• Nombre del proyecto : ULTRA-COMPACT DWARFS IN THE ANTLIA CLUSTER: SEARCHING FOR ANSWERS ON THEIR ORIGIN
• Número : G/2010A/022
• Año Concurso : 2010
• Nombre Concurso : CONCURSO PROPUESTAS DE OBSERVACIÓN ASTRONÓMICA PARA TIEMPO CHILENO EN EL OBSERVATORIO GEMINI PRIMER SEMESTRE DE 2010A
• Tiempo Asignado : 6,0 hrs.
  

While similar in colour to globular clusters (GCs), Ultra Compact Dwarf (UCDs) have properties like mass and size between classical GCs and dwarf elliptical galaxies. UCDs have now been detected in various cluster environments. Several formation scenarios have been proposed for them but their true nature is still far from being understood. This proposal aims at obtaining GMOS spectra for a simple of about 70 UCD candidates in the Antlia cluster. Firstly, we will test their membership (none of the targets has available radial velocity) and build a new list of spectroscopically confirmed UCDs. Then, spectroscopic metallicities and ages will be obtained by means of line strength indices and/or spectral synthesis, in order to characterize their population(s) properties. Finally, the sample will also serve to address the internal dynamics of UCDs via future high-dispersion studies. Four GMOS MOS fields are now requested, which are located close to the two dominant Antlia galaxies. Moreover, dwarf galaxies and GC candidates present in the fields will be included in the masks. The proposed investigation is planned as part of the future Doctoral Thesis of the student J.P. Caso, who has performed the photometric selection of the UCD candidates as part of his Master Thesis.