The energy source of the most energetic giant outbursts in MS 0735 + 7421

In this work, we investigate the power source of the most energetic giant outbursts in MS 0735 + 7421, which released ~ 10⁶² erg of energy. Due to the very high mean jet power in the cavities (P _jet/L _Edd ~ 0.02), we produce several jet formation models based on a relativistic thin disk model, i.e., general BP + BZ mechanisms (model A), Livio's (model B) and Meier's (model C) model, to explain the giant outbursts in AGNs. It is found that the energy provided by both model B and model C are inadequate for an initial black hole spin a ₀ ~ 0.1, only model A can explain the most violent outbursts in MS 0735 + 7421. But if the initial black hole spin a ₀ ~ 0.95, model B can also blow up the cavity. The final spin of the black hole is found to be very high in spite of the initial spin.