Dynamics of starbursting dwarf galaxies. III. A H I study of 18 nearby objects
Dynamics of starbursting dwarf galaxies. III. A H I study of 18 nearby objects
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DOI：
10.1051/0004-6361/201322657
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发表时间：
2014-04
影响因子：
6.5
通讯作者：
F. Lelli;M. Verheijen;Filippo Fraternali Kapteyn Astronomical Institute;U. Groningen;nl;D. Astronomy;Case Western Reserve University;Usa;D. Physics;Astronomy;U. Bologna;It
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作者：
F. Lelli;M. Verheijen;Filippo Fraternali Kapteyn Astronomical Institute;U. Groningen;nl;D. Astronomy;Case Western Reserve University;Usa;D. Physics;Astronomy;U. Bologna;It
我们使用新的和记录的H I观测来研究恒星爆裂矮星系的动力学。我们考虑了18个被HST观测分解成单星的邻近星系，提供了它们的恒星形成历史和总恒星质量。我们发现9个天体具有规则旋转的HI盘，7个天体具有运动扰动的HI盘，2个天体具有不稳定的HI分布。两个星系(NGC5253和UGC6456)显示出沿HI盘短轴的速度梯度，我们将其解释为强径向运动。对于具有规则旋转盘的星系，我们推导出旋转曲线，而对于具有运动扰动盘的星系，我们估计其外部的自转速度。我们在大约3个光学标尺长度范围内推导出重子分数，发现平均而言，重子至少占总质量的30%。尽管恒星形成在过去的500Myr期间在ISM中注入了约1056ergs，但这些爆发恒星的矮星具有与典型的矮星不规则星相似的重子和气体成分，这表明它们并没有从潜在的井中喷出大量气体。附录以电子形式在http://www.aanda.orgH上提供i数据立方体(FITS文件)只能在CDS通过匿名ftp到http://cdsarc.u-strasbg.fr(ftp://130.79.128.5)或通过http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A71)获得
We investigate the dynamics of starbursting dwarf galaxies, using both new and archival H I observations. We consider 18 nearby galaxies that have been resolved into single stars by HST observations, providing their star formation history and total stellar mass. We find that 9 objects have a regularly rotating H I disk, 7 have a kinematically disturbed H I disk, and 2 show unsettled H I distributions. Two galaxies (NGC 5253 and UGC 6456) show a velocity gradient along the minor axis of the H I disk, which we interpret as strong radial motions. For galaxies with a regularly rotating disk we derive rotation curves, while for galaxies with a kinematically disturbed disk, we estimate the rotation velocities in their outer parts. We derive baryonic fractions within about 3 optical scale lengths and find that, on average, baryons constitute at least 30% of the total mass. Despite the star formation having injected ~1056 ergs in the ISM in the past ~500 Myr, these starbursting dwarfs have both baryonic and gas fractions similar to those of typical dwarf irregulars, suggesting that they did not eject a large amount of gas out of their potential wells. Appendices are available in electronic form at http://www.aanda.orgH I datacubes (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A71