News from z 6 − 10 galaxy candidates found behind gravitational lensing clusters

Following up on the detailed results from our searches for z~ 6-10 galaxies using gravitional lensing clusters descrived in Richard et al. (2006), we have obtained new observations, which are presented here. For a general overview of the project see Schaerer et al. (2006). First, deep HST/ACS observations in the z-band confirm 17 out of 18 high redshift candidates as optical drop-out objects; the remaining object appears faint and star-like. Second, Spitzer/IRAC images at 3.6, 4.5, 5.8 and 8.0 μm have been obtained. 11 out of 18 candidates are in "free", uncominated regions. These 11 high-z candidates are undetected, with upper limits which are compatible with their SED if these objects are blue star-forming galaxies at high redshift (see Fig. 1). In conclusion, our new observations corroborate so far the high-z nature of the majority of the candidates.