论文标题
艾格二世。年轻恒星的第一光谱表征和与强h $β$相关的电离气体和[oiii]线条发射在z = 5-7的星系中的[oiii]线发射，JWST
EIGER II. first spectroscopic characterisation of the young stars and ionised gas associated with strong H$β$ and [OIII] line-emission in galaxies at z=5-7 with JWST
论文作者
论文摘要
我们使用第一个深jwst/nircam宽场宽度无镜观测来提出117 [OIII]排放星系样本的发射线测量和物理解释。我们的9.7小时集成集中在$ z = 6.3 $ quasar j0100+2802上，这是Eiger调查针对的六个字段中的第一个 - 覆盖$λ= 3-4 $ microns。我们检测到133 [oiii]双重组，但在$ \ $ \ $ \ $ 10 kpc和600 km s $^{ - 1} $之内合并，其小规模聚类过剩。我们在68中检测到H $β$，在两个星系中检测到H $γ$排放。星系的特征是紫外线亮度m $ _ {\ rm uv} \ sim-119.6 $（$ -17.7 $ to $ -22.3 $），恒星质量〜$ 10^8 $（10^{6.8-10.1} {6.8-10.1}） （最多3000埃），年轻年龄（〜100 Myr），一种激发的星际培养基（[OIII]/H $β\ of6 $）和低灰尘衰减。这些高EW在本地宇宙中非常罕见，但是我们表明它们在$ z \ sim6 $的无处不在，基于测得的数量密度。堆叠的频谱揭示了H $γ$和[OIII] $ _ {4364} $，这表明星系通常是灰尘和金属差的（E（b-v）= 0.1，12+log（o/h）= 7.4），具有高电子温度（$ 2 \ times10^4 $ K），并且生产效率（$ 2 \ times10^4 $ k）（$ iion afience）（$ ion iro的光效率（\ ion irove） ion} = 10^{25.3} $ hz erg $^{ - 1} $）。我们进一步显示了强大的质量金属关系的存在。年轻的高度电离恒星种群，中等低的金属度，低灰尘衰减和Z〜6星系中的高电离状态，共同使星系中的[OIIII]最大化，尽管在Z〜6处产生[OIIII]的亮度密度，但在Z〜2上的亮度密度显着高于Z〜2，尽管在Z〜2中均高于cosmic silt of Cosmics corsmics silt corsmics silt corsmics silt corsmics scormics scormics scormic silt。因此，使用JWST的[OIII]发射线调查证明了一种高效的方法，可以追踪电离时期的星系密度。
We present emission-line measurements and physical interpretations for a sample of 117 [OIII] emitting galaxies at $z=5.33-6.93$, using the first deep JWST/NIRCam wide field slitless spectroscopic observations. Our 9.7-hour integration is centered upon the $z=6.3$ quasar J0100+2802 -- the first of six fields targeted by the EIGER survey -- and covers $λ=3-4$ microns. We detect 133 [OIII] doublets, but merge pairs within $\approx$10 kpc and 600 km s$^{-1}$, motivated by their small scale clustering excess. We detect H$β$ in 68 and H$γ$ emission in two galaxies. The galaxies are characterised by a UV luminosity M$_{\rm UV}\sim-19.6$ ($-17.7$ to $-22.3$), stellar mass ~$10^8$ $(10^{6.8-10.1})$ M$_{\odot}$, H$β$ and [OIII] EWs $\approx$ 850 Angstrom (up to 3000 Angstrom), young ages (~100 Myr), a highly excited interstellar medium ([OIII]/H$β\approx6$) and low dust attenuations. These high EWs are very rare in the local Universe, but we show they are ubiquitous at $z\sim6$ based on the measured number densities. The stacked spectrum reveals H$γ$ and [OIII]$_{4364}$ which shows that the galaxies are typically dust and metal poor (E(B-V)=0.1, 12+log(O/H)=7.4) with a high electron temperature ($2\times10^4$ K) and a production efficiency of ionising photons ($ξ_{\rm ion}=10^{25.3}$ Hz erg$^{-1}$). We further show the existence of a strong mass-metallicity relation. The young highly ionising stellar populations, moderately low metallicities, low dust attenuations and high ionisation state in z~6 galaxies conspire to maximise the [OIII] output from galaxies, yielding an [OIII] luminosity density at z~6 that is significantly higher than at z~2, despite the order of magnitude decline in cosmic star formation. Thus, [OIII] emission-line surveys with JWST prove a highly efficient method to trace the galaxy density in the epoch of reionization.
