SIMBAD references

We have used William Herschel Telescope/INGRID K_simages on two high-latitude fields, the Coppi and Groth strips, to obtain galaxy number counts over ∼180 arcmin², to a depth of K_s∼21.0. Detection efficiency corrections as a function of object size have been calculated on each pointing. We have used a signal-to-noise threshold in two complementary half-exposure images to remove spurious detections. Our data cover the range from K_s=14.5 to K_s=21.0, so they are useful for investigating a previously reported change in the number count slope (dlogN/dm) at K∼17. We find a slope γ_b=0.54-0.63 for K<17.5 and a slope γ_f=0.25-0.29 for K>17.5. A total contribution from galaxies to the extragalactic background light (EBL) in the K band of νI_ν=10.5 nW.m^–2/sr has been calculated. This K-band EBL coming from galaxies accounts for only ∼50% of the recent measurements of the diffuse EBL. Standard number count models fail to reproduce the observed slope change at K∼17.5 unless elliptical and spiral formation is pushed to z≲2.