重返伟大吸引子：强证据表明一个立体角大小的流在GA超星团内约70 Mpc处汇聚，并与CMB偶极子对齐
Return to the Great Attractor: Strong Evidence for a Steradian-sized Flow Converging at $\sim$70 Mpc within the GA Supercluster and Aligned with the CMB Dipole
AI总结：
通过高信噪比的H带成像研究66个星系，利用表面亮度波动法测定视向速度，证实了一个立体角范围内的强流在约70 Mpc处汇聚，与CMB偶极子对齐，反驳了其他大尺度流的结论。
摘要：
我们使用Magellan-Baade上的FourStar近红外相机，获取了66个径向速度在2000 < V < 5000 km/s的星系的高信噪比H带成像。我们的目标是利用表面亮度波动（SBF）的优越距离测量来推导“异常速度”，以检验CMB偶极子各向异性（约600 km/s相对于本地组）是否源于银河系/暗物质分布中的局部过密区域——伟大吸引子。SBF能够以5%的精度测量距离，证实了一个立体角范围内的强流，峰值速度Vpec约为1000 km/s，并在距离本地组约70 Mpc处汇聚。这种适度的空间范围R_V约为5000 km/s与原始伟大吸引子模型（直径D约为140 Mpc）一致，并与CMB偶极子各向异性和CMB波动功率谱一致——后者可能是天体物理学中最可靠的测量。相比之下，我们的结果与在数百Mpc尺度上报道的类似幅度的“总体流”报告相矛盾，而这些流本身可能与ΛCDM宇宙预期的CMB波动不一致。我们主张，只有像SBF这样准确的距离估计器才能解决CMB偶极子是否源于本地组约100 Mpc范围内大尺度结构的引力影响的问题。
英文摘要：
We used the FourStar near-IR camera on Magellan-Baade to obtain high S/N H-Band imaging of 66 galaxies with radial velocities of 2000 < V < 5000 km/s. Our goal was to use the superior distance measurements of surface-brightness-fluctuations (SBF) to derive ``peculiar velocities'' to test claims that the CMB dipole anisotropy, equivalent to $\approx$600 km/s with respect to the Local Group, arises from a 'local' overdensity in the galaxy/dark-matter distribution -- the Great Attractor. SBF's ability to measure distances with 5% accuracy confirms a strong flow over a steradian of the sky peaking at Vpec $\sim$ 1000 km/s and converging to zero at D $\approx$70 Mpc from the Local Group. The modest spatial extent of this flow $R_V$ $\sim$ 5000 km/s is consistent with the original Great Attractor model (a diameter D $\sim$ 140 Mpc), as well as the magnitude and direction of the CMB dipole anisotropy, and the power spectrum of CMB fluctuations -- the latter two arguably the most secure measurements in astrophysics. In contrast, our results are at-odds with reports of comparable amplitude 'bulk flows' on scales of hundreds of Mpc that themselves may be inconsistent with the expected fluctuations in the CMB for a $Λ$CDM universe. We contend that only distance-estimators as accurate as SBF are able settle the question of whether the CMB dipole arises from the gravitational influence of large-scale structure within, or without $\sim$100 Mpc of the Local Group.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
