The Galex Release EMphot 3 (GREM3) gives access to the GALEX GR6 data from the Deep Imaging Survey (Texp > 30ksec /field) reprocessed with the EMphot photometry software. The EMphot algorithm use optical priors with UAB < 25~26 based on the T0007 release of the CFHTLS.
Photometry of astrophysical sources in crowded field images
EMphot (formerly PPrior) is a software for the photometry of astrophysical sources, galaxies and stars, in crowded field images. Its goal is to estimate the flux in a low resolution band using prior information (position and shape) from a better resolved band, in a Bayesian approach under the Poisson noise assumption. The solution is reached with an Expectation-Maximization (EM) algorithm for solving the photometry and includes several steps: prior shapes deblending in high resolution images, astrometry correction, PSF optimization, background correction from the residual.
Main changes since version 2.0
- Update input data to GALEX GR6 and CFHTLS T0007.
- Combine multiple prior catalogs for one GALEX field (useful for CFHTLS W1).
- Improve simulations : stamps, follow the density of the field, add sources in the processed area.
- Improve comparison plots.
- Change the psf.
- Recentering done with likelihood minimization.
- Lot of bugfixes and code improvements.
Browse the data online
- 2013/04/10: GREM 3 released !
- Coming next : CFHTLS/VIPERS, COSMOS.