Chemical enrichment in the cluster of galaxies Hydra A
Chemical enrichment in the cluster of galaxies Hydra A
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DOI：
10.1051/0004-6361:200810225
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发表时间：
2008-09
影响因子：
6.5
通讯作者：
A. Simionescu;N. Werner;H. Böhringer;J. Kaastra;A. Finoguenov;M. Brüggen;P. Nulsen
中科院分区：
文献类型：
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作者：
A. Simionescu;N. Werner;H. Böhringer;J. Kaastra;A. Finoguenov;M. Brüggen;P. Nulsen
我们分析了全球性的属性，径向配置文件，和二维地图的金属丰度和温度的冷核心星系长蛇座A使用深120千秒XMM-牛顿曝光。可用光谱模型中的最佳拟合由发射测量的高斯分布（gdem）提供。用EPIC能准确测定团簇核中的7种元素（O，Si，S，Ar，Ca，Fe，Ni），用RGS能准确测定团簇核中的3种元素（O，Ne，Fe）。gdem模型给出的Fe丰度比单一温度模型低。在此基础上，我们解释了为什么模拟表明，最适合的铁丰度在集群与中间温度被高估。Fe、Si、S和O的丰度分布图都呈中心峰值。结合Hydra A的结果和其他5个有详细化学丰度研究的星系团，我们发现O随半径的增加而显著减少，而O/Fe比随半径的增加在0.1 r200以内很小，其中O丰度可以精确确定，d（O/Fe）/d（log 10 r/r200）= 0.25 ± 0.09。我们比较了观测到的丰度比与不同相对量的各种Ia型超新星和核心塌陷产量模型的混合。要在长蛇座A中产生O、Si和S的估计峰值，需要恒星风喷射出的金属量比现有模型预测的高3-8倍，或者在原星团阶段核心坍缩超新星的初始富集不像以前认为的那样在大尺度上混合。温度图显示较冷的气体以臂状结构向南北延伸。这些结构，尤其是北方的结构，似乎比周围介质中的金属更丰富，并且在空间上与大尺度射电瓣相关。在不同的假设条件下，我们估算了活动星系核产生的相对论等离子体的浮力气泡抬升的冷气体的质量为1.6−6.1 × 109 M ²，与此抬升相关的能量为3.3−12.5 × 1058 erg。与冷气体一起上升的Fe质量的最佳估计为1.7 × 107 M�，占中心0.5 �区Fe总质量的15%。
We analyzed global properties, radial profiles, and 2D maps of the metal abundances and temperature in the cool core cluster of galaxies Hydra A using a deep ∼120 ks XMM-Newton exposure. The best fit among the available spectral models is provided by a Gaussian distribution of the emission measure (gdem). We can accurately determine abundances for 7 elements in the cluster core with EPIC (O, Si, S, Ar, Ca, Fe, Ni) and 3 elements (O, Ne, Fe) with RGS. The gdem model gives lower Fe abundances than a singletemperature model. Based on this, we explain why simulations show that the best-fit Fe abundance in clusters with intermediate temperatures is overestimated. The abundance profiles for Fe, Si, S, but also O are centrally peaked. Combining the Hydra A results with 5 other clusters for which detailed chemical abundance studies are available, we find a significant decrease in O with radius, while the increase in the O/Fe ratio with radius is small within 0.1 r200, where the O abundances can be accurately determined, with d(O/Fe)/d(log10r/r200) = 0.25 ± 0.09. We compare the observed abundance ratios with the mixing of various supernova type Ia and core-collapse yield models in different relative amounts. Producing the estimated O, Si, and S peaks in Hydra A requires either the amount of metals ejected by stellar winds to be 3–8 times higher than predicted by available models or the initial enrichment by core-collapse supernovae in the protocluster phase not to be as well mixed on large scales as previously thought. The temperature map shows cooler gas extending in arm-like structures towards the north and south. These structures, and especially the northern one, appear to be richer in metals than the ambient medium and spatially correlated with the large-scale radio lobes. With different sets of assumptions, we estimate the mass of cool gas, which was probably uplifted by buoyant bubbles of relativistic plasma produced by the AGN, to 1.6−6.1 × 10 9 M� , and the energy associated with this uplift to 3.3−12.5 × 10 58 erg. The best estimate of the mass of Fe uplifted together with the cool gas is 1.7 × 10 7 M� , 15% of the total mass of Fe in the central 0.5 � region.