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arXiv 1611.00528astro-ph.GA
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SDSS-IV MaNGA:具有运动学解耦的恒星和气体成分的星系的性质

SDSS-IV MaNGA: Properties of galaxies with kinematically decoupled stellar and gaseous components

Yifei Jin, Yanmei Chen, Yong Shi, C. A. Tremonti, M. A. Bershady, M. Merrifield, E. Emsellem, Hai Fu, D. Wake, K. Bundy, Lihwai Lin, M. Argudo-Fernandez, Song H… 展开作者

Yifei Jin, Yanmei Chen, Yong Shi, C. A. Tremonti, M. A. Bershady, M. Merrifield, E. Emsellem, Hai Fu, D. Wake, K. Bundy, Lihwai Lin, M. Argudo-Fernandez, Song Huang, D. V. Stark, T. Storchi-Bergmann, D. Bizyaev, J. Brownstein, J. Chisholm, Qi Guo, Lei Hao, Jian Hu, Cheng Li, Ran Li, K. L. Masters, E. Malanushenko, Kaike Pan, R. A. Riffel, A. Roman-Lopes, A. Simmons, D. Thomas, Lan Wang, K. Westfall, Renbin Yan

摘要:

我们研究了来自MaNGA巡天的66个具有运动失调气体和恒星的星系的性质。运动失调星系的比例随星系物理参数M*、SFR和sSFR的变化而变化。根据它们的sSFR,我们进一步将这66个星系分为三类,10个恒星形成星系,26个“绿谷”星系和30个静止星系。不同类型的运动失调星系的性质是不同的,恒星形成的星系具有正的D4000梯度和较高的气相金属丰度,而绿谷/静止的星系具有负的D4000梯度和较低的气相金属丰度。有证据表明,所有类型的运动失调星系往往生活在更孤立的环境中。基于所有这些观测结果,我们提出了一个恒星形成星系与运动学错位的气体和恒星的形成方案-祖先吸积来自富含气体的矮星或宇宙网的错位气体,预先存在的气体和吸积气体之间的气体-气体碰撞的角动量抵消大大加速了气体流入,导致快速集中的恒星形成。更高的金属丰度是由于从这个恒星形成的富集。对于运动学错位的绿谷星系和静止星系,它们可能是通过贫气体的前体星系吸积来自质量较小的卫星星系的运动学错位气体而形成的。

英文摘要:

We study the properties of 66 galaxies with kinematically misaligned gas and stars from MaNGA survey. The fraction of kinematically misaligned galaxies varies with galaxy physical parameters, i.e. M*, SFR and sSFR. According to their sSFR, we further classify these 66 galaxies into three categories, 10 star-forming, 26 "Green Valley" and 30 quiescent ones. The properties of different types of kinematically misaligned galaxies are different in that the star-forming ones have positive gradient in D4000 and higher gas-phase metallicity, while the green valley/quiescent ones have negative D4000 gradients and lower gas-phase metallicity on average. There is evidence that all types of the kinematically misaligned galaxies tend to live in more isolated environment. Based on all these observational results, we propose a scenario for the formation of star forming galaxies with kinematically misaligned gas and stars - the progenitor accretes misaligned gas from a gas-rich dwarf or cosmic web, the cancellation of angular momentum from gas-gas collisions between the pre-existing gas and the accreted gas largely accelerates gas inflow, leading to fast centrally-concentrated star-formation. The higher metallicity is due to enrichment from this star formation. For the kinematically misaligned green valley and quiescent galaxies, they might be formed through gas-poor progenitors accreting kinematically misaligned gas from satellites which are smaller in mass.

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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