Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies

The age and metallicity gradients for a sample of group and cluster galaxies from N-body+hydrodynamical simulation are analysed in terms of galaxy stellar mass. Dwarf galaxies show null age gradient with a tail of high and positive values for systems in groups and cluster outskirts. Massive systems have generally zero-age gradients which turn to positive for the most massive ones. Metallicity gradients are distributed around zero in dwarf galaxies and become more negative with mass; massive galaxies have steeper negative metallicity gradients, but the trend flattens with mass. In particular, fossil groups are characterized by a tighter distribution of both age and metallicity gradients. We find a good agreement with both local observations and independent simulations. Interestingly, our results suggest that environment differently affects the gradients at low and high masses. The results are also discussed in terms of the central age and metallicity, as well as the total colour, specific star formation and velocity dispersion. DOI: https://doi.org/10.1111/j.1365-2966.2010.17708.x Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-48326 Accepted Version Originally published at: Tortora, C; Romeo, A D; Napolitano, N R; Antonuccio-Delogu, V; Meza, A; Sommer-Larsen, J; Capaccioli, M (2011). Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies. Monthly Notices of the Royal Astronomical Society, 411(1):627-634. DOI: https://doi.org/10.1111/j.1365-2966.2010.17708.x ar X iv :1 00 9. 25 00 v1 [ as tr oph .C O ] 1 3 Se p 20 10 Mon. Not. R. Astron. Soc. 000, 1–?? (xxxx) Printed 15 September 2010 (MN LTEX style file v2.2) Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies C. Tortora, A.D. Romeo, N.R. Napolitano, V. Antonuccio-Delogu, A. Meza J. Sommer-Larsen, M. Capaccioli 8,9 1 Universität Zürich, Institut für Theoretische Physik, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland 2 Universidad Andres Bello, Departamento de Ciencias Fisicas, Av. Republica 220, Santiago, Chile 3 INAF – Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli, Italy 4 INAF – Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, Italy 5 Scuola Superiore di Catania, Via San Nullo, 5/i, 95123 Catania, Italy 6 Excellence Cluster Universe, Technische Universität München, Boltzmannstr. 2, D-85748 Garching bei München, Germany 7 Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark 8 Dipartimento di Scienze Fisiche, Università di Napoli Federico II, Compl. Univ. Monte S. Angelo, 80126 Napoli, Italy 9 MECENAS, Università di Napoli Federico II and Università di Bari, Italy