1 / 22

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

tania
Télécharger la présentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related