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arXiv 2102.01776astro-ph.CO
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Ia型超新星宇宙学分析中主星系相关性的改进处理

Improved Treatment of Host-Galaxy Correlations in Cosmological Analyses With Type Ia Supernovae

Brodie Popovic, Dillon Brout, Richard Kessler, Dan Scolnic, Lisa Lu

摘要:

改进Ia型超新星(SNIa)作为标准烛光的使用需要更好的方法来结合SNIa和其宿主星系之间的关系。使用光谱确认的样本$\sim$ 1600 SNIa,我们开发的第一个经验模型的基本人口SNIa光变曲线的属性,包括其对宿主星系恒星质量的依赖。这些群体是模拟的重要输入,用于模拟选择效应和校正BEAMS与偏差校正(BBC)框架内的距离偏差。在这里,我们改进BBC也占SNIA主机的相关性,我们验证这种技术的模拟数据样本。我们恢复SNIa光度和宿主星系恒星质量(质量步骤,$γ$)之间的输入关系,在0.004马格西,这是一个因素的5比以前的方法,在${\sim}0.02$的$γ$ -偏差的结果改善。我们适应BBC的一种新的灰尘为基础的模型的内在亮度变化,这导致在一个大大减少的质量步骤的数据($γ= 0.017 \pm 0.008$),和模拟($γ=0.006 \pm 0.007$)。分析模拟SNIa,暗能量状态方程,$w$的偏见,从$Δw = 0.006(5)$到$0.010(5)$与我们的新BBC方法不同,这些偏见是显着小于$0.02(5)$ $w$ -偏见使用以前的BBC方法,忽略SNIa主机的相关性。

英文摘要:

Improving the use of Type Ia supernovae (SNIa) as standard candles requires a better approach to incorporate the relationship between SNIa and the properties of their host galaxies. Using a spectroscopically-confirmed sample of $\sim$1600 SNIa, we develop the first empirical model of underlying populations for SNIa light-curve properties that includes their dependence on host-galaxy stellar mass. These populations are important inputs to simulations that are used to model selection effects and correct distance biases within the BEAMS with Bias Correction (BBC) framework. Here we improve BBC to also account for SNIa-host correlations, and we validate this technique on simulated data samples. We recover the input relationship between SNIa luminosity and host-galaxy stellar mass (the mass step, $γ$) to within 0.004 mags, which is a factor of 5 improvement over the previous method that results in a $γ$-bias of ${\sim}0.02$. We adapt BBC for a novel dust-based model of intrinsic brightness variations, which results in a greatly reduced mass step for data ($γ= 0.017 \pm 0.008$), and for simulations ($γ=0.006 \pm 0.007$). Analysing simulated SNIa, the biases on the dark energy equation-of-state, $w$, vary from $Δw = 0.006(5)$ to $0.010(5)$ with our new BBC method; these biases are significantly smaller than the $0.02(5)$ $w$-bias using previous BBC methods that ignore SNIa-host correlations.

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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