協辦單位
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協辦單位
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協辦單位
ASIAA
贊助單位
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名稱Title
2018天文年會
國立金門大學
5月18日至20日

論文摘要

Excessive shift of the CMB acoustic peaks of the Cold Spot area

[ Oral ]

Lung-Yih Chiang

Measurement of the acoustic peaks of the cosmic microwave background (CMB) temperature anisotropies has been instrumental in deciding the geometry and content of the universe. Acoustic peak positions vary in different parts of the sky due to statistical fluctuation. We present the statistics of the peak positions of small patches from ESA Planck data. We found that the peak positions have significantly high variance compared to the 100 CMB simulations with best-fit LambdaCDM model with lensing and Doppler boosting effects included. Examining individual patches, we found the one containing the mysterious "Cold Spot", an area near the Eridanus constellation where the temperature is significantly lower than Gaussian theory predicts, displays large synchronous shift of peak positions towards smaller multipole numbers with significance lower than 1.11x 10^{-4}. The combination of large synchronous shifts in acoustic peaks and lower than usual temperature at the Cold Spot area results in a 4.73-sigma detection against the LambdaCDM model. And it was already reported in Finelli et al. (2016) that in the WISE-2MASS galaxy catalog at z<0.3 the Cold Spot region is surrounded by surprisingly large underdense regions around 15deg in radius, which are found to be in the same square patch. Thus we propose there is some extra localized unknown energy to stretch out the space in the transverse direction around the Cold Spot area to simultaneously account for the Cold Spot, excessive shift of the acoustic peaks, and the large underdense regions.