New VVV Survey Globular Cluster Candidates in the Milky Way Bulge

Journal Article · Fri Nov 10 04:00:00 EST 2017 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8213/AA95B8· OSTI ID:22654349

Minniti, Dante; Gómez, Matías ^[1]; Geisler, Douglas; Fernández-Trincado, Jose G. ^[2]; Alonso-García, Javier; Beamín, Juan Carlos; Borissova, Jura; Catelan, Marcio; Ramos, Rodrigo Contreras; Kurtev, Radostin; Pullen, Joyce ^[3]; Palma, Tali; Clariá, Juan J. ^[4]; Cohen, Roger E. ^[5]; Dias, Bruno ^[6]; Hempel, Maren ^[7]; Ivanov, Valentin D. ^[8]; Lucas, Phillip W. ^[9]; Moni-Bidin, Christian; Alegría, Sebastian Ramírez ^[10] ; others, and

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1. Departamento de Física, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. Fernandez Concha 700, Las Condes, Santiago (Chile)
2. Departamento de Astronomía, Casilla 160-C, Universidad de Concepción, Casilla 160-C, Concepción (Chile)
3. Instituto Milenio de Astrofísica, Santiago (Chile)
4. Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba (Argentina)
5. Space Telescope Science Institute, 2700 San Martin Drive, Baltimore (United States)
6. European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile)
7. Pontificia Universidad Católica de Chile, Instituto de Astrofísica, Av. Vicuña Mackenna 4860, Santiago (Chile)
8. European Southern Observatory, Karl-Schwarszchild-Str. 2, D-85748 Garching bei Muenchen (Germany)
9. Dept. of Astronomy, University of Hertfordshire, Hertfordshire (United Kingdom)
10. Instituto de Astronomía, Universidad Católica del Norte, Antofagasta (Chile)

It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major problems for finding globular clusters located toward the bulge. We use the deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey to search for globular clusters projected toward the Galactic bulge, and hereby report the discovery of 22 new candidate globular clusters. These objects, detected as high density regions in our maps of bulge red giants, are confirmed as globular cluster candidates by their color–magnitude diagrams. We provide their coordinates as well as their near-IR color–magnitude diagrams, from which some basic parameters are derived, such as reddenings and heliocentric distances. The color–magnitude diagrams reveal well defined red giant branches in all cases, often including a prominent red clump. The new globular cluster candidates exhibit a variety of extinctions (0.06 < A {sub Ks} < 2.77) and distances (5.3 < D < 9.5 kpc). We also classify the globular cluster candidates into 10 metal-poor and 12 metal-rich clusters, based on the comparison of their color–magnitude diagrams with those of known globular clusters also observed by the VVV Survey. Finally, we argue that the census for Galactic globular clusters still remains incomplete, and that many more candidate globular clusters (particularly the low luminosity ones) await to be found and studied in detail in the central regions of the Milky Way.

• OSTI ID: 22654349
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 849; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPARATIVE EVALUATIONS
DENSITY
DISTANCE
GALAXY CLUSTERS
LUMINOSITY
METALS
MILKY WAY
PHOTOMETRY