English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In order to study the stellar population and possible substructures in theoutskirts of Double Cluster $h$ and $\chi$ Persei, we investigate using theGAIA DR2 data a sky area of about 7.5 degrees in radius around the DoubleCluster cores. We identify member stars using various criteria, including theirkinematics (viz, proper motion), individual parallaxes, as well as photometricproperties. A total of 2186 member stars in the parameter space were identifiedas members. Based on the spatial distribution of the member stars, we find anextended halo structure of $h$ and $\chi$ Persei, about 6 - 8 times larger thantheir core radii. We report the discovery of filamentary substructuresextending to about 200 pc away from the Double Cluster. The tangentialvelocities of these distant substructures suggest that they are more likely tobe the remnants of primordial structures, instead of a tidally disrupted streamfrom the cluster cores. Moreover, the internal kinematic analysis indicatesthat halo stars seems to be experiencing a dynamic stretching in the RAdirection, while the impact of the core components is relatively negligible.This work also suggests that the physical scale and internal motions of youngmassive star clusters may be more complex than previously thought.

The substructure and halo population of the Double Cluster $h$ and $\chi$ Persei