标题： 联合高效暗能量探测任务（JEDI）：NASA-DOE联合暗能量任务（JDEM）的候选实施方案 显示英文标题

标题： Joint Efficient Dark-energy Investigation (JEDI): a Candidate Implementation of the NASA-DOE Joint Dark Energy Mission (JDEM)

摘要： JEDI 将通过三种独立的方法探测暗能量：测量宇宙的膨胀历史：（1）使用Ia型超新星作为不同距离上的宇宙标准烛光；（2）使用重子振荡作为不同宇宙时代的宇宙标准尺；（3）绘制前景星系对背景星系不同距离图像的弱引力透镜畸变。 JEDI 将以高精度和精确性揭示暗能量的本质。 JEDI 是一台2米级的空间望远镜，具有独特的同时进行宽视场成像（五个波段0.8-4.2微米）和多狭缝光谱观测（0.8-3.2微米）的能力，视场为1平方度。 使 JEDI 高效的原因在于它能够同时获得所有超新星和宽视场内约5000个星系的高信噪比、中等分辨率的狭缝光谱，并结合成像和光谱观测，以便适当分配时间。 JEDI 将测量宇宙膨胀历史 H(z)，在红移区间 0.2-0.3 的范围内达到 <2% 的精度。 假设一个平坦宇宙和 \sigma (\Omega _m)=0.01 (0.03)，JEDI 可以测量偏离普通 \Lambda CDM 模型（w_0=-1, w'=0）的程度，其中 \sigma (w_0)=0.013 (0.031) 和 \sigma (w')=0.046 (0.063)。 JEDI 将在 Z、J、H、K、L 波段获取约 14,000 个 Ia 型超新星的良好采样的光变曲线和光谱，这些超新星的红移范围从 0 到 1.7；在 1000-10,000 平方度范围内，获取约 10-100 百万星系的红移至 H ~ 23 和 z ~ 4；并且在 Z、J、H、K、L 波段测量超过 10^9 个星系的形状，覆盖 1000-10,000 平方度，至 H ~ 25。 显示英文摘要

摘要： JEDI will probe dark energy in three independent ways by measuring the expansion history of the universe: (1) using type Ia supernovae as cosmological standard candles over a range of distances, (2) using baryon oscillations as a cosmological standard ruler over a range of cosmic epochs, (3) mapping the weak gravitational lensing distortion by foreground galaxies of the images of background galaxies at different distances. JEDI will unravel the nature of dark energy with accuracy and precision. JEDI is a 2m-class space telescope with the unique ability of simultaneous wide-field imaging (0.8-4.2 micron in five bands) and multi-slit spectroscopy (0.8-3.2 micron) with a field of view of 1 square degree. What makes JEDI efficient is its ability to simultaneously obtain high signal-to-noise ratio, moderate resolution slit spectra for all supernovae and ~ 5000 galaxies in its wide field of view, and to combine imaging and spectroscopy so that the appropriate balance of time is devoted to each. JEDI will measure the cosmic expansion history H(z) as a free function to < 2% accuracy in redshift bins of 0.2-0.3. Assuming a flat universe and \sigma(\Omega_m)=0.01 (0.03), JEDI could measure a departure from a vanilla \Lambda CDM model (w_0=-1, w'=0) with \sigma(w_0)=0.013 (0.031) and \sigma(w')=0.046 (0.063). JEDI will obtain the well-sampled lightcurves in Z, J, H, K, L bands and spectra of ~ 14,000 type Ia supernovae with redshifts ranging from 0 to 1.7; the redshifts of ~ 10-100 million galaxies to H ~ 23 and z ~ 4 over 1000-10,000 square degrees; and measurements of the shapes of galaxies over 1000-10,000 square degrees in Z,J,H,K,L for > 10^9 galaxies to H \~ 25.