标题： 星爆星系与X射线背景 显示英文标题

标题： Starburst Galaxies and the X-Ray Background

摘要： 恒星爆发星系（SBGs）演化的综合X射线谱是基于本地SBGs的观测谱确定的。除了热气体和双星系统的发射外，我们的模型SBG谱还包括由相对论电子通过强烈的近红外和（快速演化的）宇宙微波背景辐射场的康普顿散射产生的非热成分。我们利用这些综合谱计算了SBGs对宇宙X射线背景的贡献水平，假设其密度随(1+z)^q演化，最大红移为5。我们发现，在能量<10 keV时，对于q高达3的贡献水平仅为几个百分点，在q约为4.5时，贡献范围在5%-15%之间。高能处的康普顿分量被预测为主要的SBG发射，其相对贡献随着红移的增加而逐步提高。 显示英文摘要

摘要： Integrated X-ray spectra of an evolving population of starburst galaxies (SBGs) are determined based on the observed spectra of local SBGs. In addition to emission from hot gas and binary systems, our model SBG spectrum includes a nonthermal component from Compton scattering of relativistic electrons by the intense ambient far-IR and the (steeply evolving) CMB radiation fields. We use these integrated spectra to calculate the levels of contribution of SBGs to the cosmic X-ray background assuming that their density evolves as (1+z)^q up to a maximal redshift of 5. We find that at energies <10 keV this contribution is at a level of few percent for q up to 3, and in the range of 5%-15% for q ~ 4.5. The Compton component is predicted to be the main SBG emission at high energies, and its relative contribution gets progressively higher for increasing redshift.