cwitools.synthesis.cylindrical

cwitools.synthesis.cylindrical(fits_in, center, seg_mask=None, ellipticity=1.0, pos_ang=0.0, n_r=None, npa=None, r_range=None, pa_range=None, d_r=None, dpa=None, c_radec=False, compress=True, 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))
Resample a cube in cartesian coordinate to cylindrical coordinate (with ellipticity).
This function can be used to project 3D cubes to the 2D spectra in lambda-r space.
Parameters:
  • fits_in (astropy HDU or HDUList) – Input HDU/HDUList with 3D data.
  • center (float tuple) – Center of the cylindrical projection, in pixel coordinate or [RA, DEC] if c_radec is True.
  • seg_mask (float arrray) – Segment mask in 2D (typically generated by SExtractor) that masks additional continuum sources that do not corresponds to the central object.
  • ellipticity (float) – Axis-ratio.
  • pos_ang (float) – Position angle of the MAJOR axis that is east of the north direction.
  • n_r (int) – Number of pixels of the post-projection cubes in the radial direction. Default: The closest integer that makes the size of individual pixels to be 0.3 arcsec in the major axis.
  • npa (int) – Number of pixels of the post-projection cubes in the angular direction. Default: The closest integer that makes the size of individual pixels to be 1 degree.
  • r_range (float tuple) – radial bins in major axies inside which the projection is applied. Default: 0 to the minimum radius to include all signals in the input cube.
  • pa_range (float tuple) – position angles bins inside which the projections is applied. Default: [0,360]
  • d_r (float) – radial size per pixel.
  • dpa (float) – PA size per pixel.
  • c_radec (bool) – If set, the center is specified using [RA, DEC] instead of pixels.
  • compress (bool) – Remove axis with only 1 pixel. This risks of losing WCS information on the corresponding axis, but is convenient when using DS9.
  • cosmo (FlatLambdaCDM) – The cosmology to use, as one of Astropy’s cosmologies (astropy.cosmology.FlatLambdaCDM). Default is WMAP9.
  • redshift (float) – If set, an additional WCS is added to represent rest-wavelength and pkpc.
Returns:

Post-projection image/cube. HDU / HDUList*: Coverage image. *Return type matches type of fits_in argument.
Return type:

HDU / HDUList*