An XMM-Newton view of Q : an AGN without Broad Line Region? Mario Gliozzi (GMU) L. Foschini (IASF Bo) R. Sambruna (GSFC) L. Kedziora-Chudczer (Sidney) * Type I and Type II AGN Unification Model HBLR vs non-HBLR * X-ray advantage * “Naked” AGN * X-ray (XMM+Chandra) view of Q

Optical View: [Fig. from Hawkins 2004] Type I AGN: Type II AGN: Broad permitted lines Narrow forbidden & permitted lines Q Q Q Q Strong & variable continuum Weak & constant continuum

Unification Model Basic Ingredients mass *Supermassive BH *Accretion disk + corona *BLR: high velocity, high density gas on pc scales *NLR; lower velocity, lower density gas on kpc scales *Torus: gaseous & molecular absorbing medium in equatorial plane embedding BH, ADC, BLR *Jets: relativistic ejection (10% AGN) AGN intrinsically the same: Differences ascribed to viewing angle: Type I Type II

Spectropolarimetry Measure of polarization of light as a function of wavelengths Instrumental in the development of Unification Model: Detection of broad permitted lines in polarized light in Sy2 NGC 1068 (Miller & Antonucci 1983) : * presence of hidden BLR (HBLR) * constraints on location and geometry of the absorber But exceptions exist: *Only 50% of Sy2 have HBLR (e.g. Tran 2001) based on 3-m (Lick) and 5-m (Palomar) telescopes * Result confirmed by Keck 10-m telescope (Moran et al. 2007)

non-HBLR vs. HBLR Study of HBLR and non-HBLR based on L radio L [O III] or IR colors: a) Intrinsically different: L(HBLR) > L(non-HBLR) (e.g. Moran et al. 1992; Tran 2001) b) Not different : biased results, affected by dilution effects from host galaxy (e.g. Lumsden et al. 2001; Lumsden & Alexander 2001) Unified Model explains observations, not physical origin of ingredients Exceptions important not to disprove the model but gain insights into links among AGN ingredients

X-ray Advantage X-ray produced & reprocessed close to BH: Best diagnostics for central engine (Hard) X-rays less affected by absorption: Direct estimate of N H No diluting effects from host galaxy But not exhaustive: Need to complement information with other wavelengths

X-ray view: HBLR vs. non-HBLR a) non-HBLR intrinsically different Existence of a threshold L x = erg/s (Eddington ratio=10 -3 ) : Below threshold: non-HBLR Above threshold: HBLR Sample: objects from Tran with archival Chandra, XMM, ASCA, or SAX data (Nicastro et al. 2003) Nicely fit theoretical model (Nicastro et al. 2000) b) non-HBLR more heavily absorbed Sample: 4 “best” candidates from Tran sample (no BL, high S/N, low optical extinction) Chandra observations 10 ks (Gosh et al. 2007) Limits of spectropolarimetry studies: * require very high S/N (limited nearby objects) * rely on existence of appropriately placed scattering region

Naked AGN: Discovery Based on large scale optical monitoring program over 25 years from UK 1.2m Schmidt telescope in Australia. Initial sample: 1500 AGN candidates Intermediate sample: 129 Seyfert-like objects (high S/N, z<0.5) Final sample: 55 Seyfert 2 galaxies (Hawkins 2004) Selection based on spectral & temporal variability properties: *Spectrum ensures (apparent) lack of BLR *Variability ensures direct view of central engine (and jet?) 6 naked AGN (spectrally type II, but variable as type I) detected

Naked AGN: Optical Classification Seyfert 1 Seyfert 2 starburst Type I AGN : FWHM > 1500 km/s, [OIII]/Hβ 0.5 Type II AGN : FWHM 3, ∂B < 0.5 (Hawkins 2004) (∂B=B max -B min )

Naked AGN: Optical Classification Seyfert 1 Seyfert 2 starburst Type I AGN : FWHM > 1500 km/s, [OIII]/Hβ 0.5 Type II AGN : FWHM 3, ∂B < 0.5 Naked AGN : FWHM 3, ∂B > 0.5 Note : NLS1 ruled out by [OIII]/Hβ < 3, but not blazars (Hawkins 2004)

X-ray Observations of Q Goal: investigate nature of source *Constrain NH *Jet role? Q : z=0.311, Hβ FWHM = 350 km/s, [OIII]/Hβ =6, ∂B = 0.9 Chandra observations: Date: December 2005 Exposure: 4ks (part of snapshot survey) Instrument: ACIS-S (Gliozzi et al. 2007) XMM observations: Date: November 2007 Exposure: 40ks (pointed observation) Instruments: EPIC pn, MOS1, MOS2; OM

X-ray Imaging of Q * Source easily detected: bright X-ray source * Point-like appearance (consistent with ACIS PSF) * No nearby sources within 1’ Unusual optical properties not due to source confusion. Only 1 source in XMM extraction region.

X-ray Imaging of Q * Source easily detected: bright X-ray source * Point-like appearance (consistent with ACIS PSF) * No nearby sources within 1’ Unusual optical properties not due to source confusion. Only 1 source in XMM extraction region.

X-ray Spectrum of Q Chandra: XMM-Newton: Spectra well fitted with simple absorbed PL. Low N H suggests direct view of central engine.

X-ray Variability of Q Short timescales: No significant flux nor spectral variability Long timescales spectral variability HR(Chandra) = -0.57(13) HR(XMM) = -0.25(3) where HR=(h-s)/(h+s) Long timescales flux variability: L 0.5-8keV (Chandra) = erg/s L 0.5-8keV (XMM) = erg/s The luminosity decreases by a factor of 2, and the spectrum hardens.

Broadband Properties of Q Optical UV from the OM: * m B =21.0(4), m U =20.1(2), m UVW1 =20.0(2) * Extinction fully consistent with N H * Broadband spectral index α OX =1.30(6) Radio from ATCA: (2.7 hr observations at 4.8 and 8.6 GHz) * Source not detected * Low radio loudness: R O <5, R X <10 -4

Q : Summary * The source is bright: Lx > erg/s (Eddington ratio = ) * X-ray spectral properties (Г and N H ) typical of Seyfert 1 galaxies * X-ray spectral variability properties (soft when bright) typical of Seyfert 1 galaxies * Broadband properties (α OX and A V ) confirm this scenario * Low radio upper-limit rules out important contribution from putative jet

Q : Conclusions Q apparently lacks BLR but brighter than non-HBLR Important to expand this work (enlarge sample, E band): 1) Representative of a large AGN class: -high detection rate from original sample -sizable fraction of narrow-lined AGN at L x ~10 43 erg/s (Steffen et al. 2003) 2) May help shedding light on the origin of BLR and link with absorbing medium (e.g. clumpy torus model Nenkova et al. 2002)