论文标题
GRS 1915+105的高频QPO的宽频视图中观察到的“柔和”可变性类别
Wide-band view of High Frequency QPOs of GRS 1915+105 in 'softer' variability classes observed with AstroSat
论文作者
论文摘要
我们介绍了“较软”可变性类别的全面时间和光谱分析（$，$θ$，$β$，$δ$，$ρ$，$κ$，$κ$，$ω$和$γ$）的源为1915+105+105+105在2016-2021-2021-2021 $ $ 105中。宽频（$ 3-60 $ keV）的时间研究揭示了频率为68.14-72.32 $ Hz的频率的高频准周期振荡（HFQPO）的检测，其意义为$ 2.75-11σ$，RMS amplitude ablitude abliture $ 1.48-2.66 \％$ $ $ $ $ $和$δ$ $和$ grimy $和$ grimity。能源依赖的功率谱仅在$ 6-25 $ KEV Energy Band中检测到HFQPO，并且RMS振幅被发现会增加（$ 1-8 \％$ $）。 $κ$和$ω$类的动态功率光谱表明，HFQPO似乎与高计数率相关。我们观察到，宽波段（$ 0.7-50 $ keV）的能量光谱可以由$ 1.83-2.89 $的热构量组件（NTHCOMP）（$γ_{\ rm nth} $）描述为$ 1.83-2.89 $，以及额外的陡峭（$γ_ {\ rm pl} \ rm pl} \ rm pl} \ sim3 $ 3 $ 3 $ 3 $ 3 $ 3 $ sim3 $ 3 $ commention。 $ 1.82 -3.66 $ keV和光学深度（$τ$）的电子温度（$ kt_e $）的$ 2-14 $表示存在凉爽且光学厚的电晕。此外，NTHCOMP组件（$ 1.97 \ LISSSIMγ_ {\ rm nth} \ Lessim 2.44 $，$ 1.06 \ times 10^{ - 8} \ Lessim f _ {\ rm nth}〜（ 〜S}^{ - 1}）\ Lessim 4.46 \ times 10^{ - 8} $）在存在HFQPO的情况下占主导地位。总体而言，这些发现推断，由于“构成电晕”的调节，HFQPO可能是导致HFQPO的。此外，我们发现该源的辐射光度（$ 0.3-100 $ keV）位于子埃德丁顿（$ 3-34 \％$ $ $ $ l _ {\ rm edd} $）方案中。最后，我们在HFQPO上的现有模型的背景下讨论并比较了获得的结果。
We present a comprehensive temporal and spectral analysis of the 'softer' variability classes ($i.e.$, $θ$, $β$, $δ$, $ρ$, $κ$, $ω$ and $γ$) of the source GRS 1915+105 observed by AstroSat during $2016-2021$ campaign. Wide-band ($3-60$ keV) timing studies reveal the detection of High Frequency Quasi-periodic Oscillations (HFQPOs) with frequency of $68.14-72.32$ Hz, significance of $2.75-11 σ$, and rms amplitude of $1.48-2.66\%$ in $δ$, $κ$, $ω$ and $γ$ variability classes. Energy dependent power spectra impart that HFQPOs are detected only in $6-25$ keV energy band and rms amplitude is found to increase ($1-8\%$) with energy. The dynamical power spectra of $κ$ and $ω$ classes demonstrate that HFQPOs seem to be correlated with high count rates. We observe that wide-band ($0.7-50$ keV) energy spectra can be described by the thermal Comptonization component (nthComp) with photon index ($Γ_{\rm nth}$) of $1.83-2.89$ along with an additional steep ($Γ_{\rm PL}\sim3$) powerlaw component. The electron temperature ($kT_e$) of $1.82 -3.66$ keV and optical depth ($τ$) of $2-14$ indicate the presence of a cool and optically thick corona. In addition, nthComp components ($1.97 \lesssim Γ_{\rm nth} \lesssim 2.44$, $1.06 \times 10^{-8} \lesssim F_{\rm nth} ~({\rm erg} {\rm ~cm}^{-2} {\rm ~s}^{-1}) \lesssim 4.46\times 10^{-8}$) are found to dominate in presence of HFQPOs. Overall, these findings infer that HFQPOs are possibly resulted due to the modulation of the 'Comptonizing corona'. Further, we find that the bolometric luminosity ($0.3-100$ keV) of the source lies within the sub-Eddington ($3-34\%$ $L_{\rm Edd}$) regime. Finally, we discuss and compare the obtained results in the context of existing models on HFQPOs.
