论文标题
GRS的Astrosat视图1915+105在软状态下：HFQPOS的检测以及质量和自旋的估计
AstroSat view of GRS 1915+105 during the Soft State: Detection of HFQPOs and estimation of Mass and Spin
论文作者
论文摘要
我们报告了使用100 ks保证时间（GT）在软状态下获得的GRS 1915 $+$ 105的Astrosat观察结果的结果。颜色图（CCD）表示$δ$的可变性类别，在功率密度光谱（PDS）中检测到高频QPO（HFQPO）。 HFQPO在$ 67.96-70.62 $ Hz的频率范围内有所不同，RMS $ \ sim 0.83-1.90 $％，显着性从$ 1.63-7.75 $不等。能源依赖的功率光谱表明，HFQPO功能仅在$ 6-25 $ KEV Energy Band中占主导地位。 SXT（软X射线望远镜）和LAXPC（大面积X射线比例计数器）的宽带能量光谱（$ 0.7-50 $ KEV）以NTHCOMP和POWERLAW模型建模，这意味着该源还具有延伸的Corona，此外还具有紧凑的“ COMPONTACT” COMPONT，可产生高能量发射和展示HFQPOS。宽带光谱建模表明，通过电子温度（$ _ {\ rm e} $）$ 2.07-2.43 $ keV和photon-index（$γ_{\ rm nth} $）在$ 1.73-2.45 $ $ 1.73-2.45 $之间，由$ 2.43 PL} $）$ 2.94-3.28 $。在没有HFQPO的情况下，NTHCOMP组件的标准很高（$ \ sim 8 $）在强大的HFQPO和Low（$ \ sim 3 $）的情况下。此外，我们使用KERRBB模型对能光谱进行建模，以估计源的积聚率，质量和自旋。我们的发现表明，源源为$ 1.17-1.31〜 \ dot {m} _ {\ rm edd} $的源积聚。此外，我们发现该来源的质量和旋转是$ 12.44-13.09〜m _ {\ odot} $，$ 0.990-0.997 $，$ 90 \％$ $ $ $ $ $ $ 105是最大旋转的巨大旋转巨大的X射线X射线Bary Bary Black Black源。
We report the results of AstroSat observations of GRS 1915$+$105 obtained using 100 ks guaranteed-time (GT) during the soft state. The Color-Color Diagram (CCD) indicates a variability class of $δ$ with the detection of High Frequency QPO (HFQPO) in the power density spectra (PDS). The HFQPO is seen to vary in the frequency range of $67.96 - 70.62$ Hz with percentage rms $\sim 0.83 - 1.90$ % and significance varying from $1.63 - 7.75$. The energy dependent power spectra show that the HFQPO features are dominant only in $6 - 25$ keV energy band. The broadband energy spectra ($0.7 - 50$ keV) of SXT (Soft X-ray Telescope) and LAXPC (Large Area X-ray Proportional Counter) modelled with nthComp and powerlaw imply that the source has an extended corona in addition to a compact 'Comptonizing corona' that produces high energy emission and exhibits HFQPOs. The broadband spectral modelling indicates that the source spectra are well described by thermal Comptonization with electron temperature (kT$_{\rm e}$) of $2.07 - 2.43$ keV and photon-index ($Γ_{\rm nth}$) between $1.73-2.45$ with an additional powerlaw component of photon-index ($Γ_{\rm PL}$) between $2.94 - 3.28$. The norm of nthComp component is high ($\sim 8$) during the presence of strong HFQPO and low ($\sim 3$) during the absence of HFQPO. Further, we model the energy spectra with the kerrbb model to estimate the accretion rate, mass and spin of the source. Our findings indicate that the source accretes at super-Eddington rate of $1.17-1.31~ \dot{M}_{\rm Edd}$. Moreover, we find the mass and spin of the source as $12.44 - 13.09~M_{\odot}$ and $0.990-0.997$ with $90\%$ confidence suggesting that GRS 1915$+$105 is a maximally rotating stellar mass X-ray binary black hole source.
