TY - JOUR
T1 - Discovery of VVV CL001
T2 - A low-mass globular cluster next to UKS 1 in the direction of the Galactic bulge
AU - Minniti, D.
AU - Hempel, M.
AU - Toledo, I.
AU - Ivanov, V. D.
AU - Alonso-García, J.
AU - Saito, R. K.
AU - Catelan, M.
AU - Geisler, D.
AU - Jordán, A.
AU - Borissova, J.
AU - Zoccali, M.
AU - Kurtev, R.
AU - Carraro, G.
AU - Barbuy, B.
AU - Clariá, J.
AU - Rejkuba, M.
AU - Emerson, J.
AU - Moni Bidin, C.
N1 - Funding Information:
We thank the Cambridge Astronomical Survey Unit (CASU) for processing the VISTA raw data. We acknowledge support by the FONDAP Center for Astrophysics 15010003, BASAL Center for Astrophysics and Associated Technologies PFB-06, MILENIO Milky Way Millennium Nucleus P07-021-F from MIDEPLAN, FONDECYT 1090213 from CONICYT, and the European Southern Observatory. We use data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. We also thank the referee, whose comments helped to improve the paper significantly.
PY - 2011/3
Y1 - 2011/3
N2 - Context. It is not known how many globular clusters may remain undetected towards the Galactic bulge. Aims. One of the aims of the VISTA Variables in the Via Lactea (VVV) Survey is to accurately measure the physical parameters of the known globular clusters in the inner regions of the Milky Way and search for new ones, hidden in regions of large extinction. Methods. From deep near-infrared images, we derive deep JHKS-band photometry of a region surrounding the known globular cluster UKS 1 and reveal a new low-mass globular cluster candidate that we name VVV CL001. Results. We use the horizontal-branch red clump to measure E(B - V) ∼ 2.2 mag, (m - M)0 = 16.01 mag, and D = 15.9 kpc for the globular cluster UKS 1. On the basis of near-infrared colour - magnitude diagrams, we also find that VVV CL001 has E(B - V) ∼ 2.0, and that it is at least as metal-poor as UKS 1, although its distance remains uncertain. Conclusions. Our finding confirms the previous projection that the central region of the Milky Way harbours more globular clusters. VVV CL001 and UKS 1 are good candidates for a physical cluster binary, but follow-up observations are needed to decide if they are located at the same distance and have similar radial velocities.
AB - Context. It is not known how many globular clusters may remain undetected towards the Galactic bulge. Aims. One of the aims of the VISTA Variables in the Via Lactea (VVV) Survey is to accurately measure the physical parameters of the known globular clusters in the inner regions of the Milky Way and search for new ones, hidden in regions of large extinction. Methods. From deep near-infrared images, we derive deep JHKS-band photometry of a region surrounding the known globular cluster UKS 1 and reveal a new low-mass globular cluster candidate that we name VVV CL001. Results. We use the horizontal-branch red clump to measure E(B - V) ∼ 2.2 mag, (m - M)0 = 16.01 mag, and D = 15.9 kpc for the globular cluster UKS 1. On the basis of near-infrared colour - magnitude diagrams, we also find that VVV CL001 has E(B - V) ∼ 2.0, and that it is at least as metal-poor as UKS 1, although its distance remains uncertain. Conclusions. Our finding confirms the previous projection that the central region of the Milky Way harbours more globular clusters. VVV CL001 and UKS 1 are good candidates for a physical cluster binary, but follow-up observations are needed to decide if they are located at the same distance and have similar radial velocities.
KW - globular clusters: general
KW - globular clusters: individual: UKS 1
KW - globular clusters: individual: VVV CL001
KW - surveys
UR - http://www.scopus.com/inward/record.url?scp=79551544620&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201015795
DO - 10.1051/0004-6361/201015795
M3 - Article
AN - SCOPUS:79551544620
SN - 0004-6361
VL - 527
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 10
M1 - A81
ER -