AI 中文总结
该研究介绍了TFGI的调试情况与首批观测结果，验证了其性能，外推后显示该仪器有望在5.7年内达到目标偏振灵敏度，支撑北天宇宙学偏振巡天。
AI 中文摘要
我们展示了30和40吉赫兹仪器（TFGI）的调试与首批结果，该仪器利用泰德天文台的第二台QUIJOTE望远镜，以21角分和18角分的角分辨率在31吉赫兹和41吉赫兹频率下观测天空，其主要目标是对北天选定区域开展高灵敏度偏振测量的深宇宙学巡天。调试阶段覆盖2021年11月至2022年10月，期间仪器采用7个接收机的配置，其中4个工作在31吉赫兹，3个工作在41吉赫兹，在此期间共获取约1200小时的数据，其中380小时用于校准源，以表征TFGI的仪器特性，包括指向模型、波束响应、增益稳定性、偏振性能和瞬时灵敏度。我们详细表征了这些特性，并描述了如何在后续观测运行中对其进行改进。我们利用对明亮银道区域（天鹅座、W43、W44和W47）的230小时观测进一步验证仪器性能，作为示例，我们给出了W44的强度和偏振谱能量分布，发现其与现有测量结果吻合良好。从这些观测的噪声图中，我们测量得到在有效观测深度为0.57小时·度⁻²后，偏振灵敏度约为8.3μK·度⁻¹，该性能仅使用2个31吉赫兹探测器即可实现，已与WMAP的性能相当（WMAP每单位面积积分时间几乎是其3倍，为1.61小时·度⁻²）。将这些结果外推至TFGI的完整阵列（最多29个探测器），我们表明该仪器预计在5.7年的有效积分时间后，在覆盖总面积3600度²的三个宇宙学天区上，将达到31吉赫兹和41吉赫兹下约1μK·度⁻¹的目标灵敏度。
英文摘要
We present the commissioning and first results of the Thirty and Forty Gigahertz Instrument (TFGI), which observes the sky at 31 and 41 GHz with angular resolutions of 21' and 18' from the second QUIJOTE telescope at the Teide Observatory. Its primary goal is to conduct a deep cosmological survey in selected regions of the Northern sky with high-sensitivity polarization measurements. The commissioning phase covered Nov2021-Oct2022, during which the instrument operated with a configuration of 7 receivers, 4 at 31 GHz and 3 at 41 GHz. Over this period, approximately 1200 h of data were acquired. Of these, 380 h were dedicated to calibration sources, used to characterize the instrumental properties of TFGI, including the pointing model, beam response, gain stability, polarimetric performance, and instantaneous sensitivity. We provide a detailed characterization of these properties and describe how they are being improved for future observing runs. We use 230 h of observations from bright Galactic regions (Cygnus, W43, W44, and W47) to further validate the instrument performance. As an illustrative example, we present the intensity and polarization spectral energy distributions of W44, finding good agreement with existing measurements. From the noise map of these observations, we measure a polarization sensitivity of ~8.3 $μ$K deg$^{-1}$ after an effective observing depth of 0.57 h deg$^{-2}$. This performance, achieved considering only 2 detectors at 31 GHz, is already comparable to that achieved by WMAP (with almost 3 times the integration time per unit area, 1.61 h deg$^{-2}$). Extrapolating these results to the full TFGI array, with up to 29 detectors, we show that the instrument is expected to reach the target sensitivity of ~ 1 $μ$K deg$^{-1}$ at both 31 and 41 GHz over three cosmological fields covering a total area of 3600 deg$^2$ after an effective integration time of 5.7 years.
Comments32 pages, 19 figures, 17 tables. Accepted for publication in Publications of the Astronomical Society of the Pacific (PASP)
