2. AGN in X-Ray Surveys For Astro597 Jian Wu November 10, 2004

3. OUTLINE Part I AGN Surveys in Different Bands Part II AGN X-ray Surveys

4. Part I AGN Surveys in Different Bands AGN Surveys in different bands – Retrospect – Optical selection and implications – Radio selection – Infrared selection – High-Energy selection Selection Effects

5. Part II AGN X-ray Surveys Soft X-rays Surveys Hard X-ray Surveys – Pre-Chandra and XMM-Newton – Deep Chandra and XMM-Newton Surveys Deep Extragalactic X-ray Surveys 2Ms Chandra Point-Source CATA

6. Part I AGN Surveys in Different Bands

7. Retrospect Lamppost Effect – find something in where we can find it Three types of surveys – Find object – Find object consistently – Find with well-defined selection criteria

8. Retrospect First indication (optical) – NGC1068-broad emission lines (Fath, 1913) – M87-jet (Curtis 1917) – Extragalactic radio sources – The origin of name for quasar (Schmidt et.al., 1964)

9. Retrospect Early AGN Surveys – Cambridge xC Surveys – Markarian Survey – Zwichky Survey Recent Large Surveys – 2dF – SDSS How to find AGN-SED – Power law (10 13 Hz-10 20 Hz) – Highly ionized Emission lines-C N O – Low-ionization emission lines-Fe

10. Optical Selection Principle (Sandage 1971) – Systematic optical color deviation from starlight Bonus – Photometric red-shift estimation Declaration of “complete samples” Fatal bug – L b does not correlated well with L galaxy ￫ cannot see low luminosity AGN in massive galaxies (contamination) Aftermath – Omission (radio, IR, X-ray)

11. Optical selection effect – Luminosities – Hard to evaluate Alternatives – Variability – Absence of proper motion Optical Selection

12. Radio Selection Principles – Flat-spectrum, compact radio source – Object with low IR/radio – morphology Advantages – Efficient – Sensitive – Accurate – Find objects omitted by optical techniques Disadvantages – Incomplete (selection effect) – Star-forming region

13. Infrared Selection Disadvantages – Color difference is subtle – Equivalent width insufficient – An Island Potential advantages – mid-IR to be a “pivot point” in SED – PAH and high ionization IR lines Prospect – SIRTF

14. High-Energy Selection X-ray and γ-ray Disadvantages – Soft X-ray suffer from larger extinction – Red-shift distribution – γ-ray position – Soft X-ray bias

15. Selection Effect Dilution of the optical/IR brightness and color by the starlight. Obscuration Another selection effect

16. Part II AGN X-ray Surveys

17. Advantages High contrast between AGN and stellar light

18. Advantages Penetrating power of X-rays.

19. Advantages Great sensitivity of Chandra and XMM- Newton ACIS (ergs-cm -2 sec -1 in 10 5 s) HRC (ergs-cm -2 sec -1 in 10 5 s ) 4×10 -15 EPIC MOS (ergs-cm -2 sec -1 in 10 5 s) EPIC pn (ergs-cm -2 sec -1 in 10 5 s ) ~ 4×10 -14

20. Advantages Accurate positions from Chandra – ~ 0.5 arcsec EinsteinEXOSATROSATBBXRT /ASCA ChandraXMM- Newton 4184750.520

21. Advantages A relatively large fraction of the bolometric energy (3-20%) is radiated in the classical X-ray bands. High area density (400 deg -2 ) Large amplitude and frequency of variability in the X-ray band. Little Contamination from other objects High red-shift quasars are easy to detect Close to the black hole

22. Early X-ray Surveys Uhuru (1970 10-1973 3) [2-20 keV] Ariel-V (1973 10-1980 3) [0.3-40 keV] HEAO-1 (1977 8-1979 1) [0.2keV-10MeV]

23. Soft X-ray Surveys Einstein (1978 11-1981 4) [0.2-20 keV] ROSAT (1990 1-1999 2) [0.1-2.5 keV]

24. Soft X-ray Surveys Fruit – Moderate correlation of optical and X-ray

25. Hard X-ray surveys ASCA (1993 2-2001 3) [0.4-10 keV] BeppoSAX (1996 4-2002 4) [0.1-300 keV] Fruit – ~ 500 serendipitous sources over ~ 100 deg 2

26. Deep Chandra and XMM-Newton Surveys Chandra (1999 7-present) XMM-Newton (1999 10-present)

27. Deep Chandra and XMM-Newton Surveys Fruit – Numerous “optically dull” objects – Greatly enlarge the AGN population

28. Deep Extragalactic X-ray Surveys

31. Source classification difficulties – Too faint to be identified by optical spectrum – Many of the X-ray sources have modest optical luminosities, often due to obscuration – “schism” between optical (type1 and type2) and X-ray (unobscured and obscured )

32. Deep Extragalactic X-ray Surveys

33. Basic AGN Types – Unobscured AGN – Obscured AGN with clear optical/UV AGN signatures. – Optically faint X-ray sources – XBONGs (X-ray Bright Optically Normal Galaxies)

34. AGN Red-shift Distribution Most AGN in deep X-ray surveys have z =0~2 Redshift distribution show “spikes” in z=0.5~2.5 [Bargar et al. 2002] [Bargar et al. 2003]

35. Luminosity-redshift Plot

36. AGN Selection Completeness Reasons of incompleteness – Compton thick AGN – Luminous at non-X-ray, but X-ray weak How many we haven’t seen 2000-3000 deg -2

37. Key results from DEXS Large optically selected luminous quasars – PLE (Pure luminosity Evolution) Moderate-luminosity AGN – LDDE (luminosity-dependent density evolution)

38. Comoving space density

39. X-ray constraints Sky density – Bottom line (z > 4) ~ 30-150 deg -2 – AGN contribution to reionization at z ~ 6 is small Accretion[z>4] ~ Accretion[local] Infrared and sub-millimeter – star-forming processes AGN/sub-mm galaxies >=40%. X-ray survey should remain an effective way to find AGN at the highest redshift

40. Future prospects Detailed cosmic history of SMBH accretion The nature of AGN activity in young, forming galaxies X-ray measurements of clustering and large-scale structure The X-ray properties of cosmologically distant starburst and normal galaxies

41. The 2Ms CDF-N Main CATAlog – High significant Chandra sources Supplementary CATAlog – Lower significance Chandra sources 20 observations 447.8 arcmin 2 Flux limit=2.5×10 -17 erg cm -2 s -1 (0.5-2.0 keV) Flux limit=1.4 ×10 -16 erg cm -2 s -1 (2.0-8.0 keV)

42. Data reduction CIAO – Chandra Interactive Analysis of Observations Radiation damage Quantum Efficiency Losses Bad column Bad pixel Cosmic ray afterglow Standard pixel randomization Potential background events

43. Production of CATAlogs Technique feature – Matched filter Accuracy of the X-ray source position Correlation of optically bright sources with lower significance Chandra sources

44. Image and Exposure Map Creation

45. Standard Bands keV FB SB SB1SB2HB1HB2 HB

46. Point-source Detection Key criterion 1×10 -5 supplementary optically bright source CATAlog False positive probability 1×10 -7 main CATAlog

47. Source Position Refinement X –ray1.4GHz Radio 503 sources

48. Position of sources in main 138 NEW!

49. Supplementary Optically Bright Chandra Source CATA X –rayOptical R-band 79 sources

50. Primary analysis of S

51. X-ray Band ratio

52. Color-Color Diagram SB2/SB1 vs. HB1/SB2

53. Color-Color Diagram HB1/SB2 vs. HB2/HB1

54. Background

55. Prospects Doubling the exposure of a Chandra observation leads to an increase in sensitivity between and. The number of background counts is often negligible. Negative K-correction of absorbed AGN emission Longer and longer