Characterization of the VVV Survey RR Lyrae Population across the Southern Galactic Plane

Journal Article · Sat Apr 01 04:00:00 EDT 2017 · Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/AA5BE4· OSTI ID:22663725

Minniti, Dante; Palma, Tali; Pullen, Joyce; Tissera, Patricia ^[1]; Dékány, Istvan ^[2]; Majaess, Daniel ^[3]; Rejkuba, Marina; Valenti, Elena ^[4]; Alonso-García, Javier; Catelan, Marcio; Contreras Ramos, Rodrigo; Zoccali, Manuela ^[5]; Gonzalez, Oscar A. ^[6]; Hempel, Maren ^[7]; Irwin, Mike ^[8]; Lucas, Philip W. ^[9]; Saito, Roberto K. ^[10]

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1. Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. Fernández Concha 700, Las Condes, Santiago (Chile)
2. Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstr. 12-14, D-69120 Heidelberg (Germany)
3. Mount Saint Vincent University, Halifax, Nova Scotia (Canada)
4. European Southern Observatory, Karl-Schwarszchild-Str. 2, D-85748 Garching bei Muenchen (Germany)
5. Instituto Milenio de Astrofísica, Santiago (Chile)
6. Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom)
7. Pontificia Universidad Católica de Chile, Instituto de Astrofisica, Av. Vicuna Mackenna 4860, Santiago (Chile)
8. Institute of Astronomy, Cambridge University, Cambridge, CB3 0HA (United Kingdom)
9. Department of Astronomy, University of Hertfordshire, Hertfordshire (United Kingdom)
10. Departamento de Física, Universidade Federal de Santa Catarina, Trindade 88040-900, Florianópolis, SC (Brazil)

Deep near-IR images from the VISTA Variables in the Vía Láctea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a thin slice of the fourth Galactic quadrant (295° < ℓ < 350°, −2.°24 < b < −1.°05). The sample’s distance distribution exhibits a maximum density that occurs at the bulge tangent point, which implies that this primarily Oosterhoff type I population of RRab stars does not trace the bar delineated by their red clump counterparts. The bulge RR Lyrae population does not extend beyond ℓ  ∼ 340°, and the sample’s spatial distribution presents evidence of density enhancements and substructure that warrants further investigation. Indeed, the sample may be employed to evaluate Galactic evolution models, and is particularly lucrative since half of the discovered RR Lyrae are within reach of Gaia astrometric observations.

• OSTI ID: 22663725
• Journal Information: Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 4 Vol. 153; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DENSITY
DISTANCE
GALACTIC EVOLUTION
IMAGES
MILKY WAY
NEAR INFRARED RADIATION
SPATIAL DISTRIBUTION
VARIABLE STARS