Multi-frequency synthesis algorithm based on Generalized Maximum Entropy Method. Application to 0954+658
Abstract
We propose the multi-frequency synthesis (MFS) algorithm with spectral correction of frequency-dependent source brightness distribution based on maximum entropy method. In order to take into account the spectral terms of n-th order in the Taylor expansion for the frequency-dependent brightness distribution, we use a generalized form of the maximum entropy method suitable for reconstruction of not only positive-definite functions, but also sign-variable ones. The proposed algorithm is aimed at producing both improved total intensity image and two-dimensional spectral index distribution over the source. We consider also the problem of frequency-dependent variation of the radio core positions of self-absorbed active galactic nuclei, which should be taken into account in a correct multi-frequency synthesis. First, the proposed MFS algorithm has been tested on simulated data and then applied to four-frequency synthesis imaging of the radio source 0954+658 from VLBA observational data obtained quasi-simultaneously at 5, 8, 15 and 22 GHz.
Keywords
Cite
@article{arxiv.1106.3985,
title = {Multi-frequency synthesis algorithm based on Generalized Maximum Entropy Method. Application to 0954+658},
author = {Anisa T. Bajkova and Alexander B. Pushkarev},
journal= {arXiv preprint arXiv:1106.3985},
year = {2015}
}
Comments
11 pages, 12 figures, 6 tables. Accepted for publication in MNRAS, 2011