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arXiv 2602.14764astro-ph.HE
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基于脉冲星的费米大面积望远镜点扩散函数建模

Pulsar based modeling of point spread function of Fermi Large Area Telescope

École Polytechnique Fédérale de Lausanne(洛桑联邦理工学院);Université Paris Cité, CNRS, Astroparticule et Cosmologie(巴黎西岱大学,法国国家科学研究中心,粒子物理与宇宙学研究所)

J. Blunier, A. Neronov, D. Semikoz

AI总结:

通过比较费米LAT仪器响应函数与明亮脉冲星信号,改进点扩散函数参数,并应用于耀变体Mrk 501的扩展发射搜索,发现修正后无扩展信号证据。

摘要:

伽马射线源周围扩展发射搜索的灵敏度自然受到伽马射线望远镜点扩散函数(PSF)知识精度的限制。费米大面积望远镜(LAT)PSF模型的不准确性可能导致源扩展的假阳性检测。我们通过将费米/LAT仪器响应函数(IRFs)提供的PSF模型与明亮脉冲星信号进行比较,探索费米/LAT PSF的不确定性。我们将费米/LAT IRFs的解析PSF模型与脉冲星数据进行比较,并使用与费米/LAT IRFs相同的解析模型拟合脉冲星数据,以推导出一组改进的PSF参数。然后,我们将这一修正后的PSF参数化应用于耀变体Mrk 501周围扩展发射的搜索。我们发现费米/LAT IRFs的解析PSF模型参数与脉冲星数据不一致。我们从脉冲星数据的拟合中获得了一组与观测一致的改进PSF参数。如果在数据分析中使用与脉冲星数据一致的修正PSF,则未发现先前报告的Mrk 501周围扩展信号的证据。

英文摘要:

Sensitivity of searches for extended emission around gamma-ray sources is naturally limited by the precision of the knowledge of the Point Spread Function (PSF) of gamma-ray telescopes. Inaccuracies in the PSF models of the Fermi Large Area Telescope (LAT) can potentially lead to false positive detections of source extension. We explore uncertainties in the Fermi/LAT PSF by comparing the PSF models provided by the Fermi/LAT Instrument Response Functions (IRFs) with signals of bright pulsars. We compare the analytical PSF models of Fermi/LAT IRFs with pulsar data and fit the pulsar data with the same analytical model as in the Fermi/LAT IRFs to derive an improved set of PSF parameters. We then apply this revised PSF parameterisation to the search of extended emission around a blazar, Mrk 501. We find that the parameters of the analytical PSF models of Fermi/LAT IRFs are inconsistent with the pulsar data. We obtain an improved set of PSF parameters from the fits to pulsar data that is consistent with observations. We find no evidence of the previously reported extended signal around Mrk 501 if the revised PSF consistent with pulsar data is used in data analysis.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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