Understanding the origins of massive black hole seeds and their coevolution with their host galaxy requires studying intermediate-mass black holes (IMBHs) and estimating their mass. However, measuring the masses of these IMBHs is challenging, due to the high-spatial-resolution requirement. Spectrophotometric reverberation monitoring is performed for a low-luminosity Seyfert 1 galaxy, NGC 4395, to measure the size of the broad-line region and black hole mass. The data were collected using the 1.3 m Devasthal fast optical telescope and 3.6 m Devasthal optical telescope at ARIES, Nainital, over two consecutive days in 2022 March. The analysis revealed strong emission lines in the spectra and light curves of the merged 5100 Å spectroscopic continuum flux (f5100) with the photometric continuum V band and Hα, with fractional variabilities of 6.38% and 6.31% respectively. In comparison to several previous studies with lag estimation <90 minutes, our calculated Hα lag supersedes them by minutes, using the ICCF and JAVELIN methods. The velocity dispersion (σline) of the broad-line clouds is measured to be km s−1, yielding a black hole mass of ∼ and an Eddington ratio of 0.06.

中文翻译：

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中质量黑洞 NGC 4395 的分光光度混响映射


了解大质量黑洞种子的起源及其与宿主星系的共同演化需要研究中等质量黑洞 （IMBH） 并估计它们的质量。然而，由于高空间分辨率要求，测量这些 IMBH 的质量具有挑战性。对低亮度的 Seyfert 1 星系 NGC 4395 进行分光光度混响监测，以测量宽线区域的大小和黑洞质量。这些数据是在 2022 年 3 月连续两天在奈尼塔尔的 ARIES 使用 1.3 m Devasthal 快速光学望远镜和 3.6 m Devasthal 光学望远镜收集的。分析显示，合并的 5100 Å 光谱连续通量 （f5100） 与光度连续谱 V 波段和 Hα 的光谱和光曲线中具有很强的发射线，分数变异率分别为 6.38% 和 6.31%。与之前几项使用滞后估计 <90 分钟的研究相比，我们使用 ICCF 和 JAVELIN 方法计算出的 Hα 滞后用分钟取代了它们。宽线云的速度色散 （σline） 测量为 km s−1，产生 ∼ 的黑洞质量和 0.06 的爱丁顿比。