标题： 建模Halpha发射体的数密度以用于未来的光谱近红外空间任务 显示英文标题

标题： Modelling the number density of Halpha emitters for future spectroscopic near-IR space missions

摘要： 欧几里得空间任务和WFIRST-AFTA将使用氢alpha发射线来测量数千万个星系的红移。 z>0.7的氢alpha亮度函数是这些任务预测宇宙约束的主要不确定性来源之一。 我们构建了统一的经验模型，涵盖与欧几里得和WFIRST-AFTA提出的红移巡天相关的红移和线亮度范围。 通过对氢alpha巡天观测到的亮度函数进行拟合，我们建立了三种演化模型。 考虑了不同的拟合方法论、亮度函数的功能形式、经验输入数据的子集以及系统误差的处理方式，以探索结果的稳健性。 为所有三个模型提供了功能形式和模型参数，以及在z~2.5以下的不同极限通量（F_Halpha>0.5 - 3 x 10^-16 erg cm^-2 s^-1）下星系的数量和红移分布，这对未来的空间任务相关。 例如，在红移范围0.90<z<1.8内，我们的模型预测，在F_Halpha>1和2 x 10^-16 erg cm^-2 s^-1以上的通量范围内，可用星系密度分别为7700--13300和2000--4800 deg^-2，而在扩展红移范围0.40<z<1.8内，对于F_Halpha>0.5 x 10^-16 erg cm^-2 s^-1，该值为32000--48000。 我们还考虑了我们的经验模型对宇宙总氢alpha亮度密度以及密切相关的大尺度恒星形成历史的影响。 显示英文摘要

摘要： The future space missions Euclid and WFIRST-AFTA will use the Halpha emission line to measure the redshifts of tens of millions of galaxies. The Halpha luminosity function at z>0.7 is one of the major sources of uncertainty in forecasting cosmological constraints from these missions. We construct unified empirical models of the Halpha luminosity function spanning the range of redshifts and line luminosities relevant to the redshift surveys proposed with Euclid and WFIRST-AFTA. By fitting to observed luminosity functions from Halpha surveys, we build three models for its evolution. Different fitting methodologies, functional forms for the luminosity function, subsets of the empirical input data, and treatment of systematic errors are considered to explore the robustness of the results. Functional forms and model parameters are provided for all three models, along with the counts and redshift distributions up to z~2.5 for a range of limiting fluxes (F_Halpha>0.5 - 3 x 10^-16 erg cm^-2 s^-1) that are relevant for future space missions. For instance, in the redshift range 0.90<z<1.8, our models predict an available galaxy density in the range 7700--13300 and 2000--4800 deg^-2 respectively at fluxes above F_Halpha>1 and 2 x 10^-16 erg cm^-2 s^-1, and 32000--48000 for F_Halpha>0.5 x 10^-16 erg cm^-2 s^-1 in the extended redshift range 0.40<z<1.8. We also consider the implications of our empirical models for the total Halpha luminosity density of the Universe, and the closely related cosmic star formation history.