Cosmic reionization history from the view of the Gunn-Peterson trough of 64 lower luminosity quasars

Lu Ting-Yi^1*, Tomotsugu Goto², Tetsuya Hashimoto²

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
²Institute of Astronomy, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Lu Ting-Yi, email:tingyilu@gapp.nthu.edu.tw

High redshift quasars (QSOs) could be the background source for probing the cosmic reionization history directly because the wavelengths bluer than the Lyα emission line in their spectra are strongly absorbed by the intergalactic medium (IGM). Since Hydrogen is the most abundant matter especially in the early universe, the transmission of the Lyα photons points out how neutral the IGM is along the line-of-sight (LOS) toward a QSO. The absorbed region in the spectrum of the QSO is called the Gunn-Peterson through (GP through). We investigate the GP through of QSOs at redshift ~ 6 by several measurements including (1) the transmission and optical depth, (2) the near zone size, (3) the dark gap statistic, and (4) the dark pixel fraction. We present the result using the spectra of 64 QSOs at 5.8
Keywords: Cosmic reionization, High redshift quasar, Cosmology