1. Christian Knigge University of Southampton School of Physics & Astronoy Disk Stability vs Close Binary Evolution Rob Hynes (LSU) Christian Knigge University of Southampton

2. Christian Knigge University of Southampton School of Physics & Astronoy Outline Introduction –The evolution of CVs and LMXBs Disk Stability vs Close Binary Evolution –The Link Between Binary Evolution and Disk Stability Black Holes Neutron Stars White Dwarfs –Open Questions Summary

3. Christian Knigge University of Southampton School of Physics & Astronoy The Evolution of Compact Accreting Binaries WD/NS/BH Accretion Disk Red Dwarf The Simplest Possible Case WD/NS/BH primary Unevolved, low-mass ZAMS secondary Roche-lobe overflow Accretion usually via a disk 75 mins < P orb < 24 hrs Mass transfer and evolution entirely driven by angular momentum losses Evolution is (initially) from long to short periods Credit: Rob Hynes

4. Christian Knigge University of Southampton School of Physics & Astronoy The CV Orbital Period Distribution and The Standard Model of CV Evolution Knigge (2006) Howell et al. (2001) Magnetic Braking GR

5. Christian Knigge Knigge, Barraffe & Patterson 20011 Littlefair et al. 2006, Science, 314, 1578 Testing Evolution Theory University of Southampton School of Physics & Astronoy Gaensicke et al. (2009), Warner & Woudt (2012) Patterson et al. (2005 ), Knigge (2006)

6. Christian Knigge The Link Between Binary Evolution and Disk (In)Stability University of Southampton School of Physics & Astronoy Kolb & Baraffe (1999) J. Smak Y. Osaki J. Faulkner J. Cannizzo F. Meyer E. Meyer-Hofmeister J.-P. Lasota J.-M. Hameury …

7. Christian Knigge The Link Between Binary Evolution and Disk (In)Stability University of Southampton School of Physics & Astronoy

8. Christian Knigge Disk Stability vs Binary Evolution: Neutron Stars University of Southampton School of Physics & Astronoy King, Kolb & Burderi (1992) Data from Coriat et al. (2012)

9. Christian Knigge Disk Stability vs Binary Evolution: Neutron Stars University of Southampton School of Physics & Astronoy King, Kolb & Burderi (1992) Start of MS Middle of MS End of MS Podsiadlowski et al. (2002)

10. Christian Knigge Disk Stability vs Binary Evolution: Neutron Stars University of Southampton School of Physics & Astronoy Coriat et al. (2012) Persistent Transient

11. Christian Knigge Disk Stability vs Binary Evolution: Black Holes University of Southampton School of Physics & Astronoy King, Kolb & Burderi (1996) NS BH

12. Christian Knigge Disk Stability vs Binary Evolution: Black Holes University of Southampton School of Physics & Astronoy Naïve Predictions –Without irradiation: All BH LMXBs should be unstable (transient) –With irradiation: All BH LMXBs should be stable (persistent) Observation –Almost all BH LMXBs are unstable (transient) –But irradiation should matter!  So what’s wrong? King, Kolb & Burderi (1996) Data from Coriat et al. (2012)

13. Christian Knigge Disk Stability vs Binary Evolution: Black Holes University of Southampton School of Physics & Astronoy Coriat et al. (2012) Persistent Transient High-Mass XRBs (ignore)

14. Christian Knigge Disk Stability vs Binary Evolution: Black Holes University of Southampton School of Physics & Astronoy

15. Christian Knigge University of Southampton School of Physics & Astronoy Unstable Stable Disk Stability vs Binary Evolution: White Dwarfs Unstable X ? Knigge, Baraffe & Patterson (2011) DN Fraction X

16. Christian Knigge University of Southampton School of Physics & Astronoy Schreiber & Lasota (2007) Disk Stability vs Binary Evolution: White Dwarfs

17. Christian Knigge University of Southampton School of Physics & Astronoy Warner (1987) Patterson (1984)

18. Christian Knigge University of Southampton School of Physics & Astronoy McCormick & Frank (1998) King et al. (1995) Schenker et al. (1998)

19. Christian Knigge University of Southampton School of Physics & Astronoy Start of MS Middle of MS End of MS Podsiadlowski et al. (2002) Podsiadlowski et al. (2003)

20. Christian Knigge University of Southampton School of Physics & Astronoy Shafter, Wheeler & Cannizzo (1986) Shafter (1992) Theory Data

21. Christian Knigge University of Southampton School of Physics & Astronoy Disk Stability vs Binary Evolution: White Dwarfs The dominance of stable systems directly above the gap

22. Christian Knigge University of Southampton School of Physics & Astronoy Disk Stability vs Binary Evolution: White Dwarfs The dominance of stable systems directly above the gap Zangrilli et al. (1997)

23. Christian Knigge University of Southampton School of Physics & Astronoy Disk Stability vs Binary Evolution: White Dwarfs One last puzzle… What about systems inside the period gap? In the standard model, they must have been borne there with an already fully convective donor So they should evolve like short- period CVs, with AML driven just by GR So they should all be unstable! Howell et al. (2001)

24. Christian Knigge University of Southampton School of Physics & Astronoy Disk Stability vs Binary Evolution: White Dwarfs One last puzzle… Knigge, Baraffe & Patterson (2011)

25. Christian Knigge Summary University of Southampton School of Physics & Astronoy