标题： MEGARA的恒星种群：NGC 7025的内部区域 显示英文标题

标题： Stellar populations with MEGARA: the inner regions of NGC 7025

摘要： 上下文。 我们旨在确定MEGARA@GTC仪器积分场单元的能力，以研究恒星种群，并利用其在12.5"x11.3"视场内的高光谱（R\sim 6,000, 12,000和20,000）和空间（0.62"）分辨率的组合。 目标。 我们希望通过一种系统的方法来确定使用MEGARA进行观测中的恒星种群的属性，特别是MEGADES遗产项目中的属性，以及本文中NGC 7025的恒星种群属性。 方法。 我们使用了NGC 7025星系的MEGARA观测数据。 我们应用了不同的方法来尽可能准确地估计恒星种群的属性。 还进行了大量测试以检查研究的可靠性。 结果。 我们对NGC 7025的恒星种群进行的所有研究（包括全光谱拟合和吸收线指数）表明，构成其核球的恒星具有超太阳金属丰度和明显古老的年龄（\sim 10 Gyr），总体而言。 我们通过三种不同的MEGARA光谱设置组合确定了NGC 7025的核球具有轻微的负质量加权年龄梯度。 关于其更详细的恒星形成历史，我们的结果表明，除了早期时期的相对恒定的恒星形成外，核球中恒星的形成历史在3.5-4.5 Gyr前也出现了一个峰值，部分解释了所测量的质量加权年龄梯度。 结论。 NGC 7025的情况是一个孤立星系在长期演化过程中，在大约3.5-4.5 Gyr前可能经历了一次小规模合并（质量比为1/10），这导致了恒星形成的增加，并扰动了其外盘的形态。 我们报告了在GTC进行的MEGADES调查持续利用过程中学到的不同经验教训。 显示英文摘要

摘要： Context. We aim to determine the capabilities of the MEGARA@GTC instrument integral-field unit to study stellar populations and exploit its combination of high spectral (R \sim 6,000, 12,000 and 20,000) and spatial (0.62") resolutions within its 12.5"x11.3" field of view. Aims. We pursue to establish a systematic method through which we can determine the properties of the stellar populations in the observations made with MEGARA, more specifically within the MEGADES legacy project and, for this paper, those of the stellar populations of NGC 7025. Methods. We use MEGARA observations of galaxy NGC 7025. We apply different approaches to estimate the properties of the stellar populations with the highest possible certainty. Numerous tests were also performed to check the reliability of the study. Results. All the studies we conduct (both full spectral fitting and absorption line indices) on the stellar populations of NGC 7025 indicate that the stars that form its bulge have supersolar metallicity and considerably old ages (\sim 10 Gyr), in general. We determined that the bulge of NGC 7025 has a mild negative mass-weighted age gradient using three different combinations of MEGARA spectral setups. Regarding its more detailed star formation history, our results indicate that, besides a rather constant star formation at early epochs, a peak in formation history of the stars in the bulge is also found 3.5-4.5 Gyr ago, partly explaining the mass-weighted age gradients measured. Conclusions. The scenario presented in NGC 7025 is that of an isolated galaxy under secular evolution that about 3.5-4.5 Gyr ago likely experimented a minor merger (mass ratio 1/10) that induced an increase in star formation and also perturbed the morphology of its outer disc. We report on different lessons learned for the ongoing exploitation of the MEGADES survey with GTC.