@Article{LaBarberaVFPPMACRFV:2019:IMRaGr,
               author = "La Barbera, Francesco and Vazdekis, A. and Ferreras, I. and 
                         Paquali, A. and Prieto, C. Allende and Mart{\'{\i}}n-Navarro, I. 
                         and Aguado, D. S. and Carvalho, Reinaldo Ramos de and Rembold, S. 
                         and Falc{\'o}n-Barroso, J. and van de Ven, G.",
          affiliation = "{INAF – Osservatorio Astronomico di Capodimonte} and {Instituto de 
                         Astrof{\'{\i}}sica de Canarias} and {University College London} 
                         and {Universit{\"a}t Heidelberg} and {Instituto de 
                         Astrof{\'{\i}}sica de Canarias} and {University of California 
                         Observatories} and {University of Cambridge} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Federal 
                         de Santa Maria (UFSM)} and {Instituto de Astrof{\'{\i}}sica de 
                         Canarias} and {University of Vienna}",
                title = "IMF radial gradients in most massive early-type galaxies",
              journal = "Monthly Notices of the Royal Astronomical Society",
                 year = "2019",
               volume = "489",
               number = "3",
                pages = "4090--4110",
                month = "Nov.",
             keywords = "galaxies: elliptical and lenticular, cD, galaxies: formation, 
                         galaxies: fundamental parameters, galaxies: stellar content.",
             abstract = "Using new long-slit spectroscopy obtained with X-Shooter at 
                         ESO-VLT, we study, for the first time, radial gradients of optical 
                         and near-infrared initial mass function (IMF)-sensitive features 
                         in a representative sample of galaxies at the very high mass end 
                         of the galaxy population. The sample consists of seven early-type 
                         galaxies (ETGs) at z similar to 0.05, with central velocity 
                         dispersion in the range 300 less than or similar to sigma less 
                         than or similar to 350 km s(-1). Using state-of-the-art stellar 
                         population synthesis models, we fit a number of spectral indices, 
                         from different chemical species (including TiO and Na indices), to 
                         constrain the IMF slope (i.e. the fraction of low-mass stars), as 
                         a function of galactocentric distance, over a radial range out to 
                         similar to 4 kpc. ETGs in our sample show a significant 
                         correlation of IMF slope and surface mass density. The 
                         bottom-heavy population (i.e. an excess of low-mass stars in the 
                         IMF) is confined to central galaxy regions with surface mass 
                         density above similar to 10(10)M(circle dot) kpc (2), or, 
                         alternatively, within a characteristic radius of similar to 2 kpc. 
                         Radial distance, in physical units, and surface mass density are 
                         the best correlators to IMF variations, with respect to other 
                         dynamical (e.g. velocity dispersion) and stellar population (e.g. 
                         metallicity) properties. Our results for the most massive galaxies 
                         suggest that there is no single parameter that fully explains 
                         variations in the stellar IMF, but IMF radial profiles at z 
                         similar to 0 rather result from the complex formation and mass 
                         accretion history of galaxy inner and outer regions.",
                  doi = "10.1093/mnras/stz2192",
                  url = "http://dx.doi.org/10.1093/mnras/stz2192",
                 issn = "0035-8711 and 1365-2966",
             language = "en",
           targetfile = "barbera_ifm.pdf",
        urlaccessdate = "27 abr. 2024"
}