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Baye's Factor Analysis - Other Epochs: A Deeper Look Into Our Exoplanet Studyby@exoplanetology
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Baye's Factor Analysis - Other Epochs: A Deeper Look Into Our Exoplanet Study

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The theoretical spectral model was updated with respect to Paper III and it now takes into account additional physical processes. For the results presented in Section 3, we ran retrievals using the most updated version of the Bayesian framework. The additional flexibility of petitRADTRANS now allows us to quantify the impact of CIA and scattering in retrieval.
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This paper is available on arxiv under CC 4.0 license.

Authors:

(1) Eleonora Alei, ETH Zurich, Institute for Particle Physics & Astrophysics & National Center of Competence in Research PlanetS;

(2) Björn S. Konrad, ETH Zurich, Institute for Particle Physics & Astrophysics & National Center of Competence in Research PlanetS;

(3) Daniel Angerhausen, ETH Zurich, Institute for Particle Physics & Astrophysics, National Center of Competence in Research PlanetS & Blue Marble Space Institute of Science;

(4) John Lee Grenfell, Department of Extrasolar Planets and Atmospheres (EPA), Institute for Planetary Research (PF), German Aerospace Centre (DLR)

(5) Paul Mollière, Max-Planck-Institut für Astronomie;

(6) Sascha P. Quanz, ETH Zurich, Institute for Particle Physics & Astrophysics & National Center of Competence in Research PlanetS;

(7) Sarah Rugheimer, Department of Physics, University of Oxford;

(8) Fabian Wunderlich, Department of Extrasolar Planets and Atmospheres (EPA), Institute for Planetary Research (PF), German Aerospace Centre (DLR);

(9) LIFE collaboration, www.life-space-mission.com.

Abstract & Introduction

Methods

Results

Discussion

Conclusions

Next Steps & References

Appendix A: Scattering of terrestrial exoplanets

Appendix B: Corner Plots

Appendix C: Bayes’ factor analysis: other epochs

Appendix D: Cloudy scenarios: additional figures

Appendix C: Bayes’ factor analysis: other epochs

As described in Section 2, the theoretical spectral model was updated with respect to Paper III and it now takes into account additional physical processes. For the results presented in Section 3, we ran retrievals using the most updated version of the Bayesian framework.


The additional flexibility of petitRADTRANS now allows us to quantify the impact of CIA and scattering in retrievals. We ran additional retrievals on the clear sky scenarios for R = 50 and S/N = 10. In these retrievals, we altered the number of physical


Notes. Scale for the interpretation of the Bayes’ factor K = ZM1 (D)/ZM2 (D). Adapted from Paper III.


processes that were treated in the petitRADTRANS theoretical spectral model as follows:


– Including both CIA and scattering (setup used in Section 3);


– Excluding both CIA and scattering;


– Including scattering and excluding CIA;


– Including CIA and excluding scattering.


In the runs where scattering is included, we consider selfscattering, surface scattering of the thermal radiation, and gaseous Rayleigh scattering (see Table 5 for references). We do not include aerosol and cloud scattering in the calculation. Since our theoretical spectral model neglects clouds, in this analysis we considered only the cloud-free scenarios. The effect of modeling cloudy spectra using a cloud-free retrieval model will be discussed in detail in the Section 4.2.


To determine the theoretical spectral model configuration that best reproduces the input spectra we performed a Bayes’ factor analysis. The Bayes’ factor is defined as:



Fig. B.1: Corner plot for the posterior distributions from the retrievals of the clear Modern Earth (MOD-CF, dashed contour lines) and cloudy Modern Earth (MOD-C, solid contour lines) scenarios. The black lines indicate the expected values for every parameter. The retrieved values (median and 1-σ uncertainties) are shown in the Table in the top right corner, together with the expected values. The scenarios are color-coded according to Table 1.


The results for the remaining epochs exhibit similar behaviour. In Figure C.2, we show the results for the NOE Earth, Figure C.3 shows the ones for the GOE Earth, and the results for the prebiotic Earth are shown in Figure C.4.


This paper is available on arxiv under CC 4.0 license.