1. The Transient Universe: AY 250 Spring 2007 Existing Transient Surveys: High Energy II: X-ray Binaries Geoff Bower

2. The Transient Universe: AY 250 Spring 2007 Discovery of X-ray Stars Giacconi et al 1962

3. The Transient Universe: AY 250 Spring 2007 Aerobee Rocket Designed by James van Allen Aerojet booster Bumblebee second stage Maximum altitude of 225 km Above 80 km for 350 seconds Traveled for 120 km

4. The Transient Universe: AY 250 Spring 2007 New Detectors Geiger counters Greater collecting area Anti-coincidence shields 50-100 times more sensitive than solar X- ray experiments

5. The Transient Universe: AY 250 Spring 2007

6. Two Discoveries Sco X-1 No optical counterpart known –Eventually 13 th mag –  Lx ~ 10^3 Lopt Radio counterparts expected X-ray background detected Earth origin?

7. The Transient Universe: AY 250 Spring 2007 Two Sources Discovered Giacconi et al 1964

8. The Transient Universe: AY 250 Spring 2007 More Sources Found Rossi 1967 SNR Nearby AGN Galactic sources

9. The Transient Universe: AY 250 Spring 2007 Characterizing Sco X-1 Some variability –X-ray –Optical 1000 x energy in X-rays than any other band Thermal spectrum 50 x 10^6 K Atomic lines in optical No clear understanding in early days

10. The Transient Universe: AY 250 Spring 2007 Pulsations & Occultations Schreier et al 1972 ~ 4 Seconds  R < 10^9 cm

11. The Transient Universe: AY 250 Spring 2007 Binary Model Mx ~ 1 Msun M* ~ 17 – 46 Msun

12. The Transient Universe: AY 250 Spring 2007 Neutron Star & Black Hole Binaries Periodic Fluctuations Bursts of X-ray emission following accretion Masses exceeding 3 Msun

13. The Transient Universe: AY 250 Spring 2007 LMXB & HMXB Low mass companion (< 10 Msun) Star overfills its Roche lobe Lifetime – 10^7 – 10^9 y High mass companion Stellar wind drives mass accretion Lifetimes < 10^7 y Only hundreds in the entire galaxy Dozens known

14. The Transient Universe: AY 250 Spring 2007 Galactic Distribution O LMXB * HMXB Grimm et al 2002

15. The Transient Universe: AY 250 Spring 2007 Galactic Distribution

16. The Transient Universe: AY 250 Spring 2007 Luminosity Distributions

17. The Transient Universe: AY 250 Spring 2007 Super-Eddington Accretors

18. The Transient Universe: AY 250 Spring 2007 Galactic Energy Budget

19. The Transient Universe: AY 250 Spring 2007 GRS 1915+105 Discovered in gamma-rays but strong X-ray source LMXB –15 M_sun BH –K giant companion Fender & Belloni 2004

20. The Transient Universe: AY 250 Spring 2007 Variability on Wide Range of Time Scales RXTE ASM

21. The Transient Universe: AY 250 Spring 2007 Coupling Between Hardness, Temperature, and Radius

22. The Transient Universe: AY 250 Spring 2007 Well Defined X-ray States Markward et al 1999 Hard Soft Cool, distant diskHot, close disk

23. The Transient Universe: AY 250 Spring 2007 Photon Index Temperature

24. The Transient Universe: AY 250 Spring 2007 Superluminal Motion

25. The Transient Universe: AY 250 Spring 2007 Coupled Radio/X-ray Activity

26. The Transient Universe: AY 250 Spring 2007

27. Comparison to AGN Tau ~ M^-1/2 Jet Quenching at 1 - 10% L_EDD Triangles: XRB Squares: AGN

28. The Transient Universe: AY 250 Spring 2007 Chandra Observations of the Galactic Center Muno et al 2002  1 Msec  2300 sources  < 10 multi- wavelength counterparts

29. The Transient Universe: AY 250 Spring 2007 Foreground Separation

30. The Transient Universe: AY 250 Spring 2007 Galactic X-ray Sources

31. The Transient Universe: AY 250 Spring 2007 GC Transients

32. The Transient Universe: AY 250 Spring 2007 Overabundance of Transients in Central Parsec RadiusTransientsStellar MassTransient Rate 1 pc42 X 10^6 M_sun 20 20 pc33 x 10^71

33. The Transient Universe: AY 250 Spring 2007 Two Explanations for Transient Overdensity LMXBs Dynamical friction drives compact objects to GC Three-body interactions produces LMXB HMXB Ghez et al 2006

34. The Transient Universe: AY 250 Spring 2007 One LMXB Known X-ray eclipses Porquet et al 2005 Double-lobe radio source Bower et al 2005