SourceCatalogStep

class jwst.source_catalog.SourceCatalogStep(name=None, parent=None, config_file=None, _validate_kwds=True, **kws)

Bases: JwstStep

Create a final catalog of source photometry and morphologies.

Create a Step instance.

Parameters:

• name (str, optional) – The name of the Step instance. Used in logging messages and in cache filenames. If not provided, one will be generated based on the class name.

• parent (Step instance, optional) – The parent step of this step. Used to determine a fully-qualified name for this step, and to determine the mode in which to run this step.

• config_file (str or pathlib.Path, optional) – The path to the config file that this step was initialized with. Use to determine relative path names of other config files.

• **kws (dict) – Additional parameters to set. These will be set as member variables on the new Step instance.

Attributes Summary

class_alias
reference_file_types
spec

Methods Summary

process(input_model)

Create the catalog from the input datamodel.

Attributes Documentation

class_alias = 'source_catalog'

reference_file_types: ClassVar = ['apcorr', 'abvegaoffset']

spec

aperture_ee1 = integer(default=30)    # aperture encircled energy 1
aperture_ee2 = integer(default=50)    # aperture encircled energy 2
aperture_ee3 = integer(default=70)    # aperture encircled energy 3
ci1_star_threshold = float(default=2.0)  # CI 1 star threshold
ci2_star_threshold = float(default=1.8)  # CI 2 star threshold
suffix = string(default='cat')        # Default suffix for output files
starfinder = option('dao', 'iraf', 'segmentation', default='segmentation') # Star finder to use.

# general starfinder options
snr_threshold = float(default=3.0) # SNR threshold above the bkg for star finder
bkg_boxsize = integer(default=1000) # The background mesh box size in pixels.
kernel_fwhm = float(default=2.0) # Gaussian kernel FWHM in pixels

# kwargs for DAOStarFinder and IRAFStarFinder, only used if starfinder is 'dao' or 'iraf'
minsep_fwhm = float(default=0.0) # Minimum separation between detected objects in FWHM
sigma_radius = float(default=1.5) # Truncation radius of the Gaussian kernel, units of sigma
sharplo = float(default=0.5) # The lower bound on sharpness for object detection.
sharphi = float(default=2.0) # The upper bound on sharpness for object detection.
roundlo = float(default=0.0) # The lower bound on roundness for object detection.
roundhi = float(default=0.2) # The upper bound on roundness for object detection.
brightest = integer(default=200) # Keep top ``brightest`` objects
peakmax = float(default=None) # Filter out objects with pixel values >= ``peakmax``

# kwargs for SourceCatalog and SourceFinder, only used if starfinder is 'segmentation'
npixels = integer(default=25) # Minimum number of connected pixels
connectivity = option(4, 8, default=8) # The connectivity defining the neighborhood of a pixel
nlevels = integer(default=32) # Number of multi-thresholding levels for deblending
contrast = float(default=0.001) # Fraction of total source flux an object must have to be deblended
multithresh_mode = option('exponential', 'linear', 'sinh', default='exponential') # Multi-thresholding mode
localbkg_width = integer(default=0) # Width of rectangular annulus used to compute local background around each source
apermask_method = option('correct', 'mask', 'none', default='correct') # How to handle neighboring sources
kron_params = float_list(min=2, max=3, default=None) # Parameters defining Kron aperture
deblend = boolean(default=False) # deblend sources?

Methods Documentation

process(input_model)

Create the catalog from the input datamodel.

Parameters:

input_model (str or ImageModel) – A FITS filename or an ImageModel of a drizzled image.

Returns:

catalog – The source catalog, or None if no sources were found.

Return type:

astropy.table.Table or None