E_iso distribution for long (blue hatched histogram) and short (red hatched histogram). For long bursts the distribution has mean and median values of 1.4  ×  10⁵³ erg and 1.2  ×  10⁵³ erg, respectively. A log-normal fit to the long bursts (dashed line) peaks at 1.2  ×  10⁵³ erg with a FWHM = 1.9 in log-space. Short bursts have a mean and median value of 4  ×  10⁵¹ erg and 2.9  ×  10⁵¹ erg, respectively. A log-normal fit to the combined sample (dash-dotted line) peaks at 9.8  ×  10⁵² erg with a FWHM = 2.2 in log-space.