The Dark Energy Survey Six-Year Calibration Star Catalog

FILES

Overview

Here, we present a catalog of calibrated reference stars that was generated by the Forward Calibration Method (FGCM) pipeline (Burke, Rykoff, et al. 2018) as part of the FGCM photometric calibration of the Dark Energy Survey (DES) Year 6 data set. This catalog provides DES grizY magnitudes for 17 million stars with i-band magnitudes mostly in the range 16 < i < 21 spread over the full DES footprint covering 5000 sq deg over the Southern Galactic Cap at galactic latitudes b < -20deg (plus a few outlying fields disconnected from the main survey footprint). These stars are calibrated to a uniformity of better than 1.8 mmag (0.18%) RMS over the survey area, and their AB magnitudes are tied to the STISNIC.007 spectrum of the Hubble Space Telescope CalSpec standard star C26202 to better than the 0.5 mmag (0.05%) RMS level. As such, these stars provide a useful reference catalog for calibrating grizY-band or grizY-like band photometry in the Southern Hemisphere, particularly for observations within the DES footprint.

Reference: Rykoff, Tucker, Burke, et al. 2023, Fermilab Techincal Note FERMILAB-TM-2784-PPD-SCD (DES docdb#16857; arXiv:2305.01695)

Catalog Description (Y6A1_FGCM_V3_3_1_PSF_ALL_STARS.fits)

Here we describe the columns found in the catalog.

FGCM_ID Running ID number
RA RA of object (J2000.0)
DEC DEC of object (J2000.0)
FLAG FLAG; here, the FLAG is either 0 (used in the FGCM modeling fit) or 16 (randomly excluded from the fit to help with statistical measures). Roughly 10% of stars at high Galactic latitudes were excluded from the fit, and somewhat fewer at low Galactic latitudes. Both FLAG = 0 and FLAG = 16 stars are useful as calibration stars
MAG_STD_G PSF magnitude of object (g-band)
MAG_STD_R PSF magnitude of object (r-band)
MAG_STD_I PSF magnitude of object (i-band)
MAG_STD_Z PSF magnitude of object (z-band)
MAG_STD_Y PSF magnitude of object (Y-band)
MAGERR_STD_G Estimated RMS statistical error in the PSF magnitude of object (g-band)
MAGERR_STD_R Estimated RMS statistical error in the PSF magnitude of object (r-band)
MAGERR_STD_I Estimated RMS statistical error in the PSF magnitude of object (i-band)
MAGERR_STD_Z Estimated RMS statistical error in the PSF magnitude of object (z-band)
MAGERR_STD_Y Estimated RMS statistical error in the PSF magnitude of object (Y-band)
NGOOD_G Number of good independent measurements that went into MAG_STD_G
NGOOD_R Number of good independent measurements that went into MAG_STD_R
NGOOD_I Number of good independent measurements that went into MAG_STD_I
NGOOD_Z Number of good independent measurements that went into MAG_STD_Z
NGOOD_Y Number of good independent measurements that went into MAG_STD_Y