利用星团年龄分布重构合并时间线：以MCG为例+08-11-002
Reconstructing Merger Timelines Using Star Cluster Age Distributions: the Case of MCG+08-11-002
摘要：
我们目前的近红外成像和积分场光谱的尘埃明亮的红外星系合并MCG+08-11-002的中心，采取了近红外相机2（NIRC 2）和OH抑制红外成像光谱仪（OSIRIS）的凯克II。我们在K波段实现了~25 pc的空间分辨率，使我们能够在NIRC 2图像中分辨41个星团。利用CO2. 3 $μ$ m吸收特征和Br $γ$星云发射线的等效宽度，计算了OSIRIS场中22/25星团的年龄.星团的年龄分布在年龄<2000万年时有一个明显的峰值，表明当前的星暴活动与祖先星系的最终合并有关。在大约6500万年前可能有第二个峰值，这可能是星系核先前近距离通过的产物。我们拟合单星爆和双星爆模型的星团年龄分布，并使用Monte Carlo抽样结合双侧K-S检验来计算观测数据来自每个最佳拟合分布的概率。有90%以上的可能性，数据是从一个或两个星爆恒星形成的历史，但随机抽样阻止我们区分这两种情况。我们对MCG+08-11-002的分析表明，星团年龄分布为星系相互作用的时间轴提供了有价值的见解，因此可能在未来精确合并阶段分类系统的发展中发挥重要作用。
英文摘要：
We present near infrared imaging and integral field spectroscopy of the centre of the dusty luminous infrared galaxy merger MCG+08-11-002, taken using the Near InfraRed Camera 2 (NIRC2) and the OH-Suppressing InfraRed Imaging Spectrograph (OSIRIS) on Keck II. We achieve a spatial resolution of ~25 pc in the K band, allowing us to resolve 41 star clusters in the NIRC2 images. We calculate the ages of 22/25 star clusters within the OSIRIS field using the equivalent widths of the CO 2.3$μ$m absorption feature and the Br$γ$ nebular emission line. The star cluster age distribution has a clear peak at ages < 20 Myr, indicative of current starburst activity associated with the final coalescence of the progenitor galaxies. There is a possible second peak at ~65 Myr which may be a product of the previous close passage of the galaxy nuclei. We fit single and double starburst models to the star cluster age distribution and use Monte Carlo sampling combined with two-sided K-S tests to calculate the probability that the observed data are drawn from each of the best fit distributions. There is a >90 per cent chance that the data are drawn from either a single or double starburst star formation history, but stochastic sampling prevents us from distinguishing between the two scenarios. Our analysis of MCG+08-11-002 indicates that star cluster age distributions provide valuable insights into the timelines of galaxy interactions and may therefore play an important role in the future development of precise merger stage classification systems.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
