The X-ray spectra of Compton-thick Seyfert 2 galaxies as seen by BeppoSAX

By G. Matt, A. C. Fabian, M. Guainazzi, K. Iwasawa, L. Bassani, G. Malaguti. 2000

162 citations recorded by the source corpus.

Results from BeppoSAX observations of Compton-thick Seyfert 2 galaxies are summarized and reviewed, and their general properties derived and discussed. In five out of the seven observed sources, the nucleus is directly visible at high X-ray energies, where the photons penetrate absorbers with column densities in the range 1.1–4.3×1024 cm−2 (in the other two sources, NGC 1068 and NGC 7674, the nucleus is instead totally obscured at all energies, implying even larger column densities). In most sources there is unambiguous evidence of a reflection component from optically thick, cold matter, while in two (or maybe four) cases there is also evidence of reflection from ionized matter. For the sources with a measured X-ray luminosity, a comparison with the infrared luminosity is made; while in two cases (the Circinus galaxy and NGC 4945) the IR emission appears to be dominated by starburst activity, in the other three sources (NGC 6240, Mrk 3 and TOL 0109-383) it is likely to be dominated by reprocessing of the UV and X-ray photons emitted by an active galactic nucleus.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/12103228563a50e8dd8708261208a06d462cca29

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. M. Alexander
2. W. N. Brandt
3. L. Hernquist
4. P. Hopkins
5. R. Ivison
6. R. Hickox
7. I. Smail
8. Mark Dickinson

In Instrumentation

1. D. M. Alexander
2. W. N. Brandt
3. I. Smail
4. R. Ivison
5. L. Hernquist
6. P. Hopkins
7. S. Chapman
8. Mark Dickinson

Citations in the corpus

• THE SPACE DENSITY OF COMPTON-THICK ACTIVE GALACTIC NUCLEUS AND THE X-RAY BACKGROUND (2009, background): “In fact, two of the three nearest AGN are Compton thick (NGC4945 and the Circinus Galaxy; Matt et al. 2000).”
• The Fall of Active Galactic Nuclei and the Rise of Star-forming Galaxies: A Close Look at the Chandra Deep Field X-Ray Number Counts (2004, background): “Local studies have also shown that 40% of moderateto high-luminosity AGNs are Compton-thick, with very little direct emission from the AGN itself (e.g., Maiolino et al. 1998; Matt et al. 2000).”
• THREE-DIMENSIONAL INTEGRAL FIELD OBSERVATIONS OF 10 GALACTIC WINDS. I. EXTENDED PHASE (≳10 Myr) OF MASS/ENERGY INJECTION BEFORE THE WIND BLOWS (2010, background): “X-ray spectral analysis further supports the view of Circinus as a highly obscured AGN but with strong thermal dust emission dominated by heating from nuclear star formation (Matt et al. 2000).”
• The Chandra Deep Field North Survey. XIII. 2 Ms Point-Source Catalogs (2003, background): “The X-ray emission from the other AGNs with very flat X-ray spectra is still not well characterized by a simple absorbed power-law model, and these sources may be Compton thick AGNs (i.e.,NH > 1.5 1024 cm 2; e.g., Matt et al. 2000).”
• Changing look: from Compton‐thick to Compton‐thin, or the rebirth of fossil active galactic nuclei (2003, background): “As, however, the covering factor of the reflecting matter is by all evidence pretty large (e.g. Matt et al. 2000), it is unlikely that the possible lack of intermediate Compton–thick sources will result to be a serious problem.”
• Resolving the mid-infrared cores of local Seyferts (2009, background): “In X-rays, it is known to be substantially Compton-thick and reflectiondominated, with logNH>25 (Matt et al. 2000; Iwasawa et al. 1997; Koyama et al. 1989).”
• X-RAY SPECTRAL PROPERTIES OF THE BAT AGN SAMPLE (2008, background): “Matt et al. (2000) estimated that the number could be as high as an order of magnitude more than the unobscured sources, which are easily detected in optical and soft X-ray surveys.”
• A NEW DIAGNOSTIC OF ACTIVE GALACTIC NUCLEI: REVEALING HIGHLY ABSORBED SYSTEMS AT REDSHIFT >0.3 (2011, background): “However, the steep X-ray spectral slopes do not preclude the possibility that all of these objects are heavily absorbed or Compton-thick AGN because the soft X-ray emission could be dominated by either scattered nuclear emission or star formation (e.g., Matt et al. 2000).”
• Towards a complete census of AGN in nearby Galaxies: a large population of optically unidentified AGN (2009, background): “…Compton-thick AGNs (NH > 1.5 × 10 24 cm−2) can be extremely weak, making it challenging to identify the most heavily obscured AGNs using X-ray data alone (i.e., the < 10 keV emission can be a factor ≈ 30–1000 times weaker than the intrinsic emission; e.g., Risaliti et al. 1999; Matt et al. 2000).”
• The X-Ray Spectral Properties of SCUBA Galaxies (2005, background): “Absorption Correction Since accurate absorption corrections are challenging to determine even for well-studied obscured AGNs in the local universe (e.g., Turner et al. 1997b; Bassani et al. 1999; Matt et al. 2000), the absorption corrections for our X-ray–faint SMGs will be somewhat uncertain.”
• An X-ray spectral model for Compton-thick toroidal reprocessors (2009, background): “A class of type 2 active galactic nuclei are known to be heavily obscured by Compton-thick matter (e.g. Awaki et al. 1991; Done, Madejski, & Smith 1996; Matt et al. 2000; Guainazzi, Matt, & Perola 2005; Levenson et al. 2002, 2006).”
• Swift BAT Survey of AGNs (2007, unknown): “…F. Mushotzky et al. 2008, in preparation; (10) EXOSAT/R. F. Mushotzky et al. 2008, in preparation; (11) Bassani et al. 1999; (12) BeppoSAX; (13) Matt et al. 2000; (14) Immler et al. 2003; (15) XMM; (16) Sambruna et al. 2006; (17) Gilli et al. 2000; (18) RXTE; (19) Maiolino et al. 1998; (20)…”
• The Chandra Deep Field North Survey. XIV. X-Ray-detected Obscured AGNs and Starburst Galaxies in the Bright Submillimeter Source Population (2002, background): “…spectrum of a Compton-thick AGN is generally characterized by a large equivalent width iron Kα emission line (EW >∼ 0.5 keV; e.g., Matt, Brandt, & Fabian 1996; Maiolino et al. 1998; Bassani et al. 1999; Matt et al. 2000) and a flat or inverted (Γ < 0.0) X-ray spectral slope, due to pure reflection.”
• Chandra and Spitzer Unveil Heavily Obscured Quasars in the Chandra/SWIRE Survey (2006, unknown): “POLLETTA ET AL.676 Vol. 642 components (Smith & Done 1996; Matt et al. 2000).”
• Molecular line emission in NGC 1068 imaged with ALMA: I. An AGN-driven outflow in the dense molecular gas (2014, background): “…luminosity of the AGN in NGC 1068 (Lbol), estimated from MIR and Xray wavelengths, is at least three orders of magnitude larger than Lkin: Lbol ≥ 1044−45erg s−1 (Bock et al. 2000; Laurent et al. 2000; Matt et al. 2000; Raban et al. 2009; Prieto et al. 2010; AlonsoHerrero et al. 2011 and Sect.”
• X-ray spectral survey with XMM-Newton of a complete sample of nearby Seyfert galaxies (2005, background): “In particular, in Compton-thick sources with NH > 1024 cm−2, the transmitted component is completely suppressed below 10 keV and the spectrum observed in the 2–10 keV band is dominated by flattened reprocessed components from a cold and/or warm scatterer (Matt et al. 2000).”