Probing the intra-group medium of a z=0.28 galaxy group
Probing the intra-group medium of a z=0.28 galaxy group
复制标题
DOI：
10.1093/mnras/stx528
复制
发表时间：
2017-06-01
影响因子：
4.8
通讯作者：
Cantalupo, S.
中科院分区：
文献类型：
--
作者：
Bielby, R.;Crighton, N. H. M.;Cantalupo, S.
我们提出了由背景类星体探测的星系群的新 MUSE 观测结果。类星体视线在多个 z = 0.28 星系之间穿过，同时显示相同红移的低电离金属线种类，包括 Ca II、Mg I、Mg II 和 Fe II。根据 MUSE 数据测量的星系红移，我们估计这些星系是一个小星系群的一部分，其晕质量约为 6 x 10(12) M 圆点。我们使用 MUSE 数据来揭示星系群中气体和恒星的二维动力学特性，并将这些特性与吸收体运动学联系起来。有了这些数据，我们考虑了视线吸收器探测到的气体性质的多种情况：与群内单个星系相关的共旋转气体晕；由最近的恒星形成驱动的单个群体成员流出的材料；以及与组内介质相关的冷却致密气体。我们发现动力学、星系撞击参数、恒星形成速率和吸收体强度表明冷气体不能与该星系群中的任何单个星系明确相关。相反，我们发现，观测结果与所观察到的星系在落入群势时产生的冷气体云的叠加一致，并且现在很可能正在形成群内介质的过程中。
We present new MUSE observations of a galaxy group probed by a background quasar. The quasar sightline passes between multiple z = 0.28 galaxies, whilst showing at the same redshift low-ionized metal line species, including Ca II, Mg I, Mg II and Fe II. Based on the galaxy redshifts measured from the MUSE data, we estimate the galaxies to be part of a small galaxy group with a halo mass of approximate to 6 x 10(12) M-circle dot. We use the MUSE data to reveal the two-dimensional dynamical properties of the gas and stars in the group galaxies, and relate these to the absorber kinematics. With these data, we consider a number of scenarios for the nature of the gas probed by the sightline absorbers: a corotating gas halo associated with a single galaxy within the group; outflowing material from a single group member powered by recent star-formation; and cool dense gas associated with an intra-group medium. We find that the dynamics, galaxy impact parameters, star formation rates and the absorber strength suggest that the cool gas cannot be clearly associated with any single galaxy within the group. Instead, we find that the observations are consistent with a superposition of cool gas clouds originating with the observed galaxies as they fall into the group potential, and are now likely in the process of forming the intra-group medium.