X-ray spectral survey with XMM-Newton of a complete sample of nearby Seyfert galaxies

By M. Cappi, F. Panessa, L. Bassani, Mauro Dadina, G. Dicocco, A. Comastri, R. Ceca, A. Filippenko, F. Gianotti, Luis C. Ho and 8 more. 2005

186 citations recorded by the source corpus.

Results obtained from an X-ray spectral survey of nearby Seyfert galaxies using XMM–Newton are reported. The sample was optically selected, well defined, complete in B  magnitude, and distance limited: it consists of the nearest ($D \la22$ Mpc) 27 Seyfert galaxies (9 of type 1, 18 of type 2) taken from the Ho et al. (1997a, ApJS, 112, 315) sample. This is one of the largest atlases of hard X-ray spectra of low-luminosity active galaxies ever assembled. All nuclear sources except two Seyfert 2s are detected between 2 and 10 keV, half for the first time ever, and average spectra are obtained for all of them. Nuclear luminosities reach values down to 10 38  erg s -1 . The shape of the distribution of X-ray parameters is affected by the presence of Compton-thick objects ($\ga$30% among type 2s). The latter have been identified either directly from their intense FeK line and flat X-ray spectra, or indirectly with flux diagnostic diagrams which use isotropic indicators. After taking into account these highly absorbed sources, we find that (i) the intrinsic X-ray spectral properties (i.e., spectral shapes and luminosities above 2 keV) are consistent between type 1 and type 2 Seyferts, as expected from “unified models”; (ii) Seyfert galaxies as a whole are distributed fairly continuously over the entire range of N H , between 10 20 and 10 25  cm -2 ; and (iii) while Seyfert 1s tend to have lower N H and Seyfert 2s tend to have the highest, we find 30% and 10% exceptions, respectively. Overall the sample is of sufficient quality to well represent the average intrinsic X-ray spectral properties of nearby active galactic nuclei, including a proper estimate of the distribution of their absorbing columns. Finally, we conclude that, with the exception of a few cases, the present study agrees with predictions of unified models of Seyfert galaxies, and extends their validity down to very low luminosities.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7752dd387e9315b8c9fdcb296edab6ca2b941a77

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. R. Hickox
3. Luis C. Ho
4. A. Merloni
5. P. Hopkins
6. H. Netzer
7. L. Hernquist
8. A. Comastri

In Nuclear and High Energy Physics

1. D. M. Alexander
2. A. Merloni
3. Judith Croston
4. A. Comastri
5. Luis C. Ho
6. R. Hickox
7. Y. Ueda
8. R. Mushotzky

Citations in the corpus

• Resolving the mid-infrared cores of local Seyferts (2009, methodology): “Using the mean of the large range found inXMMNewton by Cappi et al. (2006) and recentINTEGRAL results by Beckmann et al. (2006), for a distance of 16.7 Mpc, results ina mean logL2−10= 42.24, to which we attach a large 1-σ error in dex of 0.3.”
• The subarcsecond mid-infrared view of local active galactic nuclei – II. The mid-infrared–X-ray correlation (2015, methodology): “43 NGC 4698 According to González-Martı́n et al. (2009b), the XMM-Newton data of NGC 4698 are dominated by off nuclear emission (but see Cappi et al. 2006).”
• Suzaku Observations of Active Galactic Nuclei Detected in the Swift BAT Survey: Discovery of a “New Type” of Buried Supermassive Black Holes (2007, background): “As far as we know these are amongst the lowest scattered fractions ever seen from an absorbed AGN (Turner et al. 1997; Cappi et al. 2006).”
• What drives the growth of black holes (2011, result): “The predicted column densities and time-variable obscuration are in good agreement with those measured in nearby obscured AGNs (NH > 1022– 1025 cm−2 with absorbing column changes on < 1 year timescales; e.g., Risaliti et al. 1999, 2002; Guainazzi et al. 2005; Cappi et al. 2006).”
• OBSCURATION-DEPENDENT EVOLUTION OF ACTIVE GALACTIC NUCLEI (2015, background): “These include optical (Risaliti et al. 1999; Cappi et al. 2006; Panessa et al. 2006; Akylas & Georgantopoulos 2009; Gilli et al. 2010; Vignali et al. 2010; Jia et al. 2013; Mignoli et al. 2013; Vignali et al. 2014), infrared (e.g. Fiore et al. 2008, 2009; Alexander et al. 2011; Brightman & Nandra…”
• THREE-YEAR SWIFT–BAT SURVEY OF ACTIVE GALACTIC NUCLEI: RECONCILING THEORY AND OBSERVATIONS? (2010, unknown): “…et al. 2006; (6) Winter et al. 2009a; (7) Ueda et al. 2007; (8) Georgantopoulos et al. 2005; (9) Winter et al. 2009b; (10) Matt et al. 2009; (11) Cappi et al. 2006; (12) Page et al. 2005; (13) Winter et al. 2008; (14) Shu et al. 2007; (15) Jiménez-Bailón et al. 2007. many objects of the…”
• An X-ray view of 82 LINERs with Chandra and XMM-Newton data (2009, background): “Nearby examples of both Seyfert 2 (Maiolino et al., 1998; Risaliti et al., 1999; Page et al., 2003; Cappi et al., 2006; Panessa et al., 2006), and Seyfert 1 (Nandra et al., 2007) or PG-QSOs (Piconcelli et al., 2005; Jimenez-Bailon et al., 2005) have been studied.”
• Nuclear Activity in Nearby Galaxies (2008, background): “In an XMM-Newton study of a distance-limited sample of 27 Palomar Seyferts, Cappi et al. (2006) detect strong Fe Kα emission in over half of objects.”
• Swift BAT Survey of AGNs (2007, background): “…2000; (18) RXTE; (19) Maiolino et al. 1998; (20) XMM/Gondoin et al. 2003; (21) XMM/Perlman et al. 2005; (22)Chandra; (23) Risaliti et al. 1999; (24) Cappi et al. 2006; (25)Chandra/R. F.Mushotzky et al. 2008, in preparation; (26)ASCA; (27) Kennea et al. 2005; (28) Reynolds 1997; (29) Kraft et al.…”
• On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies ! (2006, background): “Type 1 AGN with significant absorption have been found (Cappi et al. 2006, hereafter C06, Mateos et al. 2005, Fiore et al. 2001a, etc.) as well as type 2 AGN without X-ray absorption (Caccianiga et al. 2004; Corral et al. 2005; Barcons et al. 2003; Panessa & Bassani 2002; Pappa et al. 2001).”
• The active nuclei of z < 1.0 3CRR radio sources (2009, background): “…by guest on 30 O ctober 2018 comparisons here are difficult, since there are many Compton-thick low-luminosity Seyferts (1/3 or more of Seyfert 2s; Cappi et al. 2006), implying lower limits on the X-ray-measured NH values, whereas (as we argue above) few radio galaxies for which data are…”