Black hole transients are known to undergo spectral transitions that form q-shaped tracks on a hardness intensity diagram. In this work, we use archival RXTE data to extract a characteristic minimal timescale for the spectral states in GX 339-4 for the 2002-3, and 2010 outbursts. We use the extracted timescale to construct an intensity variability diagram for each outburst. This new diagram is comparable to the traditional hardness intensity diagram and offers the potential for probing the underlying dynamics associated with the evolution of the relevant emission regions in black hole transients. We confirm this possibility by connecting the minimal timescale with the inner disk radius, $R_{in}$ (estimated from spectral fits), and demonstrate a positive correlation between these variables as the system evolves through its spectral transitions. Furthermore, we probe the relation between the minimal timescale and the break frequencies extracted from the power spectral densities. Lastly, we examine a possible link between the extracted timescale and a traditional measure of variability i.e., the root mean square, determined directly from the power spectra.

中文翻译：

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GX 339-4 光谱状态的最小时间尺度

已知黑洞瞬变会经历光谱跃迁，在硬度强度图上形成 q 形轨迹。在这项工作中，我们使用档案 RXTE 数据为 2002-3 和 2010 年爆发的 GX 339-4 中的光谱状态提取特征最小时间尺度。我们使用提取的时间尺度为每次爆发构建强度变化图。这个新图与传统的硬度强度图相当，并提供了探测与黑洞瞬变中相关发射区域演化相关的潜在动力学的潜力。我们通过将最小时间尺度与内圆盘半径 $R_{in}$（根据光谱拟合估计）联系起来确认了这种可能性，并证明了随着系统通过其光谱跃迁演化，这些变量之间存在正相关关系。此外，我们探讨了最小时间尺度与从功率谱密度中提取的中断频率之间的关系。最后，我们检查提取的时间尺度与传统的可变性度量（即均方根）之间可能存在的联系，该度量直接从功率谱确定。