The The Large Scale Structure Large Scale Structure of of Seyferts and LINERs Seyferts and LINERs and and Implications for their Implications for their Central Engines Central Engines Anca Constantin Drexel University AGN are not unbiased tracers of the whole galaxy population, with respect to mass: - Seyferts are less clustered than galaxies less massive but actively accreting BHs - LINERs cluster like galaxies. more massive but weakly active BHs --with thanks to Michael Vogeley
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The Large Scale Structure of Seyferts and LINERs and Implications for their Central Engines Anca Constantin Drexel University AGN are not unbiased tracers.
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The The Large Scale StructureLarge Scale Structure of of Seyferts and LINERsSeyferts and LINERs
and and Implications for their Implications for their Central Central
EnginesEngines
Anca Constantin
Drexel University
AGN are not unbiased tracers of the whole galaxy population, with respect to mass:
- Seyferts are less clustered than galaxies less massive but actively accreting BHs
- LINERs cluster like galaxies. more massive but weakly active BHs
--with thanks to Michael Vogeley
The SDSS main galaxy sample -DR2
• 2627 sq. deg. footprint area • ~250,000 galaxies with spectra • 0 < z <~ 0.3• rdered < 17.77
• Broad-line objects (spectroscopically flagged as QSOs) excluded
The SDSS main galaxy sample -DR2
• 2627 sq. deg. footprint area • ~250,000 galaxies with spectra • 0 < z <~ 0.3• rdered < 17.77
• Broad-line objects (spectroscopically flagged as QSOs) excluded
“ Best” absolute magnitude limited sample
Finding AGN among SDSS galaxies
Seyferts
H II
nuclei
LINERs
Transition objects
emission-line
20% of all galaxies are strong line-emitters
among which: 52% H II20% (pure) LINERs7% Transition Objects
5% Seyferts
The Clustering Amplitude r0:
H IIs: r0= 5.7 0.2 less clustered than galaxies
Seyferts: r0= 6.0 0.6
less clustered than galaxies
LINERs: r0= 7.3 0.6 clustered like galaxies
r0 is measured in h-1 Mpc = scale where the probability of finding a galaxy pair is 2 random
all galaxies: r0= 7.8
0.5 Absolute Magnitude limited samples,
-21.6 <M < -20.2
The Clustering Amplitude r0:
H IIs: r0= 5.7 0.2 less clustered than galaxies
Seyferts: r0= 6.0 0.6
less clustered than galaxies
LINERs: r0= 7.3 0.6 clustered like galaxies
r0 is measured in h-1 Mpc = scale where the probability of finding a galaxy pair is 2 random
all galaxies: r0= 7.8
0.5
higher peaks in the density field are more clustered
Seyferts & H II’s: - less massive Dark Matter halos