Spatial correlation between submillimetre and Lyman-alpha galaxies in the SSA 22 protocluster.
Lyman-alpha emitters are thought to be young, low-mass galaxies with ages of approximately 10(8) yr (refs 1, 2). An overdensity of them in one region of the sky (the SSA 22 field) traces out a filamentary structure in the early Universe at a redshift of z approximately 3.1 (equivalent to 15 per cent of the age of the Universe) and is believed to mark a forming protocluster. Galaxies that are bright at (sub)millimetre wavelengths are undergoing violent episodes of star formation, and there is evidence that they are preferentially associated with high-redshift radio galaxies, so the question of whether they are also associated with the most significant large-scale structure growing at high redshift (as outlined by Lyman-alpha emitters) naturally arises. Here we report an imaging survey of 1,100-microm emission in the SSA 22 region. We find an enhancement of submillimetre galaxies near the core of the protocluster, and a large-scale correlation between the submillimetre galaxies and the low-mass Lyman-alpha emitters, suggesting synchronous formation of the two very different types of star-forming galaxy within the same structure at high redshift. These results are in general agreement with our understanding of the formation of cosmic structure.
Department of Astronomy, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. yoichi.tamura@nao.ac.jp
Yoichi
Y
Tamura
Kotaro
K
Kohno
Kouichiro
K
Nakanishi
Bunyo
B
Hatsukade
Daisuke
D
Iono
Grant W
GW
Wilson
Min S
MS
Yun
Tadafumi
T
Takata
Yuichi
Y
Matsuda
Tomoka
T
Tosaki
Hajime
H
Ezawa
Thushara A
TA
Perera
Kimberly S
KS
Scott
Jason E
JE
Austermann
David H
DH
Hughes
Itziar
I
Aretxaga
Aeree
A
Chung
Tai
T
Oshima
Nobuyuki
N
Yamaguchi
Kunihiko
K
Tanaka
Ryohei
R
Kawabe