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The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) has been conductedover a five-year period at the CFHT with the MegaCam instrument, totaling 450nights of observations. The Wide Synoptic Survey is one component of theCFHTLS, covering 155 square degrees in four patches of 23 to 65 square degreesthrough the whole MegaCam filter set (u*, g', r', i', z') down to i'$_{AB}$ =24.5. With the motivation of searching for high-redshift quasars at redshiftsabove 6.5, we extend the multi-wavelength CFHTLS-Wide data in the Y-band downto magnitudes of $\sim$ 22.5 for point sources (5$\sigma$). We observed thefour CFHTLS-Wide fields (except one quarter of the W3 field) in the Y-band withthe WIRCam instrument at the CFHT. Each field was visited twice, at least threeweeks apart. Each visit consisted of two dithered exposures. The images arereduced with the Elixir software used for the CFHTLS and modified to accountfor the properties of near-InfraRed (IR) data. Two series of image stacks aresubsequently produced: four-image stacks for each WIRCam pointing, andone-square-degree tiles matched to the format of the CFHTLS data release.Photometric calibration is performed on stars by fitting stellar spectra totheir CFHTLS photometric data and extrapolating their Y-band magnitudes. Wemeasure a limiting magnitude of Y$_{AB} \simeq 22.4$ for point sources(5$\sigma$) in an aperture diameter of 0.93", over 130 square degrees. Weproduce a multi-wavelength catalogue combining the CFHTLS-Wide optical datawith our CFHQSIR (Canada-France High-z quasar survey in the near-InfraRed)Y-band data. We derive the Y-band number counts and compare them to the VIDEOsurvey. We find that the addition of the CFHQSIR Y-band data to the CFHTLSoptical data increases the accuracy of photometric redshifts and reduces theoutlier rate from 13.8% to 8.8% in the redshift range 1.05 $\lesssim$ z$\lesssim$ 1.2.

CFHQSIR: a Y-band extension of the CFHTLS-Wide survey