Figure 8: (a) distribution for 41 GRBs/XRFs with measured redshifts and values. Filled circles indicate Swift GRBs. The solid line represents the best-fit line ; the dotted lines show the region within a vertical logarithmic deviation of 0.4. The dashed line represents the best-fit line computed without taking into account the sample variance. (Figure after Amati [190]; see Figure therein.) (b) The distribution of the sample in the plane. The lines indicate the best-fit line and the confidence region for LGRBs and XRFs. (Figure after Amati [193]; see Figure therein. Copyright @ 2012 World Scientific Publishing Company.) (c) distribution of 12 GRBs with uncertain values of and/or , for the subenergetic event GRB980425 and for the two SGRBs 050709 and 051221. Filled circles represent Swift GRBs. The solid line is the best-fit line ; the dotted lines mark the region within a vertical deviation in logarithmic scale of 0.4. The dashed line is the best-fit line computed without taking into account the sample variance. (Figure after Amati [190]; see Figure therein.) (d) The distribution for the LGRBs. The black line represents the best-fit line and, for each point, the color indicates the instrument which performed the spectral measurement. (Figure after Amati and Valle [197]; see Figure therein. Copyright @ 2013 World Scientific Publishing Company.)