1. Franz. Bauer (IoA -> Columbia) D. Alexander (IoA), N. Brandt (PSU), A. Fabian (IoA), M. Worsley (IoA) The CDF/GOODS AGN Teams CDF-North – 1.945 Ms 450 sq. arcmin – 503 sources CDF-South – 0.939 Ms 390 sq. acrmin – 326 sources The Evolving AGN Population in the Chandra Deep Fields

2. X-ray Background (Comastri et al. 1995) 0.5-8.0 keV Chandra has resolved ~80-95% of the 0.5-2.0 keV and ~70-90% of 2-8 keV cosmic X-ray backgrounds

3. Resolved fraction (Worsley et al. 2004, submitted) raw - all sources from field (CDF-N/CDF-S in black/grey crosses, XMM-LH are the diamonds: PN=dashed, M1/M2=dotted) sources removed above 5e-14 erg s -1 cm -2 (0.5-8 keV) and source removed below 1e-16 erg s -1 cm -2 (0.5-8 keV)

4. Unresolved fraction (Worsley et al. 2004, submitted ) (Comastri et al. 1995)

5. Magnitude vs Redshift Most X-ray sources have optical mags consistent with L* galaxy tracks rather than an M B =-23 QSO Host Galaxy dominates optical light Can use magnitudes to estimate redshift from template SED… OK for ensemble 525/829 sources in CDFs with redshifts (184 are phot-z) (Barger et al. 2003, Szokoly 2004, Mobasher et al. 2003) Spectroscopy hard even for 8-10m class telescopes

6. X-ray/Optical Diagnostic Fx/Fo is an excellent, relatively redshift- independent method of crudely identifying different source types. (e.g., Maccacaro et al. 1988; Stocke et al. 1991)

7. X-ray/Optical Diagnostic X-ray bright sources are comprised mainly of moderate redshift AGN Whereas X-ray faint sources are likely to be : 1) extension of X-ray bright AGN to higher redshifts, (e.g., Alexander et al. 2001) 2) star-forming galaxies. (Hornschemeier et al. 2001, 2002, 2003; Alexander et al. 2002; Bauer et al. 2002) Fx/Fo is an excellent, relatively redshift- independent method of crudely identifying different source types. (e.g., Maccacaro et al. 1988; Stocke et al. 1991)

8. We can gain some further insight to the number counts and resolved XRB by making cuts on Fx/Fo to represent different X-ray source populations. X-ray/Optical Diagnostic by L X

10. Simple Absorption in CDF AGN (Bauer et al. 2004, in prep.) Intrinsic N H Spectral fitting errors do not change this result. Higher assumed redshifts could shift things toward more absorption. Intrinsic N H vs. L X Weak trend in absorbed ratio with Lx. Clear bias from Chandra against low L X /high N H objects

11. Simple Absorption in CDF AGN (Bauer et al. 2004, in prep.) Some Examples: Obscured AGNQSO Soft-Excess BLAGN SPECTRAL COMPLEXITY N H given in units of 10 22 cm -2

13. AGN Space Density Lower luminosity AGN peak at lower redshift -> “cosmic down-sizing” BL AGN (Hasinger et al. 2005, in prep) BL AGN (Hasinger et al. 2005, in prep) All AGN (Ueda et al. 2003) All AGN (Ueda et al. 2003)

15. Morphologies of AGNs CDF-North CDF-South GOODS ACS (HST) observations provide the deepest and highest-quality optical data, allowing unprecedented morphologies GOODS project (ACS+SIRTF)

16. Morphologies of AGNs CDF-North CDF-South P.I.: M. Giavalisco Created by A. Koekemoer and Z. Levay Astrometry by S. Casertano and R. Hook Verification by M. Giavalisco, H. Ferguson, A. Koekemoer, M. Dickinson, N. Grogin, S. Ravindranath, T. Dahlen, and GOODS/ACS team HST ACS 5 Epochs 18000x24000 pixels F850LP (z) F775W (i) F606W (V) F435W (B)

17. 0.4<z<1.3 Host Galaxies (Bauer et al. 2004, in prep.)

18. More Detailed Host Galaxy Constraints Using the CAS morphological parameterization for M B <-19.5, it appears that AGN hosts are preferentially associated with more concentrated galaxies (implying they may more bulge- dominated) compared to field population out to z ~ 1.3, but show no difference in asymmetry. (N. Grogin et al. 2004, in press)

19. Morphological Breakdown (Simmons et al. 2004, in prep.)

21. Still to Come…Observationally Deep SIRTF observations (more AGN? mid-IR constraints) Deep Radio observations (CDF-S + deeper CDF-N) Larger SCUBA coverage (CDF-S + expanded CDF-N) Deep near-IR (CDF-N + expanded CDF-S) Deeper Chandra??? (Compton-thick AGN? better spectra) The CDFs should remain at the observational forefront in our understanding of faint X-ray AGN

22. Still to Come…Scientifically More detailed cosmic accretion history which hopefully includes missing obscured AGN (must find first)… Nature of SMBH/bulge formation and growth (need measure of bulge out to higher redshifts)…

23. Most of the 0.5-8.0 keV background now resolved (but not all!) Broad variety of source types are detected AGN source density (~6,000 deg -2 ) >15 times that in optical but few Compton thick AGNs are detected (further AGNs to be found) Significant fraction of XRB contributors are AGN in massive, late-type spiral galaxies -> analogous to local, powerful Seyferts Luminous AGN reside in more concentrated galaxies: Bulges in place by z ~ 1.3? Not strongly fed by merger activity? For all papers and data products (CDF-N and CDF-S): http://www.astro.psu.edu/user/niel/hdf-chandra.html Some Conclusions

25. Trends among these AGN… Colors and CAS parameters for GOODS-N, z<1.3, L X >10 42 sources are consistent with spirals as well Kauffmann et al. (2003) GOODS-S, z ph 10 42 AGN tend to reside in massive galaxies

26. X-ray/Optical Diagnostic by L X Using known (or estimated) redshifts and X-ray slopes (i.e. N H ), we can determine intrinsic, rest-frame L X F X /F O tracks L X

27. X-ray Emission Lines in CDF AGN (Bauer et al., in prep.) ~10% of the sample display obvious Fe K  emission-line features with EWs from ~ 0.1-1.3 keV. EW~0.1 is detection limit; stacking can probe weak lines Only ~5-10 potential Compton thick AGN: large EWs and  <1.0 characteristic of pure reflection. (e.g., Maiolino et al. 1998; Bassani et al. 1999; Matt et al. 2000) BLAGN Optical Starburst/ X-ray AGN Unidentified potential Compton Thick AGN Unidentified AGN

28. Fluctuation analysis (Miyaji & Griffiths 2002) Fluctuation analysis (Miyaji & Griffiths 2002) CDF Number Counts Bulk of the X-ray bkgd produced by sources near the “knee” in the number counts distribution

29. CDF Number Counts by F X /F O (Bauer et al. 2004, in prep.) AGN source density ~6,000 deg -2 : ~15-20 times higher than optical surveys X-ray emission very effective for finding AGNs, but still missing Compton-Thick AGN?

30. CDF Number Counts by L X 0.5-2.0 (2-8) keV XRB dominated by AGN with log(L X ) ~ 44.0 (43.0) log(L X ) < 41.5 sources (galaxies) match up well with radio estimates (Bauer et al. 2004, in prep.)

31. CDF Number Counts by N H (Bauer et al. 2004, in prep.) 0.5-2.0 (2-8) keV XRB dominated by AGN with log(N H ) ~ 21.5 (22.5) This trend illustrates the basic prediction from XRB synthesis models

32. median props  =1.69 N H =2x10 21 cm -2 Observed value for nearby AGN is  ~ 1.8 before correcting for effects of reflection or absorption (e.g., Nandra & Pounds 1994) LOCAL AGNs Risaliti et al. (1999) Some AGNs still undetected in a 2Ms Chandra exposure?

33. Formation of the Bulge

34. Why Go Deeper? 1.Discovery space (still approx. photon limited) 2.Detect more Compton-thick AGNs 3.Improve X-ray spectral analysis 4.Detect more galaxies Why Go Wider? 1.Detect rarer source types (e.g., obscured QSOs, high-z AGNs) 2.Improve statistics on AGN evolution/luminosity function 3.Trace both obscured and unobscured AGN evolution 4.Uncover extent of large-scale structure (i.e., redshift peaks) In terms of X-ray observations Deeper vs. Wider?

35. ~50 times deeper than deepest ROSAT survey Deep enough to detect mod.lum starbursts at z~1 and mod.lum AGNs at z~6 X-ray surveys in the 0.5-2.0 keV band