High‐redshift star formation rate up to z∼ 8.3 derived from gamma‐ray bursts and influence of background cosmology
High‐redshift star formation rate up to z∼ 8.3 derived from gamma‐ray bursts and influence of background cosmology
复制标题
DOI：
10.1111/j.1745-3933.2009.00751.x
复制
发表时间：
2009-11
影响因子：
--
通讯作者：
Fayin Wang;Z. Dai
中科院分区：
文献类型：
--
作者：
Fayin Wang;Z. Dai
高红移恒星形成率（SFR）即使通过现代方法也难以直接测量。由于长持续时间伽马射线暴（GRB）的高光度，它们可以在可见宇宙的边缘被探测到。长GRB的 collapsar模型表明它们可能追溯恒星形成的历史。因此，长GRB可能是测量高红移SFR的有用工具。观测表明长GRB更倾向于在低金属丰度环境中形成。我们在考虑斯威夫特GRB追溯恒星形成历史以及包括Λ冷暗物质（ΛCDM）、精质、具有时变状态方程的精质和膜世界模型等不同背景宇宙学模型中的宇宙金属丰度演化的情况下，研究了高达z∼8.3的高红移SFR。我们使用了最新的斯威夫特GRB，包括两个红移最高的GRB，即z = 6.7的GRB 080913和z = 8.3的GRB 090423。我们发现，在ΛCDM中，z>4时的SFR呈现出斜率约为−5.0的急剧下降。在其他三个模型中，高红移SFR与ΛCDM模型略有不同，但也呈现出急剧下降。
The high-redshift star formation rate (SFR) is difficult to measure directly even by modern approaches. Long-duration gamma-ray bursts (GRBs) can be detected to the edge of the visible universe because of their high luminosities. The collapsar model of long GRBs indicates that they may trace the star formation history. So, long GRBs may be a useful tool of measuring the high-redshift SFR. Observations show that long GRBs prefer to form in a low-metallicity environment. We study the high-redshift SFR up to z∼ 8.3 considering the Swift GRBs tracing the star formation history and the cosmic metallicity evolution in different background cosmological models including Λ cold dark matter (ΛCDM), quintessence, quintessence with a time-varying equation of state and brane-world model. We use latest Swift GRBs including two highest-z GRBs, GRB 080913 at z= 6.7 and GRB 090423 at z= 8.3. We find that the SFR at z > 4 shows a steep decay with a slope of ∼−5.0 in ΛCDM. In the other three models, the high-redshift SFR is slightly different from ΛCDM model and also shows a steep decay.