论文标题
黑暗能源调查第3年和eBoss：限制了亮度和色彩空间的星系固有对齐
The Dark Energy Survey Year 3 and eBOSS: constraining galaxy intrinsic alignments across luminosity and colour space
论文作者
论文摘要
我们使用暗能量调查第3年（des Y3），扩展的Baryon振荡光谱调查（EBOSS）及其前体Baryon振荡光谱调查（BOSS）对GARAXY固有比对进行了直接限制。我们的测量结果包括来自DES的光度红色序列（Redmagic）星系中间的红移$ Z \ sim0.2-1.0 $，来自Eboss的发光红星系（LRGS），$ Z \ sim0.8 $，也是SDSS-III BOSS CMASS样品，$ Z \ sim0.8 $。我们测量两个点固有的对齐相关性，我们使用包括镜头，放大倍率和光度红移误差的模型拟合。安装量表$ 6 <r _ {\ rm p} <70 $ mpc $/h $，我们在每个样本中检测到固有的对齐，为$5σ-22σ$（假设IAS的简单一个参数模型）。使用这些红色样品，我们测量了IA-Luminity关系。我们的结果在统计学上与以前的结果一致，但在约束功率方面提供了显着改善，尤其是在低光度下。有了这种提高的精度，我们看到可检测到的对广义定义的红色样品之间的颜色的依赖性。将来需要比二进制红色/蓝色拆分更复杂的方法，该方法在将来需要在IA信号中共同考虑颜色和光度依赖性。我们还比较了每个样品中参数空间中最佳拟合点的各种信号组件，并发现放大倍数和镜头贡献了总信号的$ \ sim2-18 \％$。随着精确度的继续提高，当然有必要在未来的直接IA测量中考虑这些效果。最后，我们对Eboss的排放线星系样品（ELG）进行了等效测量，以$ z \ sim 0.8 $进行。我们报告了一个零检测，将IA振幅（假设非线性对齐模型）限制为$ a_1 = 0.07^{+0.32} _ { - 0.42} $（$ | A_1 | <0.78 $ at $ 95 \％$ cl）。
We present direct constraints on galaxy intrinsic alignments using the Dark Energy Survey Year 3 (DES Y3), the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) and its precursor, the Baryon Oscillation Spectroscopic Survey (BOSS). Our measurements incorporate photometric red sequence (redMaGiC) galaxies from DES with median redshift $z\sim0.2-1.0$, luminous red galaxies (LRGs) from eBOSS at $z\sim0.8$, and also a SDSS-III BOSS CMASS sample at $z\sim0.5$. We measure two point intrinsic alignment correlations, which we fit using a model that includes lensing, magnification and photometric redshift error. Fitting on scales $6<r_{\rm p} < 70$ Mpc$/h$, we make a detection of intrinsic alignments in each sample, at $5σ-22σ$ (assuming a simple one parameter model for IAs). Using these red samples, we measure the IA-luminosity relation. Our results are statistically consistent with previous results, but offer a significant improvement in constraining power, particularly at low luminosity. With this improved precision, we see detectable dependence on colour between broadly defined red samples. It is likely that a more sophisticated approach than a binary red/blue split, which jointly considers colour and luminosity dependence in the IA signal, will be needed in future. We also compare the various signal components at the best fitting point in parameter space for each sample, and find that magnification and lensing contribute $\sim2-18\%$ of the total signal. As precision continues to improve, it will certainly be necessary to account for these effects in future direct IA measurements. Finally, we make equivalent measurements on a sample of Emission Line Galaxies (ELGs) from eBOSS at $z\sim 0.8$. We report a null detection, constraining the IA amplitude (assuming the nonlinear alignment model) to be $A_1=0.07^{+0.32}_{-0.42}$ ($|A_1|<0.78$ at $95\%$ CL).
