Confirming the Calibration of ALMA Using Planck Observations
Confirming the Calibration of ALMA Using Planck Observations
复制标题
使用普朗克观测确认 ALMA 的校准
DOI：
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发表时间：
2021
影响因子：
8.7
通讯作者：
Yaqiong Li
中科院分区：
文献类型：
--
作者：
G. Farren;B. Partridge;R. Kneissl;S. Aiola;R. Datta;M. Gralla;Yaqiong Li
我们测试的准确性比较阿尔马流量密度测量的河外源普朗克使命的测量值的阿尔马流量密度校准;普朗克绝对校准subpercent精度使用卫星的轨道周围的太阳系重心诱导的偶极子信号。然而，普朗克观测在阿尔马开始系统观测之前就结束了，而且许多源都是可变的，所以我们使用阿塔卡玛宇宙学望远镜（ACT）的测量来连接这两个时代。我们比较ACT观测在93和145 GHz普朗克测量在100和143 GHz和阿尔马测量在91.5和103.5 GHz的频带3。对于这两种比较，使用每个源的最佳可用光谱指数对通量密度测量值进行了校正，以考虑到频率的微小差异。我们发现阿尔马通量密度尺度（基于天王星的观测）与普朗克一致。用于比较的所有方法都与波段3的阿尔马通量密度一致，平均为普朗克测量的通量密度的0.99倍。一个特定的测试给出阿尔马/普朗克= 0.996 ± 0.024。我们还测试了绝对校准的ACT在93和145 GHz和南极望远镜（SPT）在97.43，152.9和215.8 GHz，再次参考普朗克测量在100，143，和217 GHz，以及内部一致性的紧凑的源的测量由所有三个仪器。
We test the accuracy of ALMA flux density calibration by comparing ALMA flux density measurements of extragalactic sources to measurements made by the Planck mission; Planck is absolutely calibrated to subpercent precision using the dipole signal induced by the satellite’s orbit around the solar system barycenter. Planck observations ended before ALMA began systematic observations, however, and many of the sources are variable, so we employ measurements by the Atacama Cosmology Telescope (ACT) to bridge the two epochs. We compare ACT observations at 93 and ∼145 GHz to Planck measurements at 100 and 143 GHz and to ALMA measurements made at 91.5 and 103.5 GHz in Band 3. For both comparisons, flux density measurements were corrected to account for the small differences in frequency using the best available spectral index for each source. We find the ALMA flux density scale (based on observations of Uranus) is consistent with Planck. All methods used to make the comparison are consistent with ALMA flux densities in Band 3 averaging 0.99 times those measured by Planck. One specific test gives ALMA/Planck = 0.996 ± 0.024. We also test the absolute calibration of both ACT at 93 and ∼145 GHz and the South Pole Telescope (SPT) at 97.43, 152.9, and 215.8 GHz, again with reference to Planck measurements at 100, 143, and 217 GHz, as well as the internal consistency of measurements of compact sources made by all three instruments.
DOI：
10.1088/1475-7516/2020/12/045
发表时间：
2020-12-01
影响因子：
6.4
作者：
Choi, Steve K.;Hasselfield, Matthew;Zhu, Ningfeng
通讯作者：
Zhu, Ningfeng