at the 3$\sigma$ confidence level). Higher resolution spectra with good signal-to-noise are necessary to determine their metal content with higher confidence.

In section \[distance\] we noted that the vast majority of our sources are located at distances greater than 3 kpc, with some being over 20 kpc distant (if we have detected either the fundamental or first over-tone mode). Similarly, many are at a height of 1 kpc or more from the Galactic plane, with several being at least 10 kpc from the plane. Some of our sources are therefore at the remote edge of our Galaxy. SX Phe stars have been found at both large distances and well into the Galactic plane (eg Berstein, Knezek & Offutt 1995; Jeon, Kim and Nemec 2010). They are therefore, in principal, potential tracers of Galactic structure such as streams or the remnants of mergers.

We note that J1356 and J1359 lie around $\sim6^{\circ}$ from the large globular cluster M3 (which is 10.4 kpc from the Sun) which places them at a distance of $\sim$2 kpc from M3. Although tidal tails have been detected at distances of several kpc from globular clusters (eg Odenkirchen et al 2003), no tidal tails have been detected 