cwitools.measurement.eff_radius

cwitools.measurement.eff_radius(obj_in, obj_id=1, unit='px', redshift=None, cosmo=FlatLambdaCDM(name="WMAP9", H0=69.3 km / (Mpc s), Om0=0.286, Tcmb0=2.725 K, Neff=3.04, m_nu=[0. 0. 0.] eV, Ob0=0.0463))

Determines the effective radius (sqrt(Area/pi)) of a 2D or 3D object.

Parameters:

• obj_in (astropy HDU or HDUList) – 2D or 3D mask of object(s) with header.
• obj_id (int) – The ID of the object to measure. Default is 1.
• unit (str) – Output unit of radius measurement. ‘px’: pixels ‘arcsec’: arcseconds ‘pkpc’: proper kiloparsec ‘ckpc’: comoving kiloparsec
• redshift (float) – The redshift of the object(s)
• cosmology (FlatLambdaCDM) – Cosmology to use, as one of the inbuilt ~astropy.cosmology.FlatLambdaCDM instances (default WMAP9)

Returns:

The effective radius in the requested units

Return type:

float