Using the X-match tool on ls_dr8 tractor tables (n and s) I cannot find a column for uncertainty on the magnitude or flux?

Question

I see columns like "flux_ivar_w1" for the ALLWISE data but not for the 'grz' bands. Is this intentional? Where can one find uncertainties on the flux or mag. (Ps. Could you add clarification to which magnitude systems and units are being used (AB for LS, Vega for Wise? nannomaggies for flux?). Thank you!

Comments

ls_dr8_n.tractor now has columns for the uncertainty in flux ('flux_ivar_<[g,r,z,w1,w2,w3,w4]>') but no error on the magnitudes (something like 'mag_ivar_...'). The south catalog, ls_dr8_s.tractor is still missing any columns with uncertainty in the magnitude of flux. Could you make sure there are columns with mag, flux, mag_err, flux_err, dered_mag, dered_flux for both the north and the south tractor tables of dr8?

Answer 1

Hi, thanks for reaching out and for your patience. Yes, ls_dr8.tractor_n now has flux_ivar_BAND columns. There are also 'snr' columns in the table, from which you can compute the errors on the magnitudes.

tractor_s is still being (re-loaded), it will take a few more days before it is available (with all columns).

Cheers,

Robert