1. Microlensing for non-experts Philip Yock 13th Microlensing Workshop Institut d'Astrophysique de Paris, January 19, 20, 21, 2009

2. January 2009 Cover story “Race to Find Alien Planets” Radial velocity, transits, Kepler - but nothing on microlensing!

4. Radial velocity and transit both conceptually simple How to present microlensing simply?

5. 1. Create strong gravitational field

6. 2. Qualitative picture  Einstein arcs slide around the ring when A max >> 1  If a low-mass planet is close to the ring, it perturbs the arc as it passes by  Width of perturbation equals ‘slide-by’ time  Height of perturbation  planet mass  Height of perturbation (roughly) independent of A max  Perturbations occur in the FWHM  24 hours

7. 3. Demonstrate magnification maps

8. 4. Teaching exercises Liebes theorem U min Masses of the lenses

9. 5. Use magnification maps

10. Typical low resolution map

11. Typical medium resolution map

12. Typical high resolution map

13. Resolution adjustable Typical star size

14. Typical track of source star

15. Parallax corrections Andy Gould ApJ 606, 319 2004

16. Parallaxed track

17. Beware the Moire effect! Shoot more rays

18. Summary Microlensing beautiful, but quite complicated Demonstrations possible Teaching exercises possible Magnification maps conceptually clear, versatile, if not fastest

19. Proof - test subjects Ian Bond, Christine Botzler, Sarah Holderness, Yvette Perrott, Lydia Phillpott, Nick Rattenbury, Sarah Schoen, Eike van Seggern, Petra Tang Ian Bond, Christine Botzler, Sarah Holderness, Yvette Perrott, Lydia Phillpott, Nick Rattenbury, Sarah Schoen, Eike van Seggern, Petra Tang

20. Proof - test subjects Ian Bond, Christine Botzler, Sarah Holderness, Yvette Perrott, Lydia Phillpott, Nick Rattenbury, Sarah Schoen, Eike van Seggern, Petra Tang Ian Bond, Christine Botzler, Sarah Holderness, Yvette Perrott, Lydia Phillpott, Nick Rattenbury, Sarah Schoen, Eike van Seggern, Petra Tang I couldn’t be happier

21. Petra Tang - MB07397 Chi 2 theta t 0

22. Eike van Seggern – MB02033 A&A 411, L493, 2003 439, 645, 2005

23. Planet orbiting the binary lens?

24. Sarah Schoen Plasma wakefield acceleration New Scientist, Jan 2009 – “Desktop atom smashers could replace LHC” Analaogous to microlensing – uses naturally occurring fields – electromagnetic, not gravitational Analaogous to microlensing – uses naturally occurring fields – electromagnetic, not gravitational Could measure the charge of the quark Could measure the charge of the quark Could test multi-muons from Fermilab Could test multi-muons from Fermilab

25. 40 GeV to 80 GeV, for $10, in one meter, riding a plasma wakefield Chan Joshi et al, Nature 445, 741-744 (2007)

26. Invitation – January 2010 meeting Auckland, New Zealand

27. Conference centre

28. Auckland harbour

29. Race

30. Piha

31. Test plasma wakefield concept