The Snapshot Hubble U-band Cluster Survey; A cluster complex in NGC 2146

TL;DR

The paper introduces the SHUCS survey using Hubble data to study star cluster populations in nearby galaxies, exemplified by the detailed analysis of the Ruby Ring in NGC 2146, revealing insights into triggered star formation.

Contribution

It presents the SHUCS survey methodology and provides a detailed case study of the Ruby Ring, demonstrating triggered star formation in an isolated cluster complex.

Findings

The Ruby Ring shows a ring-like distribution of clusters around a central object.

Evidence of spatial and temporal correlation between the central cluster and the ring clusters.

The

Abstract

We present the Snapshot Hubble U-band Cluster Survey (SHUCS), an ongoing deep U-band imaging survey of nearby star-forming galaxies. Thanks to the information provided by the U band, together with archival Hubble Space Telescope (HST) optical data, we are able to constrain reliable ages, masses, and extinctions of the cluster populations of these galaxies. We show some preliminary results from the study of one of the SHUCS galaxies, NGC 2146. Using the recovered cluster ages we try to understand the propagation of the star formation in one of the tidal streams where a ring-like cluster complex has been found. The Ruby Ring, so named due to its appearance, shows a clear ring-like distribution of star clusters around a central object. We find evidence of a spatial and temporal correlation between the central cluster and the clusters in the ring. The Ruby Ring is the product of an intense and localised burst of star formation, similar to the extended cluster complexes observed in M 51 and the Antennae, but more impressive because is quite isolated. We discuss the formation of the Ruby Ring in a "collect & collapse" framework. The predictions made by this model agree quite well with the estimated bubble radius and expansion velocity produced by the feedback from the central cluster, making the Ruby Ring an interesting case of triggered star formation.