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Getting to Eddington and beyond in AGN and binaries! Chris Done University of Durham.

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Presentation on theme: "Getting to Eddington and beyond in AGN and binaries! Chris Done University of Durham."— Presentation transcript:

1 Getting to Eddington and beyond in AGN and binaries! Chris Done University of Durham

2 L/L Edd determined by mass accretion rate onto the black hole LMXRB – roche lobe overflow of low mass companion HMXRB – wind accretion from high mass companion HMXRB – roche lobe overflow from high mass companion AGN Accreting black holes

3 L/L Edd determined by mass accretion rate onto the black hole LMXRB – roche lobe overflow of low mass companion HMXRB – wind accretion from high mass companion HMXRB – roche lobe overflow from high mass companion AGN Accreting black holes

4 L/L Edd determined by mass accretion rate onto the black hole LMXRB – roche lobe overflow of low mass companion HMXRB – wind accretion from high mass companion HMXRB – roche lobe overflow from high mass companion AGN Accreting black holes

5 L/L Edd determined by mass accretion rate onto the black hole LMXRB – roche lobe overflow of low mass companion HMXRB – wind accretion from high mass companion HMXRB – roche lobe overflow from high mass companion AGN Accreting black holes

6 LMXRB – Transient! H ionisation instability in disc – eg Lasota 2001 If T(Rout)

7 Radius of star depends on type (ie mass) Star has to fill roche lobe for mass accretion Mass accretion rate from companion depends on type Outer edge of disc can’t be larger than ½ size of binary orbit. Find all have T(Rout)

8 Peak luminosity depends on how much mass can accumulate in quiescence and how fast it accretes onto black hole Lpeak  R(out) 3 /R(out )  R(out) 2 King & Ritter 1998 Main sequence secondary is small so R(out) small so Lpeak

9 GRS is huge! 33 day period. L/L EDD ~1 for 20 years GS2023 – went to 2L Edd, then blew its disc apart… GX339 and XTEJ1550 are the next biggest but L

10 Rare systems – most end as NS in population synthesis models High mass loss rate from stellar wind, but only capture small fraction so L<

11 Main sequence high mass star. Mass accretion rate from companion is high Keeps outer disc temperature in Cyg X-1 above H ionisation so persistent HUGE mass transfer as supergiant evolves – SS 433 in our galaxy Most ULX in other galaxies Roche lobe overflow HMXRB- BH

12 Main sequence high mass star. Mass accretion rate from companion is high Keeps outer disc temperature in Cyg X-1 above H ionisation so persistent HUGE mass transfer as supergiant evolves – SS 433 in our galaxy Most ULX in other galaxies Roche lobe overflow HMXRB- BH Rappaport et al 2005

13 Intermediate mass BH? Ultra - Luminous X-ray sources in spiral arms of nearby starforming galaxies – ULX L~ ergs s -1 so M~ M  for L 50 M  Gao et al 2003

14 Hard spectra plus soft excess looks like scaled up BHB in LHS? IMBH? But break above 7keV – NOT like LHS!!! ULX state ? Gladstone Roberts & Done 2008

15 ULX state ? Gladstone Roberts & Done 2008

16 ULX state ? Gladstone Roberts & Done 2008

17 ULX state ? Gladstone Roberts & Done 2008

18 L/L Edd determined by mass supply But ~0.5% of mass in star formation ends up in the black hole to make the M-  relation AGN

19 BH-Galaxy AND environment Big black holes live in host galaxies with big bulges! Need 0.5% of bulge mass (ie starformation) to end up down the BH Black hole mass Stellar system mass

20 Black hole mass SMBH grow by gas accretion and BH-BH mergers Mergers dominate only highest BH mass (> 10 9 M). Spin of Accretion (thin disk) dominates for lower mass (<10 8 M) Accretion (hot flow) never really dominates Fanidakis et al 2010

21 Black hole mass accretion rate Not many with L/LEdd>1 in local universe - and they are predominantly low mass BH What do they look like? Fanidakis et al 2010

22 Disc spectra from 10 6 M L/L Edd ~1 Much more soft X-ray flux than expected from either disc or power law Enormous soft X-ray excess !! Jin et al 2011

23 Disc spectra from 10 6 M L/L Edd ~1 Standard SS disc temperature – assumes energy thermalises BHB discs - Colour temperature correction as scattering > absorption opacity. Tobs=1.8 Teff AGN discs even more scattering dominated as less dense !! Factor 2.4 !! Done, Davis, Jin, Blaes Ward 2011

24 Disc spectra from 10 6 M L/L Edd ~1 Enourmous soft excess in REJ1034 But actually a lot of it should be the bare disc! Plus a little bit of comptonisation ! More like disc dominated black holes Done, Davis, Jin, Blaes Ward 2011

25 Conclusions Galactic BHB can’t get to Eddington very easily Exceptions are LMXRB in wide binaries with evolved companions – GRS And HMXRB evolving into supergiants – SS 433 and probably ULX. And some nearby low mass high mass accretion rate AGN like REJ1034 (QPO AGN). Disc in these AGN MUST extend into soft X-rays. Much of soft X- ray excess in these is the bare disc. Then need SMALL comptonisation to get shape of component

26 Unsolved problems How does magnetic field stress dissipate and heat the accretion flow? Can we get as high as  ~0.1? Stress HEATS so eventually gives pressure so alpha prescription OK on average?? What happens to the disc as we go to Eddington and beyond? –How does it stay optically thick up to ~0.5L Edd ? –How important are winds Fgrav=(1-  abs /  es L/L Edd ) GM/R 2 –How important is advection of radiation – and what fraction of this escapes from the plunging region becoming optically thin: not radiatively inefficient? How does the B field manage to get the same (approx) vertical flux to launch the same power jet in lots of different BHB? How does thin cool disc truncated into hot flow? Simulations?? what are the HF QPOs ? –method for measuring a*? But LF QPOs probably don’t !!!! Can we understand iron line profiles ? And get all methods for measuring a* giving the same answer?


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