1. Swift/BAT Hard X-ray Survey Preliminary results in Markwardt et al 2005 35' energy coded color

2. BAT Instrument Parameters Energy Range14 - 195 keV Area5200 cm 2 (x 50% open fraction) Field of View2 Steradian, partially coded Background10,000 ct/s (cosmic diffuse dominated) Spatial 21’ sky pixel, centroided to <1-3’ Resolution Spectral 6 keVFWHM @ 60 keV, average Resolution Sensitivity0.2 photons/cm 2 /sec Timing Resolution100 usec Observing “Random” (piggy-back Swift StrategyGRB observing plan)

3. 9-month Swift/BAT Survey > 1.5 Ms 1-1.5 Ms 0.5-1 Ms Ecliptic Plane 8.5 mCrab (T/20 ks) -0.5 Exposure Map Covers whole sky, mostly >1Ms deficit on Ecliptic Plane due to Sun avoidance Sensitivity improves as square root of time (1.2-2 X statistical) to 0.6 milliCrab in 3 years Sensitivity vs Time

4. 9 months --------------------- 323 sources 39 unidentified sources 158 galactic 5 galaxy clusters 158 AGN 16 beamed |Galactic b| >15 (74%) ---------------------- 159 sources 9 unidentified sources 29 galactic 2 galaxy clusters 121 AGN 15 beamed already the most sensitive all-sky hard x-ray survey At 3 years expect 450 AGN. BAT Source Detections

5. BAT GALAXY Identifications 70% of the galaxies with no Sy classification are absorbed. Most unknown galaxies are absorbed Sy2's or edge on spiral galaxies with no lines (3 with no spectroscopy) Sy2/Sy1 ratio is 1.2 (0.5 Sy1.5/Sy1) and 52% of Seyfert galaxies are absorbed confirming Markwardt et al 2005 Much lower than 75% predicted by the standard model for the CXB absorbed Log nH > 22 |Gal b| >15 absunabstotal Sy133134 Sy1.551116 Sy236340 no Sy ID9413 total5349103

6. Correlations of BAT Rate with other Bands no correlation between BAT and ROSAT count rates 44 BAT sources not detected by ROSAT no close correlation with total 2MASS J band soft x-ray and IR do not measure true AGN luminosity or complete populations

7. BAT XMM peaks at 20 keV >25% of BAT sources have weak soft X-ray emission only a survey at >20 keV is unbiased by absorption Many have extremely complex spectra with soft and hard components that seem unrelated Simultaneous X-ray and hard X-ray spectra are required to understand AGN Heavily Absorbed and Complex Spectra Abound

8. LogN/LogS and Luminosity Function errors 25% in normalization, ~10% in slopes and <1% in break luminosity New, much tighter constraints will test CXB models Treister, Urry, and Lira: standard unified AGN model 2500 AGN, L BAT >10 -11 ergs cm -2 s -1 BAT measures 1100 AGN, L BAT >10 -11 ergs cm -2 s -1 Pashak Ghandi 800 AGN, L BAT >10 -11 ergs cm -2 s -1

9. Average BAT AGN Spectrum no evidence for a break below 200 keV same with brightest 36 AGN removed Same for luminosity 10 44 Contrast with strong break at 40 keV in CXB spectrum is much flatter than CXB (slope = 2.75) above the break Crab Normalized Response

10. E -2 Background vs BAT AGN Spectrum BAT AGN spectrum is a bad fit to CXB for E>40 keV Soft x-ray surveys put source of CXB at Z=0.7 to fit the CXB the BAT AGN must be at Z > 1 or show strong spectral evolution 150 keV BAT UL

11. What is the Blazar Contribution to the CXB? BAT beamed sum spectrum is 10-16% AGN sum In 3 years, BAT will detect >40 beamed sources. BAT survey can answer this question. Beamed Sources Beamed Fraction

12. Conclusions The first complete AGN survey is answering many of the old questions about AGN and their contribution to the CXB. –What are the numbers of hard x-ray AGN? 1100 AGN, L BAT >10 -11 ergs cm -2 s -1 14-200 keV –Are the hard x-ray AGN and CXB spectra the same? No –Does the standard unified model explain all? No –How many of the AGN are absorbed? ~0.6 not 3/4 –What is the blazar contribution to CXB? 10-15% Follow up of the BAT selected AGN offers many exciting new opportunities. We are just getting started!

13. BACKUP SLIDES

14. BAT Survey Characteristics survey sensitivity is still improving as the square root of time a longer survey detects more sources but it also makes better spectra for the previous sources 4 energy bands will be expanded to 8 bands soon extragalactic BAT sources are easily to identify at high latitudes –very bright IR galaxy –low redshift (z<0.06) –optical AGN or high absorption XRT positions and joint XRT/BAT spectra make ID's unambiguous 8.5 mCrab (T/20 ks) -0.5 XRT UVOT BAT joint spectra BAT XRT Sensitivity vs. Exposure

15. Tests of the Standard Model BAT selected Sy1's have higher luminosity than Sy2's (3.6  ) differences are small, so no selection effect for BAT With ~50 kev BAT measures the true nature of the continuum relatively unaffected by absorption or scattering BAT selected Sy1's have softer spectra than Sy2's (5.7  )

16. Absorption's Effect on Luminosity Function more high luminosity with NH 22 more statistics required the Swift/BAT survey will get there

17. Swift/BAT and Integral luminosity functions the INTEGRAL and Swift/BAT luminosity functions are in rough agreement The Sazanov data seems to be systematically higher