Search for Compact Stellar Groups in the Vicinity of IRAS Sources

TL;DR

This study identifies and characterizes compact stellar groups near 19 IRAS sources using UKIDSS and Spitzer data, revealing new clusters and substructures with diverse sizes and densities, many associated with young stellar objects.

Contribution

First identification of compact stellar groups near IRAS sources using infrared survey data, including new clusters and substructures within extended clusters.

Findings

Clusters identified in 15 of 19 regions.

New clusters discovered in 4 regions.

IRAS sources often associated with YSO groups.

Abstract

The results of a search for compact clusters in the vicinity of 19 IRAS sources based on data from the GPS UKIDSS and Spitzer GLIMPSE surveys are presented. Overall, clusters have been identified in 15 regions. Clusters are identified for the first time in 4 regions (IRAS 18151-1208, IRAS 18316-0602, 18517+0437, 19110+1045). In 5 regions (IRAS 05168+3634, 05358+3543, IRAS 18507+0121, IRAS 20188+3928, IRAS 20198+3716) the compact groups we have identified are substructures within more extended clusters. The radii of the identified groups and the surface star density are widely scattered with ranges of 0.3-2.7 pc and 4-1360 stars/pc^2, respectively. In 11 of the clusters, the IRAS sources are associated with a pair or even a group of YSOs. The groups identified in the near IR include representatives of a later evolutionary class II among the stellar objects associated with the IRAS sources.