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Astro 641 AGN

Astro 641 AGN. More material: This lecture!. Mapping the Evolution of AGN. 3C Radio Survey. Third (revised) Cambridge Catalogue of radio sources using extended emission at 178 MHz. Low selection frequency: steep spectra Survey of all sources north of -5 deg with f R >9 Jy. 328 sources.

herman-stout
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Astro 641 AGN

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  1. Astro 641 AGN • More material: • This lecture! Mapping the Evolution of AGN

  2. 3C Radio Survey • Third (revised) Cambridge Catalogue of radio sources using extended emission at 178 MHz. • Low selection frequency: steep spectra • Survey of all sources north of -5 deg with fR>9 Jy. 328 sources. • Complete sample: Laing, Riley and Longair (1983). 96% complete to 10 Jy.

  3. V/Vmax Test

  4. V/Vmax Test • Flux-limited sample --> at small distances larger luminosity range. • Solution: compute for each source the max. redshift at which it would still be included in a complete survey --> maximum volume Vmax. • V/Vmax is a measure of the source position within the observable volume. • V/Vmax uniform in [0,1] range. • <V/Vmax>=0.5.

  5. V/Vmax Test Laing, Riley & Longair (1983)

  6. IRAS de Grijp et al. (1987)

  7. Spitzer Lacy et al. (2004)

  8. Stern Diagram Stern et al. (2005)

  9. Power-law AGN Selection: IRAC photometry is well-fit by a line of slope <-0.5 Donley et al. (2008)

  10. Why does it work? Hickox et al. (2007)

  11. Fraction of Recovered Sources Stern et al. (2005)

  12. X-ray Selected Sources Cardamone et al. (2008)

  13. X-ray Selected Sources Cardamone et al. (2008)

  14. X-ray Selected Sources Eckart et al. (2010)

  15. X-ray Selected Sources Eckart et al. (2010)

  16. Summary Eckart et al. (2010)

  17. 24 m Selection Brand et al. (2006)

  18. 24 m Selection Brand et al. (2006)

  19. AGN Fraction Treister et al. (2006)

  20. AGN Contribution to IR Background Treister et al. (2006)

  21. Finding Heavily-Obscured AGN Mid-IR X-ray Stacking F24/FR>1000 F24/FR<200 • 4 detection in X-ray stack. Hard spectral shape, harder than X-ray detected sources. • Good CT AGN candidates. • Similar results found by Daddi et al. (2007) Fiore et al. 2008

  22. Rest-Frame Stacking Good fit with either NH1023cm-2 or combination of CT AGN with star-forming galaxies. Consistent results with observed-frame stacking. Treister et al. ApJ 2009c

  23. X-Ray to Mid-IR Ratio Both X-rays and 12µm good tracers of AGN activity. ~100x lower ratio for X-ray undetected sources. Explained by NH~5x1024 to 1025cm-2 Treister et al. ApJ 2009c

  24. X-Ray to Mid-IR Ratio Ratio for sources with L12µm>1043erg/s (~80% of the sources) ~2-3x higher than star-forming galaxies Treister et al. ApJ 2009c

  25. Near to Mid-IR Colors • Distributions significantly different • X-ray detected sources much bluer • Average f8/f24=0.2 for X-ray sources and 0.04 for X-ray undetected sample Well explained by different viewing angle (30o vs 90o) in the same torus model Can it be star-formation versus AGN? Redder Bluer Treister et al. ApJ 2009c

  26. Near to Mid-IR Colors ULIRG, LINER ULIRG, Sey2 Armus et al. 2007

  27. IRAC Colors AGN Faint 8 µm z>1 [3.6]-[4.5] (Vega) z=0-1 [5.8]-[8] (Vega) Treister et al. ApJ 2009c

  28. IRAC Colors log (f8/f4.5) Faint 8µm log (f5.8/f3.6) Treister et al. ApJ 2009c

  29. Mid-IR/Radio Selection Donley et al. (2005)

  30. Mid-IR/Radio Selection Martinez-Sansigre et al. (2005) Park et al. (2008)

  31. Mid-IR/Radio Selection Barger et al. (2007)

  32. Putting it all together Hickox et al. (2009)

  33. AGN Fraction Donley et al. (2008)

  34. q vs IR Lum Kartaltepe et al. (2010)

  35. Stern Diagram Kartaltepe et al. (2010)

  36. Mid-IR Excess Kartaltepe et al. (2010)

  37. Redshift and LIR Distributions Kartaltepe et al. (2010)

  38. AGN Fraction Kartaltepe et al. (2010)

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