论文标题
超新星红移不确定性对确定宇宙参数的影响
Effects of Supernova Redshift Uncertainties on the Determination of Cosmological Parameters
论文作者
论文摘要
当前宇宙学超新星样品中使用的红移是使用两种主要技术测量的，一种基于良好的宿主星系光谱线，另一个基于超新星主导的光谱。在这里，我们构建了一个更新的Pantheon目录，其中包含经过修订的红移，红移来源和整个样本的估计不确定性，以研究这两种技术是否会产生一致的结果。 The best-fit cosmological parameters using these two measurement techniques disagree, with a supernova-only sample producing $Ω_m$ 3.2$σ$ higher and $H_0$ 2.5$σ$ lower than a hostz-only sample, and we explore several possible sources of bias which could result from using the lower-precision supernova-dominated redshifts.在一项试点研究中，我们表明，使用唯一的红移子样本通常会产生较低的$ω_m$，并且物质密度$ω_mh^2 $且$ h_0 $略高于以前的分析，该分析（对于万神殿数据集）可能会导致Supernova和CMB的测量值和CMB的测量，同意$ω_mH^2 $ H^$ H^$ H__ $ H_____0 $ h___0 $ h_0 $ h_0 $ h_0 $ h_0 $ h_0 $ h_0 $ h_0 $ h_0 $ h_0。但是，为了获得严格的结果，应通过获得褪色的超新星的宿主光谱来改善万神殿目录，并应设计未来的调查来使用宿主星系红移，而不是较低精确的方法。
Redshifts used in current cosmological supernova samples are measured using two primary techniques, one based on well-measured host galaxy spectral lines and the other based on supernova-dominated spectra. Here, we construct an updated Pantheon catalog with revised redshifts, redshift sources and estimated uncertainties for the entire sample to investigate whether these two techniques yield consistent results. The best-fit cosmological parameters using these two measurement techniques disagree, with a supernova-only sample producing $Ω_m$ 3.2$σ$ higher and $H_0$ 2.5$σ$ lower than a hostz-only sample, and we explore several possible sources of bias which could result from using the lower-precision supernova-dominated redshifts. In a pilot study, we show that using a host redshift-only subsample will generically produce lower $Ω_m$ and matter density $Ω_m h^2$ and slightly higher $H_0$ than previous analysis which, for the Pantheon dataset, could result in supernova and CMB measurements agreeing on $Ω_m h^2$ despite tension in $H_0$. To obtain rigorous results, though, the Pantheon catalog should be improved by obtaining host spectra for supernova that have faded and future surveys should be designed to use host galaxy redshifts rather than lower-precision methods.
