Lihwai Lin, Mark Dickinson, Hung-Yu Jian, A. I. Merson, C. M. Baugh, Douglas Scott, Sebastien Foucaud, Wei-Hao Wang, Chi-Hung Yan, Hao-Jing Yan, Yi-Wen Cheng, Yicheng Guo, John Helly, Franz Kirsten, David C. Koo, Claudia del P. Lagos, Nicole Meger, Alexandra Pope, Luc Simard, Norman A. Grogin, Hugo Messias, Shiang-Yu Wang
Using a sample of $\textit{BzK}$-selected galaxies at $z \sim 2$ identified
from the CFHT/WIRCAM near-infrared survey of GOODS-North, we discuss the
relation between star formation rate (SFR), specific star formation rate
(SSFR), and stellar mass (\sm), and the clustering of galaxies as a function of
these parameters. For star-forming galaxies (\textit{sBzK}s), the UV-based SFR,
corrected for extinction, scales with the stellar mass as SFR $\propto$
\sm$^{\alpha}$ with $\alpha = 0.74\pm0.20$, indicating a weak dependence on the
stellar mass of the star formation rate efficiency. We also measure the angular
correlation function and hence infer the correlation length for \textit{sBzK}
galaxies as a function of \sm, SFR, and SSFR, as well as $K$-band apparent
magnitude. We show that passive galaxies (\textit{pBzK}s) are more strongly
clustered than \textit{sBzK} galaxies at a given stellar mass. We also find
that the correlation length of \textit{sBzK} galaxies ranges from 4 to 17 \mpc,
being a strong function of $M_{K}$, \sm, and SFR. On the other hand, the
clustering dependence on SSFR changes abruptly at $2\times 10^{-9}$ yr$^{-1}$,
which is the typical value for ``main sequence'' star-forming galaxies at $z
\sim 2$. We show that the correlation length reaches a minimum at this
characteristic value, and is larger for galaxies with both smaller and larger
SSFRs; a dichotomy that is only marginally implied from the predictions of the
semi-analytical models. Our results suggest that there are two types of
environmental effects: stronger clustering for relatively quiescent galaxies
implies that the environment has started playing a role in quenching or
reducing star formation at $z \sim 2$, while the interpretation for galaxies
with elevated SSFRs (``starbursts'') might be attributed to galaxy mergers
and/or other mechanisms which are also associated with dense environments.
View original:
http://arxiv.org/abs/1111.2135
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