A new, precise measurement of the primordial abundance of deuterium
A new, precise measurement of the primordial abundance of deuterium
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氘原始丰度的新精确测量
DOI：
10.1111/j.1365-2966.2012.21665.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Kavli Institute for Cosmology
中科院分区：
文献类型：
--
作者：
M. Pettini;Ryan Cooke Institute of Astronomy;U. Cambridge;Kavli Institute for Cosmology
贫金属在类星体SDSS J1419+0829中，红移zabs = 3.049 84的（Z 1/100 Z）阻尼莱曼α系统（DLA）具有精确测定氘原始丰度（D/H）p的近理想性质。拟合D/H值，并对影响该测定的随机误差和系统误差进行了综合评定。我们发现（D/H）DLA =（2.535 ± 0.05）× 10 −5，这意味着b，0 h2 = 0.0223 ± 0.0009，与从宇宙微波背景辐射（CMB）角功率谱推导出的b，0 h2（CMB）= 0.0222 ± 0.0004非常一致。如果这个DLA中的值确实是大爆炸核合成（BBN）产生的真实（D/H）p，那么就没有必要调用非标准物理学或早期的D测量来将b，0 h2（BBN）和b，0 h2（CMB）合在一起。文献中大多数报告的（D/H）p值之间的分散可能主要是由于未考虑的系统误差和偏倚。要在这一领域取得进一步进展，就需要有一套类似于本报告所述的数据，并以自洽的方式加以分析。这种努力虽然在观测上要求很高，但有可能提高我们对BBN物理学的理解，包括相关的核反应，以及轻核素在恒星中的后续处理。
The metal-poor (Z � 1/100 Z� ) damped Lyman α system (DLA) at redshift zabs = 3.049 84 in the zem � 3.030 QSO SDSS J1419+0829 has near-ideal properties for an accurate deter- mination of the primordial abundance of deuterium (D/H)p. We have analysed a high-quality spectrum of this object with software specifically designed to deduce the best-fitting value of D/H and to assess comprehensively the random and systematic errors affecting this determi- nation. We find (D/H)DLA = (2.535 ± 0.05) × 10 −5 , which in turn impliesb,0h 2 = 0.0223 ± 0.0009, in very good agreement withb,0h 2 (CMB) = 0.0222 ± 0.0004 deduced from the angular power spectrum of the cosmic microwave background (CMB). If the value in this DLA is indeed the true (D/H)p produced by big bang nucleosynthesis (BBN), there may be no need to invoke non-standard physics nor early astration of D to bring togetherb,0 h 2 (BBN) andb,0 h 2 (CMB). The scatter between most of the reported values of (D/H)p in the literature may be due largely to unaccounted systematic errors and biases. Further progress in this area will require a homogeneous set of data comparable to those reported here and analysed in a self-consistent manner. Such an endeavour, while observationally demanding, has the potential of improving our understanding of BBN physics, including the relevant nuclear reactions, and the subsequent processing of light nuclides through stars.