Journal article
REDDENING AND EXTINCTION TOWARD THE GALACTIC BULGE FROM OGLE-III: THE INNER MILKY WAY'S R-V similar to 2.5 EXTINCTION CURVE
The Astrophysical journal, Vol.769(2), 88
06/01/2013
DOI: 10.1088/0004-637X/769/2/88
Abstract
We combine VI photometry from OGLE-III with VISTA Variables in The Via Lactea survey and Two Micron All Sky Survey measurements of E(J - K-s) to resolve the longstanding problem of the non-standard optical extinction toward the Galactic bulge. We show that the extinction is well fit by the relation A(I) = 0.7465xE(V - I) + 1.3700xE(J - K-s), or, equivalently, A(I) = 1.217xE(V - I)(1 + 1.126x(E(J - K-s)/E(V - I) - 0.3433)). The optical and near-IR reddening law toward the inner Galaxy approximately follows an R-V approximate to 2.5 extinction curve with a dispersion sigma(RV) approximate to 0.2, consistent with extragalactic investigations of the hosts of Type Ia SNe. Differential reddening is shown to be significant on scales as small as our mean field size of 6'. The intrinsic luminosity parameters of the Galactic bulge red clump (RC) are derived to be (M-I,M-RC, sigma(I,RC,0), (V - I)(RC,0), sigma(V - I)(RC), (J - K-s)(RC,0)) = (-0.12, 0.09, 1.06, 0.121, 0.66). Our measurements of the RC brightness, brightness dispersion, and number counts allow us to estimate several Galactic bulge structural parameters. We estimate a distance to the Galactic center of 8.20 kpc. We measure an upper bound on the tilt alpha approximate to 40 degrees between the bulge's major axis and the Sun-Galactic center line of sight, though our brightness peaks are consistent with predictions of an N-body model oriented at alpha approximate to 25 degrees. The number of RC stars suggests a total stellar mass for the Galactic bulge of similar to 2.3 x 10(10) M-circle dot if one assumes a canonical Salpeter initial mass function (IMF), or similar to 1.6 x 10(10) M-circle dot if one assumes a bottom-light Zoccali IMF.
Details
- Title: Subtitle
- REDDENING AND EXTINCTION TOWARD THE GALACTIC BULGE FROM OGLE-III: THE INNER MILKY WAY'S R-V similar to 2.5 EXTINCTION CURVE
- Creators
- David M. Nataf - Australian National UniversityAndrew Gould - The Ohio State UniversityPascal Fouque - Université de ToulouseOscar A. Gonzalez - European Southern ObservatoryJennifer A. Johnson - The Ohio State UniversityJan Skowron - The Ohio State UniversityAndrzej Udalski - University of WarsawMichal K. Szymanski - University of WarsawMarcin Kubiak - University of WarsawGrzegorz Pietrzynski - University of WarsawIgor Soszynski - University of WarsawKrzysztof Ulaczyk - University of WarsawLukasz Wyrzykowski - University of WarsawRadoslaw Poleski - University of Warsaw
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.769(2), 88
- Publisher
- Iop Publishing Ltd
- DOI
- 10.1088/0004-637X/769/2/88
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Number of pages
- 23
- Grant note
- AST-1103471 / NSF; National Science Foundation (NSF) 246678 / European Research Council under the European Community; European Research Council (ERC) National Science Foundation; National Science Foundation (NSF) National Aeronautics and Space Administration; National Aeronautics & Space Administration (NASA) PGSD3-403304-2011 / NSERC; Natural Sciences and Engineering Research Council of Canada (NSERC)
- Language
- English
- Date published
- 06/01/2013
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701831002771
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