docs: def PSD_fitting_eqn_with_background(A, OmegaTrap, Gamma, FlatBackground, omega):
      """
      The value of the fitting equation:
      A / ((OmegaTrap**2 - omega**2)**2 + (omega * Gamma)**2) + FlatBackground
      to be fit to the PSD
  
      Parameters
      ----------
      A : float
          Fitting constant A
          A = γ**2*Γ_0*(2*K_b*T_0)/(π*m)
          where:
              γ = conversionFactor
              Γ_0 = Damping factor due to environment
              π = pi
      OmegaTrap : float
          The trapping frequency in the axis of interest 
          (in angular frequency)
      Gamma : float
          The damping factor Gamma = Γ = Γ_0 + δΓ
          where:
              Γ_0 = Damping factor due to environment
              δΓ = extra damping due to feedback or other effects
      FlatBackground : float
          Adds a constant offset to the peak to account for a flat 
          noise background
      omega : float
          The angular frequency to calculate the value of the 
          fitting equation at 
  
      Returns
      -------
      Value : float
          The value of the fitting equation
      """
      return A / ((OmegaTrap**2 - omega**2)**2 + omega**2 * (Gamma)**2) + FlatBackground