@Article{LaBarberaFeCaBrChPaMe:2012:ReStPo,
               author = "La Barbera, F. and Ferreras, I. and Carvalho, R. R. and Bruzual, 
                         G. and Charlot, S. and Pasquali, A. and Merlin, E.",
          affiliation = "INAF Osservatorio Astron Capodimonte, Naples, Italy. and Univ Coll 
                         London, MSSL, Dorking RH5 6NT, Surrey, England and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and Univ Nacl Autonoma 
                         Mexico, Ctr Radioastron \& Astrofis, Mexico City, DF, Mexico and 
                         UPMC, Inst Astrophys Paris, UMR7095, F-75014 Paris, France and 
                         Univ Heidelberg, Zentrum Astron, Astron Rechen Inst, D-69120 
                         Heidelberg, Germany and INAF Osservatorio Astron Padova, Padua, 
                         Italy",
                title = "SPIDER - VII. Revealing the stellar population content of massive 
                         early-type galaxies out to 8Re",
              journal = "Monthly Notices of the Royal Astronomical Society",
                 year = "2012",
               volume = "426 10.1111/j.1365-2966.2012.21848.x",
               number = "3",
                pages = "2300 - 2317",
                month = "Nov.",
             keywords = "elliptical and lenticular galaxies, cD, galaxy evolution, galaxy 
                         formation, stellar content.",
             abstract = "Radial trends of stellar populations in galaxies provide a 
                         valuable tool to understand the mechanisms of galaxy growth. In 
                         this paper, we present the first comprehensive analysis of 
                         opticaloptical and opticalNIR colours, as a function of galaxy 
                         mass, out to the halo region (8Re) of early-type galaxies (ETGs). 
                         We select a sample of 674 massive ETGs (M\⋆> 3 × 
                         1010M\⊙) from the SDSS-based SPIDER survey. By com-paring 
                         with a large range of population synthesis models, we derive 
                         robust constraints on the radial trends in age and metallicity. 
                         Metallicity is unambiguously found to decrease outwards, with a 
                         measurable steepening of the slope in the outer regions (Re < R < 
                         8Re). The gradients in stellar age are found to be more sensitive 
                         to the models used, but in general, the outer regions of ETGs 
                         feature older populations compared to the cores. This trend is 
                         strongest for the most massive galaxies in our sample (M\⋆> 
                         1011M\⊙). Furthermore, when segregating with respect to 
                         large scale environment, the age gradient is more significant in 
                         ETGs residing in higher density regions. These results shed light 
                         on the processes leading from the formation of the central core to 
                         the growth of the stellar envelope of massive galaxies. The fact 
                         that the populations in the outer regions are older and more 
                         metal-poor than in the core suggests a process whereby the 
                         envelope of massive galaxies is made up of accreted small 
                         satellites (i.e. minor mergers) whose stars were born during the 
                         first stages of galaxy formation.",
                  doi = "10.1111/j.1365-2966.2012.21848.x",
                  url = "http://dx.doi.org/10.1111/j.1365-2966.2012.21848.x",
                 issn = "1365-2966",
             language = "en",
        urlaccessdate = "02 maio 2024"
}