arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2204.06280astro-ph.CO
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UNIONS:系统误差对弱透镜峰值计数的影响

UNIONS: The impact of systematic errors on weak-lensing peak counts

Emma Ayçoberry, Virginia Ajani, Axel Guinot, Martin Kilbinger, Valeria Pettorino, Samuel Farrens, Jean-Luc Starck, Raphaël Gavazzi, Michael J. Hudson

摘要:

UNIONS是一个正在进行的北方天空深测光多波段调查。作为UNIONS的一部分,CFIS提供了r波段数据,我们使用这些数据来研究弱透镜峰计数,以进行宇宙学推断。我们评估弱透镜峰计数的系统效应及其对UNIONS调查宇宙学参数的影响。特别是,我们目前的本地校准,亚校准剪切偏置,重子反馈,源星系红移估计,内在的调整,和集群成员稀释的结果。对于每个不确定性和系统效应,我们描述了我们的缓解方案和宇宙学参数约束的影响。我们得到的宇宙学参数的MCMC使用CFIS数据和MassiveNuS N体模拟作为一个模型的峰值计数统计的约束。取决于校准(局部与全局,以及包含残余乘法剪切偏差),平均物质密度参数$Ω_m$可以移位到$-0.024$($-0.5σ$)。我们还看到,包括重子修正可以使$Ω_m$相对于仅DM模拟移动$+0.027$($+0.5 σ$)。通过信噪比削减减少固有排列和簇成员稀释的影响可导致$Ω_m$中$+0.027$($+0.5 σ$)的偏移。最后,在平均红移不确定度为$Δ\bar{z} = 0.03$的情况下,我们看到$Ω_m$($+0.001$对应于$+0.02 σ$)的位移并不显著。本文首次用UNIONS弱透镜数据和峰值计数研究了系统效应的影响。$Ω_m$的值受影响最大,根据每个分类系统的选择,可以向上移动到与$0.5σ$对应的$\sim 0.03$。我们希望约束在未来(更大)的数据目录中变得更加可靠,目前的管道将提供一个起点。

英文摘要:

UNIONS is an ongoing deep photometric multi-band survey of the Northern sky. As part of UNIONS, CFIS provides r-band data which we use to study weak-lensing peak counts for cosmological inference. We assess systematic effects for weak-lensing peak counts and their impact on cosmological parameters for the UNIONS survey. In particular, we present results on local calibration, metacalibration shear bias, baryonic feedback, the source galaxy redshift estimate, intrinsic alignment, and the cluster member dilution. For each uncertainty and systematic effect, we describe our mitigation scheme and the impact on cosmological parameter constraints. We obtain constraints on cosmological parameters from MCMC using CFIS data and MassiveNuS N-body simulations as a model for peak counts statistics. Depending on the calibration (local versus global, and the inclusion of the residual multiplicative shear bias), the mean matter density parameter $Ω_m$ can shift up to $-0.024$ ($-0.5σ$). We also see that including baryonic corrections can shift $Ω_m$ by $+0.027$ ($+0.5 σ$) with respect to the DM-only simulations. Reducing the impact of the intrinsic alignment and cluster member dilution through signal-to-noise cuts can lead to a shift in $Ω_m$ of $+0.027$ ($+0.5 σ$). Finally, with a mean redshift uncertainty of $Δ\bar{z} = 0.03$, we see that the shift of $Ω_m$ ($+0.001$ which corresponds to $+0.02 σ$) is not significant. This paper investigates for the first time with UNIONS weak-lensing data and peak counts the impact of systematic effects. The value of $Ω_m$ is the most impacted and can shift up to $\sim 0.03$ which corresponds to $0.5σ$ depending on the choices for each systematics. We expect constraints to become more reliable with future (larger) data catalogues, for which the current pipeline will provide a starting point.

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。

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