A redshift survey towards the cosmic microwave background cold spot
A redshift survey towards the cosmic microwave background cold spot
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DOI：
10.1111/j.1745-3933.2010.00837.x
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发表时间：
2010-04
影响因子：
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通讯作者：
M. N. Bremer;J. Silk;L. Davies;M. D. L. Bristol;Oxford;Gepi;Paris
中科院分区：
文献类型：
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作者：
M. N. Bremer;J. Silk;L. Davies;M. D. L. Bristol;Oxford;Gepi;Paris
我们利用VLT上的VIMOS光谱仪对宇宙微波背景冷点进行了红移测量。冷斑的一个可能原因是在中等或低红移时由一个极大的空洞(线性维度为数百MPC)所印记的积分的Sachs-Wolfe效应。从I波段通量受限的星系样本中提取的700多个发射线星系在冷斑方向的红移分布表明，没有证据表明Δz≳尺度上存在缺口，如果这样的空洞存在于0.35；z<；1。在较小尺度上的红移分布(Δz≈0.01)表明，较小尺度的空洞可能会将相隔几度的区域连接到冷点。将这种分布与从VVDS调查的大间距点处提取的类似大小的子样本所产生的分布进行比较，并不表明朝向冷斑的红移分布是反常的，或者这些小间隙可以唯一地归因于真实的空洞。
We have carried out a redshift survey using the VIMOS spectrograph on the VLT towards the cosmic microwave background cold spot. A possible cause of the cold spot is the Integrated Sachs–Wolfe effect imprinted by an extremely large void (hundreds of Mpc in linear dimension) at intermediate or low redshifts. The redshift distribution of over seven hundred z < 1 emission-line galaxies drawn from an I-band flux limited sample of galaxies in the direction of the cold spot shows no evidence of a gap on scales of Δz≳ 0.05 as would be expected if such a void existed at 0.35 < z < 1. There are troughs in the redshift distribution on smaller scales (Δz≈ 0.01) indicating that smaller scale voids may connect regions separated by several degrees towards the cold spot. A comparison of this distribution with that generated from similarly sized subsamples drawn from widely spaced pointings of the VVDS survey does not indicate that the redshift distribution towards the cold spot is anomalous or that these small gaps can be uniquely attributed to real voids.