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arXiv 2006.12872astro-ph.HE
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MAXI中B型QPO的时滞J1348-630

Time lags of the type-B QPO in MAXI J1348-630

Tomaso M. Belloni, Liang Zhang, Nikolaos D. Kylafis, Pablo Reig, Diego Altamirano

摘要:

在黑洞双星的X射线辐射中观察到的快速变化具有非常复杂的现象学,但提供了直接研究内部吸积流性质的可能性。特别是,在软中间状态下观察到的2-8 Hz范围内的B型振荡与相对论性喷流的发射有关。本文介绍了用NICER望远镜对MAXI J1348-630进行的一系列观测的时间和光谱分析结果。观测结果位于爆发的最亮部分,并且都具有约4.5 Hz的强B型QPO。我们计算的分数均方根和相位滞后在QPO频率的能量依赖性,获得高信噪比的数据和采样的能量低于2千电子伏的第一次。分数均方根从9 keV时的10%以上下降到1.5 keV时的0.6%,并且在该能量以下是恒定的。以2-3 keV带为参考,所有能量的光子都显示出硬滞后,随着与参考带的距离增加。低于2千电子伏的行为从来没有被观察到,由于以前的定时仪器的较高的能量带通。能谱可以用这种状态的标准模型拟合,该模型由薄圆盘组件和更硬的幂律组成,加上6至7 keV之间的发射线。我们讨论的结果,集中在相位滞后,并表明,它们可以解释内的康普顿化模型。

英文摘要:

The fast variability observed in the X-ray emission from black-hole binaries has a very complex phenomenology, but offers the possibility to investigate directly the properties of the inner accretion flow. In particular, type-B oscillations in the 2-8 Hz range, observed in the Soft-Intermediate state, have been associated to the emission from a relativistic jet. We present the results of the timing and spectral analysis of a set of observations of the bright transient MAXI J1348-630 made with the NICER telescope. The observations are in the brightest part of the outburst and all feature a strong type-B QPO at ~4.5 Hz. We compute the energy dependence of the fractional rms and the phase lags at the QPO frequency, obtaining high signal-to-noise data and sampling for the first time at energies below 2 keV. The fractional rms decreases from more than 10% at 9 keV to 0.6% at 1.5 keV, and is constant below that energy. Taking the 2-3 keV band as reference, photons at all energies show a hard lag, increasing with the distance from the reference band. The behaviour below 2 keV has never been observed before, due to the higher energy bandpass of previous timing instruments. The energy spectrum can be fitted with a standard model for this state, consisting of a thin disc component and a harder power law, plus an emission line between 6 and 7 keV. We discuss the results, concentrating on the phase lags, and show that they can be interpreted within a Comptonization model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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