Caltech Faint Galaxy Redshift Survey. IX. Source Detection and Photometry in the Hubble Deep Field Region

Detection and photometry of sources in the Un, G, ℛ, and Ks bands in a 9 × 9 arcmin2 region of the sky, centered on the Hubble Deep Field, are described. The data permit construction of complete photometric catalogs to roughly Un = 25, G = 26, ℛ = 25.5, Ks = 20 mag and significant photometric measurements somewhat fainter. The galaxy number density is 1.3 × 105 deg-2 to ℛ = 25.0 mag. Galaxy number counts have slopes d log N/dm = 0.42, 0.33, 0.27, and 0.31 in the Un, G, ℛ, and Ks bands, consistent with previous studies and the trend that fainter galaxies are, on average, bluer. Galaxy catalogs selected in the ℛ and Ks bands are presented, containing 3607 and 488 sources in field areas of 74.8 and 59.4 arcmin2, to ℛ = 25.5 and Ks = 20 mag.