52 0 Congresso SAIT - Teramo 2008 The Globular Clusters of the Large Magellanic Cloud : chemical abundances and ages Alessio Mucciarelli Università di Bologna

Wide age distribution : (1) Very Young Population : < 50 Myr (2) Young Population: 50 Myr Myr (3) Intermediate Population: 500 Myr - 4 Gyr (4) “ Age Gap “ ( Gyr) [ absent in the SMC ] (5) Old population: ~ Gyr LACK of an homogeneous age scale Wide metallicity distribution : [ Fe / H ] ~ / 0.0 dex (1) Low resolution spectra ( Ca II triplet) (2) Photometric metallicities (3) [[Fe/H] and  -elements from high resolution spectra of few stars in a few clusters. Necessity to define new homogeneous age and metallicity scales for these clusters LACK of an homogeneous metallicity scale based on high-resolution spectra

high resolution spectra R ~ = Å S/N ~ 40/50 Target stars selected from our Near-infrared photometry 4 LMC intermediate-age clusters: an age class not well studied with high - resolution spectra Other clusters in our database: 2 young clusters (< 1 Gyr) 3 old clusters ( ~ 13 Gyr) All these clusters are metal-rich [ Fe / H] ~ dex

Mucciarelli, Carretta, Origlia, Ferraro, 2008, arXiv: v1 [  / Fe ] : Ideal diagnostic of the relative contribution of SN II to SN Ia Solar ratio ISM enriched by SN Ia [ Al / Fe ] : Sub-solar ratio contribution by low- metallicity SN II [ Ba / Y ] : Relative contribution of the two peaks of the s-process elements (AGB stars) Over-solar ratio contribution by low- metallicity AGB stars

MILKY WAY (Thin Disk) LMC Sgr & dSphs  Solar [  / Fe ]  Solar [ Ba / Y ]  Solar [ Al / Fe ]  Solar Iron-Peak  Sub-solar [  / Fe ]  Over-solar [ Ba / Y ]  Sub-solar [ Al / Fe ]  Sub-solar Iron-Peak  Solar [  / Fe ]  Over-solar [ Ba / Y ]  Sub-solar [ Al / Fe ]  Solar Iron-Peak Intermediate abundance patterns between the Thin Disk and the dSphs

Mucciarelli, Ferraro, Origlia, Fusi Pecci, 2007, AJ, 133, 2053 RGB Bump He-Clump RGB TURN-OFF CHANGE IN SLOPE OF INTEGRAL LF = CHANGE IN EVOLUTIONARY TIME-SCALES HST-ACS

o Pisa Evolutionary Library (Castellani et al. 2003)  OS = 0.0, 0.10, 0.25 o Padua (Girardi et al. 2000)  OS = 0.25 o BaSTI - Teramo (Pietrinferni et al. 2004)  OS = 0.0, Gyr (  OS = 0.1 )

Mucciarelli, Origlia, Ferraro, 2007, AJ, 134,1813 o Pisa Evolutionary Library (Castellani et al. 2003)  OS = 0.0, 0.10, Gyr (  OS = ) 1.4 Gyr1.9 Gyr HST-ACS

Models by Pagel & Tautvaisine (1998 ) Continuos Model Bursting Model 2 clusters (NGC 1783 & 1978) already published

First results of a long-term spectroscopic and photometric project devoted to study the LMC clusters Peculiar abundance patterns for the intermediate-age clusters Necessity to include an amount of overshooting to well-reproduce observed morphology and number counts of these clusters Future perspectives: to complete the chemical analysis of the spectroscopic database and the study of the photometric database … The End !!!