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Quasars and Massive Black Holes

Quasars and Massive Black Holes. Stephen Fine. Outline. What is a quasar How do we study quasar black holes Why do we study quasar black holes What are the current difficulties in studying black holes How can we improve on the current situation. What is a quasar?. This is not a quasar.

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Quasars and Massive Black Holes

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  1. Quasars and Massive Black Holes Stephen Fine

  2. Outline • What is a quasar • How do we study quasar black holes • Why do we study quasar black holes • What are the current difficulties in studying black holes • How can we improve on the current situation

  3. What is a quasar? This is not a quasar

  4. What is a quasar? This is a picture of a quasar This is not a quasar This is not a quasar This is a spectrum of a quasar

  5. Reverberation mapping Broad-line region Continuum source

  6. Reverberation mappingresults: Line stratification Weaker continuum Low-ionisation lines Hβ, MgII… Broad Line Region Strong continuum High-ionisation lines CIV, HeII… Ionising continuum source

  7. Reverberation mappingresults: Velocity structure Solid lines give

  8. Reverberation mappingresults: The r—L relation

  9. SMBH mass estimation For a virialised system:

  10. SMBH mass estimation Reverberation mapping • Assume the broad-line region is virialised • The width of an emission line gives • is given by the time lag between continuum and emission line flux variations

  11. SMBH mass estimation Without reverberation mapping (single-epoch) • Assume the broad-line region is virialised • The width of an emission line gives • The radius-luminosity relation can be used to get an empirical estimate of

  12. SMBH mass estimation:extending to high z Can’t we do any better?

  13. Standard reverberation mapping • Cross correlate continuum and emission line light curves. • Requires 10s to 100s of observational epochs to build up the light curves. • Extremely observationally expensive. • For brighter objects the situation is worse since they have longer timescales and vary less. • To date essentially no reverberation mapping has been performed at z>0.1, M<-24 or with UV lines.

  14. Stacked reverberation mapping emission line continuum

  15. A first attempt • We have repeat spectroscopy from MMT Hectospec of 368 quasars in a Pan-STARRS field that is monitored photometricaly ~weekly • 100/75 of these have a good MgII/CIV line in their spectrum. • Is this enough to do some reverberation mapping?

  16. First results:MgII and CIV

  17. First results:CIV r-L relation

  18. First results:CIV r-L relation

  19. Summary • Until recently we have only been able to study the most nearby black holes directly. • Through modern instruments and new techniques we are pushing out to the parameter space occupied by the vast majority of known quasars.

  20. Obligatory last-slideSKA/MeerKAT reference • Time-domain astronomy is just now kicking into gear. • Time-resolved surveys are current or coming from the X-ray (e-ROSITA) to UV/optical/NIR (Pan-STARRS, DES, Skymapper, LSST). • Transient/variability surveys are major science drivers for MeerKAT, ASKAP and the SKA.

  21. Many Thanks!

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