Abstract

We present the measurement results for the spectral flux densities of 19 calibration sources observed with the RT-22 single-dish telescope of the Crimean Astrophysical Observatory of the Russian Academy of Sciences at 22.2 and 36.8 GHz in 2017–2020. About half of them belong to the commonly accepted secondary standards with periodically monitored flux densities at radio frequencies. The measurements were carried out to refine the calibration measurements of the RATAN-600 radio telescope at high frequencies. The specificity of RATAN-600 meridian observations requires a ‘‘grid’’ of calibration objects distributed over declinations from \(-35^{\circ}\) to \(+90^{\circ}\) instead of 1–3 conventional calibrators which are sufficient for observations at different heights with a single-dish antenna. The radio variability of the objects was estimated taking into account the literature measurements, the results were interpolated to a frequency of 30 GHz. It was found that radio variability at 22 GHz at time scales of about 20–30 years exceeds 10\(\%\) for the calibrators 4C \(+\)16.09 and 3C 309.1. We discuss a possibility of verifying the calibration sources at the RT-22 by a new method that uses a noise signal generator as an indicator of their relative flux density accuracy.

中文翻译：

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使用 RT-22 CrAO RAS 研究 22 和 37 GHz 频段的校准源

摘要

我们展示了 2017-2020 年俄罗斯科学院克里米亚天体物理天文台 RT-22 单口径望远镜在 22.2 和 36.8 GHz 观测到的 19 个校准源的光谱通量密度的测量结果。其中大约一半属于普遍接受的二级标准，定期监测无线电频率的通量密度。进行这些测量是为了改进 RATAN-600 射电望远镜在高频下的校准测量。RATAN-600 子午线观测的特殊性需要校准对象的“网格”分布在从\(-35^{\circ}\)到\(+90^{\circ}\)而不是 1-3 个常规校准器，这些校准器足以使用单碟天线在不同高度进行观察。考虑到文献测量，估计了物体的无线电可变性，结果被内插到 30 GHz 的频率。结果发现，对于校准器 4C \(+\) 16.09 和 3C 309.1，22 GHz 的无线电可变性在大约 20-30 年的时间尺度上超过 10 \(\%\) 。我们讨论了通过一种新方法验证 RT-22 校准源的可能性，该方法使用噪声信号发生器作为其相对磁通密度精度的指标。