NuSTAR Observations of the Compton-thick Active Galactic Nucleus and Ultraluminous X-ray Source Candidate in NGC 5643

Abstract

We present two NuSTAR observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton and Swift-BAT, we perform a high-quality broadband spectral analysis of the AGN over two decades in energy ($\sim$0.5-100 keV). Previous X-ray observations suggested that the AGN is obscured by a Compton-thick (CT) column of obscuring gas along our line-of-sight. However, the lack of high-quality $\gtrsim$ 10 keV observations, together with the presence of a nearby X-ray luminous source, NGC 5643 X-1, had left significant uncertainties in the characterization of the nuclear spectrum. NuSTAR now enables the AGN and NGC 5643 X-1 to be separately resolved above 10 keV for the first time and allows a direct measurement of the absorbing column density toward the nucleus. The new data show that the nucleus is indeed obscured by a CT column of $N_{\mathrm{H}}$ $\gtrsim$ 5 $\times$ 10${}^{24}$ cm${}^{-2}$. The range of 2-10 keV absorption-corrected luminosity inferred from the best fitting models is $L_{2-10,\mathrm{int}}=$ (0.8-1.7) $\times$ 10${}^{42}$ erg s${}^{-1}$, consistent with that predicted from multiwavelength intrinsic luminosity indicators. We also study the NuSTAR data for NGC 5643 X-1, and show that it exhibits evidence for a spectral cut-off at energy, $E$ $\sim$ 10 keV, similar to that seen in other ULXs observed by NuSTAR. Along with the evidence for significant X-ray luminosity variations in the 3-8 keV band from 2003-2014, our results further strengthen the ULX classification of NGC 5643 X-1.

Resubmitted to ApJ on Sept. 10, 2015 after incorporating the referee's comments; 14 pages, 6 figures and 3 tables

References in corpus (12)

• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• Toward the Standard Population Synthesis Model of the X-Ray Background: Evolution of X-Ray Luminosity and Absorption Functions of Active Galactic Nuclei Including Compton-Thick Populations
• Super-critically accreting stellar-mass black holes as ultraluminous X-ray sources
• On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies
• Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes
• Fueling AGN II: Spatially Resolved Molecular Inflows and Outflows
• The 2-79 keV X-ray Spectrum of the Circinus Galaxy with NuSTAR, XMM-Newton and Chandra: a Fully Compton-Thick AGN
• NuSTAR and XMM-Newton Observations of Luminous, Heavily Obscured, WISE-Selected Quasars at z ~ 2
• The NuSTAR View of Nearby Compton-thick AGN: The Cases of NGC 424, NGC 1320 and IC 2560
• The variable hard X-ray emission of NGC4945 as observed by NuSTAR
• NuSTAR unveils a Compton-thick Type 2 quasar in Mrk 34
• A direct comparison of X-ray spectral models for tori in active galactic nuclei

Cited by in corpus (51)

• Active Galactic Nuclei: what's in a name?
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• Obscured Active Galactic Nuclei
• New Spectral Model for Constraining Torus Covering Factors from Broadband X-ray Spectra of Active Galactic Nuclei
• The Galaxy Activity, Torus and Outflow Survey (GATOS) I. ALMA images of dusty molecular tori in Seyfert galaxies
• Compton thick AGN in the NuSTAR era
• A hard X-ray view of Luminous and Ultra-luminous Infrared Galaxies in GOALS: I - AGN obscuration along the merger sequence
• Resolving the nuclear obscuring disk in the Compton-thick Seyfert galaxy NGC5643 with ALMA
• New evidence for the ubiquity of prominent polar dust emission in AGN on tens of parsec scales
• Super-Eddington Accretion onto the Neutron Star NGC 7793 P13: Broadband X-ray Spectroscopy and Ultraluminous X-ray Sources
• NuSTAR observations of WISE J1036+0449, a Galaxy at z$\sim 1$ obscured by hot dust
• PAH features within few hundred parsecs of active galactic nuclei
• The NuSTAR Serendipitous Survey: Hunting for The Most Extreme Obscured AGN at >10 keV
• The Hunt for Intermediate Mass Black Holes in the JWST Era
• The Unusual Broadband X-ray Spectral Variability of NGC 1313 X-1 seen with XMM$-$Newton, Chandra and NuSTAR
• A Tight Correlation Between Millimeter and X-ray Emission in Accreting Massive Black Holes from <100 Milliarcsecond-resolution ALMA Observations
• Compton-Thick AGN in the NuSTAR era VI: The observed Compton-thick fraction in the Local Universe
• Compton Thick AGN in the 70 Month Swift-BAT All-Sky Hard X-ray Survey: a Bayesian approach
• Compton-thick AGN in the NuSTAR era III: A systematic study of the torus covering factor
• Variability-selected intermediate mass black hole candidates in dwarf galaxies from ZTF and WISE
• Upholding the Unified Model for Active Galactic Nuclei: VLT/FORS2 Spectropolarimetry of Seyfert 2 galaxies
• The weak neutral Fe fluorescence line and long-term X-ray evolution of the Compton-thick AGN in NGC 7674
• X-ray bolometric corrections for Compton-thick active galactic nuclei
• A growth-rate indicator for Compton-thick active galactic nuclei
• A New Compton-thick AGN in our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR
• NuSTAR unveils a heavily obscured low-luminosity Active Galactic Nucleus in the Luminous Infrared Galaxy NGC 6286
• NuSTAR observations of heavily obscured Swift/BAT AGN: constraints on the Compton-thick AGN fraction
• BASS XXVIII: Near-infrared Data Release 2, High-Ionization and Broad Lines in Active Galactic Nuclei
• IC 3639 - A new bona fide Compton thick AGN unveiled by NuSTAR
• NuSTAR Uncovers an Extremely Local Compton-thick AGN in NGC 4968
• An Iwasawa-Taniguchi Effect for Compton-thick Active Galactic Nuclei
• The Geometry of the Infrared and X-ray Obscurer in a Dusty Hyperluminous Quasar
• $NuSTAR$ Observations of Four Nearby X-ray Faint AGN: Low Luminosity or Heavy Obscuration?
• NuSTAR Observations of AGN with Low Observed X-ray to [OIII] Luminosity Ratios: Heavily Obscured AGN or Turned-Off AGN?
• Compton-thick AGN in the NuSTAR era II: A deep NuSTAR and XMM-Newton view of the candidate Compton thick AGN in NGC 1358
• Extended X-ray Emission in Compton Thick AGN with Deep Chandra Observations
• X-ray spectral properties of seven heavily obscured Seyfert 2 galaxies
• A Low Incidence of Mid-Infrared Variability in Dwarf Galaxies
• Compton-thick AGN in the NuSTAR era IV: A deep NuSTAR and XMM-Newton view of the candidate Compton thick AGN in ESO 116-G018
• Compton-thick AGNs in the NuSTAR era. V: Joint NuSTAR and XMM-Newton spectral analysis of three "soft-Gamma" candidate CT-AGNs in the Swift-BAT 100-month catalog
• The kpc Scale Fe K$\alpha$ Emission in the Compton Thin Seyfert 2 Galaxy NGC 4388 resolved by Chandra
• The ultraluminous X-ray source NGC 5643 ULX1: a large stellar mass black hole accreting at super-Eddington rates?
• Chandra Detection of the Circumnuclear Molecular Torus of the Compton Thick AGN in NGC 5643
• Investigating the Covering Fraction Distribution of Swift/BAT AGN with X-ray and IR Observations
• Observational hints on the torus obscuring gas behaviour through X-rays with NuSTAR data
• NuSTAR and XMM-Newton observations of the ultraluminous X-ray source NGC 5643 X-1
• The Luminosity and Stellar Mass Functions of Red W1-W2 Galaxies
• NuSTAR observations of the ultraluminous X-ray source M33 X-8: a black hole in a very high state?
• X-ray and CO-Derived Column Densities in AGN: A Study of Obscuration Properties in CTAGN and Non-CTAGN
• A broadband X-ray study of a sample of AGNs with [OIII] measured inclinations
• Compton-thick AGN Characterisation in a Multi-wavelength Context: Insights from the 70-Month \textit{SWIFT}/BAT Catalogue