Despite the increasing number of studies of barred galaxies at intermediate and high redshifts , double-barred ( S2B ) systems have only been identified in the nearby ( z \leq 0.04 ) universe thus far .
In this feasibility study we demonstrate that the detection and analysis of S2Bs is possible at intermediate redshifts ( 0.1 \la z \la 0.5 ) with the exquisite resolution of the Hubble Space Telescope Advanced Camera for Surveys ( HST /ACS ) .
We identify barred galaxies in the HST /ACS data of the Great Observatories Origins Deep Survey ( GOODS ) using a novel method .
The radial profile of the Gini coefficient – a model-independent structure parameter – is able to detect bars in early-type galaxies that are large enough that they might host an inner bar of sufficient angular size .
Using this method and subsequent examination with unsharp masks and ellipse fits we identified the two most distant S2Bs currently known ( at redshifts z = 0.103 and z = 0.148 ) .
We investigate the underlying stellar populations of these two galaxies through a detailed colour analysis , in order to demonstrate the analysis that could be performed on a future sample of intermediate-redshift S2Bs .
We also identify two S2Bs and five S2B candidates in the HST /ACS data of the Cosmic Evolution Survey ( COSMOS ) .
Our detections of distant S2Bs show that deep surveys like GOODS and COSMOS have the potential to push the limit for S2B detection and analysis out by a factor of ten in redshift and look-back time ( z \approx 0.5 , \Delta t \approx 5 Gyr ) compared to the previously known S2Bs .
This in turn would provide new insight into the formation of these objects .