通过星系-星系引力透镜和运动学Sunyaev-Zel'dovich效应进行重子气体分数的模型无关测量
Model-Independent Measurement of Baryon Gas Fractions through Galaxy-Galaxy Lensing and the Kinematic Sunyaev-Zel'dovich Effect
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中文总结 AI 辅助
通过星系-星系透镜和kSZ效应的ΔΣ滤波比值，实现模型无关的星系周围气体分数测量，发现重子亏损，并检验多种反馈模拟。
中文摘要 AI 辅助
重子反馈是弱引力透镜宇宙学中系统不确定性的主要来源，但围绕星系的气体分布测量在很大程度上依赖于参数化轮廓模型或模拟校准框架。我们提出了星系周围径向气体分数轮廓的模型无关测量，结合了星系-星系引力透镜和运动学Sunyaev-Zel'dovich（kSZ）效应。我们引入了一种方法，将相同的径向$\Delta\Sigma$孔径滤波器应用于星系-星系透镜剪切场和速度加权kSZ温度图；它们的比值直接给出$\Delta\Sigma$滤波的气体分数$f_{\rm gas}(R)$，即电离气体与总物质的比值作为投影半径的函数。我们将此方法应用于DESI DR2亮星系巡天（BGS，$\bar{z}\approx0.26$）和发光红星系（LRG，$0.4<z<1.1$）样本，使用ACT DR6分量分离的CMB图进行kSZ，以及HSC第三年剪切目录进行弱透镜。在使用模拟校准的补偿因子校正ACT波束抑制后，我们检测到相对于宇宙平均重子分数的重子亏损，信噪比分别为SNR = 17.1（BGS）和SNR = 15.8（LRG bin 1）。与来自Illustris、IllustrisTNG、SIMBA和FLAMINGO套件的六个流体动力学模拟的比较表明，没有任何单一的反馈方案能在所有尺度上重现观测到的径向气体分布，测量结果介于最强（Illustris-1）和较弱方案之间。我们警告说，南银冠（SGC）和北银冠（NGC）之间的比较显示，在一个红移区间中kSZ存在无法解释的残余系统误差的证据。该比值对恒星质量和卫星与中心星系的分裂是稳健的。这些结果确立了kSZ与弱透镜信号的$\Delta\Sigma$滤波作为星系周围重子分布的模型无关探针。
英文摘要
Baryon feedback is a leading source of systematic uncertainty for cosmology from weak lensing, but measurements of the gas distribution around galaxies have largely relied on parametric profile models or simulation-calibrated frameworks. We present model independent measurements of the radial gas fraction profile around galaxies, combining galaxy-galaxy lensing and kinematic Sunyaev-Zel'dovich (kSZ) effect. We introduce a method that applies the same radial $ΔΣ$ aperture filter to both the galaxy-galaxy lensing shear field and the velocity-weighted kSZ temperature maps; their ratio directly yields $ΔΣ$ filtered gas fraction $f_{\rm gas}(R)$, the ratio of ionized gas to total matter as a function of projected radius. We apply this approach to DESI DR2 Bright Galaxy Survey (BGS, $\bar{z} \approx 0.26$) and Luminous Red Galaxy (LRG, $0.4 < z < 1.1$) samples, using ACT DR6 component-separated CMB maps for kSZ, and the HSC Year 3 shear catalog for weak lensing. After correcting for ACT beam suppression using a simulation-calibrated compensation factor, we detect baryon depletion relative to the cosmic mean baryon fraction at SNR = 17.2 (BGS) and SNR = 13.8 (LRG bin 1). Comparison with six hydrodynamical simulations from the Illustris, IllustrisTNG, SIMBA, and FLAMINGO suites shows that the fiducial FLAMINGO run most closely tracks the observed radial gas distribution in both samples, with Illustris-1 and TNG300-1 bracketing the data from below and above at small radii. We find a mild discrepancy between the kSZ measurements in the South and North Galactic Caps in one LRG redshift bin, which may indicate residual systematics. We show that the ratio is robust to splits by stellar mass and to the removal of close pairs. These results establish $ΔΣ$ filtering of kSZ versus weak lensing signal as a model-independent probe of the baryon distribution around galaxies.
发表机构
- University of California, Berkeley（加州大学伯克利分校）
- Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
- Berkeley Center for Cosmological Physics（伯克利宇宙物理学中心）
- University of Cambridge（剑桥大学）
- Kavli Institute for Cosmology Cambridge（卡弗里宇宙学剑桥研究所）
- Stanford University（斯坦福大学）
- SLAC National Accelerator Laboratory（SLAC国家加速器实验室）
机构由 AI 辅助整理，请以论文原文为准。
