There is no consensus on the emission mechanism of γ-ray bursts (GRBs). A synchrotron model can produce γ-ray spectra with the empirical Band function form (Band et al., 1993), from a piece-wise two-power-law electron energy distribution (2EPLS). This synchrotron model predicts that for the same γ-ray spectrum, optical emission can be very different in $f_{\nu }$ log slope, and in flux relative to γ-rays, depending on model parameter values. This prediction is consistent with the huge range of optical/γ flux ratios observed. The model only allows a small set of $f_{\nu }$ log slopes in the optical—thereby allowing a clear path to verification or falsification. Measurements of prompt γ-ray burst emission in the optical thus far give no useful information about the spectral shape within the band, and therefore cannot be used to evaluate such predictions.

We describe an experiment that responds to GRB position alerts with a fast-slewing telescope outfitted with three or more simultaneously recording, high-time resolution cameras, to measure the spectral shape of the prompt optical-IR (OIR) emission. Three channels measure two independent spectral slopes in the OIR region, the minimum information required to evaluate the model, assuming a single dominant component. We propose cross-correlation of γ and OIR light curves to verify that a given GRB is single-component dominated, or to model and quantify the contributions from other components. Previous CCD measurements have limited-time resolution due to read noise, limiting cross-correlation analysis. Electron-multiplied CCDS (EMCCDs) can be used to greatly reduce read noise, and allow exposure times of a few hundred ms. Our collaboration has begun a pathfinder experiment, the Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO), with a 70 cm aperture telescope that can point anywhere above the local horizon in $\le 8\text{s}$, with three simultaneous optical channels. The NUTTelA-TAO is expected to measure the optical slopes of 3–8 GRB/yr, and should provide a clear verification/refutation of the 2EPLS model after a few single-component dominated, sufficiently bright GRBs are detected during prompt emission. A space-based platform would more easily extend the spectral coverage down to near-IR wavelengths, for greater precision in measuring spectral slopes, and increased chance of measuring the self-absorption frequency, which carries valuable information on physical conditions within the GRB jet. Additional science includes detection of dust evaporation due to the UV flash from the burst, which can be used to study dust around a single star at high redshift, independent of host galaxy dust.

关于γ射线爆发（GRBs）的发射机理尚无共识。同步加速器模型可以根据分段的两个幂律电子能量分布（2EPLS）产生具有经验带函数形式的γ射线光谱（Band等，1993）。该同步加速器模型预测，对于相同的γ射线光谱，光发射在$F_{\nu }$对数斜率以及相对于γ射线的通量，具体取决于模型参数值。该预测与观察到的大范围的光学/ γ通量比一致。该模型只允许一小部分$F_{\nu }$光学上的对数斜率-从而为验证或伪造提供了清晰的路径。迄今为止，在光学系统中对瞬态γ射线猝发发射的测量都无法提供有关频段内光谱形状的有用信息，因此无法用于评估此类预测。

我们描述了一个实验，该实验使用配备有三个或更多同时记录的高分辨率摄像机的快速旋转望远镜对GRB位置警报做出响应，以测量即时光学IR（OIR）发射的光谱形状。三个通道测量OIR区域中两个独立的光谱斜率，这是评估该模型所需的最少信息，并假设有一个主要成分。我们提出γ的互相关和OIR光曲线，以验证给定的GRB是否为单一成分主导，或者对其他成分的贡献进行建模和量化。由于读取噪声，以前的CCD测量具有有限的时间分辨率，从而限制了互相关分析。电子倍增CCDS（EMCCD）可用于大大减少读取噪声，并允许数百毫秒的曝光时间。我们的合作已经开始了探路者实验，即位于阿瑟-Turgen天体物理观测站的纳扎尔巴耶夫大学瞬态望远镜（NUTTelA-TAO），该望远镜具有70厘米的孔径望远镜，可以指向地球上方任何地方的地平线$\le 8\text{s}$，同时具有三个光通道。NUTTelA-TAO有望测量3–8 GRB / yr的光学斜率，并且在迅速发射期间检测到一些单组分主导，足够亮的GRB之后，应提供对2EPLS模型的清晰验证/驳斥。一个基于天基的平台将更容易地将光谱覆盖范围扩展到近红外波长，从而在测量光谱斜率时具有更高的精度，并增加了测量自吸收频率的机会，从而可以携带有关GRB射流中物理条件的有价值的信息。其他科学包括探测由于爆发而产生的紫外线闪光而引起的粉尘蒸发，这可用于研究高红移下单个恒星周围的尘埃，而与宿主星系尘埃无关。