arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1002.3170astro-ph.CO
收藏

红移一号LDSS-3发射线巡天(ROLES)II:巡天方法和z~1质量依赖的恒星形成率密度

The Redshift One LDSS-3 Emission line Survey (ROLES) II: Survey method and z~1 mass-dependent star-formation rate density

David G. Gilbank, Michael L. Balogh, Karl Glazebrook, Richard G. Bower, I. K. Baldry, G. T. Davies, G. K. T. Hau, I. H. Li, P. McCarthy

摘要:

出于“宇宙缩小”的建议,其中占主导地位的贡献宇宙恒星形成率密度(SFRD)收益从高到低质量的星系随着宇宙时间的增加,我们描述的红移一LDSS 3发射线调查(ROLES)的设计和实施。ROLES是对矮星系[8.5<log(M*/Msun)< 9.5]在0.89 < z < 1.15的K-选择(22.5 < K_AB < 24.0)巡天,从两个极深的场(GOODS-S和MS 1054-FIRES)绘制。使用[OII]3727发射线,我们获得了恒星形成星系的红移和恒星形成率(SFR),其极限为~0.3 Msun/yr。我们提出了在ROLES中测量的[OII]光度函数,并发现α_faint ~-1.5的a通过将ROLES与更高质量的调查相结合,我们使用[OII](有和没有各种经验修正)测量SFRD作为恒星质量的函数,并使用SED拟合从光谱红移的星系的静止框架UV光度获得SFR。我们的最佳估计的校正[OII]-SFRD和UV SFRD都独立地表明,SFRD的演变,平等的所有质量之间的z~1和z~0.1的星系。标准化的确切演变取决于所使用的指标,基于[OII]的估计值显示约2.6倍的变化,基于紫外线的估计值显示约6倍的变化。我们讨论了指标之间的正常化差异的可能原因,但注意到这种不确定性的大小与其他z~1作品中看到的指标之间的差异相当。我们的结果,SFRD的形状作为恒星质量的函数(因此,星系的质量范围占主导地位的SFRD)不演变之间的z~1和z~0.1是稳健的选择的指标。[删节]

英文摘要:

Motivated by suggestions of 'cosmic downsizing', in which the dominant contribution to the cosmic star formation rate density (SFRD) proceeds from higher to lower mass galaxies with increasing cosmic time, we describe the design and implementation of the Redshift One LDSS3 Emission line Survey (ROLES). ROLES is a K-selected (22.5 < K_AB < 24.0) survey for dwarf galaxies [8.5<log(M*/Msun)< 9.5] at 0.89 < z < 1.15 drawn from two extremely deep fields (GOODS-S and MS1054-FIRES). Using the [OII]3727 emission line, we obtain redshifts and star-formation rates (SFRs) for star-forming galaxies down to a limit of ~0.3 Msun/yr. We present the [OII] luminosity function measured in ROLES and find a faint end slope of alpha_faint ~ -1.5, similar to that measured at z~0.1 in the SDSS. By combining ROLES with higher mass surveys, we measure the SFRD as a function of stellar mass using [OII] (with and without various empirical corrections), and using SED-fitting to obtain the SFR from the rest-frame UV luminosity for galaxies with spectroscopic redshifts. Our best estimate of the corrected [OII]-SFRD and UV SFRD both independently show that the SFRD evolves equally for galaxies of all masses between z~1 and z~0.1. The exact evolution in normalisation depends on the indicator used, with the [OII]-based estimate showing a change of a factor of ~2.6 and the UV-based a factor of ~6. We discuss possible reasons for the discrepancy in normalisation between the indicators, but note that the magnitude of this uncertainty is comparable to the discrepancy between indicators seen in other z~1 works. Our result that the shape of the SFRD as a function of stellar mass (and hence the mass range of galaxies dominating the SFRD) does not evolve between z~1 and z~0.1 is robust to the choice of indicator. [abridged]

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。

↑