Posteriors of the kernel parameters for the breathing mode injection. We show the injected values in orange. We inject a draw from the kernel as a breathing mode signal into the individual detectors and analyze the resulting signal in the null stream. The k₀ posterior rules out the lower bound of the prior ﹩{\mathrm{log}}_{10}({k}_{0})=-47﹩, indicating the Gaussian process is detecting a signal.