标题： 联合高效暗能量调查（JEDI）：美国国家航空航天局-能源部联合暗能量任务（JDEM）的一个候选实施方案 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将通过测量宇宙的膨胀历史，以三种独立的方式探测暗能量：(1)利用Ia型超新星作为宇宙学标准烛光，在不同距离范围内进行测量，(2)利用重子声学振荡作为宇宙学标准尺，在不同宇宙时期范围内进行测量，(3)通过前景星系对背景星系图像的弱引力透镜畸变进行测绘。 JEDI将以准确和精确的方式揭示暗能量的本质。 JEDI是一台2米级的空间望远镜，具有同时宽视场成像（五个波段0.8-4.2微米）和多狭缝光谱学（0.8-3.2微米）的能力，视场为1平方度。 使JEDI高效的是其能够同时获得高信噪比、中等分辨率的狭缝光谱，用于其宽视场内的所有超新星和约5000个星系，并结合成像和光谱学，从而合理分配每项任务的时间。 JEDI将作为自由函数测量宇宙膨胀历史H(z)，在红移区间0.2-0.3内精度小于2%。 假设宇宙是平坦的且\sigma (\Omega _m)=0.01 (0.03)，JEDI可以以\sigma (w_0)=0.013 (0.031)和\sigma (w')=0.046 (0.063)的精度测量偏离经典\Lambda CDM模型（w_0=-1，w'=0）的情况。 JEDI将获得Z、J、H、K、L波段内充分采样的光变曲线以及约14000个红移范围从0到1.7的Ia型超新星的光谱；约10-100百万个星系的红移达到H ~ 23和z ~ 4，在1000-10,000平方度范围内；并在Z、J、H、K、L波段内对超过10^9个星系在1000-10,000平方度范围内测量星系的形状，达到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.