Saracino, S.S.SaracinoDalessandro, EmanueleEmanueleDalessandroFerraro, F. R.F. R.FerraroGeisler, D.D.GeislerMauro, F.F.MauroLanzoni, B.B.LanzoniORIGLIA, LiviaLiviaORIGLIAMiocchi, P.P.MiocchiCohen, R. E.R. E.CohenVillanova, S.S.VillanovaMoni Bidin, C.C.Moni Bidin2020-06-262020-06-2620160004-637Xhttp://hdl.handle.net/20.500.12386/26228We used ultra-deep J and K <SUB> s </SUB> images secured with the near-infrared (NIR) GSAOI camera assisted by the multi-conjugate adaptive optics system GeMS at the GEMINI South Telescope in Chile, to obtain a (K <SUB> s </SUB>, J - K <SUB> s </SUB>) color-magnitude diagram (CMD) for the bulge globular cluster NGC 6624. We obtained the deepest and most accurate NIR CMD from the ground for this cluster, by reaching K <SUB> s </SUB> ∼ 21.5, approximately 8 mag below the horizontal branch level. The entire extension of the Main Sequence (MS) is nicely sampled and at K <SUB> s </SUB> ∼ 20 we detected the so-called MS “knee” in a purely NIR CMD. By taking advantage of the exquisite quality of the data, we estimated the absolute age of NGC 6624 (t <SUB>age</SUB> = 12.0 ± 0.5 Gyr), which turns out to be in good agreement with previous studies in the literature. We also analyzed the luminosity and mass functions of MS stars down to M ∼ 0.45 M<SUB>☉</SUB>, finding evidence of a significant increase of low-mass stars at increasing distances from the cluster center. This is a clear signature of mass segregation, confirming that NGC 6624 is in an advanced stage of dynamical evolution. <P />Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). Based on observations gathered with ESO-VISTA telescope (program ID 179.B-2002).STAMPAenArticle10.3847/0004-637X/832/1/482-s2.0-84996558265000400476100011https://iopscience.iop.org/article/10.3847/0004-637X/832/1/482016ApJ...832...48SFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation