Left panels: demodulated interstellar ²H (top) and ³He (bottom) envelopes at 95% CIs times . Right panels: top-of-atmosphere secondary-to-primary ratio ²H/⁴He (top) and ³He/⁴He (bottom) ratios. The full envelopes correspond to the “best” simultaneous analysis (secondary-to-primary ratio + primary flux) for model II (blue) and III (red). The hatched envelopes correspond to the ³He/⁴He analysis (prior on source parameters). See Table A.1 for references and the corresponding demodulation (for IS) and modulation (TOA) level φ.