Generating Simulation Data

The code can generate simulation data by setting FlagRec to 0 in parameter file (see Parameter File).

The output simulation data files are sim_ptr.txt, sim_signal.txt, sim_source.txt, sim_phase.txt and sim_snr.txt in the subdirectory data/.

  • sim_ptr.txt is the simulated pulsar timing residuals, whose format is described in Data Format.

  • sim_signal.txt is the corresponding noiseless pulsar timing residuals.

  • sim_source.txt is model parameters of close binaries of supermassive black holes randomly generated. It contains eight columns, which represent right ascension (rad), sine of declination, cosine of inclination, polarization (rad), initial orbital phase (rad), logarithm of initial orbital angular frequency (rad per year) and logarithm of merging time (year).

  • sim_phase.txt contains pulsar phase parameters. It has \(N_{\rm s}\) rows and \(N_{\rm p}\) columns, where \(N_{\rm s}\) and \(N_{\rm p}\) are numbers of sources and pulsars respectively. The value in i-th row and j-th column is the pulsar phase of j-th pulsar to the i-th source.

  • sim_snr.txt is the signal-to-noise ratio of each source.

Run

python plot_sim.py

in the analysis subdirectory will output figures residual_sim.pdf and skymap_sim.pdf.

  • residual_sim.pdf is the plot of simulated pulsar timing residuals of each pulsar.

  • skymap_sim.pdf is the distribution of pulsars and sources on the celestial sphere.

_images/residual_sim.png

Example for simulated timing residuals of a pulsar. The red line is the noiseless signal.

_images/skymap_sim.png

Example for distribution of simulated pulsars and sources on the celestial sphere. The blue points and black triangles are sources and pulsars respectively. The depth of the blue color indicates the SNR of the source.