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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present a study of the kinematics and structure of the Cep OB3b clusterbased on new spectra obtained with the Hectoschelle spectrograph on the MMT anddata from Spitzer, Chandr}, and Gaia. At a distance of 819+/-16 pc, Cep OB3b isone of the closest examples of a young (~3 - 5 Myr), large (~3000 totalmembers) cluster at the late stages of gas dispersal. The cluster is brokeninto two sub-clusters surrounded by a lower density halo. We fit the empiricaldensity law of King (1962) to each sub-cluster to constrain their sizes andstructure. The richer eastern sub-cluster has circular symmetry, a modestcentral density, and lacks molecular gas toward its core suggesting it hasundergone expansion due to gas dispersal. In contrast, the western sub-clusterdeviates from circular symmetry, has a smaller core size, and containssignificant molecular gas near its core, suggesting that it is in an earlierphase of gas dispersal. We present posterior probability distributions for thevelocity dispersions from the Hectoschelle spectra. The east will continue toexpand and likely form a bound cluster with ~35% of stars remaining. The westis undergoing slower gas dispersal and will potentially form a bound clusterwith ~75% of stars remaining. If the halo dissipates, this will leave twoindependent clusters with ~300 members; proper motions suggest that the twosub-clusters are not bound to each other.

The Dynamics, Structure, and Fate of a Young Cluster During Gas Dispersal: Hectoschelle, Chandra, Spitzer, and Gaia Observations of CepOB3b