Definitive Identification of the Transition between Small- and Large-Scale Clustering for Lyman Break Galaxies

• Published in: The Astrophysical journal 2005-12, Vol.635 (2), p.L117-L120
• Main Authors: Ouchi, Masami, Hamana, Takashi, Shimasaku, Kazuhiro, Yamada, Toru, Akiyama, Masayuki, Kashikawa, Nobunari, Yoshida, Makiko, Aoki, Kentaro, Iye, Masanori, Saito, Tomoki, Sasaki, Toshiyuki, Simpson, Chris, Yoshida, Michitoshi
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology
• ISSN: 1538-4357; 0004-637X; 1538-4357
• DOI: 10.1086/499519

We present an angular correlation function (ACF) of z = 4 LBGs with unprecedented statistical quality, based on measurements of 16,920 LBGs obtained in the 1 deg super(2) sky of the Subaru/XMM-Newton Deep Field. The ACF significantly departs from a power law, and shows an excess on small scales. In particular, the ACFs of LBGs with i' < 27.5 show a clear break between the small- and large-scale regimes at an angular separation of 7, whose projected length corresponds to the virial radius of dark halos with a mass of 10 super(11)-10 super(12) M sub(z), indicating multiple LBGs residing in a single dark halo. At both small (2 < f < 3) and large (40 < f < 400) scales, clustering amplitudes increase monotonically with luminosity for the magnitude range of i' = 24.5-27.5; the small-scale clustering shows a stronger luminosity dependence than the large-scale clustering. The small-scale bias reaches b 10-50, and the outskirts of small-scale excess extend to a larger angular separation for brighter LBGs. The ACF and number density of LBGs can be explained by the cold dark matter model.