All Figures

$\begin{figure} \par\includegraphics[scale=0.4]{8843fig1.ps} \end{figure}$ Figure 1: z'-J and i'-z' colours of brown dwarfs and quasars. These synthetic colours were computed for the MegaCam i' and z' photometric system and the NTT SOFI $J_{\rm short}$ system. The bold lines represents the average colours of dwarfs (dashed) and quasars (solid). Symbols marks the individual colours of known brown dwarfs. The thin grey lines mark the colour evolution of individual synthetic quasars (described in detail in Willott et al. (2005)) as their redshift ranges from 5.5 to 6.7. The quasar redshift increases for redder colours. The vertical line at i'-z'=1.7 marks our i'-z' selection criterion. The quasar selection box is also marked (to the lower-right of the solid line).
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In the text

$\begin{figure} \par\includegraphics[scale=0.36,angle=0]{8843fig2.ps} \end{figure}$ Figure 2: Compared spectral response functions of the CFHT (thick lines) and SDSS (thin dashed lines) instruments for their i' (dark blue) and z' (red) filters. These factor in the average atmospheric transmission of the two observatory sites, the telescope reflectivities, the transmissions of the camera optics and filters, and the quantum efficiencies of the CCDs. Contrary to the SDSS bandpasses, the CFHT i' and z' filters overlap significantly, leading to less contrasted colours.
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In the text

$\begin{figure} \par\includegraphics[scale=0.31,angle=90]{8843fig3.ps} \end{figure}$ Figure 3: i'-z' synthetic colour versus spectral type for the MegaCam photometric system. The colour for a spectral type is the average over the brown dwarf spectra from Chiu et al. (2006), Golimowski et al. (2004) and Knapp et al. (2004) with that spectral type, and the error bars represent the dispersion (set to 0 when only one template per spectral bin is available).
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,angle=90,clip]{8843fig4.ps} \end{figure}$ Figure 4: Sky chart of sky area covered by CFBDS so far. Black curve marks the galactic plane while dotted curves mark $+30\hbox {$^\circ $ }$ and $-30\hbox {$^\circ $ }$ galactic latitude.
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In the text

$\begin{figure} \par\includegraphics[scale=0.36,angle=0]{8843fig5.ps} \end{figure}$ Figure 5: Histogram of the $\chi ^2$ of the psf fitting residuals. The thick red histogram shows all i'-z'>1.7 candidates after basic filtering, the medium-thick blue histogram those that additionally survived $\chi ^2$ filtering, and the thin green one the final candidates retained after visual inspection and supernovae rejection. These histograms show candidates from a 70 deg² test area.
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In the text

$\begin{figure} \par\includegraphics[scale=0.36,angle=0]{8843fig6.ps} \end{figure}$ Figure 6: Histograms of the number of i'-z' candidates as a function of i'-z' colour (light green), and of the number of these candidates for which J-band photometry is currently available (dark red).
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In the text

$\begin{figure} \par\includegraphics[scale=0.32,angle=90]{8843fig7.ps} \end{figure}$ Figure 7: i'-z' vs. z'-J colour-colour diagram of our cool dwarf candidates (black). The error bars are 1 $\sigma$ when we have i' and z' measurements. An arrow is used when i'-z' is only a lower limit. For clarity, the z'-J errors are not shown; they are usually under 0.15 mag. The spectra of the highlighted T3, T3.5 and T5 objects are presented in this article. The big blue squares represent the coolest brown dwarfs known, ULAS J003402.77-005206.7/CFBDS J003402-005206, recently published by Warren et al. (2007) and independently identified in our survey and CFBDS J005910.83-011401.3, presented in Delorme et al. (2008). The T7 object highlighted here was published by Chiu et al. (2006) while queued for our CFBDS spectroscopy. The spectral type domains are based on our synthetic photometry.
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In the text

$\begin{figure} \par\includegraphics[width=12cm,angle=270]{8843fig8.ps} \end{figure}$ Figure 8: GNIRS near-IR spectra of the three T Dwarfs observed on Gemini-South. The two fainter targets originate from the CFHTLS-Deep, while the brighter ones comes from the CFHTLS-VW. Templates of spectral types T2 and T4.5 from McLean et al. (2003) are shown for comparison. All spectra are normalised at 1.26 microns and displayed with integer offsets for clarity.
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In the text

$\begin{figure} \par\begin{tabular}{c} \includegraphics[scale=0.3]{8843fig9_1.ps... ...9_3.ps}\\ \includegraphics[scale=0.3]{8843fig9_2.ps}\end{tabular} \end{figure}$ Figure A.1: Finding charts from z' band images of the 3 T dwarfs whose spectra are presented in this article. The fields are $45\hbox {$^{\prime \prime }$ }\times 45\hbox {$^{\prime \prime }$ }$ north is up, east is left.
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In the text

$\begin{figure} \par\includegraphics[scale=0.31,angle=90]{8843fig3.ps} \end{figure}$	Figure 3: i'-z' synthetic colour versus spectral type for the MegaCam photometric system. The colour for a spectral type is the average over the brown dwarf spectra from Chiu et al. (2006), Golimowski et al. (2004) and Knapp et al. (2004) with that spectral type, and the error bars represent the dispersion (set to 0 when only one template per spectral bin is available).
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$\begin{figure} \par\includegraphics[width=8.5cm,angle=90,clip]{8843fig4.ps} \end{figure}$	Figure 4: Sky chart of sky area covered by CFBDS so far. Black curve marks the galactic plane while dotted curves mark $+30\hbox {$^\circ $ }$ and $-30\hbox {$^\circ $ }$ galactic latitude.
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$\begin{figure} \par\includegraphics[scale=0.36,angle=0]{8843fig5.ps} \end{figure}$	Figure 5: Histogram of the $\chi ^2$ of the psf fitting residuals. The thick red histogram shows all i'-z'>1.7 candidates after basic filtering, the medium-thick blue histogram those that additionally survived $\chi ^2$ filtering, and the thin green one the final candidates retained after visual inspection and supernovae rejection. These histograms show candidates from a 70 deg² test area.
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$\begin{figure} \par\includegraphics[scale=0.36,angle=0]{8843fig6.ps} \end{figure}$	Figure 6: Histograms of the number of i'-z' candidates as a function of i'-z' colour (light green), and of the number of these candidates for which J-band photometry is currently available (dark red).
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$\begin{figure} \par\includegraphics[width=12cm,angle=270]{8843fig8.ps} \end{figure}$	Figure 8: GNIRS near-IR spectra of the three T Dwarfs observed on Gemini-South. The two fainter targets originate from the CFHTLS-Deep, while the brighter ones comes from the CFHTLS-VW. Templates of spectral types T2 and T4.5 from McLean et al. (2003) are shown for comparison. All spectra are normalised at 1.26 microns and displayed with integer offsets for clarity.
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$\begin{figure} \par\begin{tabular}{c} \includegraphics[scale=0.3]{8843fig9_1.ps... ...9_3.ps}\\ \includegraphics[scale=0.3]{8843fig9_2.ps}\end{tabular} \end{figure}$	Figure A.1: Finding charts from z' band images of the 3 T dwarfs whose spectra are presented in this article. The fields are $45\hbox {$^{\prime \prime }$ }\times 45\hbox {$^{\prime \prime }$ }$ north is up, east is left.
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