Transcript PARIS - Institut d'astrophysique de Paris

Microlensing for non-experts
13th Microlensing Workshop
Institut d'Astrophysique de Paris,
January 19, 20, 21, 2009
Philip Yock
January 2009
Cover story
“Race to Find Alien Planets”
Radial velocity, transits, Kepler
- but nothing on microlensing!
Radial velocity and transit both
conceptually simple
How to present microlensing simply?
1. Create strong gravitational field
2. Qualitative picture
 Einstein arcs slide around the ring when Amax >> 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 Amax
 Perturbations occur in the FWHM  24 hours
3. Demonstrate magnification maps
4. Teaching exercises
Liebes theorem
Umin
Masses of the lenses
5. Use magnification maps
Typical low resolution map
Typical medium resolution map
Typical high resolution map
Resolution adjustable
Typical star size
Typical track of source star
Parallax corrections
Andy Gould ApJ 606, 319 2004
Parallaxed track
Beware the Moire effect!
Shoot more rays
Summary
Microlensing beautiful, but quite
complicated
Demonstrations possible
Teaching exercises possible
Magnification maps conceptually clear,
versatile, if not fastest
Proof - test subjects
Ian Bond, Christine Botzler, Sarah
Holderness, Yvette Perrott, Lydia Phillpott,
Nick Rattenbury, Sarah Schoen, Eike van
Seggern, Petra Tang
Proof - test subjects
Ian Bond, Christine Botzler, Sarah
Holderness, Yvette Perrott, Lydia Phillpott,
Nick Rattenbury, Sarah Schoen, Eike van
Seggern, Petra Tang
I couldn’t be happier
Petra Tang - MB07397
Chi2
theta
t0
Eike van Seggern – MB02033
A&A 411, L493, 2003
439, 645 , 2005
Planet orbiting the binary lens?
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
Could measure the charge of the quark
Could test multi-muons from Fermilab
40 GeV to 80 GeV, for $10, in one
meter, riding a plasma wakefield
Chan Joshi et al, Nature 445, 741-744 (2007)
Invitation – January 2010 meeting
Auckland, New Zealand
Conference centre
Auckland harbour
Race
Piha
Test plasma wakefield concept