AGN Demographics Christine Black 3/1/12

Major Points What is a demographical study? Very brief overview of AGNs Galaxy evolution roadmap Studies of AGN in the local universe Studies from 0 < z < 1 Studies around z = 1

What is a Demographical Study? Compare fraction of AGN to normal galaxies in collection How are AGN fueled Galaxy morphology Must be able to see host galaxy, that way can study stellar pop., structure, mass, etc

AGN vs ‘normal’ galaxy Actively accreting SMBH at center of host Seen in several wavelengths –Radio, optical, Hard/Soft Xray Luminosities of L > ergs/s –This helps in seeing them at higher z (1+)

Galaxy Evolution Move through ‘clouds’ –Blue cloud –Green Valley (Transition Zone) –Red Cloud/Sequence Georgakakis 08

Local Studies Kauffmann 03 –Looked at ~ 123,000 galaxies from SDSS 22,623 host AGN From 0.02 < z < 0.3 Use OIII emission line –Strong for AGN –Weak for metal-rich, star forming galaxies

Local Type 2 AGN found in more massive hosts –3x M  AGN fraction of massive galaxies is dependent on z Hosts are similar in size and mass to ‘early type’ galaxies

Local Stars in Type 2 AGN are the same as those found in QSO with the same redshift and OIII luminosity Strong correlation btwn age and OIII luminosity –Low-luminosity have older stars –High-luminosity are like late-type galaxies Large number type 2 AGN had burst of SF 1- 2 GY ago

Local Bluer hosts than normal galaxies of same mass Massive Galaxies (log(M) > 10.5) are preferentially spirals Ultra hard luminosity increases with stellar mess BAT AGN found massive hosts with large bulge- disk ratios and SMBH Koss 11 BAT Ulta Hard Xray 0.01 < z < 0.07

Local Best 05 –Radio luminosity is independent of BH mass –More massive BHs host a larger fraction of radio- loud AGN Ho 08 –2/3 E-Sb galaxies have activity in nuclei Most are AGNs fueled by accretion –Detect AGNs in bulge-less galaxies

0 < z < 1 Haggard ‘10 –Chandra and SDSS –100k+ galaxies to.7z –L >10 42 ergs/s Fraction evolves with z and correlates with mag –(1+z) 3 and (1+z) 4 Larger fraction of bluer hosts possibly dependent on z

Other Theories Probability of a host with AGN defined by a universal Eddington Ratio is independent of stellar mass AGN not related to quenching or color change Aird ‘12 More in Blue/Green by factor of 2

z ~ 1 Nandra 07 –0.6 < z < 1.4 –See low-level AGN in dense environments –Majority of AGN in red sequence Supports quenching –AGN activity is linked to host evolution in the late stages

z ~ 1 Gerogakakis 08 –Chandra All Wavelength –0.4 < z < 0.9 Find AGN in the valley –Some are obscured: gas/dust must reform Based on morphology - not major mergers Accretion last longer than SF –Find post-starburst at z ~ 0.8

Conclusions Red vs Green vs Blue? –Depends on z Star formation is not only fuel for AGN Morphology –Soft-Hard Xray may not need bulges –Ultra hard Xray found in Spirals Mergers –Yes and No