Gas Engaged in Noncircular Motions in LITTLE THINGS Dwarf Irregular Galaxies

被引：4
作者：
Hunter, Deidre A. [1 ]
Laufman, Lauren [1 ,2 ,5 ]
Oh, Se-Heon [3 ]
Levine, Stephen E. [1 ]
Simpson, Caroline E. [4 ]
机构：
[1] Lowell Observ, 1400 West Mars Hill Rd, Flagstaff, AZ 86001 USA
[2] No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA
[3] Sejong Univ, Dept Phys & Astron, 209 Neungdong Ro, Seoul, South Korea
[4] Florida Int Univ, Dept Phys, CP 204,11200 SW 8th St, Miami, FL 33199 USA
[5] Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 USA
来源：
ASTRONOMICAL JOURNAL | 2019年 / 158卷 / 01期
基金：
美国国家科学基金会;
关键词：
galaxies: irregular; galaxies: ISM; galaxies: kinematics and dynamics; galaxies: star formation; STAR-FORMATION; LARGE-SAMPLE; DIVERSITY; STABILITY; EVOLUTION; DISKS;
D O I：
10.3847/1538-3881/ab223d
中图分类号：
P1 [天文学];
学科分类号：
0704 ;
摘要：
We have examined gas engaged in noncircular motions in 22 of the nearby LITTLE THINGS dwarf irregular galaxies. The H I data cubes have been deconvolved into kinematic components-bulk rotation and noncircular motions-to produce maps of integrated gas, velocity field, and velocity dispersion in the different components. We found significant regions of gas engaged in noncircular motions in half of the galaxies, involving 1%-20% of the total H I mass of the galaxy. In one galaxy we found a pattern in the velocity field that is characteristic of streaming motions around the stellar bar potential and star formation at the end of bar. Two galaxies have large-scale filamentary structures found in their outer disks, and these filaments could be transient instabilities in the gas. We found no spatial correlation between noncircular motion gas and enhanced star formation. We found noncircular motion gas in only one galaxy associated with higher H I velocity dispersion.
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页数：21
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