Spitzer IRAC 3.6 μm coverage of the XXL-North field. The gray map corresponds to the GMRT 610 MHz mosaic. The red region denotes the IRAC data. The largest mismatch occurs in the inner part of the radio field, where the number of sources is lower. The sources in the radio catalog are denoted by green circles and black crosses. Sources marked by green symbols correspond to the noisy edges, as described in the text.