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Calculating Weak Magnification PDFs for Survey Fields

Charlotte Mason edited this page Mar 6, 2015 · 2 revisions

Calculating Weak Magnification PDFs for Survey Fields

Gravitational lensing (strong, weak and 'intermediate') can affect the bright end of high-redshift galaxy luminosity functions (Wyithe et al. (2011)). We want to quantify this and correct for it in estimations of the LF. This is presented in Mason et al. (2015) for the BoRG z~8 LF.

We correct for this so-called magnification bias by convolving luminosity pdfs with magnification pdfs for all the observed sources, and correcting for (de-)magnification of solid angle in a Bayesian framework for estimating LFs (developed by Kelly et al. (2012)).


Pangloss Implementation

To estimate the weak lensing P(mu):

  • we included functions to calculate induced magnifications in Pangloss
  • calculated mu for 10^4 lines of sight in simulation catalogs - for completeness as our sources are at z~8
  • calibrated so that =1 and =0 over all lines of sight
  • match simulation lines of sight to survey fields via overdensity to build P(mu)

Future Improvements...

  • Use more up-to-date cosmological simulations!
  • ...