Forecast for FAST: from galaxies survey to intensity mapping
Forecast for FAST: from galaxies survey to intensity mapping
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DOI：
10.1093/mnras/staa650
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发表时间：
2019-09
影响因子：
4.8
通讯作者：
Wenkai Hu;Xin Wang;Fengquan Wu;Yougang Wang;Pengjie Zhang;Xuelei Chen
中科院分区：
文献类型：
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作者：
Wenkai Hu;Xin Wang;Fengquan Wu;Yougang Wang;Pengjie Zhang;Xuelei Chen
500米口径球面射电望远镜（FAST）是世界上最大的单碟射电望远镜。本文利用模拟观测资料对FAST Hilarge-scale结构调查进行了预报。我们考虑用L波段19波束接收机进行漂移扫描巡天，它可以与脉冲星搜索和银河系巡天相结合。我们还考虑调查在较低的频率，使用当前的单馈宽带接收机或未来的多波束相控阵饲料（PAF）在UHF波段。我们估计了探测到的Higaloptera的数密度和位置的测量误差，并使用Fisher矩阵和模拟观测来评估调查的精度。在Higaldom功率谱的测量误差估计，我们发现，即使在中等红移的错误是相对较大的，积极检测到的星系的数量急剧下降，增加红移。然而，良好的宇宙学测量可以获得与强度映射技术，其中大规模的Hidistribution测量没有解决个别星系。计算了不同观测时间下暗能量状态方程的优值，发现利用现有的L波段多光束接收器，可以获得较好的低红移大尺度结构测量，是对现有光学测量的补充。在UHF波段的PAF，约束可以更强，达到暗能量任务组第四阶段实验的水平。
The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) is the largest single-dish radio telescope in the world. In this paper, we make forecast on the FAST Hilarge-scale structure survey by mock observations. We consider a drift scan survey with the L-band 19 beam receiver, which may be commensal with the pulsar search and Galactic Hisurvey. We also consider surveys at lower frequency, using either the current single feed wide-band receiver or a future multibeam phased array feed (PAF) in the UHF band. We estimate the number density of detected Higalaxies and the measurement error in positions and the precision of the surveys are evaluated using both Fisher matrix and simulated observations. The measurement error in the Higalaxy power spectrum is estimated, and we find that the error is relatively large even at moderate redshifts, as the number of positively detected galaxies drops drastically with increasing redshift. However, good cosmological measurement could be obtained with the intensity mapping technique where the large scale Hidistribution is measured without resolving individual galaxies. The figure of merit for the dark energy equation of state with different observation times is estimated, and we find that with the existing L-band multibeam receiver, a good measurement of low redshift large-scale structure can be obtained, which complements the existing optical surveys. With a PAF in the UHF band, the constraint can be much stronger, reaching the level of a dark energy task force stage IV experiment.