Spatial distribution boundaries of the UV, optical, IR, and spectroscopic redshift data used to build OTELO’s multi-wavelength catalogue (left panel). In black: the OTELO raw field, cyan: GALEX, red: IRAC, green: PACS, yellow: SPIRE, magenta: photo-z (CFHTLS), blue: spec-z (DEEP2). The right panel expands the surveyed area, showing the coadded RTF data of OTELO with its weight map (see Sect. 4.1 for details) overlapped in order to highlight the survey sensitivity footprint. The red polygon defines the survey’s final area (7.5′ × 7.4′). Blue circles indicate the position of the flux calibration stars (Sect. 4.4).