论文标题

Chandra的气体均匀性和湍流的chandra测量值

Chandra measurements of gas homogeneity and turbulence at intermediate radii in the Perseus Cluster

论文作者

de Vries, Martijn, Mantz, Adam B., Allen, Steven W., Morris, R. Glenn, Zhuravleva, Irina, Ehlert, Rebecca E. Canning. Steven, Ogorzałek, Anna, Simionescu, Aurora, Werner, Norbert

论文摘要

我们介绍了Chandra研究的表面亮度波动在Perseus簇的散布内介质中。我们的研究利用了群集核心的深层档案成像,以及29个短5 ks观测值的新镶​​嵌物,在8个不同的方向上延伸至R_500〜2.2R_2500的半径。在假设给定半径处的密度分布是对数正态分布的假设,可以从给定的空间尺度上的对数 - 正态密度分布的宽度得出两个重要数量:密度偏置等于集成因子C的平方根C;和一个组分的湍流速度,v_(k,1d)。我们向测量表面亮度(包括天体物理和粒子背景成分)进行前向模型,并说明了测量信号的泊松性质。测量1个Arcmin^2区域表面亮度波动的分布,跨越径向范围为0.3-2.2 R_2500(7.8-57.3 Arcmin),我们发现在1.6R_2500以下的半径下,半径约为3%。我们还推断在V_1D <400 km S^-1的这些半径处的平均湍流速度。直接确认我们对从表面亮度波动推断出的湍流速度的结果,应该使用X射线热量计光谱仪在Xrism和achena上飞行。天文台。

We present a Chandra study of surface brightness fluctuations in the diffuse intracluster medium of the Perseus Cluster. Our study utilizes deep, archival imaging of the cluster core as well as a new mosaic of 29 short 5 ks observations extending in 8 different directions out to radii of r_500 ~ 2.2r_2500. Under the assumption that the distribution of densities at a given radius is log-normally distributed, two important quantities can be derived from the width of the log-normal density distribution on a given spatial scale: the density bias, which is equal to the square root of the clumping factor C; and the one-component turbulent velocity, v_(k, 1D). We forward-model all contributions to the measured surface brightness, including astrophysical and particle background components, and account for the Poisson nature of the measured signal. Measuring the distribution of surface brightness fluctuations in 1 arcmin^2 regions, spanning the radial range 0.3-2.2 r_2500 (7.8-57.3 arcmin), we find a small to moderate average density bias of around 3% at radii below 1.6r_2500. We also infer an average turbulent velocity at these radii of v_1D <400 km s^-1. Direct confirmation of our results on turbulent velocities inferred from surface brightness fluctuations should be possible using the X-ray calorimeter spectrometers to be flown aboard the XRISM and Athena. observatories.

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