XMM-Newton study of 0.012 < z < 0.024 groups - I. Overview of the IGM thermodynamics
XMM-Newton study of 0.012 < z < 0.024 groups - I. Overview of the IGM thermodynamics
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DOI：
10.1111/j.1365-2966.2006.11194.x
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发表时间：
2006-11
影响因子：
4.8
通讯作者：
A. Finoguenov;T. Ponman;J. Osmond;J. Osmond;M. Zimer
中科院分区：
文献类型：
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作者：
A. Finoguenov;T. Ponman;J. Osmond;J. Osmond;M. Zimer
我们利用XMM-Newton观测，研究了0.012-0.024红移范围内的热气体的热力学性质。我们提出了温度、熵、压力和铁丰度的测量方法。非参数拟合用于推导样本的平均性质，并研究熵和压力值的离散性。熵在0.2r 500处的比例与Ponman， Sanderson和Finoguenov的结果很匹配。然而，与冷星团相比，与纯引力加热的预测和星团的观测结果相比，我们样本中的星团在内部半径处显示出更大的熵，而在外围的熵斜率则明显平坦。这种差异对应于先前报道的系统平坦的组表面亮度曲线。用n = 4的Sersic模型可以很好地逼近按比例调整后的压力分布。我们发现，与星系团相比，星系团在压力方面表现出更大的系统色散，而熵的色散是相似的。
We study the thermodynamic properties of the hot gas in a sample of groups in the 0.012-0.024 redshift range, using XMM-Newton observations. We present measurements of temperature, entropy, pressure and iron abundance. Non-parametric fits are used to derive the mean properties of the sample and to study dispersion in the values of entropy and pressure. The scaling of the entropy at 0.2r 500 matches well the results of Ponman, Sanderson & Finoguenov. However, compared to cool clusters, the groups in our sample reveal larger entropy at inner radii and a substantially flatter slope in the entropy in the outskirts, compared to both the prediction of pure gravitational heating and observations of clusters. This difference corresponds to the systematically flatter group surface brightness profiles, reported previously. The scaled pressure profiles can be well approximated with a Sersic model with n = 4. We find that groups exhibit a systematically larger dispersion in pressure, compared to clusters of galaxies, while the dispersion in entropy is similar.