While baryonic feedback is one of the most important astrophysical systematics that we need to address in order to achieve precision cosmology, few weak lensing studies have directly measured its impact on the matter power spectrum. We report measurement of the baryonic feedback parameter with the constraints on its lower and upper limits from cosmic shear.We use the public data from the Kilo-Degree Survey and the VISTA Kilo-Degree Infrared Galaxy Survey spanning 450 deg2. Estimating both cosmological and feedback parameters simultaneously, we obtain Ab= 1.01+ 0.80-0.85 which shows a consistency with the dark matter-only (DMO) case at the ~1.2σ level and a tendency toward positive feedback; the Ab=0 (0.81) value corresponds to the DMO (OWLS AGN) case. Despite this full constraint of the feedback parameter, our S8 (≡σ8 √m/0.3 ) measurement ( 0.739+0.036-0.035) shifts by only ~6% of the statistical error, compared to the previous measurement. When we assume the flat ΛCDM cosmology favored by the Nine-Year Wilkinson Microwave Anisotropy Probe (Planck) result, the feedback parameter is constrained to be Ab =1.21+0.61- 0.54( 1.60+0.53-0.52), which excludes the DMO case at the ~2.2σ (~3.1σ) level.
Bibliographical noteFunding Information:
We thank Nora Elisa Chisari, Henk Hoekstra, Tilman Tr?ster, Shahab Joudaki, Angus H. Wright, Alexander Mead, Hendrik Hildebrandt, and Catherine Heymans for carefully reading the manuscript and providing useful comments. M.Y acknowledges support from the Max Planck Society and the Alexander von Humboldt Foundation in the framework of the Max Planck- Humboldt Research Award endowed by the Federal Ministry of Education and Research. M.Y also acknowledges support from the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) under no.2019R1C1C1010942. M.J.J acknowledges support for the current research from the National Research Foundation of Korea under the program nos. 2017R1A2B2004644 and 2017R1A4A1015178.
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All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science