or PSPC, may exist in a region bounded by Region B. It is noted that the pair creation in the OG is the key to make the magnetosphere active even in the aligned rotator, although the diocotron instability is also proposed to play a similar role (see, eg, [@b16; @b17]). If pair creation does not occur anywhere, the dome-disk magnetosphere, such as the magnetosphere in @b18, is formed in our simulation. In contrast, if the pair creation occurs in the OG, the generated electrons go back to the star and are re-emitted around the magnetic poles, and then, they flow out to the magnetosphere. In this way, pair creation in the OG can change a static magnetosphere into an active magnetosphere without diocotron instability.

Next, let us discuss the region around the OG. The corotation Region D, where $\Phi=0$, is identified as a traditional dead zone, but Region D is smaller than the traditional one and does not reach the light cylinder. Instead, Region E exists between Region D and the light cylinder. In Region E, $E_{||}=0$, but $\Phi \neq 0$ as seen in figure \[fig:dis01\] because the magnetic field lines which pass through Region E go through the OG, 