Journal article
THE OPTICAL GRAVITATIONAL LENSING EXPERIMENT: ANALYSIS OF THE BULGE RR LYRAE POPULATION FROM THE OGLE-III DATA
The Astrophysical journal, Vol.750(2), pp.1-11
05/10/2012
DOI: 10.1088/0004-637X/750/2/169
Abstract
We have analyzed the data on 16,836 RR Lyrae (RR Lyr) variables observed toward the Galactic bulge during the third phase of the Optical Gravitational Lensing Experiment (OGLE-III), which took place in 2001-2009. Using these standard candles, we show that the ratio of total-to-selective extinction toward the bulge is given by R-I = A(I)/E(V - I) = 1.080 +/- 0.007 and is independent of color. We demonstrate that the bulge RR Lyr stars form a metal-uniform population, slightly elongated in its inner part. The photometrically derived metallicity distribution is sharply peaked at [Fe/H] = -1.02 +/- 0.18, with a dispersion of 0.25 dex. In the inner regions (vertical bar l vertical bar < 3 degrees, vertical bar b vertical bar < 4 degrees) the RR Lyr tend to follow the barred distribution of the bulge red clump giants. The distance to the Milky Way center inferred from the bulge RR Lyr is R-0 = 8.54 +/- 0.42 kpc. We report a break in the mean density distribution at a distance of similar to 0.5 kpc from the center indicating its likely flattening. Using the OGLE-III data, we assess that (4-7) x 10(4) type ab RR Lyr variables should be detected toward the bulge area of the ongoing near-IR VISTA Variables in the Via Lactea (VVV) survey, where the uncertainty partially results from the unknown RR Lyr spatial density distribution within 0.2 kpc from the Galactic center.
Details
- Title: Subtitle
- THE OPTICAL GRAVITATIONAL LENSING EXPERIMENT: ANALYSIS OF THE BULGE RR LYRAE POPULATION FROM THE OGLE-III DATA
- Creators
- P. Pietrukowicz - University of WarsawA. Udalski - University of WarsawI. Soszynski - University of WarsawD. M. Nataf - The Ohio State UniversityL. Wyrzykowski - University of WarsawR. Poleski - University of WarsawS. Kozlowski - University of WarsawM. K. Szymanski - University of WarsawM. Kubiak - University of WarsawG. Pietrzynski - University of WarsawK. Ulaczyk - University of Warsaw
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.750(2), pp.1-11
- Publisher
- Iop Publishing Ltd
- DOI
- 10.1088/0004-637X/750/2/169
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Number of pages
- 11
- Grant note
- 246678 / ERC; European Research Council (ERC); European Commission IP2010 031570 / Polish Ministry of Sciences and Higher Education; Ministry of Science and Higher Education, Poland European Research Council under the European Community; European Research Council (ERC)
- Language
- English
- Date published
- 05/10/2012
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701724202771
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