Analysis

mpol.onedim.radialI(icube, geom, chan=0, bins=None)

Obtain a 1D (radial) brightness profile I(r) from an image cube.

Parameters:

• icube (mpol.images.ImageCube object) – Instance of the MPoL images.ImageCube class

• geom (dict) –

  Dictionary of source geometry. Keys:

  ”incl”float, unit=[deg]

  Inclination

  ”Omega”float, unit=[deg]

  Position angle of the ascending node

  ”omega”float, unit=[deg]

  Argument of periastron

  ”dRA”float, unit=[arcsec]

  Phase center offset in right ascension. Positive is west of north.

  ”dDec”float, unit=[arcsec]

  Phase center offset in declination.

• chan (int, default=0) – Channel of the image cube corresponding to the desired image

• bins (array, default=None, unit=[arcsec]) – Radial bin edges to use in calculating I(r). If None, bins will span the full image, with widths equal to the hypotenuse of the pixels

Returns:

• bin_centers (array, unit=[arcsec]) – Radial coordinates of image at center of bins

• Is (array, unit=[Jy / arcsec^2] (if image has these units)) – Azimuthally averaged pixel brightness at rs

mpol.onedim.radialV(fcube, geom, rescale_flux, chan=0, bins=None)

Obtain the 1D (radial) visibility model V(q) corresponding to a 2D MPoL image.

Parameters:

• fcube (~mpol.fourier.FourierCube object) – Instance of the MPoL fourier.FourierCube class

• geom (dict) –

  Dictionary of source geometry. Keys:

  ”incl”float, unit=[deg]

  Inclination

  ”Omega”float, unit=[deg]

  Position angle of the ascending node

  ”omega”float, unit=[deg]

  Argument of periastron

  ”dRA”float, unit=[arcsec]

  Phase center offset in right ascension. Positive is west of north.

  ”dDec”float, unit=[arcsec]

  Phase center offset in declination

• rescale_flux (bool) – If True, the visibility amplitudes are rescaled to account for the difference between the inclined (observed) brightness and the assumed face-on brightness, assuming the emission is optically thick. The source’s integrated (2D) flux is assumed to be: \(F = \cos(i) \int_r^{r=R}{I(r) 2 \pi r dr}\). No rescaling would be appropriate in the optically thin limit.

• chan (int, default=0) – Channel of the image cube corresponding to the desired image

• bins (array, default=None, unit=[klambda]) – Baseline bin edges to use in calculating V(q). If None, bins will span the model baseline distribution, with widths equal to the hypotenuse of the (u, v) coordinates

Returns:

• bin_centers (array, unit=:math:[lambda]) – Baselines corresponding to u and v

• Vs (array, unit=[Jy]) – Visibility amplitudes at q

Notes

This routine requires the frank package