论文标题
JWST揭示了可能的$ z \ sim 11 $ Galaxy合并，以三镜Macs0647 $ - $ JD
JWST reveals a possible $z \sim 11$ galaxy merger in triply-lensed MACS0647$-$JD
论文作者
论文摘要
MacS0647 $ - $ JD是最初用Hubble Space望远镜发现的三个三角镜$ z \ sim11 $ Galaxy。在这里，我们报告了新的JWST成像，该成像显然可以解决MACS0647 $ - $ JD，因为它们在单个星系中具有两个组件，它们要么合并星系或恒星复合体。两者都很小，带有出色的质量$ \ sim10^8 \，m_ \ odot $和radii $ r <100 \，\ rm pc $。更明亮的较大组件“ A”本质上是非常蓝色的（$β\ sim-2.6 $），这可能是由于最近的星形形成而没有灰尘，并且在空间上以有效的半径$ \ sim70 \，\ rm pc $进行空间扩展。较小的组件“ b”显得红色（$β\ sim-2 $），可能是因为它较早（$ 100-200 \，\ rm myr $），并带有轻度的灰尘灭绝（$ a_v \ sim0.1 \，\ rm mag $），而较小的Radius $ \ sim20 \，\ sim20 \，\ rm \ rm \ rmm pc $。我们在高红移模拟中识别具有相似颜色的星系，发现其星形构造历史不相相。估计出色的质量比大约为2：1，而物理预计的分离$ \ sim400 \，\ rm pc $，我们可能会在大爆炸后4亿年见证了星系合并。我们还确定了一个候选伴侣星系C $ \ sim3 \，{\ rm kpc} $，可能注定要与星系A和B融合。星系a+b的组合光被$ 8、5、5和2的因子放大了三个镜头jd1 $ \ sim $ \ sim $ \ sim $ \ sim 2，2，$ sim jd1 $ sim $ sim $ sim $ sim $ \ sim $ \ sim $ \ sim \ sim \ sim \ sim \ sim \ sim \ sim \ sim \ sim $ 86 \，\ rm njy $（AB MAG 25.1，25.6，26.6）。 MacS0647 $ - $ JD比最近在JWST类似的红移中发现的其他星系明显要明显。没有放大倍率，它将具有AB MAG 27.3（$ M_ {UV} = -20.4 $）。在较高的置信度下，我们根据6 nircam滤波器测量的光度法获得$ z = 10.6 \ pm0.3 $的光度红移，涉及$ 1-5 \rmμm$，$ 4300 \，$ 4300 \，Å$ rets-frame。计划于2023年1月计划的JWST NIRSPEC观察结果将提供光谱红移，并对MACS0647 $ -JD的物理特性进行更详细的研究。
MACS0647$-$JD is a triply-lensed $z\sim11$ galaxy originally discovered with the Hubble Space Telescope. Here we report new JWST imaging, which clearly resolves MACS0647$-$JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. Both are very small, with stellar masses $\sim10^8\,M_\odot$ and radii $r<100\,\rm pc$. The brighter larger component "A" is intrinsically very blue ($β\sim-2.6$), likely due to very recent star formation and no dust, and is spatially extended with an effective radius $\sim70\,\rm pc$. The smaller component "B" appears redder ($β\sim-2$), likely because it is older ($100-200\,\rm Myr$) with mild dust extinction ($A_V\sim0.1\,\rm mag$), and a smaller radius $\sim20\,\rm pc$. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be out of phase. With an estimated stellar mass ratio of roughly 2:1 and physical projected separation $\sim400\,\rm pc$, we may be witnessing a galaxy merger 400 million years after the Big Bang. We also identify a candidate companion galaxy C $\sim3\,{\rm kpc}$ away, likely destined to merge with galaxies A and B. The combined light from galaxies A+B is magnified by factors of $\sim$8, 5, and 2 in three lensed images JD1, 2, and 3 with F356W fluxes $\sim322$, $203$, $86\,\rm nJy$ (AB mag 25.1, 25.6, 26.6). MACS0647$-$JD is significantly brighter than other galaxies recently discovered at similar redshifts with JWST. Without magnification, it would have AB mag 27.3 ($M_{UV}=-20.4$). With a high confidence level, we obtain a photometric redshift of $z=10.6\pm0.3$ based on photometry measured in 6 NIRCam filters spanning $1-5\rmμm$, out to $4300\,Å$ rest-frame. JWST NIRSpec observations planned for January 2023 will deliver a spectroscopic redshift and a more detailed study of the physical properties of MACS0647$-$JD.
