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首页> 外文期刊>The Astrophysical journal >Chandra Observation of the Cooling Flow Cluster Abell 2052
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Chandra Observation of the Cooling Flow Cluster Abell 2052

机译:Chandra观察冷却流团Abell 2052

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We present an analysis of the Chandra X-ray observation of A2052, including large-scale properties of the cluster as well as the central region, which includes the bright radio source 3C 317. We present temperature and abundance profiles using both projected and deprojected spectral analyses. The cluster shows the cooling flow signatures of excess surface brightness above a β-model at the cluster center and a temperature decline into the center of the cluster. For A2052, the temperature drops by a factor of 3 from approximately 3 to 1 keV. The heavy-element abundances initially increase into the center, but decline within 30''. Temperature and abundance maps show that the X-ray-bright shells surrounding the radio source are the coolest and least abundant regions in the cluster. The mass deposition rate in the cooling flow is 26 M☉ yr-1 42 M☉ yr-1. This rate is approximately a factor of 3 lower than the rates found with previous X-ray observatories. Based on a stellar population analysis using imaging and spectra at wavelengths spanning the far-ultraviolet to the near-infrared, we find a star formation rate of 0.6 M☉ yr-1 within a 3'' radius of the nucleus of the central cluster galaxy. Total and gas mass profiles for the cluster are also determined. We investigate additional sources of pressure in the X-ray holes formed by the radio source and limit the temperature of any hot, diffuse, thermal component that provides the bulk of the pressure in the holes to kT 20 keV. We calculate the magnetic field in the bright-shell region and find B ≈ 11 μG. The magnetic pressure in the cluster center is significantly lower than the gas pressure. The current luminosity of the central AGN is LX = 7.9 × 1041 ergs s-1, and its spectrum is well fitted by a power-law model with no excess absorption above the Galactic value. The energy output from several radio outbursts, occurring episodically over the lifetime of the cluster, may be sufficient to offset the cooling flow near the center.
机译:我们介绍了对A2052的Chandra X射线观察结果的分析,包括星团以及中心区域(包括明亮的无线电源3C 317)的大规模属性。我们使用投影和投影光谱展示了温度和丰度曲线分析。集群显示出冷却流的特征,即在集群中心的β模型上方表面亮度过高,并且温度下降到集群的中心。对于A2052,温度从大约3到1 keV下降了3倍。最初,重元素的丰度增加到中心,但在30英寸以内下降。温度和丰度图显示,围绕无线电源的X射线明亮的壳层是星团中最凉爽,最不富裕的区域。冷却流中的质量沉积速率为26M☉yr-142M☉yr-1。该速率比以前的X射线观测站的速率低约3倍。基于使用成像和光谱的恒星种群分析,该光谱和光谱范围涵盖了从远紫外线到近红外的波长,在中央星系星系核的3''半径内,恒星形成速率为0.6M☉yr-1 。还确定了群集的总质量和气体质量分布。我们研究了由无线电源形成的X射线孔中的其他压力源,并将将孔中大部分压力提供给kT 20 keV的任何热,扩散,热成分的温度限制。我们计算了亮壳区域的磁场,发现B≈11μG。簇中心的磁压明显低于气压。中央AGN的当前光度为LX = 7.9×1041 ergs s-1,并且它的光谱通过幂律模型很好地拟合,没有超过银河系值的过量吸收。在簇的整个生命周期中,从几次无线电爆发中发出的能量输出可能足以抵消中心附近的冷却流。

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