Navigating the Stellar Landscape: Insights from SigMA Analysis of Orion's Young Star Clusters

Recent advancements in large-scale astronomical survey data have enabled an unprecedented exploration of the intricate dynamics of young stellar populations and clusters. These technical developments, such as precise astrometry and high-resolution mapping of stellar positions and motions, are particularly enticing when applied to the investigation of young stellar populations and clusters within star-forming regions. One such region of interest is the Orion molecular cloud complex, which, despite its scientific prominence, still remains incompletely characterized. Understanding the dynamics and properties of young stellar populations in this region is essential for unraveling the complexities of star formation.

We present a comprehensive analysis of the spatio-kinematic structure of the Orion star forming complex using the Significance Mode Analysis (SigMA) clustering algorithm. SigMA is highly sensitive to low stellar volume densities and velocity dispersions as well as specifically tailored to extract co-moving and co-eval groups from 5D positional and kinematic phase-space data. With our investigation, we aim to access the information of the region's complex structure and evolution that is encoded within its stellar populations.

We identified more than 15,000 comoving and co-eval young stars in the Orion region, organized into approximately 40 clusters. Comparing our findings to the study conducted by Chen et al. in 2020, we confirm the existence of almost all previously identified populations. However, our analysis often reveals between 50% to 100% more sources than previously recognized. Additionally, we identify 8 clusters not included in their selection, some of which are situated near Rayleigh-Taylor fingers or associated with nebulae or gas cavities. This discovery carries significant implications for our understanding of star formation processes and propagation.

Finally, we estimate ages for each of the sub-populations identified with SigMA, providing valuable insights into the formation history of the region. We also explore potential age-position patterns, shedding light on the dynamic processes shaping the Orion star-forming complex.