jedisim

jedisim is a tool to generate galaxy cluster simulations from real galaxy observational images.

The goal of jedisim is to generate image simulations for galaxy clusters as a part of ARCLETS (Analysis of Realistic Cluster Lensing through Extensive Training Simulations). It is also used to test and calibrate the shape measurements and deblanding in LSST DM stack, as well as mass measurements in CFHT Clusters pipeline.

Copyright: jedisim is property of Ian Dell'Antonio's group. The original source code was developed by Ian Dell'Antonio and Daniel Parker, etc., maintained and updated by Robert Binyang Liu and Shenming Fu. For more details about the copyright, please refer to the LICENSE file.
Claim: Due to the limitation of single file size on github, we cannot upload all the galaxy postage stamps here. We will upload them somewhere else.

Updates:

2019-6-28: Updated the Copyright section and the LICENSE file.

2018-10-31: jedisim6.0 has created the new jedidistortDC2 code to ingest DC2 alpha map as a single lens plane.

2018-02-28: jedisim5.4 has updated jedinoise code to generate sky noise with a Gaussian distribution. The config parameter noise_mean is now replaced with noise_std.

2017-08-18: jedisim5.3 has scripts to add fake WCS information to the simulation images (at LSST pixel scale).

2016-07-17: jedisim5.2 has added 201 images from CANDELS GOODS-S sect23 F814W corresponding to the F606W images. In the distortion code, type=3 generates the distortion table with a single shear, thus we suggest to use type=2 in grid simulations.

2016-02-22: jedisim5.1 has included 201 images from CANDELS GOODS-S sect23 F606W.

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1. Introduction and implementation

• Please refer to the documentations:

  • jedisim/documentation/jedisim4_jedisim.pdf

  • jedisim/documentation/jedisim4_lensing.pdf

2. Configuration

Modify your settings in jedisim/physics_settings/

(The config files can be stored anywhere you like. By default, I put them under this folder. If you have them in different directories or with different file names, make sure you modify the simulation command in the next section accordingly).

Lens parameter

• Modify the lens parameter file "lens*.txt".

• Modify the file name of "lens*.txt" in "config" or "config_grid" correspondingly.

• Format of lens parameter file "lens*.txt": x y type p1 p2

  • where x - x center of lens (in pixels)

    • y - y center of lens (in pixels)

    • type - type of mass profile

      1 = Singular isothermal sphere

      2 = Navarro-Frenk-White profile

      3 = NFW constant distortion profile for grid simulations

    • p1 - first profile parameter

      1 = sigma_v [km/s]

      2 = M200 parameter [10^14 solar masses]

      3 = Distance to center in pixels. M200 fixed at 20 default, which can be modified in case 3

    • p2 - second profile parameter

      1 = not applicable, can take any numerical

      2 = concentration parameter [dimentionless]

      3 = concentration parameter [dimentionless]

  • We recommend to use type=2 (NFW profile) for cluster simulations, and type=1 (SIS profile) for grid simulations.

Configuration file

• Modify the configuration file "config" for cluster simulation or "config_grid" for grid simulation.

• Include the PSF file into the "physics_settings/" folder, and specify the PSF file name in the configuration file.

• The simulation output is rescaled from HST pixel scale to the final pixel scale set in the configuration file.

• For grid simulations:

  • Set the grid_radius (in pixels) and grid_angle (in radian) in the configuration file.
  • Set sigma_v (in km/s) in the lens parameter file.
  • Make sure the grid_radius is smaller than half of the image size.

3. Usage

Under "jedisim" directory:

make
python jedimaster.py physics_settings/config

Please note that you may need to modify the makefile according to your dependency library path.

4. Output

• Specify the directory of output images (eg. "trial_1/") in the output settings section of "config" file.

• Specify the output prefix (eg. "trial1_") in the output settings section of "config" file.

• There are corresponding simulation output in which the galaxies are 90 degree rotated in output directory (eg. "90_trial_1/").

5. WCS

• By default, cluster and grid simulations have no WCS information in fits headers. To add ra-dec coordinates, run

python jediWCS.py /path/to/LSST/simulation

6. Others

• The original images and radius/redshift data are in "jedisim/simdatabase/".

• The source codes are in "jedisim/sources/".

• Other parameters can be modified in "jedisim/sources/jedidistort.c" (eg. OMEGA_M, G, H0).

• If any modifications are made in "jedisim/source/" folder, remove the UNIX executable files in "jedisim/" (jedicatalog, jediconvolve, jedidistort, jedigrid_a, jedigrid_b, jedinoise, jedipaste, jedirescale, jeditransform) and regenerate them.

Citation

Please cite the following paper(s) if you are using jediSim:

• Liu et al., Measurement and Calibration of Non-Linear Shear Terms in Galaxy Cluster Fields, Front. Astron. Space Sci., Volume 11 - 2024, doi: 10.3389/fspas.2024.1411810