Probing the nature of EROs through ASTRO-F/AKARI observations

摘要

We present a preliminary analysis of ASTRO-F data of a complete sample of ~ 150 EROs (R - K > 5) down to Kyega, < 19, for which reliable photometric redshifts are available, in the range 0 8 < z < 2, selected over two fields (S7 and S2) of the MUNICS survey The area covered is about 420arcmin2 We have imaged this area with AKARI telescope in N3 (3.4/mi), N60 (65/an) and WL (150/xm) down to 12/tJy in the N3 filter, in order to detect the rest frame H- or if-band emission, thus providing an excellent sampling of the SED of our EROs From a first analysis we have an identification rate of ~ 63% in the N3 filter over the S7 field. These data allow us to distinguish starburst from passive early-type phenomena, to measure the SFR of the starburst component and to constrain the mass assembly of early-type galaxies.