arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0903.0429astro-ph.HEastro-ph.CO
收藏

用XMM和Chandra观测早型星系X射线气体的元素丰度

Elemental Abundances in the X-Ray Gas of Early-Type Galaxies with XMM and Chandra Observations

Jun Ji, Jimmy A. Irwin, Alex Athey, Joel N. Bregman, Edward J. Lloyd-Davies

摘要:

椭圆星系中的热气体来源被认为是由于恒星质量的损失,超新星事件的贡献,也可能来自周围环境的下降。这张照片预测了星系内部气体金属丰度的超太阳值,这可以通过测量气相丰度来测试。我们使用来自XMM-牛顿的10个附近早期星系的高质量数据,其中包括EPIC和反射光栅光谱仪,其中最强的发射线几乎没有混合;还使用了一些钱德拉数据。我们发现不同的XMM仪器之间的元素丰度和良好的一致性与钱德拉之间的良好的一致性。丰度与孔径大小和模型的复杂性的差异进行了检查,但很少发生大的差异。对于两个温度的热模型加上点源的贡献,中值Fe和O的丰度是0.86和0.44的太阳值,而Si和Mg的丰度是类似的Fe。这与这些星系的恒星丰度相似,但超新星预计会大大增加气相丰度,但没有观察到。

英文摘要:

The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the metallicity of the gas toward the inner part of the galaxy, which can be tested by measuring the gas phase abundances. We use high-quality data for 10 nearby early-type galaxy from XMM-Newton, featuring both the EPIC and the Reflection Grating Spectrometer, where the strongest emission lines are detected with little blending; some Chandra data are also used. We find excellent consistency in the elemental abundances between the different XMM instruments and good consistency with Chandra. Differences in abundances with aperture size and model complexity are examined, but large differences rarely occur. For a two-temperature thermal model plus a point source contribution, the median Fe and O abundances are 0.86 and 0.44 of the Solar value, while Si and Mg abundances are similar to that for Fe. This is similar to stellar abundances for these galaxies but supernovae were expected to enhance the gas phase abundances considerably, which is not observed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑