Large volumes of high-quality spectroscopic data are now becoming available thanks to the James Webb Space Telescope, as well as major ground-based facilities such as SUBARU/PFS and VLT/MOONS. In response to this exciting development, we are releasing a brand-new version of CIGALE.
This release not only preserves the extensive range of physical processes that can be modeled and the exceptional speed inherited from earlier versions, but also introduces a major new feature: the ability to analyze spectroscopic and/or photometric data simultaneously. ore specifically, we would like to highlight the following:
- Spectroscopic data can be normalized to the available photometric data, if any are provided. To do this, CIGALE integrates the spectrum through the corresponding photometric filters and models the resulting slit correction using polynomials of degree 0, 1, or 2. The optimal degree is then selected via a BIC test. However, caution is warranted when applying this correction, for reasons discussed in the literature—the most obvious being that spectroscopic and photometric observations often probe different regions of a galaxy.
- Documentation for running the spectro-photometric version of CIGALE is available, together with a sample dataset of galaxies and the corresponding fit results. You can install CIGALE and test it directly on this sample, as all the required files are provided.
- This version of CIGALE incorporates the new line-emission models of (Theulé et al. 2024). The inclusion of spectral information further improves the estimation of key parameters such as dust attenuation and gas metallicity (see Burgarella et al. 2025).
- All the features of the standard version of CIGALE remain available. Note, however, that the current spectroscopic implementation is built on the last-but-one CIGALE 2022.1. An update to a more recent base version will be released in the future.
It is recommended to use a recent version of Python, it has been tested with version 3.11.