Target Selection of F Star Photometric Standards
We select F type stars as photometric standards for the BOSS survey. In the following, we use PSF magnitudes. Magnitudes are extinction corrected linear mags defined as
m = 22.5 – 2.5*alog10( psf_flux ) m = m – extinction
Star Selection
We select stars by demanding objc_type == 6
.
Flag Cuts
F star standards must be
STATIONARY in OBJECT2 objc flags SURVEY_PRIMARY in RESOLVE_STATUS flags PHOTOMETRIC in CALIB_STATUS flags
Standards must not be
in OBJECT1 objc_flags BLENDED, TOO_MANY_PEAKS, CR, SATUR, BADSKY in OBJECT2 objc_flags2 PEAKS_TOO_CLOSE, NOTCHECKED_CENTER, SATUR_CENTER, INTERP_CENTER, PSF_FLUX_INTERP INTERP
and must fall in these magnitude and color ranges:
- 15.0 < r < 19
- [((u–g) – 0.82)2 + ((g–r) – 0.30)2 +
((r–i) – 0.09)2 + ((i–z) – 0.02)2]1/2 < 0.08