@article{10902/25145,
year = {2013},
month = {9},
url = {http://hdl.handle.net/10902/25145},
abstract = {Recent results of the ESA Planck satellite have confirmed the existence of some anomalies in the statistical distribution of the cosmic microwave background (CMB) anisotropies. One of the most intriguing anomalies is the cold spot, first detected in the Wilkinson Microwave Anisotropy Probe (WMAP) data by Vielva et al. In a later paper, Vielva et al. (2011) developed a method to probe the anomalous nature of the cold spot by using the cross-correlation of temperature and polarization of the CMB fluctuations. Whereas this work was built under the assumption of analysing full-sky data, in this paper we extend such approach to deal with realistic data sets with a partial-sky coverage. In particular, we exploit the radial and tangential polarization patterns around temperature spots. We explore the capacity of the method to distinguish between a standard Gaussian CMB scenario and an alternative one, in which the cold spot arises from a physical process that does not present correlated polarization features (e.g. topological defects), as a function of the instrumental-noise level. Moreover, we consider more in detail the case of an ideal noise-free experiment and the ones with the expected instrumental-noise levels in QUIJOTE and Planck experiments. We also present an application to the 9-year WMAP data, without being able to obtain firm conclusions, with a significance level of 32 per cent. In the ideal case, the alternative scenario could be rejected at a significance level of around 1 per cent, whereas for expected noise levels of QUIJOTE and Planck experiments the corresponding significance levels are 1.5 and 7.4 per cent, respectively.},
organization = {The authors thank Rita Belen Barreiro and Airam Marcos-Caballero for comments and useful discussions. We acknowledge partial financial support from the Spanish Ministerio de Economía y Competitividad Projects AYA2010-21766-C03-01, AYA2012-39475-C02- 01 and Consolider-Ingenio 2010 CSD2010-00064. RFC thanks financial support from Spanish CSIC for a JAE-predoc fellowship, cofinanced by the European Social Fund. The authors acknowledge the computer resources, technical expertise and assistance provided by the Spanish Supercomputing Network (RES) node at Universidad de Cantabria. We acknowledge the use of Legacy Archive for Microwave Background Data Analysis (LAMBDA). The HEALPIX package was used throughout the data analysis (Gorski et al. 2005).},
publisher = {Oxford University Press},
publisher = {Monthly Notices of the Royal Astronomical Society Volume 435, Issue 4, Pages 3096-3102},
title = {Using cmb polarization to constrain the anomalous nature of the cold spot with an incomplete-sky coverage},
author = {Fernández Cobos, Raúl and Vielva Martínez, Patricio and Martínez González, Enrique and Tucci, M. and Cruz Rodríguez, Marcos},
}