1. ULIRGs: IR-Optical-X-ray properties ULIRGs: IR-Optical-X-ray properties Valentina Braito

2. ULIRGs: IR-Optical-X-ray properties Results from XMM observations of 10 ULIRGs Searching possible multi wavelength diagnostics Results on L band observations (P.I. Risaliti)

3. ULIRGs are a class of sources with L IR >10 12 L  comparable to QSO luminosities. L IR >10 12 L  comparable to QSO luminosities. Background ULIRGs are predominantly powered by heavily dust enshrouded AGN or circumnuclear starbursts? ULIRGs classification strongly depends on the energy band Starburst dominated ULIRGs revealing an obscured AGN when observed in the X-rays (i.e. NGC6240) With this survey all the ULIRGs of Genzel sample (complete at F 60  m >5.4 Jy and L FIR ~10 12 L  ) will have X-ray data

4.  AGN activity is present in 1/3 of the observed sources  AGN-ULIRGs have hard X-ray luminosity lower than typical QSO luminosity  We found 2 ULIRG with high X-ray luminosity & deeply absorbed (Superantennae; Mkr231)  SB-ULIRGs have L X (2-10 keV)  10 41 -10 42 ergs/s Main goals characterize the hard X-ray continuum investigate the presence of AGN activity

5. Thermal emission absorbed power law (AGN)  ~1.7-2 or a flat power law (X-ray binaries) E 1-  e -E/Ec Ec=8 keV X Ray Spectral properties

6. X-ray & FIR emission  No evident correlation between X-ray thermal and FIR luminosity  No evident difference between SB and AGN ULIRGs Thermal vs FIR luminosity X-ray AGN-ULIRGs  X-ray SB-ULIRGs

7. X-ray & FIR emission 2-10 keV luminosity vs FIR luminosity AGN SB X-ray AGN-ULIRGs  X-ray SB-ULIRGs

8. Our results confirm that for ULIRGs without a dominant AGN component, the 2-10 keV emission is a good SFR indicator (Persic et al. 2004). Arp 299 Comparison with local SBs SB-ULIRGs

9. The observed hard X-ray emission can be used to highlight AGNs in LIRGs X-ray & FIR emission X-ray AGN-ULIRGs  X-ray SB-ULIRGs

10. Optical-IR-X-ray Work in progress… AGN REGIONSB REGION Compton-thin Compton-thick

11. Results from L band spectroscopy The waveband coverage allows to determine of the 3-4  m continuum level a correct estimate of the PAH strength Broad absorption feature at 3.4  m indicative of heavily absorbed AGN PAH at 3.3  m with low EW typical of AGN dominated sources IRAS 19254-7245 P.I. Guido Risaliti see poster by Risaliti for all the spectra

12. A possible dignostic diagram PAH EW vs L IR Risaliti et al. in prep PURE SB AGN Composite SB AGN  vs PAH EW AGN-dominated SB-dominated

13. Conclusion and future L X (2-10) keV as a SFR indicator or to preselect AGN in IR sources the F x /F IR vs F OIII /F IR diagram allows to select heavily absorbed AGN in composite sources like ULIRGs check the peculiar sources in this diagram complete the Genzel sample (IRAS22491-1808 and IRAS 20100-4156) in L band spectra of the 4-5 brightest ULIRGs at 4-5  m

14. XMM + the BeppoSAX data... THERMAL EMISSION Fe LINE PN MOS1 MOS2 PDS MECS THERMAL EMISSION TRANSMITTED PLREFLECTED - SCATTERED PLHMXBs-EMISSION

15. Optical-IR-X-ray Work in progress… AGN REGION SB REGION

16. Optical-IR-X-ray Work in progress… Compton-thin Compton-thick AGN REGION SB REGION

17. SB vs AGN: X-ray spectral properties STARBURST a low temperature thermal emission hard X-ray component: thermal or PL (Dahlem et al. 2000, Persic et al. 2002) X-ray luminosity <10 -3 of the total emission AGN Hard power law continuum with a low energy cutoff (depending on the amount of absorption present) or in the extremely case a flat reflected spectrum. Cold iron K  at 6.4 with eventually high EW High X-ray luminosity

18. A good fit for the continuum is found with a reflection spectra plus a scattered power law. From the best fit we derived L(2-10 keV)= 3x10 42 erg s -1 If the source is Compton thick the hard X-ray luminosity could be L(2-10 keV)~10 44 erg s -1 IRAS 19254-7245 in QSO regime

19. Results from L band spectroscopy Spectral coverage allows:  correct estmate of 3-4  m continuum level  measurements of correct EW of PAH at 3.3  m  investigate dust absorption feat. at 3.4  m Risaliti XMM results for the 10 ULIRGs

20. The X-ray spectra of the sources show that:  a thermal emission at kT~0.7 keV is always present (Starburst)  a hard X-ray PL component This hard X-ray emission can be due to an hidden AGN or a population of X-ray binaries X Ray Spectral properties