Visibilities simulation and shape model fitting of radio star-forming galaxies for Radio Weak Lensing
This is a MPI+OpenMP code for simulating visibilities of observed SF galaxies by using SKA1-MID configuration, and measuring galaxy ellipticities in the visibility domain adopting a Bayesian model fitting approach. It uses an exponential Sersic model and works in the visibility domain avoiding Fourier Transform.
v1.0 - single galaxy at the phase centre (MPI+OpenMP parallelization)
v1.1 - single galaxy in the field of view, natural gridding
GSL library is required.
- Edit the Makefile:
- enable/disable MPI and OpenMP (default: serial)
- enable/disable gridding (default: gridding enabled)
- set the compiler and compilation flags you want to use (default: GNU)
- Make.
The radio telescope configuration is set at the beginning of the main() function for SKA1-MID. The source catalog is generated according to the galaxy parameters distributions.
RadioLensfit.x <filename u-coord> <filename v-coord> <nge> <shear1> <shear2> <flux-cut>
- nge*10 galaxies will be simulated with flux larger than <flux-cut> [in muJy].
- g = (g1,g2) is the shear to apply to the ellipticity of each galaxy.
- Coordinate files are assumed to be txt containing one coordinate per line.
The code produces a file, called ellipticities<n>.txt, for each MPI task (n=0,1,...N) where each row contains the following galaxy data:
- flux [muJy]
- scalelength [arcsec]
- e1 (original)
- m_e1 (measured)
- err1 (e1 measure error)
- e2 (original)
- m_e2 (measured)
- err2 (e2 measure error)
- 1D likelihood variance
- SNR
- l (source coordinates with respect to the phase centre)
- m
If you use RadioLensfit and find it useful, please consider citing the related paper:
Radio Weak Lensing Shear Measurement in the Visibility Domain I. Methodology, Rivi M., Miller L., Makhathini S., Abdalla F. B., 2016, MNRAS, 463, 1881 - arXiv:1603.04784