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The ubiquitous UV murmurs of sleeping supermassive BHs

The ubiquitous UV murmurs of sleeping supermassive BHs. Dani Maoz With: Neil Nagar, Heino Falcke, Andrew Wilson. Peterson et al. (2004). High-L accretion physics: (geometrically ) thin accretion disk. Manners 2002. accretion disk?. Kormendy & Gebhardt 2001.

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The ubiquitous UV murmurs of sleeping supermassive BHs

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  1. The ubiquitous UV murmurs of sleeping supermassive BHs DaniMaoz With: Neil Nagar, Heino Falcke, Andrew Wilson

  2. Peterson et al. (2004)

  3. High-L accretion physics: (geometrically ) thin accretion disk

  4. Manners 2002 accretion disk?

  5. Kormendy & Gebhardt 2001

  6. M32; Ho, Terashima, & Ulvestad (2003) MBH=2.5x106 Msun LX=1036 erg/s =3x10-9 LEdd stellar mass loss: ~10-6 Msun/yr Bondi accretion: ~3x10-7 Msun/yr Lacc=(e/0.1)1040erg/s

  7. if very large or very small, thermal instability, high T, inefficient cooling, other accretion solutions: geometrically thick accretion disks ADAF CDAF ADIOS Outflow “RIAF” Ho (2003)

  8. What is the connection between active and “normal” galactic nuclei? (AGNs and NGNs): How can SMBHs sleep so quietly?

  9. One way to progress: study the subtle signs of activity from “normal” nuclei demographics, accretion physics SMBH history

  10. The most common manifestation of (possibly) non-stellar nuclear activity is LINERs

  11. QSO

  12. Seyfert 1

  13. Seyfert 2

  14. LINER (low ionization nuclear emission-line region)

  15. SDSS; Kaufmann et al. (2003)

  16. LINERs are very common in bulges Manyof our best friends are LINERs…

  17. M87

  18. NGC 4594

  19. At least 1/2 of LINERs have a compact radio source.... Nagar et al. (2002)

  20. ...at least 1/2 of which are time variable... Nagar et al. (2002)

  21. ...and at milli-arcsec resolution the cores remain unresolved – TB~108K -- and sometimes have jetlike structures. Nagar et al. (2003)

  22. Unresolved (1”) nuclear X-ray source... Terashima & Wilson (2003)

  23. ...in about 1/2 of LINERs... Ho et al. (2001)

  24. ...with flux falling ~ on AGN L(Ha) vs LX relation. Ho et al. (2001)

  25. ~1/4 of LINERs have broad (variable) Ha wings NGC 4579; Barth et al. (2001)

  26. But.... -what about all those “~1/2’s”? -many LINERs have not revealed AGN signatures

  27. Do LINERs have anything to do with the BH? LINERs can be excited by: Photoionization by an AGN Ferland & Netzer (1983); Halpern & Steiner (1983); Filippenko & Halpern (1984); Ho et al. (1993) Photoionization by stars – WR stars: Terlevich & Melnick (1985); O-stars: Filippenko & Terlevich (1992); Shields (1992); Schultz & Fritsch (1994) Young starburst: Barth & Shields (2000) Post-AGB stars: Binnette et al. (1994); Taniguchi et al. (2000) Shocks Koski & Osterbrock (1976); Heckman (1980); Aldrovandi & Contini (1984); Dopita & Sutherland (1996)

  28. Maybe SMBHs and LINERs are both common in galactic nuclei but an optical LINER spectrum is not directly related to the accretion process.

  29. LINER definition based on optical emission lines; Excitation determined by far-UV light; Look in the UV!

  30. 250 nm 330 nm Nuclear UV sources in nearby LINER galaxies:

  31. NGC 404 NGC 3642 NGC 4203 NGC 4258 M81 NGC 4736

  32. Nucleus is obscured by dust in all LINERs w/0 UV nucleus; Probably all LINERs have UV nucleus Pogge et al. (2000)

  33. UV spectrum of LINERs NGC 4579; Barth et al. (1996)

  34. Maoz et al. (1998)

  35. NGC 1741B starburst

  36. So, how to distinguish stellar from nonstellar? VARIABILITY! (defining characteristic of AGNs) Monitor in UV a sample of LINERs:

  37. Snapshot Monitoring with HST/ACS/HRC in 2002-2003 at 2500 Ang and 3300 Ang

  38. The sample: (all) 17 LINERs with known UV nuclei L(UV)~10^(39-41) erg/s Includes all kinds: LINERs 1 / 2, radio / X-ray detected / undetected, AGN-like / starburst-like, pure / transition types.

  39. Big worry: detector stability Boffi et al. 2004: ACS stable in UV to < 1% !

  40. Results: “historical” (5~10 yr earlier) level F330 f250

  41. Summary of results: 1. 11/15 vary significantly on short (month) timescales, typical amplitudes ~10% 2. Correlated variations in 2500 A and 3300 A 3. Long timescale (years-decade) variations common, amplitudes factor few 4. Only 3/17 vary neither on long or short timescales, but even these may be due to sparse sampling 5. All LINER types vary

  42. Conclusion: LINERs are indeed genuine signposts of nonstellar activity (i.e., AGNs). SMBHs in most “normal” galaxies are producing (in one way or another) a LINER spectrum. Variable UV flux gives lower limit on AGN UV luminosity – can constrain accretion models

  43. ADAFs predict wrong radio slope; radio emission probably dominated by jets Nagar et al. (2001) Also, wrong slope in X-rays Terashima & Wilson (2003) Perhaps UV is also from jets?

  44. b NGC 4736: a binary/merging BH? nucleus

  45. 60 pc 6

  46. 3C 75 7 kpc

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