X-RAY PROPERTIES OF FR II/NLRG X-RAY PROPERTIES OF FR II/NLRG E. Trussoni 1, A. Capetti 1, B. Balmaverde 2 1 INAF – Osservatorio Astronomico di Torino, Italy 2 Università di Torino, Italy A sample of Fanaroff Riley II Radio Galaxies with Narrow and High Excitation Lines has been observed with Chandra and XMM. All the objects show luminous and absorbed cores, in agreement with the Unified Scheme for AGN, plus a soft excess. The bright emission is related to a QSO obscured by a torus, while different processes can be associated to the soft flux - 1 -

Unified Model: Radio Galaxies  AGN Fanaroff – Riley I (FR I)  BL Lac Radio, optical, X – ray luminosities correlated (1)  Emission from the inner jet  Negligible instrinsic obscuration, no torus Fanaroff – Riley II (FR II)  More complex (3 classes of obj.) 1 - LEG (Low Excit.): Similar to FR I 2 - BLRG: QSO (Emission from a bright accretion disk ) Multifrequency data confirm this scenario (2-6) 3 - HEG (High Excit.): Obscured QSO ? - 2 -

What are the HEG ? HEG : The EW of [OIII] and the ratio [OII]/[OIII] reveal the presence of a relevant underlying ionizing flux  A hidden bright source must be present (2-3) Data at X-ray energies are crucial to confirm this view: obscured cores could be detected at high energies For this purpose have been analyzed the X-ray properties of a sample of HEG extracted from the 3C catalogue with available pointings of Chandra and XMM: 14 objects (listed in Tab. 1) - 3 -

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Results - Interpretation - All sources show a two components spectrum (Fig. 1) - The brightest components (L h X in Tab. 1) are consistent with a power law spectrum with quite a relevant local obscuration (N z H = cm -2 ) - L h X is much higher than in FR I (except 3C 15, Fig. 2) - In 7 objects an Iron line at 6.4 keV has been detected  The above arguments confirm that in HEG obscuration effects are relevant and L h X is related to a brigth accretion disk obscured by a torus - 5 -

3C 388 3C 228 3C 33 3C 403 (a) FR II Unobscured (b) FR II Obscured + Soft Comp. Fig C 15 3C 33 3C 295 3C

Blue squares : L h X Red crosses : L s X Green: FR I correl. (1) (+/- 1 r.m.s.) Fig

Results – Interpretation (ctd.) Results – Interpretation (ctd.) The second soft component (L s X in Tab. 1) is weaker, unabsorbed and consistent with a non-thermal spectrum It has been suggested that L s X is related to a unabsorbed relativistic jet, as in FR I (4-6) HOWEVER - In 3C 33 and 3C 452 the emission is likely related to reflection from a disk - In 50 % of the objects L s X is higher than expected from the radio – X correlation holding for FR I (1) (Fig. 2)

Where does the soft emission come from ? Where does the soft emission come from ? Various emission processes may be associated to L s X :  Relativistic jet (e.g. 3C 295, 3C 321)  Reflection from the torus (e.g. 3C 33, 3C 452)  Inner core partially covered  ………………. Further, soft emission has been detected also in other objects : In obscured radio quite Sey 2 (where jets are not present) it has been argued that the soft emission originates from a photoionzed plasma near the NLR (7) - 9 -

Summary - X-ray data on our sample confirm that in HEG there is a QSO hidden by a torus - The soft unabsorbed flux is common in all HEG but has different origins. Accordingly the emission regions may be very close ( > 1 pc) from the core in the various objects - Soft X-ray excess is a common property of other classes of obscured AGN, where however the physical conditions may be very different (e.g. the presence or not of a relativistic jet) 

References 1 - Balmaverde B. et al., A&A 451, 35 (2006) 2 - Chiaberge M. et al., A&A 394, 791 (2002) 3 - Varano S. et al., A&A 428, 401 (2004) 4 - Belsole et al., MNRAS 366, 339 (2005) 5 - Evans et al, ApJ 642, 96 (2006) 6 - Hardcastle et al., MNRAS 370, 1893 (2006) 7 - Bianchi et al., A&A 448, 499 (2006) 