luciagarate/HSC_PSFs: HSC-PDR3 PSFs

PSF FITS files

The HSC-SSP PDR3 PSF 2-D models are available as FITS files at PSF_fits/. These files are compressed FITS files of 4001x4001 pix², where the second extension contains the image data. These PSFs models are appropriate for the HSC-PDR3 intermediate-state data which do not have applied the final aggressive background subtraction. The intermediate-state data is especially stored for users interested in large extended objects

There are two versions of each PSF file: symmetric (HSC_PSF_band.FITS) and assymetric (HSC_PSF_band_asymmetric.FITS). The first versions were obtained by applying an extra step to make them rotationally symmetric 2-D PSFs. The user should choose which one to use depending on their science goals. Check MNRAS paper for more details: https://doi.org/10.1093/mnras/stae1292.

Scripts for reconstruction

The reconstruction of the PSF is divided into 3 scripts available at Scripts/: "1_StarSelection.R", "2_Stacking.R", and "3_Combining.R". "1_StarSelection.R" selects the coordinates of stars from the GAIA catalogue (available as CSV files at GAIA_catalogues/), finds the HSC image of each star, and creates cutouts. This is done for each region of the PSF (outer, middle, inner, and core) and per HSC band (g, r, i, Z, Y). The next step is "2_Stacking.R", which performs an stack of all the selected stars per PSF region and band. In the last script, "3_Combining.R", we construct an HSC-SSP PDR3PSF per HSC band by combining the outer + middle + inner + core regions. The resulting stack is saved as a FITS file.