radvel

sofia_redux.spectroscopy.radvel.radvel(header, equinox='J2000')[source]

Calculate the expected extrinsic radial velocity wavelength shift.

The procedure is:

  1. Read date and RA/Dec from header.

  2. Compute barycentric and LSR velocity along line of sight.

  3. Return velocities / speed of light

Parameters:
headerfits.Header

FITS header of the observation, including DATE-OBS, TELRA, and TELDEC

equinoxstr, optional

Equinox of TELRA, TELDEC coordinates

Returns:
float, float

delta lambda / lamdba (positive = shift toward blue). First value is barycentric shift, second value is an additional shift to correct to the local standard of rest (LSR)