Euclid Perseus ETG photometry

We combined the exceptional image quality and depth of the ERO Perseus with FUV and NUV observations from GALEX and AstroSat/UVIT, as well as with ugrizHa data from MegaCam at the CFHT, to deliver FUV-to-NIR magnitudes of the 87 brightest galaxies within the Perseus cluster. We reconstructed the star-formation history (SFH) of 59 early-type galaxies (ETGs) within the sample, through the spectral energy distribution (SED) fitting code CIGALE and state-of-the-art stellar population (SP) models to reproduce the galactic UV emission from hot, old, low-mass stars (i.e. the UV upturn).

In addition, for the six most massive ETGs in Perseus [stellar masses log(Mstellar/M_{sun}_)>=10.3], we analysed their spatially resolved SP and SFH through a radial SED fitting. In agreement with our previous work on Virgo ETGs, we found that (i) the majority of the analysed galaxies needs the presence of an UV upturn component to explain their FUV emission, with average temperatures <T_UV_>~33800K; (ii) the ETGs of Perseus have grown their stellar masses quickly, with star- formation timescales tau<~1500Myr.