make_image_catalog

romanisim.catalog.make_image_catalog(image_filenames, psf, out_base_filename, pixel_scale=0.05)

Construct a RealGalaxyCatalog from a list of image filenames.

GalSim supports catalogs of real galaxies from input images that can be inserted into output images. This function makes it easy to produce a set of files that can be used as a GalSim RealGalaxyCatalog from a list of fits input images. These input images can come from anywhere, but are expected to come from either real imaging or from hydrodynamical simulations.

This routine assumes that all images share a common PSF, which is given as the PSF argument. This PSF is deconvolved before reconvolving with the appropriate filter-specific PSF when rendering a Roman image.

Files are written to the provided base filename, plus “.fits”, “_image.fits”, and “_psf.fits” extensions. The first file contains a binary table with some metadata about the included images; the second contains a file with one HDU for each image; the third includes the PSF image.

Parameters:

image_filenameslist[str]

filenames of images of images to use

psfnp.ndarray[float]

image of PSF through which images were seen

out_base_filenamestr

output filename to use for RealGalaxyCatalog files output here

pixel_scalefloat

pixel scale of PSF and images