Simple morphological distribution of the sample groups in the three projection planes. The size of the open circles is proportional to the inverting area(s) of the sample groups at each projection plane. All colored arrows point to the maximum directions of stretching (Athe above) of the sample groups at each projection level. The red crosses in each panel represent sample groups without the layered structure. An open celestial pentagram in each panel indicates the Sun and a thick gray arrow in the left panel indicates the direction of the galactic center. The yellow dashed line (Z = -20.8 pc) in the middle and right panels is modeled as the galactic midplane of the Milky Way. credit: Astronomy and astrophysics (2023). DOI: 10.1051/0004-6361/202244199
The morphological study of open clusters can provide observational evidence to trace the formation mechanism of star clusters and help explore the evolution of star clusters.
The shape of the open clusters on two-dimensional (2D) projection planes mostly corresponds to the structure of the underlying structure. However, it is not known whether this layered structure actually exists in three-dimensional (3D) space.
Recently, researchers from the Xinjiang Astronomical Observatory (XAO) of the Chinese Academy of Sciences proposed a rosette-shaped overlay method based on Gaia data to study the 3D structure of open-cluster samples within 500 parsecs (computers) near the Sun.
The results show that the proposed method can quantitatively visualize the morphology of open star clusters and provide support for the method to determine the 3D structure of open cluster samples. The method may play an important role in the structural classification of open clusters. The study has been published in Astronomy and astrophysics.
The researchers used rosette graphs to quantitatively depict the random shape of open clusters on three projection surfaces in three-dimensional space. The synthetic rosette diagram of each open cluster sample was obtained by superimposition, and whether the composite diagram contained a stable core circuit was used as an indicator to determine whether the open cluster sample had a three-dimensional structure.
They found that if a stable inner circle appears in the pink superimposed diagram of the cluster, then the open cluster has a three-dimensional structure. In addition, they determined the basic parameters of the 3D layered structure, including the core-circle area, the irregular nuclear area, the unstable nucleus area, and the unstable parameters of the layered structure.
Through statistical analysis, they also found that the core-circle area of the open cluster sample maintained a relatively significant positive correlation with the number of member stars, while there was a significant negative correlation between the irregular nuclear area of the stratified cluster structure. Sample open cluster and the number of its member stars.
This study is the first of its kind to explore the 3D structure of open star clusters using the rosette diagram overlay method. The physical mechanism behind the 3D structure of star clusters and the formation conditions of the 3D layered structure of star clusters still need to be further studied.
more information:
Qingshun Hu et al, revealed the layered structure of close open groups, Astronomy and astrophysics (2023). DOI: 10.1051/0004-6361/202244199
the quote: Researchers develop new method for detecting layered structure in open star clusters (2023, April 26) Retrieved April 26, 2023 from https://phys.org/news/2023-04-method-layered-star-clusters.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without written permission. The content is provided for informational purposes only.
