近期停止恒星形成星系中的极端MgII发射：来自DESI早期数据发布的中红移后星暴类星体新样本
Extreme MgII Emission in Recently-Quenched Galaxies: A New Sample of Intermediate-Redshift Post-Starburst Quasars from the DESI Early Data Release
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中文总结 AI 辅助
本研究利用DESI数据发现十个具有极端MgII发射的后星暴类星体，构成首个从后星暴星系母样本选出的类星体样本，并揭示后星暴选择方法对高光度活动星系核存在偏差，可能遗漏了驱动熄灭外流的类星体。
中文摘要 AI 辅助
后星暴星系是近期迅速停止恒星形成的星系。活动星系核活动常被用来解释这种快速熄灭，但大多数后星暴选择方法会排除光学活动星系核，这促使人们寻找“后星暴类星体”。我们展示了十个具有显著MgII发射（$L_{\text{MgII}} \geq 3 \times 10^{41}$ erg/s）的后星暴类星体的DESI观测结果。这是首个从后星暴星系母样本而非类星体星表中选出的后星暴类星体样本。在$0.49 \leq z \leq 1.39$范围内，类星体占后星暴母样本的$4.6^{+1.6}_{-1.2}\\%$。利用多波段活动星系核诊断，我们发现母样本中$26^{+3.0}_{-2.8}\\%$的后星暴星系拥有活动星系核。我们发现后星暴选择方法对$\text{L}_{\text{Bol}}\gtrsim10^{45} \textrm{erg s}^{-1}$的活动星系核存在偏差，可能排除了那些驱动有助于熄灭恒星形成的外流活动的类星体。最后，我们发现样本中10个后星暴类星体中有9个未探测到宽H$\beta$发射，类似于所谓的“MgII发射体”，它们可能是正在消退的类星体的遗迹；如果得到证实，这些天体表明后星暴星系与变活动星系核之间存在联系。我们的新后星暴类星体样本在宇宙恒星形成整体下降时期，为先前报道的局域和高中红移后星暴类星体提供了联系。
英文摘要
Post-starburst galaxies are galaxies which have recently and rapidly shut off star formation. AGN activity is often invoked to explain this rapid quenching, but most post-starburst selection methods select against optical AGN, motivating searches for "post-starburst quasars." We present DESI observations of ten post-starburst quasars with significant MgII emission ($L_{\text{MgII}} \geq 3 \times 10^{41}$ erg/s). This is the first sample of post-starburst quasars to be selected from a post-starburst galaxy parent sample rather than a quasar catalog. Quasars make up $4.6^{+1.6}_{-1.2}\%$ of the post-starburst parent sample at $0.49 \leq z \leq 1.39$. Using multiwavelength AGN diagnostics, we find that $26^{+3.0}_{-2.8}\%$ of post-starbursts in the parent sample host AGN. We find that post-starburst selection methods are biased against AGN with $\text{L}_{\text{Bol}}\gtrsim10^{45} \textrm{erg s}^{-1}$, potentially removing the quasars responsible for driving outflows that aid in quenching. Finally, we find that 9/10 post-starburst quasars in our sample have no detected broad H$β$, similar to so-called "MgII emitters" that may be the remnants of fading quasars; if confirmed, these objects suggest a link between post-starburst galaxies and variable AGN. Our new sample of post-starburst quasars provides a link between previously reported local and high redshift post-starburst quasars during the epoch when star formation throughout the universe was declining.
发表机构
- University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）
- The Johns Hopkins University（约翰斯·霍普金斯大学）
- Princeton University（普林斯顿大学）
- University of Nottingham（诺丁汉大学）
- Space Telescope Science Institute（太空望远镜科学研究所）
机构由 AI 辅助整理，请以论文原文为准。
