Unraveling Nonlinear Physics of High-Z Regions Using Neural Networks
This research explores the nonlinear physics of high-metallicity (high-Z) regions through neural networks, focusing on the calibration of abundances and the development of new abundance indicators. It discusses the application of AI in astrophysics, specifically for resolving empirical relations between emission line fluxes and fundamental parameters such as ionization, metallicity, and temperature. The study presents an innovative approach to model and analyze the astrophysical phenomena observed in Galactic and extra-Galactic HII regions, paving the way for future advancements in astrophysical data analysis.
Unraveling Nonlinear Physics of High-Z Regions Using Neural Networks
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Presentation Transcript
Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz michael@damir.iem.csic.es Sun M51 Rosette CNSFR
Fundamental Functional parameters Abundances AI - A new opportunity n-D Calibrations Ideas for the future De-projection Theory Physics & knowledge Emission Line Fluxes (I) Imaging Photoionisation Modelling & Simulation Empirical Relations & Calibrations Abundance indicators S23 O23 all fundamental parameters eta Softness parameter Abundance indicator S23 Z Metallicity Effective Temperature Ionisation parameter T* U Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
The IDEAL Indicator xn? Abundances AI - A new opportunity n-D Calibrations Ideas for the future Would be MONOTONIC with respect to metallicity Z Would be observationally detectable up to high Z Would have low average dispersion (least-square error) Would span a W I D E range of Zwhen empirically-calibrated using REAL galaxy data & IF ALL THAT WENT PERFECTLY… It would also be independent of chemical evolution and have an understandable behaviour with Z ? Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Observational Limits at high Z Abundances AI - A new opportunity n-D Calibrations Ideas for the future Z=12+log(O/H)=8.66±0.05 Asplund et al 2004 Commonly used auroral-to-nebular emission line ratios… Bresolin 2006 8m telescope observing limit Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Indicators in HII-like regions Abundances AI - A new opportunity n-D Calibrations Ideas for the future Galactic HII-Regions Extra-Galactic HII-Regions HII Galaxies CNSFRs? Perez-Montero 2002 Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
AI: An opportunity Abundances AI - A new opportunity n-D Calibrations Ideas for the future Scale-invariant And Genetic Algorithm Network(SAGAN) Architecture Weights Node Functions Dimensional Analysis Taylor & Diaz 2006 Net DNA Ecoding Multi-Layer Perceptron + Genetic Operators Mutation Cross-over + Back-Propagation + Pruning Algorithm UNIVERSAL FUNCTION APPROXIMATOR Taylor 2005 103 ERROR REDUCTION Taylor 2005 EQUATIONS Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
A new strategy Abundances AI - A new opportunity n-D Calibrations Ideas for the future LINE RATIOS 1 Emission line fluxes 4 5 6 2 3 GA (Genetic Algorithm) CALIBRATIONS About the sample Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
How it Works: e.g. Newton’s Law Abundances AI - A new opportunity n-D Calibrations Ideas for the future IDEAL SOLUTION m h3 1 1 a h3 h2 F e h3 PRUNED NODES inputs outputs Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Newton’s Law: F=ma (EXACT) Abundances AI - A new opportunity n-D Calibrations Ideas for the future G=2 G=5 G=8 G=38 Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Newton’s Law: F=ma (10% Errors) Abundances AI - A new opportunity n-D Calibrations Ideas for the future G=38 10% Errors G=780 G=995 G=161 Error Generation Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
HII-like regions: HIIGs, GHIIRs & EGHIIRs Abundances AI - A new opportunity n-D Calibrations Ideas for the future log(S23) elog(S23) SAGAN h3 h2 eZ Z e h3 e-space Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Training & Evaluation Data Abundances AI - A new opportunity n-D Calibrations Ideas for the future Exponential Space Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
SAGAN Evolution (2 days on a dual 3Ghz PC) Abundances AI - A new opportunity n-D Calibrations Ideas for the future Taylor & Diaz, 2007, PASP, 374, 104 Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Evolution of the calibration: Z=f(S23) Abundances AI - A new opportunity n-D Calibrations Ideas for the future Dispersion=0.183 dex Dispersion=0.22 dex Dispersion=0.181 dex Dispersion=0.16 dex Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Fitting & n-D Calibrations Abundances AI - A new opportunity n-D Calibrations Ideas for the future e.g. Dimensionless Line Ratios Needs a big and homogeneous data-set Can potentially reduce subjectivity Can potentially identify new indicators Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
A sample for n-D studies Abundances AI - A new opportunity n-D Calibrations Ideas for the future Izotov et al 2006 144 objects (another 163 from other sources) using Pilyugin, Thuan and Vilchez, 2006 Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Data classification with the BPT plot Abundances AI - A new opportunity n-D Calibrations Ideas for the future Kniazev et al 2004 This work Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Metallicity and O23 Abundances AI - A new opportunity n-D Calibrations Ideas for the future Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Metallicity and S23 Abundances AI - A new opportunity n-D Calibrations Ideas for the future ? Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
The role of S (S+, S2+, S, ICF) Abundances AI - A new opportunity n-D Calibrations Ideas for the future ! ? What do these curves depend on? Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Trends of U and η with S23 Abundances AI - A new opportunity n-D Calibrations Ideas for the future U(o) U(o) v U(s) η T* or age? ZAMS Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Data in the η-U-S23 space Abundances AI - A new opportunity n-D Calibrations Ideas for the future Clustering objects with Z Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Fitting with a plane Abundances AI - A new opportunity n-D Calibrations Ideas for the future Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Fitting with a Gaussian surface Abundances AI - A new opportunity n-D Calibrations Ideas for the future Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
The biggest question… Abundances AI - A new opportunity n-D Calibrations Ideas for the future This mapping is possible if we can define a scale of effective temperature T* using empirical measures ONLY. But how? Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz
Ideas for the Future Abundances AI - A new opportunity n-D Calibrations Ideas for the future To find new n-D indicators & improve calibrations of the form: Z=f(c, x1,x2…xn) for HII-like regions and then for AGNs and PNs Find the relation and to test its robustness To investigate finding an empirical scale for T* On behalf of myself, Pepe and Angeles, I would like to thank Guille Hägele, Enrique Perez-Montero and Mariluz Martin for kindly making observational data available and to everyone who has patiently and carefully taken accurate images Many thanks Unravelling the nonlinear physics of high-Z regions with neural networks Mike Taylor, Pepe Vilchez & Angeles Diaz