What intensity in Gauss defines the upper range of a magnetar's magnetic field?
10^15 Gauss
Magnetars possess an exceptionally powerful magnetic field, which is a defining characteristic separating them from ordinary neutron stars. This field strength is quantified in the text as reaching intensities up to $10^{15}$ Gauss. This level of magnetic power is orders of magnitude greater than anything achievable in terrestrial laboratories, emphasizing the extreme nature of these celestial objects. This phenomenal strength is thought to result from the differential rotation of the star's internal layers occurring during or immediately following its formation, which twists and consequently amplifies the initial magnetic flux embedded within the stellar remnant.

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