标题： 由线性化温度引起的CMB全尺度黑体畸变 显示英文标题

标题： CMB all-scale blackbody distortions induced by linearizing temperature

摘要： 宇宙微波背景（CMB）实验，例如WMAP和Planck，通过线性化的公式来测量强度各向异性并构建地图，该公式将它们与黑体温度涨落联系起来。 然而，这一过程也会在地图中生成一种以y型畸变形式存在的信号，这种信号与热Sunyaev-Zel'dovich（tSZ）效应具有退化性。 这些是小效应，它们不是源于原始物理，而是由于制图程序的局限性，在温度涨落的二阶项中产生。 它们构成了对我们速度、tSZ以及原始y畸变测量的污染。 然而，这些效应可以很好地建模和处理。 我们展示了畸变来源于CMB偶极子泄漏到y通道的现象，它耦合到所有多极子，主要影响范围为$\ell$ < ~400。 这应该在Planck的y图中可见，估计信噪比约为12。 然而，我们注意到这些频率相关的项对CMB偶极子的本质没有提供新的信息。 这意味着Planck的多普勒耦合测量的实际意义实际上低于合作组织所报告的。 最后，我们量化了tSZ和原始y型畸变中的污染水平，并表明它高于下一代CMB实验的灵敏度。 显示英文摘要

摘要： Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a linearized formula for relating them to the temperature blackbody fluctuations. However, this procedure also generates a signal in the maps in the form of y-type distortions which is degenerate with the thermal Sunyaev Zel'dovich (tSZ) effect. These are small effects that arise at second-order in the temperature fluctuations not from primordial physics but from such a limitation of the map-making procedure. They constitute a contaminant for measurements of: our peculiar velocity, the tSZ and primordial y-distortions. They can nevertheless be well-modeled and accounted for. We show that the distortions arise from a leakage of the CMB dipole into the y-channel which couples to all multipoles, mostly affecting the range $\ell$ < ~400. This should be visible in Planck's y-maps with an estimated signal-to-noise ratio of about 12. We note however that such frequency-dependent terms carry no new information on the nature of the CMB dipole. This implies that the real significance of Planck's Doppler coupling measurements is actually lower than reported by the collaboration. Finally, we quantify the level of contamination in tSZ and primordial y-type distortions and show that it is above the sensitivity of proposed next generation CMB experiments.