VVVX-Gaia Discovery of a Low Luminosity Globular Cluster in the Milky Way Disk

Abstract

Milky Way globular clusters (MW GCs) are difficult to identify at low Galactic latitudes because of high differential extinction and heavy star crowding. The new deep near-IR images and photometry from the VISTA Variables in the Via Láctea Extended Survey (VVVX) allow us to chart previously unexplored regions. Our long term aim is to complete the census of MW GCs. The immediate goals are to estimate the astrophysical parameters, measuring their reddenings, extinctions, distances, total luminosities, proper motions, sizes, metallicities and ages. We use the near-IR VVVX survey database, in combination with Gaia DR2 optical photometry, and with the Two Micron All Sky Survey (2MASS) photometry. We report the detection of a heretofore unknown Galactic Globular Cluster at $RA=$ 14:09:00.0; $DEC=-$65:37:12 (J2000). We calculate a reddening of $E(J-K_s)=(0.3\pm 0.03)$ mag and an extinction of $A_{K_s}=(0.15\pm 0.01)$ mag for this new GC. Its distance modulus and corresponding distance were measured as $(m-M)=(15.93\pm 0.03)$ mag and $D=(15.5\pm 1.0)$ kpc, respectively. We estimate the metallicity and age by comparison with known GCs and by fitting PARSEC and Dartmouth isochrones, finding $[Fe/H]=(-0.70\pm 0.2)$ dex and $t=(11.0\pm 1.0)$ Gyr. The mean GC PMs from Gaia are ${\mu }_{{\alpha }^{\ast }}=(-4.68\pm 0.47)$ mas $y{r}^{-1}$ and ${\mu }_{\delta }=(-1.34\pm 0.45)$ mas $y{r}^{-1}$. The total luminosity of our cluster is estimated to be $M_{Ks}=(-7.76\pm 0.5)$ mag. We have found a new low-luminosity, old and metal-rich globular cluster, situated in the far side of the Galactic disk, at $R_G=11.2$ kpc from the Galactic centre, and at $z=1.0$ kpc below the plane. Interestingly, the location, metallicity and age of this globular cluster are coincident with the Monoceros Ring (MRi) structure.

References in corpus (18)

• The Dartmouth Stellar Evolution Database
• The UKIDSS Galactic Plane Survey
• The accretion origin of the Milky Way's stellar halo
• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• Substructure in Tidal Streams; Tributaries in the Anticenter Ring
• A Sequoia in the Garden: FSR 1758 - Dwarf Galaxy or Giant Globular Cluster?
• Spiral structure of the Third Galactic Quadrant and the solution to the Canis Major debate
• Empirical photometric calibration of the Gaia Red Clump: colours, effective temperature and absolute magnitude
• Purveyors of fine halos: Re-assessing globular cluster contributions to the Milky Way halo build-up with SDSS-IV
• Three candidate globular clusters discovered in the Galactic bulge
• Does the stellar distribution flare? A comparison of stellar scale heights with LAB HI data
• The mass fraction of halo stars contributed by the disruption of globular clusters in the E-MOSAICS simulations
• Obscured clusters. II. GLIMPSE-C02 - A new metal rich globular cluster in the Milky Way
• VVV WIN 1733$-$3349: a low extinction window to probe the far side of the Milky Way bulge
• Photometry of a Galactic field at l = 232, b = -6. The old open cluster Auner 1, the Norma-Cygnus spiral arm and the signature of the warped Galactic Thick Disk
• Properties of the Young Milky Way Globular Cluster Whiting 1 from Near-Infrared Photometry
• On the Origin of the Monoceros Ring - I: Kinematics, proper motions, and the nature of the progenitor
• Gemini spectroscopy of the outer disk star cluster BH176

Cited by in corpus (19)

• The VISTA Variables in the Vía Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy
• VVV CL001: Likely the Most Metal-Poor Surviving Globular Cluster in the Inner Galaxy
• Confirmation and physical characterization of the new bulge globular cluster Patchick 99 from the VVV and Gaia surveys
• A census of new globular clusters in the Galactic bulge
• The e-TidalGCs Project: Modeling the extra-tidal features generated by Galactic globular clusters
• Hidden in the Haystack: Low-luminosity globular clusters towards the Milky Way bulge
• Unveiling the nature of 12 new low-luminosity Galactic Globular Cluster Candidates
• Inspection of 19 globular cluster candidates in the Galactic bulge with the VVV survey
• Survey for Distant Stellar Aggregates in Galactic Disk: Detecting Two Thousand Star Clusters and Candidates, along with the Dwarf Galaxy IC10
• Physical characterization of recently discovered globular clusters in the Sagittarius dwarf spheroidal galaxy II. Metallicities, ages and luminosities
• A new low-luminosity globular cluster discovered in the Milky Way with the VVVX survey
• APOGEE-2S view of the globular cluster Patchick 125 (Gran 3). New metallicity and elemental abundances from high-resolution spectroscopy
• Gaia-IGRINS synergy: Orbits of Newly Identified Milky Way Star Clusters
• Three New Galactic Globular Cluster Candidates: FSR1700, Teutsch67, and CWNU4193
• High-precision astrometry with VVV -- II. A near-infrared extension of Gaia into the Galactic plane
• Confirmation Of Two New Galactic Bulge Globular Clusters: FSR 19 and FSR 25
• Consensus based Algorithm for Nonparametric Detection of Star Clusters (CANDiSC)
• Revealing the stellar population of the ultra-obscured Galactic globular cluster Glimpse-C02
• Spectroscopic analysis of VVV CL001 cluster with MUSE