CAIXA: a catalogue of AGN in the <i>XMM-Newton</i> archive

Ponti, G.; Papadakis, I. E.; Bianchi, S.; Guainazzi, M.; Matt, Giorgio; Uttley, P.; Bonilla, Nuria Fonseca

doi:10.1051/0004-6361:200810620

Cited by 224 publications

(273 citation statements)

References 68 publications

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“…This result agrees with the recent finding that the temperature of the soft excess is remarkably constant regardless of the luminosity and mass of the objects (e.g. Bianchi et al 2009;Crummy et al 2006;Gierliński & Done 2004). Figure 10 also shows the soft excess luminosity (rest-frame 0.5−2 keV, corrected for absorption) vs. the power-law X-ray luminosity (rest-frame 2−10 keV).…”

Section: Soft Excesssupporting

confidence: 93%

The XMM-NewtonWide Angle Survey (XWAS): the X-ray spectrum of type-1 AGN

Mateos¹,

Carrera

Page

et al. 2010

A&A

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Aims. We discuss the broad band X-ray properties of one of the largest samples of X-ray selected type-1 AGN to date (487 objects in total), drawn from the XMM-Newton Wide Angle Survey (XWAS). The objects presented in this work cover 2−10 keV (rest-frame) luminosities from ∼10 42 −10 45 erg s −1 and are detected up to redshift ∼4. We constrain the overall properties of the broad band continuum, soft excess and X-ray absorption, along with their dependence on the X-ray luminosity and redshift. We discuss the implications for models of AGN emission. Methods. We fitted the observed 0.2−12 keV broad band spectra with various models to search for X-ray absorption and soft excess. The F-test was used with a significance threshold of 99% to statistically accept the detection of additional spectral components. Results. We constrained the mean spectral index of the broad band X-ray continuum to Γ = 1.96 ± 0.02 with intrinsic dispersion σ Γ = 0.27 +0.01 −0.02 . The continuum becomes harder at faint fluxes and at higher redshifts and hard (2−10 keV) luminosities. The dependence of Γ with flux is likely due to undetected absorption rather than to spectral variation. We found a strong dependence of the detection efficiency of objects on the spectral shape. We expect this effect to have an impact on the measured mean continuum shapes of sources at different redshifts and luminosities. We detected excess absorption in > ∼ 3% of our objects, with rest-frame column densities ∼a few ×10 22 cm −2 . The apparent mismatch between the optical classification and X-ray properties of these objects is a challenge for the standard orientation-based AGN unification model. We found that the fraction of objects with detected soft excess is ∼36%. Using a thermal model, we constrained the soft excess mean rest-frame temperature and intrinsic dispersion to kT ∼ 100 eV and σ kT ∼ 34 eV. The origin of the soft excess as thermal emission from the accretion disk or Compton scattered disk emission is ruled out on the basis of the temperatures detected and the lack of correlation of the soft excess temperature with the hard X-ray luminosity over more than 2 orders of magnitude in luminosity. Furthermore, the high luminosities of the soft excess rule out an origin in the host galaxy.

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Section: Soft Excesssupporting

confidence: 93%

The XMM-NewtonWide Angle Survey (XWAS): the X-ray spectrum of type-1 AGN

Mateos¹,

Carrera

Page

et al. 2010

A&A

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“…In Fig. 10 we plot the flux of the PAH feature at 6.2μ as measured by Spitzer as a function of the unobscured 2-10 keV luminosity as measured by CAIXA (Bianchi et al 2009b) in a sample of obscured and unobscured local Universe AGN. PAH features are a strong indicator of star formation in active galaxies (see, e.g., Lutz et al 2008, and references therein).…”

Section: Properties Of the Collisionally Ionised Plasma In Ngc 1365mentioning

confidence: 99%

AGN/starburst connection in action: the half million second RGS spectrum of NGC 1365

Guainazzi¹,

Risaliti

Nucita³

et al. 2009

A&A

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Context. High-resolution X-ray observations in the imaging and spectral domain have recently opened a new window on active galactic nuclei (AGN) feedback onto the circumnuclear gas. Spectral diagnostics, as well as the remarkable morphological coincidence between [O iii] and X-rays, point to AGN photoionisation as the dominant ionisation mechanism on scales as large as a few kpc.Aims. In this paper we extend these studies to the nearby Seyfert 2 galaxy NGC 1365, known to host a circumnuclear ring of intense star formation at 1.3 kpc from the nucleus. The main scope of this investigation is to study the connection between nuclear activity and star formation in nearby AGN. Methods. We present a deep ( 5.8 days) 0.3-2 keV high-resolution spectrum of NGC 1365, collected with the reflection grating spectrometer (RGS) on board XMM-Newton. Results. The spectrum is dominated by strong recombination lines of He-and H-like transitions from carbon to silicon, as well as by L transitions from Fexvii. The continuum is strong, especially in the 10 to 20 Å range. Formal fits require two optically thin, collisionally ionised plasma components, with temperatures 300 and 640 eV. However, they leave the bulk of the forbidden components of the He-α Ovii and Nvi triplets unaccounted for. These features can be explained as being produced by photoionised gas. NGC 1365 is therefore the first obscured AGN, whose high-resolution X-ray spectrum requires both collisional ionisation and photoionisation. Conclusions. The relative weakness of photoionisation does not stem from the intrinsic weakness of its AGN, whose X-ray luminosity is ∼ > 10 42 erg s −1 . We suggest that it may instead come from the line-of-sight from the active nucleus to the NLR being blocked by optically thick matter in the broad line region, at the same time responsible for the large observed variation of the column density obscuring the X-ray active nucleus. Alternatively, NGC 1365 could host a remarkably luminous nuclear starburst when compared to the AGN accretion power.

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“…Applying a bolometric correction of 30 to the observed 2-10 keV luminosity (as appropriate in this luminosity range, according to Marconi et al 2004), we recover L bol /L edd 0.1−1. Although a better BH mass estimate is needed to assess the reliability of this accretion rate, the difference with respect to NGC 7213 is clear, being it characterised by a low accretion rate ( 3 × 10 −3 : Bianchi et al 2009a). This could explain the lack of relativistic signatures in the latter, where the accretion disc may be truncated and its inner part replaced by some sort of inefficient disc (see e.g.…”

Section: A Global Scenariomentioning

confidence: 99%

The broad-band X-ray spectrum of the Seyfert 1 galaxy, MCG+8-11-11

Bianchi

Angelis

Matt

et al. 2010

A&A

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Aims. Evidence is mounting that the main ingredients of the unification models of active galactic nuclei may behave differently from expectations, and be intimately related to fundamental physical parameters. The availability of high signal-to-noise broad-band X-ray spectra provides us with the opportunity to study in detail all the contributions from the materials invoked in these models, and infer their general properties, including whether their presence or absence is related to other quantities. Methods. We present a long (100 ks) Suzaku observation of one of the X-ray brightest AGN, MCG+8-11-11. These data are complemented with the 54-month Swift BAT spectrum, allowing us to perform a broad-band fit to the 0.6-150 keV range. Results. The fits performed in the 0.6-10 keV band provide results consistent with those of a a previous XMM-Newton observation, i.e. a lack of a soft excess, warm absorption along the line of sight, a large Compton reflection component (R 1), and an absence of a relativistic component of the neutral iron Kα emission line. However, when the PIN and Swift BAT data are included, the reflection amount drops significantly (R 0.2−0.3), and a relativistic iron line is required, the latter being confirmed by a phenomenological analysis in a restricted energy band (3-10 keV). When a self-consistent model is applied to the whole broad-band data, the observed reflection component appears to be entirely associated with the relativistic component of the iron Kα line. Conclusions. The implied scenario, though strongly model-dependent, requires that all the reprocessing spectral components from Compton-thick material be associated with the accretion disc, and no evidence of a classical pc-scale torus is found. The narrow core of the neutral iron Kα line is therefore produced in Compton-thin material, such as the BLR, similarly to what is found in another Seyfert galaxy, NGC 7213, but with the notable difference that MCG+8-11-11 presents spectral signatures from an accretion disc. The very low accretion rate of NGC 7213 could explain the lack of relativistic signatures in its spectrum, but the absence of the torus in both sources is more difficult to explain, since their luminosities are comparable, and their accretion rates are completely different.

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CAIXA: a catalogue of AGN in the XMM-Newton archive

Cited by 224 publications

References 68 publications

The XMM-NewtonWide Angle Survey (XWAS): the X-ray spectrum of type-1 AGN

The XMM-NewtonWide Angle Survey (XWAS): the X-ray spectrum of type-1 AGN

AGN/starburst connection in action: the half million second RGS spectrum of NGC 1365

The broad-band X-ray spectrum of the Seyfert 1 galaxy, MCG+8-11-11

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