Kinematic analysis of the super-extended H I disk of the nearby spiral galaxy M 83
Kinematic analysis of the super-extended H I disk of the nearby spiral galaxy M 83
复制标题
附近螺旋星系 M 83 超扩展 H I 盘的运动学分析
DOI：
10.1051/0004-6361/202245290
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发表时间：
2023
影响因子：
6.5
通讯作者：
Eibensteiner C
中科院分区：
文献类型：
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作者：
Eibensteiner C
我们给出了用JVLA在21“角分辨率(≈500pc)下对附近的大质量螺旋星系M∼83进行的新的H GBT I观测，这是一个扩展的(GBT1.5°2)十点马赛克结合GBT单盘数据。我们研究了M83的超扩展H I盘(半径为∼50kpc)，特别是盘的运动学、自转和原子星际介质的湍流性质。我们在外盘(中央光盘)上定义了不同的区域，包括环、南区、南臂和北臂。我们测试了H I气体的表面密度、速度色散和外围的非圆运动，并与内部光盘进行了比较。我们发现向明显的HσI环方向的速度色散( v)增加，这表明H I气体更加湍动。此外，我们还报告了较大的半乳着丝点半径范围(直到∼ 50kpc)，其中σVis略大于热分量(即>；8 KM S−1)。我们发现，较高的恒星形成率(由远紫外辐射追踪)并不一定与较高的H I速度弥散有关，这表明径向输运可能是速度弥散增强的主要驱动因素。此外，我们还发现了一个可能的分支，它将扩展的H I盘连接到矮小不规则星系UGCA365，并且偏离了北臂的大致方向。最后，我们比较了质量流量分布(基于2D和3D倾斜环模型)，找到了流出气体闭塞∼2kpc、流入气体闭塞∼5.5kpc和流出气体闭塞∼ 14kpc的证据。我们警告说，质量流量对假定的运动盘参数高度敏感，特别是对倾角。
We present new H I observations of the nearby massive spiral galaxy M 83 taken with the JVLA at 21″ angular resolution (≈500 pc) of an extended (∼1.5 deg2) ten-point mosaic combined with GBT single-dish data. We study the super-extended H I disk of M 83 (∼50 kpc in radius), in particular disk kinematics, rotation, and the turbulent nature of the atomic interstellar medium. We define distinct regions in the outer disk (rgal> central optical disk), including a ring, a southern area, a southern arm and a northern arm. We examine H I gas surface density, velocity dispersion, and noncircular motions in the outskirts, which we compare to the inner optical disk. We find an increase of velocity dispersion (σv) toward the pronounced H I ring, indicative of more turbulent H I gas. Additionally, we report over a large galactocentric radius range (untilrgal∼ 50 kpc) whereσvis slightly larger than thermal component (i.e., > 8 km s−1). We find that a higher star-formation rate (as traced by far UV emission) is not necessarily always associated with a higher H I velocity dispersion, suggesting that radial transport could be a dominant driver for the enhanced velocity dispersion. Furthermore, we find a possible branch that connects the extended H I disk to the dwarf irregular galaxy UGCA 365 and that deviates from the general direction of the northern arm. Lastly, we compare mass flow rate profiles (based on 2D and 3D tilted ring models) and find evidence for outflowing gas atrgal∼ 2 kpc, inflowing gas atrgal∼ 5.5 kpc, and outflowing gas atrgal∼ 14 kpc. We caution that mass flow rates are highly sensitive to the assumed kinematic disk parameters, in particular to inclination.