GOODS-N中BzK-selected星系的成团性质：z ~ 2处的环境猝灭和恒星形成的触发
Clustering properties of BzK-selected galaxies in GOODS-N: environmental quenching and triggering of star formation at z ~ 2
摘要：
本文利用CFHT/WIRCAM GOODS-North近红外巡天中确定的z~2处的BzK选择星系样本，讨论了恒星形成率（SFR）、比恒星形成率（SSFR）和恒星质量（M_{*}）之间的关系，以及星系成团作为这些参数的函数。对于恒星形成星系（sBzKs），基于紫外线的SFR，经过消光校正后，与恒星质量成比例关系为SFR ~ M_{*} ^{alpha}，其中alpha = 0.74+/-0.20，下至M_{*} ~ 10^{9} M_{solar}，表明SSFR对恒星质量的依赖性较弱。我们还测量了角关联函数，从而推断sBzK星系的相关长度作为M_{*}，SFR和SSFR，以及K波段视星等的函数。我们发现，被动星系（pBzKs）更强烈的集群比SBZK星系在一个给定的恒星质量，反映了色密度关系在较低的红移。我们还发现sBzK星系的相关长度在4 ~ 20 h^{-1}Mpc之间，是M_{K}、M_{*}和SFR的强函数。另一方面，在2 × 10 ^{-9} yr^{-1}处，成团对SSFR的依赖性突然变化，这是z~2处“主序星”成星星系的典型值。我们发现，相关长度达到最小值在这个特征值，是较大的星系与较小和较大的SSFR;二分法，这是只暗示从半分析模型的预测。我们的研究结果表明，有两种类型的环境效应在工作中的z~2。相对静止的星系更强的聚集意味着环境已经开始在淬灭恒星形成中发挥作用。与此同时，SSFR（“星爆”）升高的星系更强的聚集可能归因于密集环境中星系相互作用和合并的效率提高。
英文摘要：
Using a sample of BzK-selected galaxies at z~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 (M_{*}), and the clustering of galaxies as a function of these parameters. For star-forming galaxies (sBzKs), the UV-based SFR, corrected for extinction, scales with the stellar mass as SFR ~ M_{*}^{alpha} with alpha = 0.74+/-0.20 down to M_{*} ~ 10^{9} M_{solar}, indicating a weak dependence on the stellar mass of the SSFR. We also measure the angular correlation function and hence infer the correlation length for sBzK galaxies as a function of M_{*}, SFR, and SSFR, as well as K-band apparent magnitude. We show that passive galaxies (pBzKs) are more strongly clustered than sBzK galaxies at a given stellar mass, mirroring the color-density relation seen at lower redshifts. We also find that the correlation length of sBzK galaxies ranges from 4 to 20 h^{-1}Mpc, being a strong function of M_{K}, M_{*}, and SFR. On the other hand, the clustering dependence on SSFR changes abruptly at 2x10^{-9} yr^{-1}, which is the typical value for "main sequence" star-forming galaxies at z~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 at work at z~2. Stronger clustering for relatively quiescent galaxies implies that the environment has started to play a role in quenching star formation. At the same time, stronger clustering for galaxies with elevated SSFRs ("starbursts") might be attributed to an increased efficiency for galaxy interactions and mergers in dense environments.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
