论文标题
NGC5128光环中两个田地的星形形成历史
Star Formation History of Two Fields in the Halo of NGC5128
论文作者
论文摘要
NGC5128 Galaxy是一个巨大的椭圆星系，位于Centaurus Geraxies组为3.8 MPC。我们旨在研究星系的两个不同领域的恒星形成史（SFH）。东北田（田野1）位于18.8 kpc的距离，而南部田地（田2）为9.9 kpc。我们使用一种基于识别长时间变量（LPV）恒星和渐近巨型分支（AGB）恒星的光度法方法，因为它们是由于它们的亮度和变异性而导致的恒星形成和星系进化的强示踪剂；已经确定了野外1和671 LPV中的395个LPV。尽管磁场2的SF速率更加增强，但这两个字段呈现出相似的SFH。我们发现Galaxy有三个主要的明星编队剧集T $ \ SIM $ 800 MYR以前，T $ \ sim $ 3.2 Gyr of of of of，t $ \ sim $ 10 gyr of of the t tough the tough to-back time。 $ \ sim $ 800 MYR以前的恒星形成率与以前的研究一致，这表明银河系在那个时候经历了合并。此外，NGC5128在其最近的历史上经历了较低的恒星形成率，这本可以是由射流恒星形成和该银河系中AGN活动的多次爆发所驱动的，以及大约400 Myr以前的小合并。
NGC5128 galaxy is a giant elliptical galaxy located in the Centaurus group of galaxies at 3.8 Mpc. We aim to study the star formation history (SFH) of two different fields of the galaxy. The northeastern field (Field 1) is located at a distance of 18.8 kpc, while the southern field (Field 2) is at 9.9 kpc. We use a photometric method that is based on identifying long period variable (LPV) stars and asymptotic giant branch (AGB) stars, as they are strong tracers of star formation and galaxy evolution due to their luminosity and variability; 395 LPVs in Field 1 and 671 LPVs in Field 2 have been identified. These two fields present similar SFHs, although the SF rate of Field 2 is more enhanced. We find that the galaxy has three major star formation episodes t $\sim$ 800 Myr ago, t $\sim$ 3.2 Gyr ago, and t $\sim$ 10 Gyr ago, where t is look-back time. The rate of star formation at $\sim$ 800 Myr ago agrees with previous studies suggesting that the galaxy experienced a merger around that time. Furthermore, NGC5128 has experienced a lower star formation rate in its recent history which could have been driven by jet-induction star formation and multiple outbursts of AGN activity in this galaxy, as well as a minor merger around 400 Myr ago.
