Noise from undetected sources in Dark Energy Survey images
Noise from undetected sources in Dark Energy Survey images
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暗能量巡天图像中未检测到的噪声源
DOI：
10.1093/mnras/staa2133
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发表时间：
2020
影响因子：
4.8
通讯作者：
Kuropatkin, N
中科院分区：
文献类型：
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作者：
Eckert, K;Bernstein, G M;Amara, A;Amon, A;Choi, A;Everett, S;Gruen, D;Gruendl, R A;Huff, E M;Kuropatkin, N
对于目前使用CCD技术的地面光学成像，源和天空背景光子到达时的泊松波动主导着噪声预算，并且很容易估计。然而，噪声的另一个组成部分是来自未被检测到的恒星和星系的信号。使用将人造星系注入图像中，我们证明了暗能量调查(DES)图像中测量的星系矩(用于弱引力透镜测量)的方差大大超过泊松预测，高达30% %，并且当前的软件高估了背景天空水平。通过互相关空天空区域的不同图像，我们建立了来自未检测到的静态源(US)的显著图像噪声贡献，平均而言，这些噪声在DES分辨率下被温和地分辨。将这些US视为平稳噪声源，计算对泊松噪声期望的矩协方差矩阵的修正。校正后的协方差矩阵与在注射DES图像上测量的矩的方差匹配到5% %以内。因此，我们有了一种经验方法，可以在统计上解释美国在弱透镜测量中的情况，而不是需要极深的天空模拟。我们还发现，当地的天空测量可以消除通量测量中的大部分偏差，但对额外的但可量化的噪声有很小的影响。
For ground-based optical imaging with current CCD technology, the Poisson fluctuations in source and sky background photon arrivals dominate the noise budget and are readily estimated. Another component of noise, however, is the signal from the undetected population of stars and galaxies. Using injection of artifical galaxies into images, we demonstrate that the measured variance of galaxy moments (used for weak gravitational lensing measurements) in Dark Energy Survey (DES) images is significantly in excess of the Poisson predictions, by up to 30 per cent, and that the background sky levels are overestimated by current software. By cross-correlating distinct images of ‘empty’ sky regions, we establish that there is a significant image noise contribution from undetected static sources (US), which, on average, are mildly resolved at DES resolution. Treating these US as a stationary noise source, we compute a correction to the moment covariance matrix expected from Poisson noise. The corrected covariance matrix matches the moment variances measured on the injected DES images to within 5 per cent. Thus, we have an empirical method to statistically account for US in weak lensing measurements, rather than requiring extremely deep sky simulations. We also find that local sky determinations can remove most of the bias in flux measurements, at a small penalty in additional, but quantifiable, noise.
约束未检测到的微弱 i-dropout 星系的光度函数
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
V. Calvi;V. Calvi;A. Pizzella;A. Pizzella;M. Stiavelli;L. Morelli;L. Morelli;E. Corsini;E. Corsini;E. Bontà;E. Bontà;L. Bradley;A. Koekemoer
通讯作者：
A. Koekemoer
赫歇尔边缘螺旋观测 (HEROES) - I. 远红外形态和尘埃质量测定
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
J. Verstappen;J. Fritz;M. Baes;M. Smith;F. Allaert;S. Bianchi;J. Blommaert;G. D. Geyter;I. D. Looze;G. Gentile;K. Gordon;B. Holwerda;S. Viaene;E. M. X. S. Observatorium;Universiteit Gent;S. O. Physics;Astronomy;Cardiff University;Inaf ;Instituut voor Sterrenkunde;K. Leuven;Vakgroep Fysica en Sterrenkunde;V. U. Brussel;S. S. Institute;E. S. Agency;Estec;Institute for Astronomy;Astrophysics;Space Applications;R. Sensing;National Observatory of Athens
通讯作者：
National Observatory of Athens
DOI：
10.1086/427716
发表时间：
2004
期刊：
The Astronomical Journal
影响因子：
--
作者：
B. Holwerda;R. González;R. Allen;P. Kruit
通讯作者：
P. Kruit