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Balrog matches to deep field and photo-z's » History » Version 4

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Huan Lin, 03/21/2019 02:25 PM


Balrog matches to deep field and photo-z's

Notes by Huan Lin, 21 Mar 2019

Matching Balrog detections to deep field coordinates

The Balrog Run 1 detected objects were matched to the Y3 deep field coadd objects in order to obtain the original true RA and Dec of the respective parent deep field objects.

Query used on DESSCI for the Balrog/COSMOS detections:

select y.bal_id, y.true_id, y.true_tilename, y.true_ra, y.true_dec, y.meas_cm_mag_g, y.meas_cm_mag_r,
y.meas_cm_mag_i, y.meas_cm_mag_z, y.true_cm_mag_deredden_g, y.true_cm_mag_deredden_r, 
y.true_cm_mag_deredden_i, y.true_cm_mag_deredden_z, c.tilename, c.ra, c.dec 
from YANNY.BALROG_MATCHED_CATALOG_FLATTEN y, Y3A2_MISC_MOF_V3_COSMOS c 
where y.true_id = c.coadd_object_id and y.true_tilename like '%COSMOS%'; > balrog_cosmos.fits

Query used on DESSCI for the Balrog/SN detections:

select y.bal_id, y.true_id, y.true_tilename, y.true_ra, y.true_dec, y.meas_cm_mag_g, y.meas_cm_mag_r, 
y.meas_cm_mag_i, y.meas_cm_mag_z, y.true_cm_mag_deredden_g, y.true_cm_mag_deredden_r, 
y.true_cm_mag_deredden_i, y.true_cm_mag_deredden_z, c.tilename, c.ra, c.dec 
from YANNY.BALROG_MATCHED_CATALOG_FLATTEN y, Y3A2_MISC_MOF_V1_COADD_TRUTH c 
where y.true_id = c.coadd_object_id and y.true_tilename like '%SN%'; > balrog_sn.fits

The resulting fits files are here:

Matching to COSMOS/Laigle photo-z's

The Balrog/COSMOS data in balrog_cosmos.fits were then matched to the Laigle et al. (2016) high-precision photo-z catalog, using the closest match within a 1-arcsec match radius. Before matching, the Laigle et al. catalog objects were first cut using the following criteria:
  • FLAG_COSMOS = 1 to select the 2 deg^2 COSMOS area
  • FLAG_PETER = 0 to select "good", non-masked areas
  • FLAG_HJMCC = 0 to select overlap with UltraVISTA near-IR data
  • TYPE = 0 to select galaxies
  • ZMIN_CHI2 > 0 to select photo-z > 0
Out of the 466925 Balrog detected objects in balrog_cosmos.fits, 328474 objects have a match in the (cut) Laigle et al. catalog, and the resulting matches are given in these fits file, which are row-by-row the same objects: