论文标题
一个双峰的Lyman-$α$发射极，具有强蓝色峰值由Galaxy群集RXC J0018.5+1626成像
A double-peaked Lyman-$α$ emitter with a strong blue peak multiply imaged by the galaxy cluster RXC J0018.5+1626
论文作者
论文摘要
我们报告了$ z = 3.2177 \ pm0.0001 $ in VLT/MUSE DATA的发现，发现了双峰lyman-$ $ $ $ $α$（ly $α$）发射极（LAE）。 Galaxy在文物调查中最近观察到的Galaxy群集RXC〜J0018.5+1626强烈镜头，并且在Muse the Muse-tof-of-tear-of-tear-of-tear-of-timape中清楚地检测到了双峰的LY $α$排放。我们测量$ \ Mathrm {ew} _ {\ Mathrm {ly}α，0} =（63 \ pm2）\，\ Mathring {\ Mathring {\ Mathrm {a}} $的相对较高的$α$ rest-rest frame等效宽度（EW）_ {额外的近红外（NIR）光谱学使我们能够测量H $β$，[OIII] $ \ LAMBDA4959 \，\ MATHRING {\ MATHRM {a}} $和[OIIII] $ \ \ \ lambda5007 \ \ lambda5007 \ \，\ Mathring {几个$ \ sim10-100 \，\ Mathring {\ Mathrm {a}} $，[OIII] $ \ lambda5007 \，\ Mathring {\ Mathrm {\ Mathrm {a}} $/H $β$β$比为$ 4.8 \ pm0.7 $的比率，and \ pm0.7 $的limii] $> 5.6 $。银河系具有非常蓝色的紫外线斜率，为$β_ {\ mathrm {fuv}} = - 2.23 \ pm0.06 $和$β_ {\ mathrm {nuv}} = - 3.0 \ pm0.2 $，并通过因子$μ-μ-10 $ shim a a imabl a image a image a in Image a image a Implay a in aim 7-10 （$ m _ {\ star} \ simeq10^{7.5} \，\ mathrm {m} _ {\ odot} $）高雷德希夫星系模拟。值得注意的是，LY $α$曲线的蓝色峰明显高于红色峰，这表明物质流入，其圆形气体中可能非常低的HI柱密度。这些特性与高透镜放大倍率和图像多样性相结合，使该星系成为搜索LYC发射并限制LYC光子逃逸分数的后续观测值的主要候选者。
We report the discovery of a double-peaked Lyman-$α$ (Ly$α$) emitter (LAE) at $z=3.2177\pm0.0001$ in VLT/MUSE data. The galaxy is strongly lensed by the galaxy cluster RXC~J0018.5+1626 recently observed in the RELICS survey, and the double-peaked Ly$α$ emission is clearly detected in the two counter images in the MUSE field-of-view. We measure a relatively high Ly$α$ rest-frame equivalent width (EW) of $\mathrm{EW}_{\mathrm{Ly}α,0}=(63\pm2)\,\mathring{\mathrm{A}}$. Additional near-infrared (NIR) spectroscopy allows us to measure the H$β$, [OIII]$\lambda4959\,\mathring{\mathrm{A}}$ and [OIII]$\lambda5007\,\mathring{\mathrm{A}}$ emission lines, which show moderate rest-frame EWs of the order of a few $\sim10-100\,\mathring{\mathrm{A}}$, an [OIII]$\lambda5007\,\mathring{\mathrm{A}}$/H$β$ ratio of $4.8\pm0.7$, and a lower limit on the [OIII]/[OII] ratio of $>5.6$. The galaxy has very blue UV-continuum slopes of $β_{\mathrm{FUV}}=-2.23\pm0.06$ and $β_{\mathrm{NUV}}=-3.0\pm0.2$, and is magnified by factors $μ\sim7-10$ in each of the two images, thus enabling a view into a low-mass ($M_{\star}\simeq10^{7.5}\,\mathrm{M}_{\odot}$) high-redshift galaxy analog. Notably, the blue peak of the Ly$α$ profile is significantly stronger than the red peak, which suggests an inflow of matter and possibly very low HI column densities in its circumgalactic gas. Combined with the high lensing magnification and image multiplicity, these properties make this galaxy a prime candidate for follow-up observations to search for LyC emission and constrain the LyC photon escape fraction.
