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DarkEnergySurvey / ugali

Ultra-faint galaxy likelihood toolkit
MIT License
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Update Johnson-Cousin transformations #95

Open kadrlica opened 2 years ago

kadrlica commented 2 years ago

Douglas has derived some transformations from DES to Johnson-Cousins. We should update to use these to calculate M_V

https://des.ncsa.illinois.edu/releases/dr2/dr2-docs/dr2-transformations https://cdcvs.fnal.gov/redmine/projects/descalibration/wiki/DESDR2_Tranformation_Interpolations#Johnson-Cousins-gt-DES

V = g{DES} - 0.465 (g-r){DES} - 0.020 [-0.5 < (g-r){DES} ≤ 0.2] (RMS: 0.012 mag)
V = g{DES} - 0.496 (g-r){DES} - 0.015 [ 0.2 < (g-r){DES} ≤ 0.7] (RMS: 0.011 mag)
V = g{DES} - 0.445 (g-r){DES} - 0.062 [ 0.7 < (g-r){DES} ≤ 1.8] (RMS: 0.024 mag)

Relevant code in ugali here https://github.com/DarkEnergySurvey/ugali/blob/82abffcc92bddf830d89f85cb3966870f7d9f720/ugali/isochrone/model.py#L76

and here: https://github.com/DarkEnergySurvey/ugali/blob/82abffcc92bddf830d89f85cb3966870f7d9f720/ugali/isochrone/model.py#L329

Still need some general transformations for SDSS, DES, PS1, LSST.

kadrlica commented 3 months ago

See PR #97 too.