CAIXA: a catalogue of AGN in the XMM-Newton archive - II. Multiwavelength correlations
By S. Bianchi, N. F. Bonilla, M. Guainazzi, G. Matt, G. Ponti. 2009
189 citations recorded by the source corpus.
Aims. The availability of large amounts of multiwavelength data allows us to perform an extensive statistical analysis to look for correlations between different parameters of AGN. The physical implications of these correlations, when considered within the framework of current AGN models, can be enlightening in the resolution of the problems and the open issues which still characterise this class of sources. Methods. We presented CAIXA, a Catalogue of AGN in the XMM-Newton Archive, in a companion paper. It consists of radio-quiet X-ray unobscured sources, which cover a range in X-ray luminosities between L2−10 keV = 2.0 × 10 41 and 3.9 × 10 46 erg s −1 ,a nd in redshift from z = 0.002 to z = 4.520. Here, a systematic search for correlations between the X-ray spectral properties and the multiwavelength data was performed for the sources in CAIXA. All the significant (>99.9% confidence level) correlations are discussed along with their physical implications for current models of AGN. Results. Two main correlations are discussed in this paper: a) a very strong anti-correlation between the FWHM of the Hβ optical line and the ratio between the soft and the hard X-ray luminosity. Although similar anti-correlations between optical line width and X-ray spectral steepness have already been discussed in the literature, we consider the formulation we present in this paper as more fundamental, as it links model-independent quantities. Coupled with a strong anti-correlation between the V to hard X-ray flux ratio and the Hβ FHWM, it supports scenarios for the origin of the soft excess in AGN, which require strong suppression of the hard X-ray emission; b) a strong (and expected) correlation between the X-ray luminosity and the black hole mass. Its slope, flatter than 1, is consistent with Eddington ratio-dependent bolometric corrections. Moreover, we critically review through various statistical tests the role that distance biases play in the strong radio to X-ray luminosity correlation found in CAIXA and elsewhere; we conclude that only complete, unbiased samples should be used to draw observational constraints on the origin of radio emission in radio-quiet AGN.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/f42e452adc81461d0c25bd513a880622c210cd5d
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Citations in the corpus
- A global look at X-ray time lags in seyfert galaxies (2016, methodology): “They looked at the time lags for all sources in that catalog that have long (> 40 ks) observations, have a fractional excess variance above zero at the > 2σ confidence level (Ponti et al. 2012), and have published black hole mass estimates.”
- The subarcsecond mid-infrared view of local active galactic nuclei – II. The mid-infrared–X-ray correlation (2015, unknown): “…Guainazzi, Matt & Perola (2005); 14: Komossa et al. (2003); 15: Puccetti et al. (in prep); 16: Brightman & Nandra (2011a); 17: Levenson et al. (2005); 18: Bianchi et al. (2009b); 19: Dong et al. (2004); 20: Wang & Gao (2010); 21: Della Ceca et al. (2001); 22: Yankulova, Golev & Jockers (2007). c©…”
- Discovery of a relation between black hole mass and soft X-ray time lags in active galactic nuclei (2011, methodology): “…T H E S A M P L E The sources analysed are extracted from the CAIXAvar sample – a subsample of the CAIXA sample by Bianchi et al. (2009a) – presented in Ponti et al. (2012), which includes all the well-exposed, X-ray unobscured (NH < 2 × 1022 cm−2), radio quiet AGN observed by XMM–Newton in…”