Abstract Details
| Name: Prasun Dutta Affiliation: IISER BHOPAL Conference ID: ASI2015_894 Title : The Bispectrum Way Authors and Co-Authors : Suman Majumdar Stockholm University · Department of Astronomy Abstract Type : Poster Abstract Category : Instrumentation and Techniques Abstract : Many aspects of radio astronomy deals with statistical fluctuations of the observed intensity, HI intensity fluctuations from reionization or nearby galaxy, synchrotron emission from spiral galaxies or supernovae remnant of our galaxy are to name a few. Most of the present estimators of these statistical fluctuations aims to measure the power spectrum or the two point correlation functions, hence quantifying its Gaussian nature completely. Higher order statistics are particularly important for quantifying the non linear structures from the epoch of Reionization Era, or ISM turbulence, where three point interactions are natural. However, literature present lacks estimators of the higher order statistics. In this work we propose a visibility based estimator to quantify the bispectrum of the sky brightness fluctuations in the radio interferometric data. Since bispectrum is a function of three variables (which are shown to constitute the sides of a triangle), in literature several bispectrum estimators are considered based on triangles of specific geometry. We realise, given an interferometric array configuration and the direction in the sky an observation is carried out, it is possible to estimate the efficacy of measuring bispectrum for triangles of all possible shapes from an observed data. For an upcoming radio telescope, like Square Kilometre Array (SKA), using this method one can predict the best possible antenna configurations to get the best estimates of bispectrum for triangles of required geometry set by the science objectives. Challenges in estimating bispectrum, our approach and its applications will be discussed. |