Three Galactic globular cluster candidates

C. Moni Bidin, F. Mauro, D. Geisler, D. Minniti, M. Catelan, M. Hempel, E. Valenti, A. A R Valcarce, J. Alonso-García, J. Borissova, G. Carraro, P. Lucas, A. N. Chené, M. Zoccali, R. G. Kurtev

Resultado de la investigación: Article

39 Citas (Scopus)

Resumen

Context. The census of Galactic globular clusters (GCs) is still incomplete, and about ten new objects are supposed to await discovery, hidden behind the crowded and reddened regions of the Galactic bulge and disk. Aims. We investigated the nature of three new GC candidates, discovered in the frames collected by the Vista Variables in the Via Lactea (VVV) near-infrared survey. They will be called VVV CL002, VVV CL003, and VVV CL004. Methods. We studied the results of point-spread-function near-infrared photometry from VVV data for the three objects and their surrounding fields, the proper motion information available in the literature and, when possible, we derived the cluster parameters by means of calibrated indices measured on the color-magnitude diagrams. Results. The evidence shows that VVV CL002 is a newly discovered, small, moderately metal-rich ([Fe/H] ∼-0.4) Galactic GC. It is located at a Galactocentric distance of 0.7 ± 0.9 kpc, and it could be one of the nearest GC to the Galactic center. Its characteristics are more similar to those of low-mass, Palomar-like GCs than to more classical, old, and massive bulge GCs. VVV CL003 is the first star cluster discovered in the Galactic disk on the opposite side of the center with respect to the Sun, at a Galactocentric distance of ∼5 kpc. Its high metallicity ([Fe/H] ≈-0.1) and location point to an open cluster, but a GC cannot be excluded. VVV CL004, on the contrary, is most probably only a random clump of field stars, as indicated by both its low statistical significance and by the impossibility to distinguish its stars from the surrounding field population. Conclusions. We claim the detection of i) a new Galactic GC, deriving an estimate of its basic parameters; ii) a stellar aggregate, probably an open cluster, in the disk directly beyond the Galactic center; and iii) an overdensity of stars, most probably an asterism.

Idioma originalEnglish
Número de artículoA33
PublicaciónAstronomy and Astrophysics
Volumen535
DOI
EstadoPublished - 10 nov 2011

Huella dactilar

globular clusters
near infrared
census
diagram
metal
open clusters
stars
infrared photometry
galactic bulge
star distribution
parameter
color-magnitude diagram
star clusters
proper motion
clumps
point spread functions
metallicity
sun
detection
index

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

Moni Bidin, C., Mauro, F., Geisler, D., Minniti, D., Catelan, M., Hempel, M., ... Kurtev, R. G. (2011). Three Galactic globular cluster candidates. Astronomy and Astrophysics, 535, [A33]. https://doi.org/10.1051/0004-6361/201117488
Moni Bidin, C. ; Mauro, F. ; Geisler, D. ; Minniti, D. ; Catelan, M. ; Hempel, M. ; Valenti, E. ; Valcarce, A. A R ; Alonso-García, J. ; Borissova, J. ; Carraro, G. ; Lucas, P. ; Chené, A. N. ; Zoccali, M. ; Kurtev, R. G. / Three Galactic globular cluster candidates. En: Astronomy and Astrophysics. 2011 ; Vol. 535.
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title = "Three Galactic globular cluster candidates",
abstract = "Context. The census of Galactic globular clusters (GCs) is still incomplete, and about ten new objects are supposed to await discovery, hidden behind the crowded and reddened regions of the Galactic bulge and disk. Aims. We investigated the nature of three new GC candidates, discovered in the frames collected by the Vista Variables in the Via Lactea (VVV) near-infrared survey. They will be called VVV CL002, VVV CL003, and VVV CL004. Methods. We studied the results of point-spread-function near-infrared photometry from VVV data for the three objects and their surrounding fields, the proper motion information available in the literature and, when possible, we derived the cluster parameters by means of calibrated indices measured on the color-magnitude diagrams. Results. The evidence shows that VVV CL002 is a newly discovered, small, moderately metal-rich ([Fe/H] ∼-0.4) Galactic GC. It is located at a Galactocentric distance of 0.7 ± 0.9 kpc, and it could be one of the nearest GC to the Galactic center. Its characteristics are more similar to those of low-mass, Palomar-like GCs than to more classical, old, and massive bulge GCs. VVV CL003 is the first star cluster discovered in the Galactic disk on the opposite side of the center with respect to the Sun, at a Galactocentric distance of ∼5 kpc. Its high metallicity ([Fe/H] ≈-0.1) and location point to an open cluster, but a GC cannot be excluded. VVV CL004, on the contrary, is most probably only a random clump of field stars, as indicated by both its low statistical significance and by the impossibility to distinguish its stars from the surrounding field population. Conclusions. We claim the detection of i) a new Galactic GC, deriving an estimate of its basic parameters; ii) a stellar aggregate, probably an open cluster, in the disk directly beyond the Galactic center; and iii) an overdensity of stars, most probably an asterism.",
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author = "{Moni Bidin}, C. and F. Mauro and D. Geisler and D. Minniti and M. Catelan and M. Hempel and E. Valenti and Valcarce, {A. A R} and J. Alonso-Garc{\'i}a and J. Borissova and G. Carraro and P. Lucas and Chen{\'e}, {A. N.} and M. Zoccali and Kurtev, {R. G.}",
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Moni Bidin, C, Mauro, F, Geisler, D, Minniti, D, Catelan, M, Hempel, M, Valenti, E, Valcarce, AAR, Alonso-García, J, Borissova, J, Carraro, G, Lucas, P, Chené, AN, Zoccali, M & Kurtev, RG 2011, 'Three Galactic globular cluster candidates', Astronomy and Astrophysics, vol. 535, A33. https://doi.org/10.1051/0004-6361/201117488

Three Galactic globular cluster candidates. / Moni Bidin, C.; Mauro, F.; Geisler, D.; Minniti, D.; Catelan, M.; Hempel, M.; Valenti, E.; Valcarce, A. A R; Alonso-García, J.; Borissova, J.; Carraro, G.; Lucas, P.; Chené, A. N.; Zoccali, M.; Kurtev, R. G.

En: Astronomy and Astrophysics, Vol. 535, A33, 10.11.2011.

Resultado de la investigación: Article

TY - JOUR

T1 - Three Galactic globular cluster candidates

AU - Moni Bidin, C.

AU - Mauro, F.

AU - Geisler, D.

AU - Minniti, D.

AU - Catelan, M.

AU - Hempel, M.

AU - Valenti, E.

AU - Valcarce, A. A R

AU - Alonso-García, J.

AU - Borissova, J.

AU - Carraro, G.

AU - Lucas, P.

AU - Chené, A. N.

AU - Zoccali, M.

AU - Kurtev, R. G.

PY - 2011/11/10

Y1 - 2011/11/10

N2 - Context. The census of Galactic globular clusters (GCs) is still incomplete, and about ten new objects are supposed to await discovery, hidden behind the crowded and reddened regions of the Galactic bulge and disk. Aims. We investigated the nature of three new GC candidates, discovered in the frames collected by the Vista Variables in the Via Lactea (VVV) near-infrared survey. They will be called VVV CL002, VVV CL003, and VVV CL004. Methods. We studied the results of point-spread-function near-infrared photometry from VVV data for the three objects and their surrounding fields, the proper motion information available in the literature and, when possible, we derived the cluster parameters by means of calibrated indices measured on the color-magnitude diagrams. Results. The evidence shows that VVV CL002 is a newly discovered, small, moderately metal-rich ([Fe/H] ∼-0.4) Galactic GC. It is located at a Galactocentric distance of 0.7 ± 0.9 kpc, and it could be one of the nearest GC to the Galactic center. Its characteristics are more similar to those of low-mass, Palomar-like GCs than to more classical, old, and massive bulge GCs. VVV CL003 is the first star cluster discovered in the Galactic disk on the opposite side of the center with respect to the Sun, at a Galactocentric distance of ∼5 kpc. Its high metallicity ([Fe/H] ≈-0.1) and location point to an open cluster, but a GC cannot be excluded. VVV CL004, on the contrary, is most probably only a random clump of field stars, as indicated by both its low statistical significance and by the impossibility to distinguish its stars from the surrounding field population. Conclusions. We claim the detection of i) a new Galactic GC, deriving an estimate of its basic parameters; ii) a stellar aggregate, probably an open cluster, in the disk directly beyond the Galactic center; and iii) an overdensity of stars, most probably an asterism.

AB - Context. The census of Galactic globular clusters (GCs) is still incomplete, and about ten new objects are supposed to await discovery, hidden behind the crowded and reddened regions of the Galactic bulge and disk. Aims. We investigated the nature of three new GC candidates, discovered in the frames collected by the Vista Variables in the Via Lactea (VVV) near-infrared survey. They will be called VVV CL002, VVV CL003, and VVV CL004. Methods. We studied the results of point-spread-function near-infrared photometry from VVV data for the three objects and their surrounding fields, the proper motion information available in the literature and, when possible, we derived the cluster parameters by means of calibrated indices measured on the color-magnitude diagrams. Results. The evidence shows that VVV CL002 is a newly discovered, small, moderately metal-rich ([Fe/H] ∼-0.4) Galactic GC. It is located at a Galactocentric distance of 0.7 ± 0.9 kpc, and it could be one of the nearest GC to the Galactic center. Its characteristics are more similar to those of low-mass, Palomar-like GCs than to more classical, old, and massive bulge GCs. VVV CL003 is the first star cluster discovered in the Galactic disk on the opposite side of the center with respect to the Sun, at a Galactocentric distance of ∼5 kpc. Its high metallicity ([Fe/H] ≈-0.1) and location point to an open cluster, but a GC cannot be excluded. VVV CL004, on the contrary, is most probably only a random clump of field stars, as indicated by both its low statistical significance and by the impossibility to distinguish its stars from the surrounding field population. Conclusions. We claim the detection of i) a new Galactic GC, deriving an estimate of its basic parameters; ii) a stellar aggregate, probably an open cluster, in the disk directly beyond the Galactic center; and iii) an overdensity of stars, most probably an asterism.

KW - globular clusters: general

KW - globular clusters: individual: VVV CL002

KW - globular clusters: individual: VVV CL003

KW - surveys

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DO - 10.1051/0004-6361/201117488

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JO - Astronomy and Astrophysics

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Moni Bidin C, Mauro F, Geisler D, Minniti D, Catelan M, Hempel M y otros. Three Galactic globular cluster candidates. Astronomy and Astrophysics. 2011 nov 10;535. A33. https://doi.org/10.1051/0004-6361/201117488