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The Differences in the SEDs of Type 1 and Type 2 AGNs: Contributions from starbursts

The Differences in the SEDs of Type 1 and Type 2 AGNs: Contributions from starbursts. Xue-Bing Wu Collaborator: Ran Wang (Astronomy Department, Peking University) See also poster of Ran Wang. Content. Introduction AGN Data & SEDs Bolometric luminosity and nuclear AGN power

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The Differences in the SEDs of Type 1 and Type 2 AGNs: Contributions from starbursts

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  1. The Differences in the SEDs of Type 1 and Type 2 AGNs: Contributions from starbursts Xue-Bing Wu Collaborator: Ran Wang (Astronomy Department, Peking University) See also poster of Ran Wang

  2. Content • Introduction • AGN Data & SEDs • Bolometric luminosity and nuclear AGN power • Discussions & summary

  3. 1. Introduction • Orientation-dependent unification scheme of AGN (Antonucci 1993); Supported by the polarized spectral observations of NGC 1068 • Only about half of Sy2s showing polarized broad emission lines (HBLRs). Are HBLRs physically different from Non-HBLRs? • Observational differences of two types of Sy2s • IRAS flux ratio (f25 / f60 ) (Heisler et al. 1997) • Narrow line flux ratio (f [OIII] / f H) (Tran 2003) • Luminosity (Tran 2003) • X-ray spectra (Deluit 2004)

  4. BLR could disappear if the luminosity is lower • The effective photo-ionization region is too close to the central BH for low-L narrow line AGNs (Laor 2003) • Non-HBLRs have lower accretion rate (<1E-3, in Eddington unit) than HBLRs (Nicastro, Martocchia & Matt 2003)

  5. AGN SEDs • RL & RQ Quasars (Sanders et al. 1989; Elvis et al. 1994) • Seyfert 1s & 2s (Mas-Hesse et al. 1995) • Seyfert 2s, comparisons with SEDs of starburst galaxies, LINERs and normal galaxies (Schmitt 1997) • Purpose of our work • SEDs of HBLRs & Non-HBLRs • True AGN power of Sy2s

  6. 2. AGN Data & SEDs • Sy 2s: Schmitt et al. (1997); Gu & Huang (2002); Tran (2003) • HBLRs & Non-HBLRs • Sy 1s: Woo & Urry (2002) • Intermediate type Sy 1s (Sy 1.8, 1.9) & NLS1s excluded • Sample: 16 Sy 1s, 12 HBLRs, 11 Non-HBLRs,

  7. X-ray: ASCA, BeppoSAX, EXOSAT; corrected for absorption • UV: IUE • Optical: ground-based observations; NED • IR: NED(2MASS,IRAS,ISO); corrected for Galactic extinction in near-infrared • Radio: NED • Choose the data with similar apertures whenever possible

  8. AGN sample Sample: 16 Sy 1s, 12 HBLRs, 11 Non-HBLRs

  9. Individual SEDs

  10. Average SEDs for S1, HBLRs & Non-HBLRs

  11. Differences in SEDs: • Non-HBLRs seem to be much weaker in hard X-ray band • S1s and HBLRs show different features in IR & optical bands; HBLRs are relatively stronger in IR • Non-HBLRs show a steeper increase towards the far IR band than S1 and HBLRs; Strong far IR emission seems to dominate the bolometric luminosity of Non-HBLRs

  12. 3. Bolometric luminosity and nuclear AGN power • Column density (NH) S1s are all compton thin; HBLRs & Non-HBLRs consist of both Compton thin and thick sources

  13. Bolometric luminosity The total emission of HBLRs & Non-HBLRs are similar, but their SEDs are different.

  14. 2-10keV hard X-ray luminosity Compton thin HBLRs are similar to S1s, but compton thin Non-HBLRs are different and have lower X-ray energy,

  15. Hard X-ray luminosity & bolometric luminosity

  16. A relation between hard-X-ray luminosity & nuclear bolometric luminosity

  17. Eddington luminosity (BH mass calculated from the M- relation) No significant difference for different types of Sys, consistent with the suggestion that BH mass distributions are similar in whole Sy classes (Wu & Han 2001)

  18. 4. Discussions & summary • Intrinsic differences may exist in different types of AGNs; Different physics processes dominate the energy production in different bands • Factors affect the far IR emission • Nuclear emission • UV emission from massive stars (heating the dusts and re-radiating in far IR) • Circumnuclear star formation/starburst activities in whole Seyfert classes (Wilson 1991; Mouri & Taniguchi 1992, 2004; Hecman et al. 1997)

  19. SEDs of Seyferts and starburst galaxies

  20. SEDs of Seyferts, NLS1s & Quasars

  21. Differences in accretion rate (Eddington ratio) BLR may not exist at lower accretion rate!

  22. Summary • Average SEDs of HBLRs & Non-HBLRs are presented; Though with a stronger IR bump, HBLRs display many similar feature with S1s • Bolometric luminosity of Non-HBLRs is dominated by far IR emission, while their hard X-ray emission is weaker than S1 and HBLRs • Bolometric luminosity of Non-HBLRs is affected significantly by star formation activities and may not indicate the true AGN power • Dimensionless accretion rates of Non-HBLRs is significantly smaller than that of HBLRs and S1s BLR may not exist at lower accretion rate

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