Measuring galaxy environment with the synergy of future photometric and spectroscopic surveys
Measuring galaxy environment with the synergy of future photometric and spectroscopic surveys
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DOI：
10.1093/mnras/stw1729
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发表时间：
2016-04
影响因子：
4.8
通讯作者：
O. Cucciati;O. Cucciati;F. Marulli;F. Marulli;A. Cimatti;A. Merson;P. Norberg;L. Pozzetti;C. Ba
中科院分区：
文献类型：
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作者：
O. Cucciati;O. Cucciati;F. Marulli;F. Marulli;A. Cimatti;A. Merson;P. Norberg;L. Pozzetti;C. Ba
我们利用低分辨率光谱学和光度红移之间的协同作用，研究环境对星系演化的影响，从空间的无缝光谱调查。作为一个测试案例，我们考虑未来的欧几里得深测量（140 ° 2），它结合了限制在Hα通量≥5 × 10−17 erg cm−2 s−1的无狭缝光谱测量和限制在H波段（H ≤ 26）的光度测量。我们使用欧几里德星系模拟目录，其中我们锚的光度红移的三维星系分布的光谱红移。然后，我们通过计算半径为1 ~ 10 h− 1 Mpc的圆柱形晶胞中的物体，在红移范围0.9 < z < 1.8内，估计局域密度对比度。我们比较了这个密度场与一个模拟目录中计算的深度相同的欧几里得深调查（H = 26），但没有红移测量误差。我们发现，我们的方法成功地将高密度环境与低密度环境分开，（密度分布的第一个五分位数的最后一个），在低红移和大细胞中具有更高的效率：低密度区域被高密度峰误认为的比例在所有尺度和红移探测中<1%，但对于1 h− 1 Mpc的尺度，这是百分之几。这些结果表明，如果光谱信息可用于较小样本的对象，稀疏采样相同体积，我们可以有效地研究测光样本中的环境。我们证明，这些研究是可能的，在欧几里得深调查，即在红移范围内的环境效应是不同于在本地宇宙中观察到的，从而提供了新的限制星系演化模型。
We exploit the synergy between low-resolution spectroscopy and photometric redshifts to study environmental effects on galaxy evolution in slitless spectroscopic surveys from space. As a test case, we consider the future Euclid Deep survey (∼40 deg2), which combines a slitless spectroscopic survey limited at Hα flux ≥5 × 10−17 erg cm−2 s−1 and a photometric survey limited in H band (H ≤ 26). We use Euclid-like galaxy mock catalogues, in which we anchor the photometric redshifts to the 3D galaxy distribution of the available spectroscopic redshifts. We then estimate the local density contrast by counting objects in cylindrical cells with radius from 1 to 10 h−1Mpc, over the redshift range 0.9 < z < 1.8. We compare this density field with the one computed in a mock catalogue with the same depth as the Euclid Deep survey (H = 26) but without redshift measurement errors. We find that our method successfully separates high- from low-density environments (the last from the first quintile of the density distribution), with higher efficiency at low redshift and large cells: the fraction of low-density regions mistaken by high-density peaks is <1 per cent for all scales and redshifts explored, but for scales of 1 h−1Mpc for which is a few per cent. These results show that we can efficiently study environment in photometric samples if spectroscopic information is available for a smaller sample of objects that sparsely samples the same volume. We demonstrate that these studies are possible in the Euclid Deep survey, i.e. in a redshift range in which environmental effects are different from those observed in the local Universe, hence providing new constraints for galaxy evolution models.