One normal outburst and three mini-outbursts have been detected by Rossi X-ray Timing Explorer (RXTE) satellite after 2000 in the well-known black hole X-ray binary XTE J1550-564. In our work, we explored the energy spectral properties of the four outbursts and the three mini-outbursts retained in the Low/Hard state. The results show that the X-ray spectra of the three mini-outbursts are harder than that of normal outburst and have no disk component. In the correlation analysis, the $\mathrm{\Gamma }-L_{\mathrm{X}}/L_{\mathrm{Edd}}$ anti-relationship of the three mini-outbursts suggested that it may be a result of the incomplete evolutionary success of Shakura-Sunyaev disk. The whole X-ray spectral correlation evolution shows well the state transition from the Shakura-Sunyaev disk to the advection-dominated accretion flow. We think that the three mini-outbursts may originated from a small discrete accretion event.

中文翻译：

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黑洞X射线双星XTE J1550-564正常爆发和小型爆发光谱对比研究

2000年后，罗西X射线定时探测器（RXTE）卫星在著名的黑洞X射线双星XTE J1550-564中检测到了一次正常爆发和三次小型爆发。在我们的工作中，我们探索了低/硬状态下保留的四个爆发和三个小型爆发的能谱特性。结果表明，这三个小型爆发的X射线谱比正常爆发的X射线谱更硬，并且没有盘状成分。在相关性分析中，$\mathrm{\gamma }-L_{\mathrm{X}}/L_{\mathrm{埃德}}$三个小型爆发的反关系表明，这可能是夏库拉-苏尼亚耶夫圆盘不完全进化成功的结果。整个X射线谱相关演化很好地显示了从Shakura-Sunyaev盘到平流主导的吸积流的状态转变。我们认为这三个小型爆发可能源于一次小型离散吸积事件。