Co-accreting disk/corona system in AGNs with double-peaked emission lines

1. Co-accreting disk/corona system in AGNs with double-peaked emission lines XuYun

2. outline 1.The properties of AGNs with double-peaked emission lines. 2.Our models. Co-accreting disk/corona system. 3.Other models. 4.Our research method. 5. Final result .

3. Introduction of AGNs with double－peaked emission lines A small class of AGNs do show the double peaked broad lines characteristic of disk emission in the optical band. ( Hα, Hβ and MgII) Some additional properties that they possess[Eracleous et 1994,2003] • 1. average Hα full width at half-maximum twice as broad as the normal radio-loud AGNs. (12,500km/s vs 5700km/s) • 2. an unusually large contribution of starlight to the optical continuum around Hα . • 3. unusually large equivalent widths of low-ionization lines such as [OI] and [SII]. • 4. unusually large [OI]/[OIII] flux ratios .

4. The spectra of 3C332(a double –peaked radio galaxy )

5. Disk model

6. The disk model of BLRG without double-peakedemission lines

7. A supermassive black holeis surrounded by astandard geometrically thin, opticallythick accretion disk, whoseinner part radiates thermalUV/soft X-ray emission .This thermal emission ionizesgas clouds in thebroad-line region (BLR) andthe narrow-line region (NLR),which are shown bysmall and large circles,respectively. Because of alow temperature, an outerpart of this standarddisk does not radiateionizing photons and permittedlines effectively.

8. Our model of double-peaked BLRG A sketch of how the structure of the accretion disk/corona and its associated wind.

9. Some properties about the model[Witt et, 1997, Fabrizio 2000] • Disk: cold, optically thick, geometrically thin orbital keplerian disk. • Corona: very hot, optically thin , geometric thick , vertically outflowing, Keplerian motion. • Wind : cold , high density, high velocity, originating at a critical distance in the accretion corona.

10. Interpretation of our model A supermassive black hole is surrounded by co-accreting disk/corona system. The hot corona radiates a relatively hard X-ray continuum which ionizes which ionizes gas in the surrounding BLR and NLR . A part of this hard continuum emission irradiates gas in the wind, from which the double-peaked Balmer lines arise.

11. Other models • The most popular model in which the inner disk is an ion-supported torus which illuminates the outer disk with a hard ionizing continuum. • supermassive binary black holes. • jets • radial flows .

12. Research method • The approximate analytical relationship giving the fraction of energy dissipated in the corona, in a dynamical disk/corona configuration: • (1) βis the fraction of gravitational energy released in the cold disk

13. the maximum radius below which a stable co-accreting disk/corona configuration can exist. The minimum external accretion rate needed for a thermally unstable radiation pressure- dominated region to exist.

14. We can get corona luminosity from these equations

15. Bolometric luminosity • The bolometric luminosity obtained from the Eddington luminosity and accretion rate. • Assuming a relation between the bolometric luminosity and optical continuum luminosity[xue-bing wu , 2004]

16. Final result Relation between ratio of coronae luminosity versus bolometric luminosity and maximum radius . The triangles represent the source in the radio-loud AGN survey (Eracleous 1994, 2003) .The solid lines represent the relations for the cases with viscosity coefficient of 0.01, 0.1 and 1.0 respectively.

17. Thank you!!