Transcript An Analytic Investigation of the Effect of Systematics on

QuickTime™ and a
decompressor
are needed to see this picture.
Tom Kitching
QuickTime™ and a
decompressor
are needed to see this picture.
Tom Kitching
QuickT ime™ and a
decompressor
are needed to see t his picture.
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
Coordination Team:
THOMAS KITCHING, ADAM AMARA, SARAH BRIDLE,
MANDEEP GILL, CATHERINE HEYMANS,
RICHARD MASSEY, BARNABY ROWE, LISA VOIGT
Advisory Team:
SREE BALAN, GARY BERNSTEIN, MATTHIAS BETHGE,
FREDERIC COURBIN, MARC GENTILE, STEFAN HARMELING,
ALAN HEAVENS, MICHAEL HIRSCH, RESHAD HOSSEINI,
DONNACHA KIRK, KONRAD KUIJKEN, RACHEL
MANDELBAUM, BABACK MOGHADDAM, GULDARIYA
NURBAEVA, STEPHANE PAULIN-HENRIKSSON, ANAIS
RASSAT, JASON RHODES, BERNHARD SCHOLKOPF, TIM
SCHRABBACK, JOHN SHAWE-TAYLOR, MARINA SHMAKOVA,
ANDY TAYLOR, MALIN VELANDER, LUDOVIC VAN
WAERBEKE, DUGAN WITHERICK, DAVID WITTMAN
The Challenge of Measuring Shapes
 

Typical galaxy
used for cosmic
shear analysis
Typical star
Used for finding
Convolution kernel
Slide from S. Bridl
Cosmic Lensing
gi~0.2
Real data:
gi~0.03
5/19
Slide from S. Bridle
Atmosphere and Telescope
Convolution with kernel
Real data: Kernel size ~ Galaxy size
6/19
Slide from S. Bridle
Pixelisation
Sum light in each square
Real data: Pixel size ~ Kernel size /2
7/19
Slide from S. Bridle
Noise
Mostly Poisson. Some Gaussian and bad pixels.
Uncertainty on total light ~ 5 per cent
8/19
Slide from S. Bridle
QuickTime™ and a
decompressor
are needed to see this picture.
Need to measure shear to 10-3
Current Methods
 
 

QuickTime™ and a
decompressor
are needed to see this picture.
 



STEP : Shear Testing Programme
 


 

 




 
QuickTime™ and a
decompressor
are needed to see this picture.
Heymans et al., 2006; Massey et al., 2007 & Kitching et al., 2008
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
KSB
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
 



 




QuickTime™ and a
decompressor
are needed to see this picture.
Quality Factor
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
Kitching et al., 2008 (form filling functions); Amara & Refregier (2007)
QuickTime™ and a
decompressor
are needed to see this picture.
7 non-lensing participants
Q~1000 in some regimes
GREAT08 : Stacking Procedure is Important
Average Data
Individual
Object
Statistic
QuickTime™ and a
decompressor
are needed to see this picture.
Ensemble
Statistic
Average
Estimators
Winning Methods (Q=1000) Stacked the Data
STEP
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
2006
2008
2010
QuickTime™ and a
decompressor
are needed to see this picture.
 
 

 

QuickTime™ and a
decompressor
are needed to see this picture.
Massey et al. 2008
QuickTime™ and a
decompressor
are needed to see this picture.
Fu et al. 2008
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
 





Bonus Star Challenge:
Reconstruct the PSF at

non-star positions

 
Get Ready !
QuickTime™ and a
decompressor
are needed to see this picture.
 

 

 

 
 

 
 
http://www.greatchallenges.info/
QuickTime™ and a
decompressor
are needed to see this picture.
GREAT10 Handbook, Kitching et al., 2010
http://www.greatchallenges.info/
“Every time the amount of data increases by a factor of ten
we should totally rethink the way we analyze it”
Jerome Freidman, Data Mining and Statistics, 1997