We have developed the Smoothed Bandpass Calibration (SBC) method and the best suitable scan pattern to optimize radio spectroscopic observations. Adequate spectral smoothing is applied to the spectrum toward OFF-source blank sky adjacent to a target source direction for the purpose of bandpass correction. Because the smoothing process reduces noise, the integration time for OFF-source scans can be reduced keeping the signal-to-noise ratio. Since the smoothing is not applied to ON-source scans, the spectral resolution for line features is kept. An optimal smoothing window is determined by bandpass flatness evaluated by Spectral Allan Variance (SAV). An efficient scan pattern is designed to the OFF-source scans within the bandpass stability timescale estimated by Time-based Allan Variance (TAV). We have tested the SBC using the digital spectrometer, VESPA, on the VERA Iriki station. For the targeted noise level of 5e-4 as a ratio to the system noise, the optimal smoothing window was 32 - 60 ch in the whole bandwidth of 1024 ch, and the optimal scan pattern was designed as a sequence of 70-s ON + 10-s OFF scan pairs. The noise level with the SBC was reduced by a factor of 1.74 compared with the conventional method. The total telescope time to achieve the goal with the SBC was 400 s, which was 1/3 of 1200 s required by the conventional way. Improvement in telescope time efficiency with the SBC was calculated as 3x, 2x and 1.3x for single-beam, dual-beam, and on-the-fly (OTF) scans, respectively. The SBC works to optimize scan patterns for observations from now, and also works to improve signal-to-noise ratios of archival data if ON- and OFF-source spectra are individually recorded, though the efficiency depends on the spectral stability of the receiving system.
A Classifier Framework for ALMA Bandpass Calibration Anomalies
National Radio Astronomy Observatory（国家射电天文台）；NSF–Simons AI Institute for Cosmic Origins（NSF-Simons宇宙起源人工智能研究所）；University of Utah（犹他大学）；Joint ALMA Observatory（ALMA联合观测站）
针对射电干涉观测中带通校准异常检测，提出基于 XGBoost 和扫描统计特征的分类器框架，在 ALMA 数据上显著降低误分类率，可扩展至下一代设施。
Calibration requirements for Epoch of Reionization 21-cm signal observations -- IV. Bias and variance with time and frequency correlated residual gains
SNR 1E 0102.2-7219 as an X-ray Calibration Standard in the 0.5-1.0 keV Bandpass and Its Application to the CCD Instruments aboard Chandra, Suzaku, Swift and XMM-Newton
我们希望对以下天文台上的当前一代CCD仪器的绝对有效面积进行简单的比较：Chandra ACIS-S3，XMM-Newton（EPIC-MOS和EPIC-pn），Suzaku XIS和Swift XRT，并直接比较这些仪器在各自任务寿命期间的随时间变化的响应。我们一直在使用1 E 0102.2-7219，在小麦哲伦星云最明亮的超新星遗迹，以评估和修改这些仪器的响应模型。1 E 0102.2-7219具有低于1.5 keV的O、Ne和Mg的强谱线，并且几乎没有或没有Fe发射，从而使光谱复杂化。作为国际天文学高能定标联合会（IACHEC）活动的一部分，我们开发了1 E 0102.2-7219的标准光谱模型。该模型是经验的，因为它包括高斯识别线，在银河系中的吸收组件，在SMC的另一个吸收组件，和两个热连续分量。在我们的拟合中，该模型受到高度约束，因为仅允许四个最亮线/线复合体（O vi He $α$三重体、O vi Ly $α$线、Ne ix He $α$三重体和Ne x Ly $α$线）的标准化和总体标准化发生变化。我们已经检查了这些测得的线通量作为时间的函数，每个仪器后，应用最新的校准，占每个仪器的时间依赖性的响应。当辐射损伤和污染层处于最低限度时，我们与具有代表性的早期任务数据进行了有效面积比较。我们发现，这些线的测量通量一般同意在+/-10%的所有仪器，与我们的48个拟合归一化在…
Trottier Space Institute, McGill University（特罗蒂尔太空研究所，麦吉尔大学）；Department of Physics, McGill University（麦吉尔大学物理系）；Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安东·潘内科克天文学研究所）；ASTRON, Netherlands Institute for Radio Astronomy（ASTRON，荷兰射电天文研究所）
An empirical calibration of the spectral resolution of JWST NIRSpec PRISM
School of Astronomy and Space Science, University of Chinese Academy of Sciences (UCAS)（中国科学院大学天文与空间科学学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与空间科学学院前沿天文与天体物理研究所）；Centre for Astrophysics and Supercomputing, Swinburne University of Technology（斯威本科技大学天体物理学与超算中心）；Sydney Institute for Astronomy, School of Physics, The University of Sydney（悉尼大学物理学院悉尼天文学研究所）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）
The CHIME/FRB Outriggers: Commissioning the Hat Creek Outrigger and an Updated Calibration Scheme for Mitigating RFI
ASTRON, Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）；Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安东·潘内科克天文学研究所）；MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理学与空间研究研究所）；Department of Physics, Massachusetts Institute of Technology（麻省理工学院物理学系）
本文介绍 CHIME/FRB Outrigger 中 Hat Creek Outrigger 的调试，采用高斯过程回归校准方案缓解射频干扰，将点源灵敏度提升约 1.69-1.87 倍，并验证了该框架对大型干涉阵列的适用性。
