We present near-infrared integral-field spectroscopic observations targeting Hα in eight submillimeter galaxies (SMGs) at z?=?1.3–2.5 using the Very Large Telescope/Spectrograph for Integral Field Observations in the Near Infrared, obtaining significant detections for six of them. The star formation rates derived from the Hα emission are ~100 M ⊙ yr?1, which account for only ~20%–30% of the infrared-derived values, thus suggesting that these systems are very dusty. Two of these systems present [N ii]/Hα ratios indicative of the presence of an active galactic nucleus. We mapped the spatial distribution and kinematics of the star-forming regions in these galaxies on?kiloparsec?scales. In general, the Hα morphologies tend to be highly irregular and/or clumpy, showing spatial extents of ~3–11?kpc. We find evidence for significant spatial offsets, of ~01–04 or 1.2–3.4 kpc, between the Hα and the continuum emission in three of the sources. Performing a kinemetry analysis,?we conclude that the majority of the sample is not consistent with disk-like rotation-dominated kinematics. Instead, they tend to show irregular and/or clumpy and turbulent velocity and velocity dispersion fields. This can be interpreted as evidence for a?scenario in which these extreme star formation episodes are triggered by galaxy–galaxy interactions and major mergers. In contrast to recent results for SMGs, these sources appear to follow the same relations between gas and star-forming rate densities as less luminous and/or normal star-forming galaxies.
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机译：我们使用超大型望远镜/光谱仪对近红外积分场进行观测，以z？=？1.3–2.5的八个亚毫米星系（SMGs）为目标，介绍了针对Hα的近红外积分场光谱观测，获得了其中六个的重要探测结果。 Hα发射产生的恒星形成率约为100 M yryr-1，仅占红外衍生值的约20％–30％，因此表明这些系统非常尘土飞扬。这些系统中的两个呈现[N ii] /Hα比，表明存在活跃的银河核。我们以千分秒尺度绘制了这些星系中恒星形成区域的空间分布和运动学。通常，Hα形态趋于高度不规则和/或结块，显示〜3–11？kpc的空间范围。我们发现三个来源的Hα和连续发射之间存在明显的空间偏移，约为〜01–04或1.2–3.4 kpc。通过进行运动学分析，我们得出结论，大部分样品与盘状旋转为主的运动学不一致。取而代之的是，它们倾向于显示不规则的和/或成块的和湍流的速度和速度色散场。这可以解释为一种场景的证据，在这些场景中，这些极端恒星形成事件是由星系-星系相互作用和重大合并触发的。与SMG的最新结果相反，这些源似乎遵循的气体和恒星形成速率密度之间的关系与发光和/或正常恒星形成星系相同。
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