2MTF – IV. A bulk flow measurement of the local Universe
2MTF – IV. A bulk flow measurement of the local Universe
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2MTF – IV. 本地宇宙的整体流量测量
DOI：
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发表时间：
2014
期刊：
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通讯作者：
T. Jarrett
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作者：
T. Hong;C. Springob;L. Staveley;Morag I. Scrimgeour;K. Masters;L. Macri;B. Koribalski;D. Jones;T. Jarrett
利用Arecibo、绿色Bank、Nancay和Parkes望远镜的2 MASS近红外测光和高信噪比HI 21-cm数据，计算了2018年亮倾斜螺旋星系的红移无关距离和特有速度。该项目是2 MASS Tully-Fisher巡天（2 MTF）的一部分，旨在绘制100 h−1 Mpc范围内的星系特有速度场，除银河系纬度外，还覆盖全天|B| <5分。采用χ2最小化方法分析了J、H和K波段的Tully-Fisher特征速度场，并使用高斯滤波器。我们将来自三个波段的联合收割机信息结合起来，分别在20、30和40 h-1 Mpc深度提供了310.9 ± 33.9、280.8 ± 25.0和292.3 ± 27.8 km s-1的整体流量测量值。这些整体流动矢量中的每一个指向与先前测量所发现的方向类似的方向。在这三个深度的每一个，整体流量大小与冷暗物质（CDM）模型在1σ水平上的预测一致。最大似然法和最小方差法也被用来分析2 MTF样本，得到类似的结果。
Using the 2MASS near-infrared photometry and high-signal-to-noise HI 21-cm data from the Arecibo, Green Bank, Nancay, and Parkes telescopes, we calculate the redshift-independent distances and peculiar velocities of 2018 bright inclined spiral galaxies over the whole sky. This project is part of the 2MASS Tully-Fisher survey (2MTF), aiming to map the galaxy peculiar velocity field within 100 h−1 Mpc, with an all-sky coverage apart from Galactic latitudes |b|<5◦. A χ2 minimization method was adopted to analyse the Tully–Fisher peculiar velocity field in J, H, and K bands, using a Gaussian filter. We combine information from the three wavebands, to provide bulk flow measurements of 310.9 ± 33.9 , 280.8 ± 25.0, and 292.3 ± 27.8 km s−1 at depths of 20, 30, and 40 h−1 Mpc, respectively. Each of these bulk flow vectors points in a direction similar to those found by previous measurements. At each of the three depths, the bulk flow magnitude is consistent with predictions made by the cold dark matter (CDM) model at the 1σ level. The maximum likelihood and minimum variance method were also used to analyse the 2MTF samples, giving similar results.