HSW VOID AS THE ORIGIN OF COLD SPOT
Keywords:
CMB, cosmic voids, ISW effectAbstract
The cosmic microwave background (CMB) cold spot (CS) anomaly is one of the most important unresolved issues in CMB observations. The CS has an angular radius in the sky greater than 5o and a temperature at the centre of about 160 μK which is lower than the average (8.3 times the root mean square of CMB fluctuations). This research is aimed at investigating the origin of the CS as the secondary anisotropy CMB fluctuations, specifically the integrated Sachs-Wolfe (ISW) effect by cosmic voids. The Hamaus, Sutter, and Wendelt void profile is used in the ISW calculation. The calculation shows that the radius of void rv, the central density contrast δc, and the redshift z are needed to be 𝟏𝟗𝟎𝟐𝟎 𝟑𝟎Mpc h−1, −0.5 (specific value), and 𝟎. 𝟒𝟓𝟎.𝟏𝟑 𝟎.𝟔𝟎, respectively. The void profile can fit the data quite well except for the positive fluctuation region in the CS and the probability of finding such a void is only 10−17.
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