Fitting infrared ice spectra with genetic modelling algorithms Presenting the ENIIGMA fitting tool
| Autor: | W. R. M. Rocha, Lars E. Kristensen, G. Perotti, Jes K. Jørgensen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
Infrared Evolutionary algorithm MU-M FOS: Physical sciences Context (language use) LOW-MASS STARS 01 natural sciences Spectral line Matrix decomposition symbols.namesake 0103 physical sciences Range (statistics) OPTICAL-CONSTANTS Instrumentation and Methods for Astrophysics (astro-ph.IM) 010303 astronomy & astrophysics SPITZER SPECTROSCOPIC SURVEY Solar and Stellar Astrophysics (astro-ph.SR) molecules [ISM] protostars [stars] ASTROPHYSICAL ICES 0105 earth and related environmental sciences Physics ABSORPTION FEATURES astrochemistry INTERSTELLAR ICE ISM [infrared] Astronomy and Astrophysics LINE-OF-SIGHT YOUNG STELLAR OBJECTS Astrophysics - Astrophysics of Galaxies Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science Gaussian noise Astrophysics of Galaxies (astro-ph.GA) symbols Astrophysics::Earth and Planetary Astrophysics ORGANIC-MOLECULES Astrophysics - Instrumentation and Methods for Astrophysics Degeneracy (mathematics) Algorithm volatile [solid state] |
| Zdroj: | Rocha, W R M, Perotti, G, Kristensen, L E & Jorgensen, J K 2021, ' Fitting infrared ice spectra with genetic modelling algorithms Presenting the ENIIGMA fitting tool ', Astronomy & Astrophysics, vol. 654, A158 . https://doi.org/10.1051/0004-6361/202039360 |
| DOI: | 10.1051/0004-6361/202039360 |
| Popis: | Context. A variety of laboratory ice spectra simulating different chemical environments, ice morphology as well as thermal and energetic processing are demanded to provide an accurate interpretation of the infrared spectra of protostars. To answer which combination of laboratory data best fit the observations, an automated statistically-based computational approach becomes necessary. Aims. To introduce a new approach, based on evolutionary algorithms, to search for molecules in ice mantles via spectral decomposition of infrared observational data with laboratory ice spectra. Methods. A publicly available and open-source fitting tool, called ENIIGMA (dEcompositioN of Infrared Ice features using Genetic Modelling Algorithms), is introduced. The tool has dedicated Python functions to carry out continuum determination of the protostellar spectra, silicate extraction, spectral decomposition and statistical analysis to calculate confidence intervals and quantify degeneracy. As an assessment of the code, several tests were conducted with known ice samples and constructed mixtures. A complete analysis of the Elias 29 spectrum was performed as well. Results. The ENIIGMA fitting tool can identify the correct ice samples and their fractions in all checks with known samples tested in this paper. Concerning the Elias 29 spectrum, the broad spectral range between 2.5-20 $\mu$m was successfully decomposed after continuum determination and silicate extraction. This analysis allowed the identification of different molecules in the ice mantle, including a tentative detection of CH$_3$CH$_2$OH. Conclusions. The ENIIGMA is a toolbox for spectroscopy analysis of infrared spectra that is well-timed with the launch of the James Webb Space Telescope. Additionally, it allows for exploring the different chemical environments and irradiation fields in order to correctly interpret astronomical observations. Comment: 23 pages, 19 figures, 3 tables. Accepted for publication in A&A |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|