ELFO Documentation
This document describes the principles behind ELFO and explains how to install and use ELFO.
ELFO (Emission Line Fitting Optimization) is a Python package designed to improve emission‐line fitting in integral‐field spectroscopy (IFS) data taken with the Chinese Space Station Telescope (CSST‑IFS).
ELFO uses PyQSOFit to fit each spectrum individually and leverages the spatial correlation inherent in IFS data—stemming from the continuity of physical processes across neighboring spaxels—to improve emission‑line fitting. PyQSOFit employs the Levenberg–Marquardt least‐squares algorithm, and choosing appropriate initial guesses for the model parameters is critical. ELFO processes spectra in a user‑defined spatial sequence, using the fitted results of neighboring spaxels to set the initial parameters for each fit.
We also provide a selection algorithm to pick the best results from different fitting orders. Currently ELFO is used to improve Hα emission‐line fits in quasar spectra, but its general framework makes it easy to apply to other quasar lines or to emission‐line fitting in any other IFS data.
Usage
API/Code Reference
Additional Notes / More Details
- Author
Hui Guo
- Institute
university of science and technology of china
- Contact
- Last updated
2025-09
Acknowledgments
This project is supported by the CSST scientific data processing and analysis system of the China Manned Space Project and Shanghai Academic/Technology Research Leader (22XD1404200).