Microlensing%20for%20non-experts

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

• Philip Yock

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January 2009 Cover story
Race to Find Alien Planets
Radial velocity, transits, Kepler - but nothing
on microlensing!
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(No Transcript)
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Radial velocity and transit both conceptually
simple
How to present microlensing simply?
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1. Create strong gravitational field
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2. Qualitative picture

• Einstein arcs slide around the ring when Amax
  gtgt 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

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3. Demonstrate magnification maps
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4. Teaching exercises
Liebes theorem Umin Masses of the lenses
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5. Use magnification maps
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Typical low resolution map
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Typical medium resolution map
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Typical high resolution map
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Resolution adjustable
Typical star size
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Typical track of source star
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Parallax corrections
Andy Gould ApJ 606, 319 2004
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Parallaxed track
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Beware the Moire effect!
Shoot more rays
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Summary

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

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Proof - test subjects

• Ian Bond, Christine Botzler, Sarah Holderness,
  Yvette Perrott, Lydia Phillpott, Nick Rattenbury,
  Sarah Schoen, Eike van Seggern, Petra Tang

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Proof - test subjects

• Ian Bond, Christine Botzler, Sarah Holderness,
  Yvette Perrott, Lydia Phillpott, Nick Rattenbury,
  Sarah Schoen, Eike van Seggern, Petra Tang

I couldnt be happier
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Petra Tang - MB07397
Chi2
theta
t0
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Eike van Seggern MB02033
AA 411, L493, 2003
439, 645 , 2005
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Planet orbiting the binary lens?
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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

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40 GeV to 80 GeV, for 10, in one meter, riding a
plasma wakefield
Chan Joshi et al, Nature 445, 741-744 (2007)
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Invitation January 2010 meeting
Auckland, New Zealand
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Conference centre
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Auckland harbour
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Race
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Piha
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Test plasma wakefield concept