1. Model-independent Timing Analysis of Bright Seyfert 1 Galaxies Massimo Cappi (IASF-CNR, Bologna) in collaboration with G. Ponti, M. Dadina and G. Malaguti Many thanks for help go to G. DiCocco, M. Trifoglio, F. Gianotti, J. Stephen, G. Ghisellini, F. Haardt, S. Molendi and the EPIC calibration teams

2. Haardt, Maraschi and Ghisellini (1994) Adapted from Fabian et al. (1997) Typical X-ray Spectrum of a Seyfert 1 Galaxy   Standard two-phase Comptonization model Typical X-ray Spectrum of a Seyfert 1 Galaxy   Standard two-phase Comptonization model

3. In my opinion, two major unsolved problems in this field are: - What is the exact geometry of the corona-disk system? - FeK fluorescence lines: Broad? How much broad? + Also soft disklines? (Haardt '96) Wilms et al. (2001) Fabian et al. (2002, 2003) Vaughan et al. (2003) (Branduardi-Raymond et al., '00 Sako et al., '02; Lee et al., '01)

4. How to address these issues? High throughput and continuous coverage of XMM-Newton  allow for the first time a detailed timing analysis of the brightest Seyfert 1 galaxies...great because model-independent, so complementary to spectral fittings. (Extragalactic astronomers need to learn these “new” analysis tools!!) Here, I give some illustrative examples on a few sources... Source name Type Exposure Obs. Date MCG6-30-15 Sy1.2 ~92 ks 12/06/2000 Mkn766 Sy1.5 ~99 ks 20/05/2001 NGC4051 Sy1.5 ~105 ks 16/05/2001 Available tools...: Power Spectral Densities (PSD)  to characterise the type of variability RMS Spectra  to disentangle/separate various spectral components Cross-Correlation Functions (CCFs)  to detect time-lags and also PHA ratios, flux-to-flux plots, etc....

5. Strong spectral variability Lightcurves: I- MCG-6-30-15 ∆F~2 in 1000 s

6. Lightcurves: II- Mkn766 ∆F~2 in 2000 s Strong spectral variability

7. Lightcurves: III- NGC4051 ∆F~3 in 1000 s Strong spectral variability

8.  MCG-6-30-15 shows significant power in the variability down to ~100-200 s  Important to follow a model-independent approach to resolve all variability and spectral variations Frequency [Hz] 10 -4 10 -3 0.010.1 Power 1000 100 10 10 4 See also La Palombara et al. (2003) ~100 s Power spectrum density

9. Hopes to definitely estimate contribution from soft disklines...model-independently Significant (ΔΧ 2 ~15) enhancement in the ~4.5-6 keV band  strong, model- independent, evidence of red-shifted relativistic matter supposedly falling into the black-hole. RMS spectrum: RMS (E,t) = 2 ➀ ➁ ➀ ➁ S 2 -  (e.g. Nandra 1997, Inoue 2000, Edelson et al. 2003, Vaughan et al. 2003) MCG6-30-15

10. ➀ RMS Spectra: Mkn 766 and NGC4051 Interpretation NOT straightforward, but all is model-independent (fractional variations only...)...still working on it... soft disklines and/or warm-absorber? soft disklines and/or warm-absorber? ? ?

11. Cross-Correlation Analysis: MCG6-30-15; I- During whole observation  No significant signal, maybe marginal detection of soft-to-hard skewness asymetry (with delay ~ 2000 s) 0.2-0.6 vs. 0.6-2.2 keV 0.6-2.2 vs. 6.8-10 keV 0.6-2.2 vs. 2.2-2.6 keV 0.6-2.2 vs. 2.6-4.5 keV 0.6-2.2 vs 4.5-6.8keV Soft-soft Soft-Hard

12. ...but during the flare... Spectral ratios  qualitative evidence for soft-to-hard spectral variations

13. .  Detection of soft-to-hard time lag ( ~ 600 s) during the flare (similar to Vaughan et al. 2003, but on a short-duration event...with high coherence though...) Assuming that it is due to Compton up-scattering, and estimating ~ 5-10 brownian interactions/displacements  estimate of Flare dimensions R flare  6x10 12 cm (40 r g for M BH =10 6 M Sun ) Assuming optical depth  of ~ 0.1-1   e-  T r flare  2.5-25 x 10 10 cm -3 Cross-Correlation Analysis: MCG6-30-15; II- During the Flare

14. Spectral ratios during/after the flare Assuming that the line is produced in the accretion disk and in response to the flare  upper-limit estimate of Flare-to-Disk distance: D≤ 4x10 13 cm  240 r g N.B.1N.B.1: FeK @ 6.4-7 keV  significant ionization occured during and/or after flare N.B.2: consistent also with CCF

15. Summary I illustrated some of the new possibilities offered by XMM-Newton for the timing analysis of Seyfert galaxies  great potential to address issues like broadening of FeK line + source geometry...without any modelling/fitting ! Applied in more details to MCG-6-30-15 (Ponti et al. 2003, A&A, in press)  ● RMS spectrum  resolves a broad component between  4.5-6 keV significantly more variable than adjacent continuum  strong, model-independent, evidence for the broad redshifted Fe line. ● Cross-Correlation analysis  soft-to-hard time lag during the flare. If interpreted as due to Comptonization up-scatterings   e-  2.5-25 x 10 10 cm -3 and R flare  6x10 12 cm. ● FeK line increase  1500-3000 s after the flare  (upper-limit) estimate of distance Flare-to-Disk (  240 r g )

19. Geometry? Ingredients? (Haardt '96)...but see also Ghisellini et al. (astro-ph/0310106) on aborted jets....

20. Chandra and ASCA Lee et al. (2002) XMM-Newton (300 ks) + BeppoSAX Fabian et al. (2002) XMM-Newton (100 ks) Wilms et al. (2001) Broad...but how much broad?...the (a)typical case of MCG-6-30-15  Spectra from all satellites agree that a strong, broad, redshifted FeK line is needed in MCG6, but many scientists not working directly with this data are still skeptical (either on reality or true amount of broadening)...because always skeptical if not main author... or because of the source strong spectral variability... ASCA Tanaka et al. (1995)

21. - Short introduction on spectral variability of Seyfert galaxies and on timing analysis - Timing analysis based on XMM-Newton data on: MCG-6-30-15 (~95 ks GT observation) Mkn 766 (~100 ks GT observation) NGC4051 (~100 ks GT observation) - RMS Spectra - Cross-Correlation Functions (CCFs) - Spectral ratios Outline

22. ''Standard'' RMS spectrum: (i.e. normalized excess variance)  Drop of variability below ~0.7 keV and above 1.5 keV consistent with gradual onset of (soft) thermal disk emission plus (hard) reflection component that vary more slowly than direct power-law (Fabian 2003, Miniutti et al. 2003)...consistent also with power law continuum varying with a pivot point @ E>10 keV and/or with warm absorber effects? (but recent flux-flux results shall exclude these...).narrow.black body.broad.power law.reflection continum It measures the fractional rms variability amplitude... at given energies, for timescales > t (e.g. Nandra 1997, Edelson et al. 2003, Vaughan et al. 2003) Fvar(E,t) = S 2 - 2 

23. Time Resolved Spectral Analysis.spectrum number (4000 s each) Spectral analysis on 4 ks time intervals data (~40000 source counts) Adopted Model: a simple absorbed power-law + a Black Body for the low energy soft excess. 1. Clear spectral variations 2.. nH stable as well as the T BB 3. Γ and n Γ correlate 4. Γ and n BB also seems to correlate as well n BB and n Γ 2 main problems: 1) Fits are highly model- dependent and parameters degenerate. 2) Time bins (4 ks) are higher than minimum variability time scale..n BB T BB nn .nH 2 1.5 0.015 0 0 0 0 10 21 0.25 10 -3

24. Broad band spectral variability during the biggest Flare This behaviour could be due to a soft-to-hard time lag.bin time (300 s long).photon index (  ) During the rising part of the Flare the spectrum becomes softer In the fainting part of the Flare the spectrum becames harder

25. MKN 766 like MCG-6-30-15.soft band  similar drop of variability.hard band  similar drop of variability.the tight component of the Fe K  line similarly to what happen for MCG-6-30-15, varys less than the continum

26. Moreover, increasing the RMS energy resolution....the tight component of the Fe K  line varys less than the continum! (thus indicating that it Comes from regions distant from the main photons source - far parts of the disk?)  2) if the Fe K redshifted component is strong even to 2 keV: Strong variability between ~4.8-5.8 keV that may be due to.  1) if the Fe K  redshifted component is strong even to 4-5 keV:  the encrease of variability should be due to the Fe K redshifted component  other component like absorption or  modification of standard disk structures or flare dispersion in the corona

27. The shape of the Fe K  line reflected by disk Physical mechanisms that broaden the line Fe K  shape in MCG-6-30-15 [Tanaka et al. (1995)] Fabian 2001

30. SUMMARY Introduction Tipical X-ray spectrum of a Seyfert Galaxies The shape of the Fe K line The source MCG-6-30-15 MCG-6-30-15 temporal analysis of the whole observation Light curve and hardness ratio Spectral variability temporal resolved (standard method) Power spectrum density RMS Spectrum The variability of the Fe K line MCG-6-30-15 temporal analysis during the biggest flare Soft-to-hard time lag Variation of the Fe K line after the flare Conclusions Future perspective