Oral contribution: Disentangling the evolutionary history of galaxies through non-standard properties of their globular cluster systems

L.P. BASSINO; J.P. CASO

Puerto Ayora, Islas Galapagos

Workshop; On the Origin (and Evolution) of Baryonic Galaxy Halos; 2017

Observatorio Astronomico de Quito (Ecuador) and Swinburne Univ. of Technology (Australia)

Hints on the evolutionary history of galaxies can be obtained from globular cluster (GC) systems whose properties depart from those considered as "standard" ones. For instance, GC color distributions that show three sub-populations instead of just two (i.e. regular old metal-poor and metal-rich GCs). On the one hand, the sub-population of "intermediate" color may be younger clusters that originated during a recent merger like in NGC 4753 (Caso et al. 2015), where the presence of two type Ia SNe reinforces such scenario. On the other hand, it can be interpreted as the signature of a quite old starburst like in NGC 7507 (Caso et al. 2013), where no signs of a merger are identifiable. We have recently performed a new analysis of NGC 3610 and its GC system, based on GMOS/GEMINI data, which is the first wide-field study of this system (Bassino et al. 2016). This galaxy is considered as a prototype of an intermediate-age merger remnant. We detect an extended disk in the galaxy outskirts, where a rich fine structure (shells, plumes, etc.) is also present at a very low surface-brightness level. The cluster population that seems to be associated to this outer component has "intermediate" colors. Thus, the outer disk as well as the fine structure and the atypical clusters, may have originated in the disk-disk merger that produced the remnant.