

• Investigating Changing-Look Active Galactic Nuclei with Long-term Optical and X-Ray Observations
• Multi-wavelength properties of changing-state active galactic nuclei: I. the evolution of soft excess and X-ray continuum
• X-ray Unveiling Events in a z~1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South