Program: GS-2018B-Q-302

Title:Disentangling the complex chemical evolution of the SMC with GMOS: the counter-bridge
PI:Bruno Dias
Co-I(s): Leandro Kerber, Doug Geisler, Lilia Bassino, Mateus Angelo, Bruno de Bortoli, Orlando Katime Santrich, Beatriz Barbuy, Celeste Parisi

Abstract

The evolution and structure of the Magellanic Clouds is currently under debate. The classical scenario where both Large and Small Magellanic Clouds (LMC, SMC) are orbiting the Milky Way has been challenged by another where the LMC and SMC are in their first close passage to our Galaxy. Stellar population studies in these key nearby galaxies can constrain the proposed scenarios. In particular, the SMC presents a complex chemical history as revealed by its stellar clusters. An efficient strategy to disentangle this complexity is to split the SMC stellar cluster system in at least four different spatial groups, three of them probably related to tidal stripping. The photometric analysis of stellar clusters in the SMC outskirts has suggested the presence of a metallicity gradient as well as an age-metallicity relation compatible with a burst model of chemical enrichment (Dias et al. 2014, 2016b, 2018a in prep). We have already probed the west halo with GMOS spectra (Dias et al. 2018b in prep.). We propose now a spectrocospic follow-up of 11 stellar clusters located in the SMC counter-bridge to fully characterise its anomalous V-shape metallicity gradient (Parisi et al. 2015, 2016). We plan to use the GMOS in the multi-object mode to collect spectra of red giants in the CaII triplet region. The data analysis will provide mean metallicities and radial velocities for these clusters with unprecedented accuracy (< 0.05 dex and < 3 km/s).

Publications using this program's data