徑向速度法是測量緻密雙星系統軌道參數與天體質量的重要方法。然而，在蜘蛛雙星（Spider Binary）等受到強烈輻照作用的系統中，伴星表面的不均勻溫度分布可能改變觀測光譜的形成位置，進而影響由吸收線所測得的徑向速度，造成質量估計上的系統性偏差。為研究此效應，本研究開發了一套緻密雙星光譜合成模型，結合 Roche 幾何、數值表面建模與哥廷根光譜庫（Göttingen Spectral Library），可模擬受潮汐形變伴星的相位解析光譜。

以蜘蛛雙星系統 PSR J0952-0607 為例，本研究分別模擬輻照與非輻照情況下的觀測光譜，並探討輻照對徑向速度量測的影響。結果顯示，輻照會使光通量加權的光心（Center of Light）向緻密主星方向偏移。當使用非輻照模型解讀受輻照影響的光譜時，所測得的徑向速度半振幅將被低估約 7.33 ± 0.57% 至 10.28 ± 0.86%，其所對應的一階質量函數偏差約為 21.88 ± 1.70% 至 30.84 ± 2.59%。進一步利用馬可夫鏈蒙地卡羅方法進行參數擬合，得到 $7.60^{+0.13}_{-0.13},%$ 的半振幅偏差以及約 21.44% 的質量函數偏差，與前述一階估計結果一致。本研究顯示，對於此系統，若在徑向速度測量中忽略輻照效應，一顆真實質量為 2.35M⊙ 的中子星，其推得質量可能被系統性低估為約 1.85M⊙。

The radial-velocity method is one of the primary techniques for determining the orbital parameters and masses of compact binary systems. However, in strongly irradiated systems such as spider binaries, the non-uniform temperature distribution across the companion surface can alter the formation of the observed spectrum, potentially introducing systematic biases into radial-velocity measurements and the inferred masses. To investigate this effect, we develop a compact-binary spectral-synthesis framework that combines Roche geometry, numerical surface modeling, and the Göttingen Spectral Library to generate phase-resolved spectra of tidally distorted companion stars.

Using the spider-binary system PSR J0952-0607 as a case study, we simulate the observed spectra under both irradiated and non-irradiated conditions and investigate the impact of irradiation on radial-velocity measurements. The results show that irradiation shifts the flux-weighted center of light toward the compact primary. When irradiated spectra are interpreted using a non-irradiated model, the inferred radial-velocity semi-amplitude is underestimated by approximately 7.33 ± 0.57% to 10.28 ± 0.86 %, depending on the adopted velocity template. The corresponding first-order bias in the mass function is estimated to be 21.88±1.70% to 30.84±2.59 %. Furthermore, parameter estimation using a Markov Chain Monte Carlo approach yields a radial-velocity semi-amplitude bias of $7.60^{+0.13}_{-0.13},%$ and a mass-function bias of approximately 21.44 %, in excellent agreement with both the direct radial-velocity measurements and the first-order prediction derived from the center-of-light analysis. Our results demonstrate that, for this system, neglecting irradiation effects in radial-velocity measurements may cause a neutron star with a true mass of .35M⊙ to be inferred to have a mass of only approximately 1.85M⊙.

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