Pulsars and neutron stars/ptaSimulate manual

Introduction
The ptaSimulate software has been developed to simulate data files from radio pulsar observations. The majority of the code is based on simulating realistic pulse arrival times, but the code can also produce simulated pulse profiles. The code produces tempo2 parameter (.par) and arrival time (.tim) files. These files can then be run through other pipelines (such as gravitational wave detection pipelines) as if they were actual observations.

Getting the software
The code is relatively straightforward to compile as it is completely written in C and only uses the fftw external library. Compilation will be similar to:

Basic usage
The software makes use of an input text file that must be created by the user. This input file can have any filename and provides a description of the pulsars and the observing system to be simulated. The software is then run as

The software automatically produces a set of directories in the local directory. It then partially fills those directories with output files and also produces a set of tcsh scripts that need to be run to complete the simulations. Typical usage would be:

The output is placed in  where X is the realisation number of the simulation. That directory contains the .par and .tim files for each simulated pulsar. For general usage of ptaSimulate, the following programs are required:


 * psrcat (with up-to-date database file)
 * tempo2 with the $TEMPO2 environment variable correctly set

In order to make profile templates to simulate realistic error bar sizes then the "ptime" software is also required.

Simple single pulsar simulation
The following script demonstrates how to make a very simple simulation. A single pulsar (J0437-4715) is simulated. The data sampling is regular (20 day cadence) and all ToAs have the same frequency (1400 MHz) and uncertainty (1us).

Multiple pulsar simulation
The following script demonstrates how easy it is to simulate multiple pulsars.