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arXiv 1706.01896astro-ph.GA
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合并LIRG NGC 2623中空间分辨的恒星星族和电离气体性质

The spatially resolved stellar population and ionized gas properties in the merger LIRG NGC 2623

C. Cortijo-Ferrero, R. M. González Delgado, E. Pérez, S. F. Sánchez, R. Cid Fernandes, A. L. de Amorim, P. Di Matteo, R. García-Benito, E. A. D. Lacerda, R. Lóp… 展开作者

C. Cortijo-Ferrero, R. M. González Delgado, E. Pérez, S. F. Sánchez, R. Cid Fernandes, A. L. de Amorim, P. Di Matteo, R. García-Benito, E. A. D. Lacerda, R. López Fernández, C. Tadhunter, M. Villar-Martín, M. M. Roth

摘要:

我们报告的详细研究合并LIRG NGC 2623中的恒星种群和电离气体的性质,分析光学积分场光谱的CALIFA调查和PMAS LArr,多波长HST成像,和OSIRIS窄带H $α$和[NII] $λ$ 6584成像。用STARLIGHT全谱拟合程序对光谱进行了处理,并与两个早期并合LIRGs(IC 1623 W和NGC 6090)以及CALIFA Sbc/Sc星系的结果进行了比较。我们发现NGC 2623经历了两个恒星形成增加的时期(SF),第一个广泛的插曲,由中间年龄的恒星种群ISP(140百万年至1.4 Gyr)跟踪,第二个由年轻恒星种群YSP($<$ 140百万年)跟踪,它集中在中心区域($<$ 1.4 kpc)。我们的研究结果与动力学模型预测的第一次近中心通过($\sim$ 2亿年前)和合并($<$ 1亿年前)的时代相一致,并且与文献中的高分辨率合并模拟相一致,与NGC 2623代表早期合并的进化版本相一致。大多数电离气体集中在$<$ 2.8 kpc,在那里发现LINER样电离和高速色散($\sim$ 220 km/s),与以前报道的外流一致。最高分辨率的OSIRIS和HST数据显示,HII区域的集合也存在于星系平面中,这解释了该系统中电离机制的混合。NGC 2623的外流不太可能从星系逃逸,因为它的SFR强度很低($\sim$ 0.5 M $_{\odot}$ yr $^{-1}$ kpc $^{-2}$),外流速率比当前的SFR低3倍,而且中心区域的逃逸速度比外流速率高。

英文摘要:

We report on a detailed study of the stellar populations and ionized gas properties in the merger LIRG NGC 2623, analysing optical Integral Field Spectroscopy from the CALIFA survey and PMAS LArr, multiwavelength HST imaging, and OSIRIS narrow band H$α$ and [NII]$λ$6584 imaging. The spectra were processed with the STARLIGHT full spectral fitting code, and the results compared with those for two early-stage merger LIRGs (IC 1623 W and NGC 6090), together with CALIFA Sbc/Sc galaxies. We find that NGC 2623 went through two periods of increased star formation (SF), a first and widespread episode, traced by intermediate-age stellar populations ISP (140 Myr-1.4 Gyr), and a second one, traced by young stellar populations YSP ($<$140 Myr), which is concentrated in the central regions ($<$1.4 kpc). Our results are in agreement with the epochs of the first peri-center passage ($\sim$200 Myr ago) and coalescence ($<$100 Myr ago) predicted by dynamical models, and with high resolution merger simulations in the literature, consistent with NGC 2623 representing an evolved version of the early-stage mergers. Most ionized gas is concentrated within $<$2.8 kpc, where LINER-like ionization and high velocity dispersion ($\sim$220 km/s) are found, consistent with the previously reported outflow. As revealed by the highest resolution OSIRIS and HST data, a collection of HII regions is also present in the plane of the galaxy, which explains the mixture of ionization mechanisms in this system. It is unlikely that the outflow in NGC 2623 will escape from the galaxy, given the low SFR intensity ($\sim$0.5 M$_{\odot}$yr$^{-1}$kpc$^{-2}$), the fact that the outflow rate is 3 times lower than the current SFR, and the escape velocity in the central areas higher than the outflow velocity.

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。

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