Context. One of the key tools for understanding the evolution of young stellar objects (YSOs) is to analyse their spectral energy distributions (SEDs). As part of the NEMESIS project, we have performed a large-scale SED fitting analysis of the Orion star formation complex (OSFC).
Aims. We aim to derive key physical parameters, including temperature, luminosity, mass, and age, for a large sample of sources in the OSFC using synthetic SED models. Our goal is to establish a statistically robust characterisation of the stellar population and its evolutionary state across the entire complex.
Methods. We utilize a set of new radiative transfer model SEDs that span a variety of geometries and parameter spaces. These SEDs are fitted to multi-wavelength photometric data from optical to submillimeter wavelengths. We conducted SED fitting on a sample of 15 396 sources. Among these, 5062 have at least a reliable W3 (12 µm) detection at longer wavelengths, and 63 have sub-millimeter detections in APEX/SABOCA at 350 µm or APEX/LABOCA at 870 µm. The resulting physical parameters are cross-referenced with stellar evolutionary tracks to ensure consistency with theoretical predictions.
Results. The derived parameters reveal a diverse stellar population. Sources placed on the Hertzsprung-Russell diagram show distinct evolutionary sequences. The results are provided with varying levels of completeness and reliability, depending on the available data for each source. The catalogue includes quality indicators such as the flux code, which represents the longest detected wavelength for each source, as well as Prob_W3 and Prob_W4 values that quantify the reliability of the AllWISE W3 and W4 detections. All results, including SED fitting outcomes, uncertainty estimates, and source metadata, are publicly available in a comprehensive CDS table.
Conclusions. This dataset provides a statistically significant view of the evolutionary processes within the OSFC. The publicly accessible dataset offers a valuable resource for future studies on star and planet formation.
