arXiv 1003.47332010-03-24astro-ph.CO

漫宇宙红外背景起源的物理模型

A physical model for the origin of the diffuse cosmic infrared background

Joshua D. Younger, Philip F. Hopkins

备注：: 14 pages, 13 figures, submitted to MNRAS
DOI：: 10.1111/j.1365-2966.2010.17594.x

摘要：

提出了一个宇宙漫红外背景辐射（CDIRB）起源的物理模型.通过利用观测到的恒星质量函数及其演化作为星系形成的半经验模型的输入，我们隔离的物理驱动弥漫红外辐射。该模型包括三个主要来源的红外辐射的贡献：由于孤立的盘星系，相互作用驱动的恒星形成的爆发，由于近距离接触和合并，和模糊的活动星系核（AGN）的稳定状态的恒星形成。我们发现，大多数CDIRB是由来自z=0.5-1和z>1的物体的相等贡献产生的，正如最近的观测所表明的那样。在这些源中，绝大多数的发射源都来自于低到中等红外光度的系统（L_{IR} <10^{12} $L_sun）;最明亮的天体只在高红移（z>2）处贡献了显著的通量。在所有波长和红移下，正在进行的合并中的所有恒星形成占总数的10%以下，而直接归因于相互作用驱动的爆发本身的辐射占5%以下。我们还发现，在所有波长和红移下，被遮蔽的活动星系核贡献了<1-2%的CDIRB，其上限小于总发射的4%。最后，由于电子-正电子对产生与CDIRB的相互作用代表了极高能量（VHE：E_γ> 1 TeV）γ射线不透明的主要来源，该模型提供了对最高能光子的宇宙光学深度的预测。我们发现，这些预测与附近耀变体中TeV能量的高能截止点的观测结果一致，并表明虽然宇宙在>10 TeV时具有极高的光学厚度，但下一代VHE γ射线望远镜可以合理地预期从50-150 Mpc的探测。

英文摘要：

We present a physical model for origin of the cosmic diffuse infrared background (CDIRB). By utilizing the observed stellar mass function and its evolution as input to a semi-empirical model of galaxy formation, we isolate the physics driving diffuse IR emission. The model includes contributions from three primary sources of IR emission: steady-state star formation owing to isolated disk galaxies, interaction-driven bursts of star formation owing to close encounters and mergers, and obscured active galactic nuclei (AGN). We find that most of the CDIRB is produced by equal contributions from objects at z=0.5-1 and z>1, as suggested by recent observations. Of those sources, the vast majority of the emission originates in systems with low to moderate IR luminosities (L_{IR}<10^{12} $L_sun); the most luminous objects contribute significant flux only at high-redshifts (z>2). All star formation in ongoing mergers accounts for <10% of the total at all wavelengths and redshifts, while emission directly attributable to the interaction-driven burst itself accounts for <5%. We furthermore find that obscured AGN contribute <1-2% of the CDIRB at all wavelengths and redshifts, with a strong upper limit of less than 4% of the total emission. Finally, since electron-positron pair production interactions with the CDIRB represent the primary source of opacity to very high energy (VHE: E_γ> 1 TeV) γ-rays, the model provides predictions for the optical depth of the Universe to the most energetic photons. We find that these predictions agree with observations of high-energy cutoffs at TeV energies in nearby blazars, and suggest that while the Universe is extremely optically thick at >10 TeV, the next generation of VHE γ-ray telescopes can reasonably expect detections from out to 50-150 Mpc.

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。

摘要：

英文摘要：

相关论文