A panchromatic view of the bulge globular cluster NGC 6569. (arXiv:1902.05558v1 [astro-ph.GA])

A panchromatic view of the bulge globular cluster NGC 6569. (arXiv:1902.05558v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Saracino_S/0/1/0/all/0/1">S. Saracino</a> (1 and 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Dalessandro_E/0/1/0/all/0/1">E. Dalessandro</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Ferraro_F/0/1/0/all/0/1">F. R. Ferraro</a> (1 and 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Lanzoni_B/0/1/0/all/0/1">B. Lanzoni</a> (1 and 2), <a href="http://arxiv.org/find/astro-ph/1/au:+Geisler_D/0/1/0/all/0/1">D. Geisler</a> (3 and 4), <a href="http://arxiv.org/find/astro-ph/1/au:+Cohen_R/0/1/0/all/0/1">R. E. Cohen</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Bellini_A/0/1/0/all/0/1">A. Bellini</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Vesperini_E/0/1/0/all/0/1">E. Vesperini</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Salaris_M/0/1/0/all/0/1">M. Salaris</a> (7), <a href="http://arxiv.org/find/astro-ph/1/au:+Cassisi_S/0/1/0/all/0/1">S. Cassisi</a> (8), <a href="http://arxiv.org/find/astro-ph/1/au:+Pietrinferni_A/0/1/0/all/0/1">A. Pietrinferni</a> (8), <a href="http://arxiv.org/find/astro-ph/1/au:+Origlia_L/0/1/0/all/0/1">L. Origlia</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Mauro_F/0/1/0/all/0/1">F. Mauro</a> (9), <a href="http://arxiv.org/find/astro-ph/1/au:+Villanova_S/0/1/0/all/0/1">S. Villanova</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Bidin_C/0/1/0/all/0/1">C. Moni Bidin</a> (9) ((1) DIFA-UNIBO, (2) INAF-OAS Bologna, (3) Universidad de Concepcion, (4) Universidad de La Serena, (5) Space Telescope Science Institute, (6) Indiana University, (7) Liverpool John Moores University, (8) INAF – Osservatorio Astronomico di Teramo, (9) Universidad Catolica del Norte)

We used high-resolution optical HST/WFC3 and multi-conjugate adaptive optics
assisted GEMINI GeMS/GSAOI observations in the near-infrared to investigate the
physical properties of the globular cluster NGC 6569 in the Galactic bulge. We
have obtained the deepest purely NIR color-magnitude diagram published so far
for this cluster using ground-based observations, reaching $K_{s}$ $approx$
21.0 mag (two magnitudes below the main-sequence turn-off point). By combining
the two datasets secured at two different epochs, we determined relative proper
motions for a large sample of individual stars in the center of NGC 6569,
allowing a robust selection of cluster member stars. Our proper motion analysis
solidly demonstrates that, despite its relatively high metal content, NGC 6569
hosts some blue horizontal branch stars. A differential reddening map has been
derived in the direction of the system, revealing a maximum color excess
variation of about $delta E(B-V)$ $sim$ 0.12 mag in the available field of
view. The absolute age of NGC 6569 has been determined for the first time. In
agreement with the other few bulge globular clusters with available age
estimates, NGC 6569 turns out to be old, with an age of about 12.8 Gyr, and a
typical uncertainty of 0.8-1.0 Gyr.

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