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The Cosmic Thermal History Probed by Sunyaev–Zeldovich Effect Tomography
The Astrophysical Journal ( IF 4.8 ) Pub Date : 2020-10-12 , DOI: 10.3847/1538-4357/abb403
Yi-Kuan Chiang 1 , Ryu Makiya 2 , Brice Mnard 2, 3 , Eiichiro Komatsu 2, 4
Affiliation  

The cosmic thermal history, quantified by the evolution of the mean thermal energy density in the universe, is driven by the growth of structures as baryons get shock heated in collapsing dark matter halos. This process can be probed by redshift-dependent amplitudes of the thermal Sunyaev-Zeldovich (SZ) effect background. To do so, we cross-correlate eight sky intensity maps in the $\it{Planck}$ and Infrared Astronomical Satellite missions with two million spectroscopic redshift references in the Sloan Digital Sky Surveys. This delivers snapshot spectra for the far-infrared to microwave background light as a function of redshift up to $z\sim3$. We decompose them into the SZ and thermal dust components. Our SZ measurements directly constrain $\langle bP_{\rm e} \rangle$, the halo bias-weighted mean electron pressure, up to $z\sim 1$. This is the highest redshift achieved to date, with uncorrelated redshift bins thanks to the spectroscopic references. We detect a threefold increase in the density-weighted mean electron temperature $\bar{T}_{\rm{e}}$ from $7\times 10^5~{\rm K}$ at $z=1$ to $2\times 10^6~{\rm K}$ today. Over $z=1$-$0$, we witness the build-up of nearly $70\%$ of the present-day mean thermal energy density $\rho_{\rm{th}}$, with the corresponding density parameter $\Omega_{\rm th}$ reaching $1.5 \times10^{-8}$. We find the mass bias parameter of $\it{Planck}$'s universal pressure profile of $B=1.27$ (or $1-b=1/B=0.79$), consistent with the magnitude of non-thermal pressure in gas motion and turbulence from mass assembly. We estimate the redshift-integrated mean Compton parameter $y\sim1.2\times10^{-6}$, which will be tested by future spectral distortion experiments. More than half of which originates from the large-scale structure at $z<1$, which we detect directly.

中文翻译:

Sunyaev-Zeldovich效应层析成像探测的宇宙热史

宇宙热历史由宇宙中平均热能密度的演变量化,是由结构的增长驱动的,因为重子在坍缩的暗物质晕中受到冲击加热。这个过程可以通过热 Sunyaev-Zeldovich (SZ) 效应背景的红移相关振幅来探测。为此,我们将 $\it{Planck}$ 和红外天文卫星任务中的八张天空强度图与斯隆数字巡天中的 200 万光谱红移参考进行了交叉关联。这提供了远红外到微波背景光的快照光谱,作为高达 $z\sim3$ 的红移函数。我们将它们分解为 SZ 和热粉尘成分。我们的 SZ 测量直接约束 $\langle bP_{\rm e} \rangle$,晕偏加权平均电子压力,最高可达 $z\sim 1$。这是迄今为止实现的最高红移,由于光谱参考,红移箱不相关。我们检测到密度加权平均电子温度 $\bar{T}_{\rm{e}}$ 从 $7\times 10^5~{\rm K}$ 在 $z=1$ 增加到 $2 \times 10^6~{\rm K}$ 今天。在 $z=1$-$0$ 期间,我们目睹了近 $70\%$ 的当今平均热能密度 $\rho_{\rm{th}}$ 的累积,以及相应的密度参数 $\ Omega_{\rm th}$ 达到 $1.5 \times10^{-8}$。我们发现 $\it{Planck}$ 的通用压力剖面的质量偏差参数为 $B=1.27$(或 $1-b=1/B=0.79$),与气体中非热压的大小一致来自质量集合的运动和湍流。我们估计红移积分平均康普顿参数 $y\sim1.2\times10^{-6}$,这将通过未来的光谱失真实验进行测试。其中一半以上来自我们直接检测到的 $z<1$ 处的大规模结构。
更新日期:2020-10-12
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