CorrSim: a multiwavelength timing observation simulator

Abstract

Abstract Studying the rapid variability of many astronomical objects is key to understanding the underlying processes at play. However, obtaining data well-suited to this task can be tricky, especially for simultaneous multiwavelength observations. Parameters often have to be fine-tuned while ‘on-site,’ or observations may only be found to not achieve their goals later. Here, we present CorrSim; a program tailored to X-ray Binary analysis, and expandable to many kinds of multiwavelength coordinated observations. CorrSim takes power spectra, coherence, and lags, and returns a simulated multiwavelength observation. The goals of this are: (i) To simulate a potential observation; (ii) To investigate how different Fourier models affect a system’s variability, including data products like cross-correlation functions); and (iii) To simulate existing data and investigate its trustworthiness. We outline CorrSim’s methodology, show how a variety of parameters (e.g. noise sources, observation length, telescope choice) can affect data, and present examples of the software in action. Through CorrSim, we also detail the effects of the length of the data train on Fourier and correlation function uncertainties. We also highlight previous CorrSim modelling, noting that the ‘pre-cognition dip’ seen in X-ray binaries can be constructed by periodic processes, and discuss this result in the wider context.