How Real Detector Thresholds Create False Standard Candles

GRB satellites are relatively inefficient detectors of dim hard bursts. For example, given two bursts of identical peak luminosity near the detection threshold, a dim soft burst will be preferentially detected over a dim hard burst. This means that a high $Epeak$ burst will need a higher peak luminosity to be detected than a low $Epeak$ GRB. This purely detector‐created attribute will appear as a correlation between $Epeak$ and luminosity, and should not be interpreted as a real standard candle effect. This result derives from Monte Carlo simulations utilizing a wide range of initial GRB spectra, and retriggering to create a final “detected” sample. In sum, $Epeak$ is not a good standard candle, and its appearance as such in seeming correlations such as the Amati and other $Liso$ vs. $Epeak$ relations is likely a ghost of real energy‐related detection thresholds.