COSMOS SED Diagnostics

Purpose

COSMOS-template SEDs are pseudo-ground truth diagnostics. They are useful for visual checks against the DSPS SED inferred from Euclid + LSST photometry, but they are not wavelength-by-wavelength physical SPS truth.

Current Workflow

MAP fits write SED diagnostics directly:

euclid-dsps fit \
  --config configs/fs2_phz1_science.yaml \
  --limit 100 \
  --batch-size 50 \
  --sed-samples 8 \
  --out outputs/runs/science_fit

For batch runs, the saved SED diagnostics are selected from the worst fits rather than the first rows. Inspect sed_diagnostics_manifest.csv for the row index, rank, and score.

Standalone checks remain available through check:

euclid-dsps check \
  --config configs/fs2_phz1_science.yaml \
  --kind cosmos \
  --limit 20 \
  --out outputs/check/cosmos

Interpretation

The science preset uses dust_model: cosmos_proxy_fixed. COSMOS dust columns are injected into DSPS so SED shape comparison is not mixed with a free dust fit. Rest-frame *_abs columns from LSST and Euclid anchor the proxy SED when present. Emission-line target sets stay out of the likelihood until a compatible line model or SSP line assets exist.