Journal article
Interstellar extinction curve variations towards the inner Milky Way: a challenge to observational cosmology
Monthly notices of the Royal Astronomical Society, Vol.456(3), pp.2692-2706
03/01/2016
DOI: 10.1093/mnras/stv2843
Abstract
We investigate interstellar extinction curve variations towards similar to 4 deg(2) of the inner Milky Way in VIJK(s) photometry from the OGLE-III (third phase of the Optical Gravitational Lensing Experiment) and VVV (VISTA Variables in the Via Lactea) surveys, with supporting evidence from diffuse interstellar bands and F435W, F625W photometry. We obtain independent measurements towards similar to 2000 sightlines of A(I), E(V - I), E(I - J) and E(J - K-s), with median precision and accuracy of 2 per cent. We find that the variations in the extinction ratios A(I)/E(V - I), E(I - J)/E(V - I) and E(J - Ks)/E(V - I) are large (exceeding 20 per cent), significant and positively correlated, as expected. However, both the mean values and the trends in these extinction ratios are drastically shifted from the predictions of Cardelli and Fitzpatrick, regardless of how RV is varied. Furthermore, we demonstrate that variations in the shape of the extinction curve have at least two degrees of freedom, and not one (e.g. RV), which we confirm with a principal component analysis. We derive a median value of < A(V)/A(Ks)> = 13.44, which is similar to 60 per cent higher than the 'standard' value. We show that the Wesenheit magnitude W-I = I - 1.61(I - J) is relatively impervious to extinction curve variations. Given that these extinction curves are linchpins of observational cosmology, and that it is generally assumed that RV variations correctly capture variations in the extinction curve, we argue that systematic errors in the distance ladder from studies of Type Ia supernovae and Cepheids may have been underestimated. Moreover, the reddening maps from the Planck experiment are shown to systematically overestimate dust extinction by similar to 100 per cent and lack sensitivity to extinction curve variations.
Details
- Title: Subtitle
- Interstellar extinction curve variations towards the inner Milky Way: a challenge to observational cosmology
- Creators
- David M. Nataf - Australian National UniversityOscar A. Gonzalez - European So Observ, Casilla 19001, Santiago 19, ChileLuca Casagrande - Australian National UniversityGail Zasowski - University of California, Santa BarbaraChristopher Wegg - Max Planck Institute for Extraterrestrial PhysicsChristian Wolf - Australian National UniversityAndrea Kunder - University of PotsdamJavier Alonso-Garcia - Millennium Institute of AstrophysicsDante Minniti - Millennium InstituteMarina Rejkuba - European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, GermanyRoberto K. Saito - Universidade Federal de SergipeElena Valenti - European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, GermanyManuela Zoccali - Millennium Institute of AstrophysicsRadoslaw Poleski - University of WarsawGrzegorz Pietrzynski - University of WarsawJan Skowron - University of WarsawIgor Soszynski - University of WarsawMichal K. Szymanski - University of WarsawAndrzej Udalski - University of WarsawKrzysztof Ulaczyk - University of WarwickLukasz Wyrzykowski - University of Warsaw
- Resource Type
- Journal article
- Publication Details
- Monthly notices of the Royal Astronomical Society, Vol.456(3), pp.2692-2706
- Publisher
- Oxford Univ Press
- DOI
- 10.1093/mnras/stv2843
- ISSN
- 0035-8711
- eISSN
- 1365-2966
- Number of pages
- 15
- Grant note
- IC120009 / Ministry for the Economy, Development, and Tourism's Programa Iniciativa Cientifica Milenio NSF PHY11-25915 / National Science Foundation; National Science Foundation (NSF) 30321072 / FIC-R Fund PFB-06 / BASAL CATA Center for Astrophysics and Associated Technologies; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT); CONICYT PIA/BASAL National Science Foundation; National Science Foundation (NSF) National Aeronautics and Space Administration; National Aeronautics & Space Administration (NASA) MAESTRO 2014/14/A/ST9/00121 / National Science Centre, Poland FL110100012 / Australian Research Council 1130196; 1150345; 3130552 / FONDECYT; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT); CONICYT FONDECYT 179.B-2002 / ESO Public Survey programme
- Language
- English
- Date published
- 03/01/2016
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701723302771
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