Heavily reddened z ~ 2 Type 1 quasars - II. H a star formation constraints from SINFONI IFU observations
Heavily reddened z ~ 2 Type 1 quasars - II. H a star formation constraints from SINFONI IFU observations
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严重变红的 z ~ 2 1 型类星体 - II。
DOI：
10.1093/mnras/stw682
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发表时间：
2016
影响因子：
4.8
通讯作者：
Alaghband-Zadeh S
中科院分区：
文献类型：
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作者：
Alaghband-Zadeh S
利用近红外积分场单位光谱分析了28个重红（E(B−V)≃0.5-1.9）、超亮（）宽线类星体（z≃1.4-2.7）的样品中与恒星形成相关的H α辐射。28个类星体中有16个显示出恒星形成的证据，平均消光校正的恒星形成速率（SFR）为320±70 M⊙yr−1。探测到的叠加光谱显示微弱的[Nii]，与恒星形成作为窄H α发射的起源相一致。在16次探测中，有11次的恒星形成区域在空间上无法确定，并且被限制在类星体发射的6 kpc范围内。在五个分辨的探测中，我们发现恒星形成区域在类星体发射周围以~ 8 kpc的尺度扩展。高SFRs的普遍存在与重红色类星体群的识别是一致的，它们代表了从明显的“星暴星系”到光学发光类星体的过渡阶段。确定了10个未探测到恒星形成的类星体的上限。在两个类星体中，SFR被限制为相对适度的，<50 M⊙yr−1，但在其他8个类星体中可能存在明显更高水平的恒星形成。16个强恒星形成探测和8个高SFR极限的结合意味着高水平的恒星形成可能存在于大多数样本中。更高的空间分辨率数据，多发射线，将使我们更好地了解这些过渡类星体中恒星形成和活跃星系核活动之间的相互作用。
We use near-infrared integral field unit spectroscopy to search for H α emission associated with star formation in a sample of 28 heavily reddened (E(B−V) ≃ 0.5–1.9), hyperluminous () broad-line quasars atz≃ 1.4–2.7. 16 of the 28 quasars show evidence for star formation with an average extinction-corrected star formation rate (SFR) of 320 ± 70 M⊙yr−1. A stacked spectrum of the detections shows weak [Nii], consistent with star formation as the origin of the narrow H α emission. The star-forming regions are spatially unresolved in 11 of the 16 detections and constrained to lie within ∼6 kpc of the quasar emission. In the five resolved detections we find the star-forming regions are extended on scales of ∼8 kpc around the quasar emission. The prevalence of high SFRs is consistent with the identification of the heavily reddened quasar population as representing a transitional phase from apparent ‘starburst galaxies’ to optically luminous quasars. Upper limits are determined for 10 quasars in which star formation is undetected. In two of the quasars the SFR is constrained to be relatively modest, <50 M⊙yr−1, but significantly higher levels of star formation could be present in the other eight quasars. The combination of the 16 strong star formation detections and the eight high SFR limits means that high levels of star formation may be present in the majority of the sample. Higher spatial resolution data, of multiple emission lines, will allow us to better understand the interplay between star formation and active galactic nucleus activity in these transitioning quasars.