小天區的全天球聲峰偏移

Abstract

宇宙微波背景輻射紀錄了宇宙的歷史，而宇宙的歷史也藉由微波背景的頻譜圖被 揭露。甚至對小片天區，頻譜圖的偏移也顯露了小片天區的訊息，如重力透鏡效 應、都卜勒增強效應、或者其他未知的效應。在分析隨機選擇的普朗克微波背景 小片天區時，我們建立了聲峰偏移的全天球特徵圖（feature map），這提供了我們 對全天球宇宙學研究的新途徑。在聲峰特徵圖中，我們發現了不少區域的聲峰有 往大尺度偏移的現象，也包括了著名的冷斑（Cold Spot）區域。在做聲峰圖的多 極展開時，與模擬相比，我們聲峰圖的偶極明顯大於大部分的模擬。另外，我們 還發現了這個偶極與 SDSS-II/SNLS3 超新星的距離殘差有空間相關性。這個相關 性可能顯示了膨脹在偶極方向上有變化性。

Cosmic microwave background (CMB) temperature anisotropies encode the history of the universe, which manifest itself in the angular power spectrum. Variations in the power spectra even from small patches reveal informative details such as gravitational lensing, Doppler boosting effects, or even unknown effect. In doing data mining from ESA Planck CMB map, we compute the relative shifts of acoustic peak positions in power spectra from small patches and construct a full-sky peak-shift feature map, which provides a new way for statistics of full-sky cosmology. We found significant strong global dipole signal compared with simulations. The direction of the dipole, furthermore, spatially correlates with residuals of supernovae distances from best-fit ΛCDM cosmology in SDSS-II/SNLS3 Joint Light-Curve Analysis data. This correlation might indicate the variations of the expansion on the peak-shift dipole direction.