Astro 641 AGNAstro 641 AGN

Mapping the Evolution Mapping the Evolution of AGNof AGN

More material:

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3C Radio Survey3C 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.

V/VV/Vmaxmax Test Test

V/VV/Vmaxmax Test 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.

V/VV/Vmaxmax Test Test

Laing, Riley & Longair (1983)

IRASIRAS

de Grijp et al. (1987)

SpitzerSpitzer

Lacy et al. (2004)

Stern DiagramStern Diagram

Stern et al. (2005)

Power-law AGNPower-law AGN

Donley et al. (2008)

Selection: IRAC photometry is well-fit by a line of slope <-0.5

Why does it work?Why does it work?

Hickox et al. (2007)

Fraction of Recovered Fraction of Recovered SourcesSources

Stern et al. (2005)

X-ray Selected SourcesX-ray Selected Sources

Cardamone et al. (2008)

X-ray Selected SourcesX-ray Selected Sources

Cardamone et al. (2008)

X-ray Selected SourcesX-ray Selected Sources

Eckart et al. (2010)

X-ray Selected SourcesX-ray Selected Sources

Eckart et al. (2010)

SummarySummary

Eckart et al. (2010)

24 24 m Selectionm Selection

Brand et al. (2006)

24 24 m Selectionm Selection

Brand et al. (2006)

AGN FractionAGN Fraction

Treister et al. (2006)

AGN Contribution to IR AGN Contribution to IR BackgroundBackground

Treister et al. (2006)

Fiore et al. 2008

Finding Heavily-Obscured AGNFinding Heavily-Obscured AGN

Mid-IRMid-IR X-ray StackingX-ray Stacking

FF2424/F/FRR>1000>1000

FF2424/F/FRR<200<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)

Rest-Frame StackingRest-Frame Stacking

Good fit with either NH1023cm-2 or combination of CT AGN with star-forming galaxies.

Consistent results with observed-frame stacking.

Treister et al. ApJ 2009c

X-Ray to Mid-IR RatioX-Ray to Mid-IR Ratio

~100x lower ratio for X-ray undetected sources.

Explained by NH~5x1024 to 1025cm-2

Treister et al. ApJ 2009c

Both X-rays and 12µm good tracers of AGN activity.

X-Ray to Mid-IR RatioX-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

Near to Mid-IR ColorsNear 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

BluerRedder

Well explained by different viewing angle (30o vs 90o) in the same torus model Can it be star-formation versus AGN?

Treister et al. ApJ 2009c

Near to Mid-IR ColorsNear to Mid-IR Colors

Armus et al. 2007

ULIRG, LINER

ULIRG, Sey2

IRAC ColorsIRAC Colors

[5.8]-[8] (Vega)

z=0-1

z>1

AGNFaint 8 µm

Treister et al. ApJ 2009c

IRAC ColorsIRAC Colors

log (f5.8/f3.6)F

ain

t 8µ

m

Treister et al. ApJ 2009c

Mid-IR/Radio SelectionMid-IR/Radio Selection

Donley et al. (2005)

Mid-IR/Radio SelectionMid-IR/Radio Selection

Park et al. (2008)

Martinez-Sansigre et al. (2005)

Mid-IR/Radio SelectionMid-IR/Radio Selection

Barger et al. (2007)

Putting it all togetherPutting it all together

Hickox et al. (2009)

AGN FractionAGN Fraction

Donley et al. (2008)

q vs IR Lumq vs IR Lum

Kartaltepe et al. (2010)

Stern DiagramStern Diagram

Kartaltepe et al. (2010)

Mid-IR ExcessMid-IR Excess

Kartaltepe et al. (2010)

Redshift and LRedshift and LIRIR DistributionsDistributions

Kartaltepe et al. (2010)

AGN FractionAGN Fraction

Kartaltepe et al. (2010)