A Pixon-based Method for Reverberation-mapping Analysis in Active Galactic Nuclei

We present an alternative method for reconstructing a velocity-delay map in reverberation mapping (RM) based on the pixon algorithm initially proposed for image reconstruction by Pina. The pixon algorithm allows for a variable pixon basis to adjust resolution of each image pixel according to the information content in that pixel, which therefore enables the algorithm to make the best possible use of measured data. The final optimal pixon basis functions would be those that minimize the number of pixons while still providing acceptable descriptions to data within the accuracy allowed by noises. We adapt the pixon algorithm to RM analysis and develop a generic framework to implement the algorithm. Simulation tests and comparisons with the widely used maximum entropy method demonstrate the feasibility and high performance of our pixon-based RM analysis. This paper serves as an introduction to the framework and the application to velocity-unresolved RM. An extension to velocity-resolved cases will be presented in a companion paper.

Automated summary

The proposed method uses the Pixon algorithm to adjust the resolution of each image pixel based on the information content, allowing for optimal use of measured data. The algorithm minimizes the number of pixons while providing acceptable descriptions within the accuracy allowed by noise, demonstrating feasibility and high performance compared to the maximum entropy method in reverberation mapping analysis.