Analysis of the Kinematic Structure of the Cygnus OB1 association

TL;DR

This study characterizes the velocity field of the Cygnus OB1 association, revealing multiple kinematic groups and structures through analysis of radial velocities and clustering methods, enhancing understanding of its complex substructure.

Contribution

The paper introduces a detailed kinematic analysis of Cygnus OB1 using radial velocity data and clustering techniques, identifying distinct groups and shells within the association.

Findings

Detection of two main kinematic groups with different velocities and distances.

Identification of structures associated with Halpha emission shells.

Discovery of a separate group occupying the entire region, called 'common shell'.

Abstract

The main objective of this study is the characterization of the velocity field in the Cygnus OB1 association using the radial velocity data currently available in the literature. This association is part of a larger star-forming complex located in the direction of the Cygnus region, but whose main subsystems may be distributed at different distances from the sun. We have collected radial velocity data for more than 300 stars in the area of 5 x 5 square degrees centred on the Cygnus OB1 association. We present the results of a kinematic clustering analysis in the subspace of the phase space formed by angular coordinates and radial velocity using two independent methodologies. We have found evidence of structure in the phase space with the detection of two main groups, corresponding to different radial velocity and distance values, belonging to the association, and associated with two main shells defined by the Halpha emission. A third grouping well separated from the other two in velocity appears to occupy the whole region associated with what has been called "common shell".