arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0812.4951astro-ph
收藏

NICMOS用于高精度近红外成像偏振测量

High Accuracy Near-infrared Imaging Polarimetry with NICMOS

D. Batcheldor, G. Schneider, D. C. Hines, G. D. Schmidt, D. J. Axon, A. Robinson, W. Sparks, C. Tadhunter

备注：
13 pages, 9 figures, PASP accepted
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

在HST周期15期间进行的9轨道校准计划的调查结果，以充分确定NICMOS相机2（2.0微米）偏振校准的高精度，报告。最近Ueta等人和Batcheldor等人提出NICMOS具有1.2- 1.5%水平的剩余仪器极化。这将完全抑制许多GO程序中的数据减少，并妨碍仪器执行高精度偏振测定的能力。我们获得了三个偏振标准的偏振校准观测在三个航天器滚转角分离~ 60度。结合档案数据，这些观测结果被用来表征剩余仪器极化，以使NICMOS在p~ 1%时充分发挥其精确成像极化的潜力。使用这些数据，我们放置一个0.6%的上限上的仪器偏振和计算值的平行传输系数，再现地面的结果的偏振标准。平行透射系数的不确定性，观测的光度重复性的结果，被认为是主导的p和θ的准确性。然而，更新后的系数确实允许在+/-0.6%和+/-15 °的准确度下对p~1.0%的目标进行成像偏振测定。这项工作使一个新的科学口径与HST。

英文摘要：

The findings of a nine orbit calibration plan carried out during HST Cycle 15, to fully determine the NICMOS camera 2 (2.0 micron) polarization calibration to high accuracy, are reported. Recently Ueta et al. and Batcheldor et al. have suggested that NICMOS possesses a residual instrumental polarization at a level of 1.2-1.5%. This would completely inhibit the data reduction in a number of GO programs, and hamper the ability of the instrument to perform high accuracy polarimetry. We obtained polarimetric calibration observations of three polarimetric standards at three spacecraft roll angles separated by ~60deg. Combined with archival data, these observations were used to characterize the residual instrumental polarization in order for NICMOS to reach its full potential of accurate imaging polarimetry at p~1%. Using these data, we place an 0.6% upper limit on the instrumental polarization and calculate values of the parallel transmission coefficients that reproduce the ground-based results for the polarimetric standards. The uncertainties associated with the parallel transmission coefficients, a result of the photometric repeatability of the observations, are seen to dominate the accuracy of p and theta. However, the updated coefficients do allow imaging polarimetry of targets with p~1.0% at an accuracy of +/-0.6% and +/-15deg. This work enables a new caliber of science with HST.

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。

↑