compute_SEP_auto_params

grizli.prep.compute_SEP_auto_params(data, data_bkg, mask, pixel_scale=0.06, err=None, segmap=None, tab=None, grow_kron=6.0, autoparams=[2.5, <Quantity 0.35 arcsec>, 2.4, 3.8], flux_radii=[0.2, 0.5, 0.9], subpix=0, verbose=True)[source]

Compute SourceExtractor-like AUTO params with sep https://sep.readthedocs.io/en/v1.0.x/apertures.html#equivalent-of-flux-auto-e-g-mag-auto-in-source-extractor

Parameters
data2D array

Image data

data_bkg2D array

Background-subtracted image data

mask2D array

Pixel mask

pixel_scalefloat

Pixel scale, arcsec

err2D array

Uncertainty array

segmap2D array

Associated segmentation map

tabTable

Table from, e.g., sep.extract.

grow_kronfloat

Scale by which semimajor and semiminor axes are multiplied for calculating the Kron moment. This is hard-coded as grow_kron=6.0 in SourceExtractor.

autoparamslist

Provided as [k, MIN_APER, MIN_KRON, MAX_KRON], where the usual SourceExtractor PHOT_AUTOPARAMS would be [k, MIN_KRON]. Here, k is the scale factor of the Kron radius, and MIN_KRON is the minimum scaled Kron radius to use. MIN_APER is then the smallest circular Kron aperture to allow, which can be provided with attached units (e.g. arcsec).

flux_radiilist

Light fraction radii, e.g., [0.5] will calculate the half-light radius (FLUX_RADIUS)

subpixint

Pixel oversampling with the sep aperture functions

Returns
autoTable

Table with the derived parameters

Column

Description

kron_radius

Kron radius, pixels

kron_rcirc

Circularized Kron radius, pixels

flux_auto

Flux within AUTO aperture

fluxerr_auto

Uncertainty within AUTO aperture

bkg_auto

Background within AUTO aperture

flag_auto

sep flags for AUTO aperture

area_auto

Pixel area of AUTO aperture