Version 4.3.0

• Add de los Reyes et al.
  equation for covariance noise calibration

• Improve ability to toggle off analysis modules

• Emission-line modeling updates:

  • Enable the stellar velocity to be tied to the gas velocities. The goal is
    to allow for fitting a stellar continuum that can nominally account for
    stellar absorption and nebular emission, even when the continuum has very
    low S/N.
  • Allow kinematic components to be fixed (full integration into the code is
    still in development).
  • Allow for only gas templates to be fit. The continuum will be fit by a
    polynomial.
  • Old construction of emission-line continuum baseline extension ("BASE")
    deprecated. The continuum fit during the stellar-kinematics module and
    the continuum fit during the emission-line model fitting are now
    independent of each other in the reference files.
  • Added parameters that can be used to set how ppxf errors are treated, and
    whether or not groups of spectra should be treated as an "ensemble"; i.e.,
    part of the same galaxy at the same redshift.

• Basic code maintenance