论文标题
Mosel：Zfourge调查的（3 <Z <4）的强[OIII]5007Å发射星系
MOSEL: Strong [OIII]5007 Å Emitting Galaxies at (3<z<4) from the ZFOURGE Survey
论文作者
论文摘要
为了了解强烈的发射线星系（ELG）如何促进星系的整体增长和宇宙恒星形成历史的整体增长，我们瞄准了Zfourge成像调查的强ELGS（SELG），这些调查融合了（HB+[OIIII]）REST-FRAME等效宽度> 230a和2.5 <Zphot> 230a和2.5 <Zphot <4.0。使用Keck/Mosfire，作为我们多对象光谱发射线（MOSEL）调查的一部分，我们测量了比KS = 25 mag更明亮的星系的49个红移。我们的光谱成功率为〜53％，ZPHOT不确定性为sigma_z = [delta（z）/（1+z）] = 0.0135。我们在3 <zspec <3.8中确认31个ELG，并表明强烈的ELG具有光谱式休息框[OIII] 5007a等效宽度为100-500A，并且与更典型的星星形成的星系相比，质量较低（MSTAR/MSUN/MSUN）〜8.2-9.6]。强烈的ELG位于Z〜3.5处的恒星形成主要序列上方的〜0.9 DEX，并且具有较高的FGAS气体分数〜60％，即推断的气体质量很容易在〜10-100 MYR中燃料至双重恒星质量。结合使用Zfourge的最新结果，我们的分析表明，1）强[OIII] 5007A发射信号是早期发作的低质量（MSTAR <0.1M*）星系的强烈恒星生长的早期发作，而2）许多（如果不是大多数）（如果不是大多数，则在Z> 3处的星系）在这一Starburst阶段进行。如果是正确的，则具有强[OIII] 5007A发射（EW_REST> 200A）的低质量星系可能是Z> 3处电离紫外线辐射的越来越重要的来源。
To understand how strong emission line galaxies (ELGs) contribute to the overall growth of galaxies and star formation history of the universe, we target Strong ELGs (SELGs) from the ZFOURGE imaging survey that have blended (Hb+[OIII]) rest-frame equivalent widths of >230A and 2.5<zphot<4.0. Using Keck/MOSFIRE, we measure 49 redshifts for galaxies brighter than Ks=25 mag as part of our Multi-Object Spectroscopic Emission Line (MOSEL) survey. Our spectroscopic success rate is ~53% and zphot uncertainty is sigma_z= [Delta(z)/(1+z)]=0.0135. We confirm 31 ELGs at 3<zspec<3.8 and show that Strong ELGs have spectroscopic rest-frame [OIII]5007A equivalent widths of 100-500A and tend to be lower mass systems [log(Mstar/Msun)~8.2-9.6] compared to more typical star-forming galaxies. The Strong ELGs lie ~0.9 dex above the star-forming main-sequence at z~3.5 and have high inferred gas fractions of fgas~>60%, i.e. the inferred gas masses can easily fuel a starburst to double stellar masses within ~10-100 Myr. Combined with recent results using ZFOURGE, our analysis indicates that 1) strong [OIII]5007A emission signals an early episode of intense stellar growth in low mass (Mstar<0.1M*) galaxies and 2) many, if not most, galaxies at z>3 go through this starburst phase. If true, low-mass galaxies with strong [OIII]5007A emission (EW_rest>200A) may be an increasingly important source of ionizing UV radiation at z>3.
