Emulating the global 21-cm signal from Cosmic Dawn and Reionization
Emulating the global 21-cm signal from Cosmic Dawn and Reionization
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模拟来自 Cosmic Dawn 和再电离的全球 21 厘米信号
DOI：
10.1093/mnras/staa1530
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发表时间：
2019
影响因子：
4.8
通讯作者：
R. Monsalve
中科院分区：
文献类型：
--
作者：
Aviad Cohen;A. Fialkov;R. Barkana;R. Monsalve
中性氢的21厘米信号是再电离时代（EoR），宇宙黎明和黑暗时代的敏感探针。目前，运行中的射电望远镜已经迎来了一个数据驱动的21厘米宇宙学时代，为驱动这种信号的源的天体物理特性提供了第一个约束。然而，从数据中提取天体物理信息是非常重要的，需要在广泛的天体物理参数范围内快速生成理论模板。为此，通常采用仿真器，以前的努力集中在预测功率谱上。在这项工作中，我们介绍了21 cmgem-第一个来自宇宙黎明和EoR的全球21厘米信号的模拟器。输出信号的平滑度通过设计得到保证。我们利用一个包含30 000个模拟信号的数据库来训练神经网络预测宇宙学信号，这些模拟信号是通过改变七个天体物理参数而产生的：星星形成效率和恒星形成晕的最小质量，第一X射线源的效率和它们的光谱，由光谱指数和低能截止参数化;电离光子的平均自由程和宇宙微波背景光深。我们用一组2000个模拟信号测试了性能，结果表明预测的相对误差为0.0159。该算法是有效的，每个参数集的运行时间为0.16秒。最后，我们使用模型数据库来检查我们以前报告的全球信号的特征和天体物理参数之间的关系的鲁棒性。
The 21-cm signal of neutral hydrogen is a sensitive probe of the Epoch of Reionization (EoR), Cosmic Dawn, and the Dark Ages. Currently, operating radio telescopes have ushered in a data-driven era of 21-cm cosmology, providing the first constraints on the astrophysical properties of sources that drive this signal. However, extracting astrophysical information from the data is highly non-trivial and requires the rapid generation of theoretical templates over a wide range of astrophysical parameters. To this end emulators are often employed, with previous efforts focused on predicting the power spectrum. In this work, we introduce 21cmgem– the first emulator of the global 21-cm signal from Cosmic Dawn and the EoR. The smoothness of the output signal is guaranteed by design. We train neural networks to predict the cosmological signal using a database of ∼30 000 simulated signals which were created by varying seven astrophysical parameters: the star formation efficiency and the minimal mass of star-forming haloes; the efficiency of the first X-ray sources and their spectrum parametrized by spectral index and the low-energy cut-off; the mean-free path of ionizing photons, and the cosmic microwave background optical depth. We test the performance with a set of ∼2000 simulated signals, showing that the relative error in the prediction has an rms of 0.0159. The algorithm is efficient, with a running time per parameter set of 0.16 s. Finally, we use the database of models to check the robustness of relations between the features of the global signal and the astrophysical parameters that we previously reported.
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影响因子：
4.8
作者：
W. D. Jennings;C. Watkinson;F. Abdalla;J. McEwen
通讯作者：
W. D. Jennings;C. Watkinson;F. Abdalla;J. McEwen
DOI：
10.3847/1538-4357/ab40a8
发表时间：
2019-09
期刊：
The Astrophysical Journal
影响因子：
--
作者：
N. Barry;M. Wilensky;C. Trott;B. Pindor;A. Beardsley;B. Hazelton;I. Sullivan;M. Morales;J. Pober;J. Line;B. Greig;R. Byrne;A. Lanman;W. Li;C. Jordan;R. Joseph;B. McKinley;M. Rahimi;S. Yoshiura;J. Bowman;B. Gaensler;J. Hewitt;D. Jacobs;D. Mitchell;N. Udaya Shankar;S. Sethi;R. Subrahmanyan;S. Tingay;R. Webster;J. Wyithe
通讯作者：
N. Barry;M. Wilensky;C. Trott;B. Pindor;A. Beardsley;B. Hazelton;I. Sullivan;M. Morales;J. Pober;J. Line;B. Greig;R. Byrne;A. Lanman;W. Li;C. Jordan;R. Joseph;B. McKinley;M. Rahimi;S. Yoshiura;J. Bowman;B. Gaensler;J. Hewitt;D. Jacobs;D. Mitchell;N. Udaya Shankar;S. Sethi;R. Subrahmanyan;S. Tingay;R. Webster;J. Wyithe
DOI：
10.3847/1538-3881/ab2629
发表时间：
2019-06
期刊：
The Astronomical Journal
影响因子：
--
作者：
M. Eastwood;M. Anderson;R. Monroe;G. Hallinan;M. Catha;J. Dowell;H. Garsden;L. Greenhill;B. Hicks;J. Kocz;D. Price;F. Schinzel;H. Vedantham;Yuankun Wang
通讯作者：
M. Eastwood;M. Anderson;R. Monroe;G. Hallinan;M. Catha;J. Dowell;H. Garsden;L. Greenhill;B. Hicks;J. Kocz;D. Price;F. Schinzel;H. Vedantham;Yuankun Wang
影响因子：
4.9
作者：
Kern, Nicholas S.;Liu, Adrian;Greig, Bradley
通讯作者：
Greig, Bradley
DOI：
10.1088/1538-3873/129/974/045001
发表时间：
2017-04-01
影响因子：
3.5
作者：
DeBoer, David R.;Parsons, Aaron R.;Zheng, Haoxuan
通讯作者：
Zheng, Haoxuan