AI 中文总结
本研究通过10个QPE宿主星系的恒星族群模拟构建QPE延迟时间分布，发现QPE率在约1 Gyr时达峰值，高爆发质量占比的QPE宿主星系占比更高，或支持EMRIs形成通道。
AI 中文摘要
准周期性爆发（QPEs）是在星系核中观测到的准周期性X射线爆发。多项观测证据将QPEs与潮汐瓦解事件（TDEs）关联起来，TDEs是恒星过于接近超大质量黑洞后被瓦解时发生的事件。恒星形成后星系在TDEs和QPEs的宿主星系中占比过高，尽管导致这种占比过高的机制尚不清楚。尽管QPEs的物理起源尚不明确，但QPEs的延迟时间分布（DTD，即QPE率随恒星形成爆发后时间的函数）可约束影响QPE率的机制及可能的QPE形成通道。我们汇编了10个带有光学光谱的QPE宿主星系的目录，使用Bagpipes模型模拟恒星族群，并获取最近一次恒星形成爆发的年龄以构建QPEs的DTD。我们发现，相对于控制样本，QPE率随爆发后年龄增长而上升，在约1 Gyr时达到峰值，与观测到的TDE DTD相似，尽管我们无法排除相对于控制样本的爆发年龄呈平坦分布的情况。然而，QPE宿主星系中高（>1%）爆发质量占比的星系比例，高于TDE宿主星系样本或控制星系样本中高爆发质量占比的星系比例。如果偏好的QPE形成通道需要极端质量比旋近（EMRIs），那么此类EMRIs可能更容易由约1 Gyr的大型恒星形成爆发产生。
英文摘要
Quasi-periodic eruptions (QPEs) are quasi-periodic X-ray bursts observed in the nucleus of a galaxy. Multiple pieces of observational evidence link QPEs to tidal disruption events (TDEs), which occur when stars are disrupted after approaching a supermassive black hole too closely. Post-starburst galaxies are overrepresented among the host galaxies of both TDEs and QPEs, though the mechanism causing this overrepresentation is unknown. While their physical origin is unclear, the delay time distribution (DTD) of QPEs, or rate of QPEs as a function of time since a burst of star formation, can constrain what mechanisms influence the QPE rate and possible QPE formation channels. We compile a catalog of 10 QPE host galaxies with optical spectra, model the stellar populations with Bagpipes, and retrieve the age of the most recent burst of star formation to construct the DTD of QPEs. We find that the QPE rate increases with post-burst age to reach a peak at ~1 Gyr relative to a control sample, similar to the observational TDE DTD, though we cannot rule out a flat distribution of burst ages relative to a control sample. However, the fraction of QPE host galaxies with high (>1%) burst mass fractions is larger than the fraction of galaxies with high burst mass fractions in either a sample of TDE host galaxies or a sample of control galaxies. If the preferred QPE formation channel requires extreme mass ratio inspirals (EMRIs), then such EMRIs may be more readily produced by large, ~1-Gyr-old bursts of star formation.
Comments13 pages, 4 figures, accepted to ApJL
