标题： 校准SPI-ACS/INTEGRAL用于伽马射线暴，并重新估算伽马射线范围内的GRB/GW 190425的能量特性 显示英文标题

标题： Calibrating SPI-ACS/INTEGRAL for gamma-ray bursts and re-estimating energetics of GRB/GW 190425 in gamma-ray range

摘要： SPI-ACS/INTEGRAL 是 80 keV 能量范围以上最灵敏的轨道伽马射线探测器之一。 自 2002 年以来，它记录了数千个伽马射线暴，包括与 LIGO-Virgo 引力波事件 GW 170817 和 GW 190425 相关的爆发。 未对 SPI-ACS/INTEGRAL 进行专用的在轨校准，这使得事件的能谱和能量特性估计变得复杂。 利用 Fermi/GBM 的数据，我们基于两个实验共同记录的 1032 个明亮伽马射线暴进行了 SPI-ACS/INTEGRAL 的交叉校准。 我们发现 SPI-ACS 仪器计数与 GBM 能量单位之间的转换因子依赖于伽马射线暴谱的硬度（定义为特征能量值，$E_{p}$）以及源在航天器坐标系中的位置。 我们确定了相应的解析模型来计算转换因子，并通过经验方法估算其准确性。 还研究了 SPI-ACS/INTEGRAL 探测伽马射线瞬变的灵敏度。 利用校准结果重新评估了仅由 SPI-ACS/INTEGRAL 检测到的 GRB/GW 190425 的能量学特性。 使用$ E_{p,i} $--$ E_{iso} $（Amati）相关性，我们限制了 GRB 190425 的特征能量$E_{p}$和伽马射线中发射的各向同性等效总能量$E_{iso}$的可能范围。 该校准模型可应用于任何具有类似伽马射线暴能谱的暂现源。 显示英文摘要

摘要： SPI-ACS/INTEGRAL is one of the most sensitive orbital gamma-ray detectors in energy range above 80 keV. Since 2002 it registered several thousands of gamma-ray bursts, including the bursts associated with LIGO-Virgo gravitational wave events GW 170817 and GW 190425. No dedicated in-flight calibrations were performed for SPI-ACS/INTEGRAL, complicating estimation of spectral and energetic characteristics of an event. Using data of GBM/Fermi we perform cross-calibration of SPI-ACS/INTEGRAL, based on 1032 bright GRBs registered by both experiments. We find the conversion factor between instrumental counts from SPI-ACS and energy units from GBM to be dependent on hardness of GRB spectrum (defined as the characteristic energy value, $E_{p}$) and on location of a source in spacecraft based coordinate system. We determine the corresponding analytical model to calculate the conversion factor and estimate its accuracy empirically. Sensitivity of SPI-ACS/INTEGRAL to detect gamma-ray transients is also investigated. Using the calibration we re-estimate energetics of GRB/GW 190425, detected by SPI-ACS/INTEGRAL alone. We constrain possible range of the characteristic energy $E_{p}$ and isotropic equivalent of total energy, emitted in gamma-rays $E_{iso}$ for GRB 190425, using the $ E_{p,i} $ -- $ E_{iso} $ (Amati) correlation. The calibration model could be applied to any transients with energy spectrum, analogous to gamma-ray bursts.