FUSE-Observations of the Hell 304 A Forest in two QSOs from the Hamburg Quasary Surveys and the fluctuating metagalactic UV background radiation

FUSE 在汉堡准星巡天的两个 QSO 中对地狱 304 A 森林的观测以及波动的超星系紫外线背景辐射

• 批准号: 13451572
• 负责人: Professor Dr. Dieter Reimers (†)
• 金额: --
• 依托单位: Hamburger Sternwarte
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/13451572?language=en
• 关键词: FUSE; Observations; Hell; 304; Forest

We apply for support of an empirical investigation of the ionizing metagalactic UV background. For z < 3 the ionizing background radiation is due to both QSOs and stars. Recently there has been growing evidence, in particular from high resolution Hell 304 A forest observations, that the shape of the ionizing background might fluctuate on length scales as short as 1 Mpc (comoving). If true, this would have severe consequences for the determination of the heavy element content of QSO metal line systems. We plan to investigate the Hell (and simultaneous HI) spectra of the only two bright QSOs for which FUSE could take high resolution Hell spectra (both HE 2347-4342 and HS 1700+6416 are from the Hamburg QSO surveys) by more elaborate methods than hitherto applied. In particular we shall test the evaluation methods on artificial data from simulations of the Lya forest (from large scale structure simulations). We shall also study the population of sources along the two lines of sight both by direct imaging and by studies of the ionization in strong metal line systems. The question of the influence of background radiation fluctuations on metal abundances in the general IGM will be considered. Finally, realistic transfer calculations of QSO radiation in the cosmic web will be performed.

我们申请支持的电离元银河系紫外线背景的实证调查。当z < 3时，电离背景辐射来自类星体和恒星。最近有越来越多的证据，特别是从高分辨率的地狱304 A森林观测，电离背景的形状可能波动的长度尺度短至1百万秒差距（共动）。如果属实，这将对确定类星体金属线系统的重元素含量产生严重后果。我们计划用比迄今为止所用的更精细的方法来研究仅有的两个明亮类星体的Hell（和同时HI）谱，FUSE可以为这两个亮类星体拍摄高分辨率的Hell谱（HE 2347-4342和HS 1700+6416都来自汉堡类星体巡天）。特别是，我们将测试评估方法的人工数据从模拟的Lya森林（从大规模结构模拟）。我们还将通过直接成像和强金属线系统中电离的研究来研究沿这两条视线沿着的源的总体。将考虑背景辐射波动对一般IGM中金属丰度的影响问题。最后，将进行类星体辐射在宇宙网中的实际传输计算。