Estimation of HⅡBubble Size Distribution from 21 cm Power Spectrum with Artificial Neural Networks  

作　　者：Hayato Shimabukuro Yi Mao Jianrong Tan 

机构地区：[1]Yunnan University,SWIFAR,No.2 North Green Lake Road,Kunming 650500,China [2]Department of Astronomy,Tsinghua University,Beijing 100084,China [3]Department of Physics&Astronomy,University of Pennsylvania,209 South 33rd Street,Philadelphia,PA 19104,United States of America

出　　处：《Research in Astronomy and Astrophysics》2022年第3期285-296,共12页天文和天体物理学研究（英文版）

基　　金：supported by the National SKA Program of China(Grant No.2020SKA0110401);NSFC(Grant Nos.12103044,11821303 and 11850410429);National Key R&D Program of China(Grant No.2018YFA0404502);supported in part by grants from Yunnan University。

摘　　要：The bubble size distribution of ionized hydrogen regions probes information about the morphology of HⅡbubbles during reionization.Conventionally,the HⅡbubble size distribution can be derived from the tomographic imaging data of the redshifted 21 cm signal from the epoch of reionization,which,however,is observationally challenging even for upcoming large radio interferometer arrays.Given that these interferometers promise to measure the 21 cm power spectrum accurately,we propose a new method,which is based on artificial neural networks,to reconstruct the HⅡbubble size distribution from the 21 cm power spectrum.We demonstrate that reconstruction from the 21 cm power spectrum can be almost as accurate as being directly measured from the imaging data with fractional error■10%,even with thermal noise at the sensitivity level of the Square Kilometre Array.Nevertheless,the reconstruction implicitly exploits the modeling in reionization simulations,and hence the recovered HⅡbubble size distribution is not an independent summary statistic from the power spectrum,and should be used only as an indicator for understanding HⅡbubble morphology and its evolution.

关 键 词：methods:data analysis methods:numerical (cosmology:)dark ages REIONIZATION first stars (cosmology:)diffuse radiation cosmology:theory 

分 类 号：P15[天文地球—天文学]