No Ly α emitters detected around a QSO at z = 6.4: Suppressed by the QSO?★. (3rd June 2017)

• Record Type: Journal Article
• Authors: Goto, Tomotsugu; Utsumi, Yousuke; Kikuta, Satoshi; Miyazaki, Satoshi; Shiki, Kensei; Hashimoto, Tetsuya
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 470:Number 1(2017:Sep.)
• Page Start: L117
• Page End: L121
• Publication Date: 2017-06-03
• Subjects: black hole physics -- galaxies: high-redshift; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/slx088
• Languages: English
• ISSNs: 1745-3933

Abstract

Abstract: Understanding how quasars' (QSOs') ultraviolet (UV) radiation affects galaxy formation is vital to our understanding of the reionization era. Using a custom-made narrow-band filter, NB 906, on Subaru/Suprime-Cam, we investigated the number density of Ly α emitters (LAEs) around a QSO at z = 6.4. To date, this is the highest redshift narrow-band observation, where LAEs around a luminous QSO are investigated. Due to the large field of view of Suprime-Cam, our survey area is ∼5400 cMpc 2, much larger than previous studies at z = 5.7 (∼200 cMpc 2 ). In this field, we previously found a factor of 7 overdensity of Lyman break galaxies. Based on this, we expected to detect ∼100 LAEs down to NB 906 = 25 ABmag. However, our 6.4 h exposure found none. The obtained upper limit on the number density of LAEs is more than an order lower than the blank fields. Furthermore, this lower density of LAEs spans a large scale of 10 p Mpc across. A simple argument suggests that a strong UV radiation from the QSO can suppress star formation in haloes with M vir < 10 10 M⊙ within a p Mpc from the QSO, but the deficit at the edge of the field (5 p Mpc) remains to be explained.