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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 of the whole galaxy population, with respect to mass: - Seyferts are less clustered than galaxies
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The Large Scale Structure of Seyferts and LINERsand Implications for their 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
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
emission-line Finding AGN among SDSS galaxies Seyferts LINERs 20% of all galaxies are strong line-emitters among which: 52% H II 20% (pure) LINERs 7% Transition Objects 5% Seyferts Transition objects H II nuclei
The Clustering Amplitude r0: r0 is measured in h-1 Mpc = scale where the probability of finding a galaxy pair is 2 random • 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 all galaxies: r0= 7.8 0.5 Absolute Magnitude limited samples, -21.6 <M < -20.2
The Clustering Amplitude r0: higher peaks in the density field are more clustered r0 is measured in h-1 Mpc = scale where the probability of finding a galaxy pair is 2 random • 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 Seyferts&H II’s: - less massive Dark Matter halos LINERs: - more massive Dark Matter halos all galaxies: r0= 7.8 0.5 Absolute Magnitude limited samples, -21.6 <M < -20.2
The Clustering Amplitude r0: higher peaks in the density field are more clustered r0 is measured in h-1 Mpc = scale where the probability of finding a galaxy pair is 2 random • 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 Seyferts&H II’s: - less massive Dark Matter halos LINERs: - more massive Dark Matter halos all galaxies: r0= 7.8 0.5 MDM halo ~ MBH (Ferraresse 2002, Baes et al. 2003) MBHSeyferts < MBHLINERs Absolute Magnitude limited samples, -21.6 <M < -20.2
Driven by the host morphology? bluered-ishred-ish, KScolor = 0.617 late typeearlier types like Seyferts! KSconc = 0.104 H IIs SeyfertsLINERs early late blue red
Driven by the host morphology? NO! bluered-ishred-ish, KScolor = 0.617 late typeearlier types like Seyferts! KSconc = 0.104 H IIs SeyfertsLINERs early late blue red
lowest L[O I],[O III] objects= strongly clustered highest L[O I],[O III] objects= weakly clustered Low L[O I]: r0= 13.15 1.09 LINER dominated High L[O I]: r0= 6.1 0.3 H II dominated low L[O I] high L[O I] Low L[O III]: r0= 8.8 0.7 LINER dominated High L[O III]: r0= 6.2 0.6 almost no LINERs! mostly H II low L[O III] high L[O III]
Different availability of fuel? LINERsshow particularly low levels of obscuration & gas densities Seyfertsexhibit generally high gas densities & moderately high NHI
Summary & Possible interpretation r0: weakly weakly clustered like clustered clustered average galaxies H IIs Seyferts LINERs hosts: blue red-ish red-ish, late typeearlier typeslike the Seyferts fueling average relativelyhigh (very) low rate: -efficient? -inefficient? gaslowhigh lower than density:in Seyferts obscuration:high wide range (very) low BH mass:small small large life-time: ? short long Constantin & Vogeley 2006, in ApJ today
Accretion rate, [O I] Accretion rate, [O III] BH mass Stellar mass Obscuration Stellar ages Dist to 3rd nearest Dist to 1st nearest