EVIDENCE FOR THE DISKY ORIGIN OF LUMINOUS VIRGO DWARF ELLIPTICALS FROM THE KINEMATICS OF THEIR GLOBULAR CLUSTER SYSTEMS
EVIDENCE FOR THE DISKY ORIGIN OF LUMINOUS VIRGO DWARF ELLIPTICALS FROM THE KINEMATICS OF THEIR GLOBULAR CLUSTER SYSTEMS
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DOI：
10.1088/0004-6256/137/6/5146
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发表时间：
2009-03
期刊：
影响因子：
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通讯作者：
M. Beasley;A. Cenarro;J. Strader;J. Brodie
中科院分区：
文献类型：
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作者：
M. Beasley;A. Cenarro;J. Strader;J. Brodie
我们报告了两个明亮的室女座矮椭圆星系VCC1261和VCC1528的球状星团系统中动态显著旋转的证据。包括先前VCC1087的结果，迄今为止详细研究的三个室女座矮椭圆的球状星团系统都表现出vrot/σlos>1。将在球状星团中看到的旋转作为最大的圆盘旋转，并考虑任何假设的祖星系可能的衰落，我们发现所有三个矮椭圆星系（dEs）都位于r波段Tully-Fisher关系上。我们认为，这些数据支持了发光de是转化盘状星系残余物的假设。我们还获得了VCC1261和VCC1528中恒星的深缝数据。这两个星系在其内部区域显示出快速旋转，空间尺度为~ 0.5 kpc。这些旋转速度与在球状星团系统中看到的惊人相似。在更大的半径上，我们看到dEs本身很少旋转。由于我们的室女dEs的长缝数据延伸到1-2个有效半径（典型的深度观测），而球状星团延伸到4-7个有效半径，我们得出结论，在许多发光de中未检测到旋转可能仅仅是由于恒星数据中缺乏径向覆盖，球状星团代表了de动力学的异常敏感探测器。我们认为，气体盘是早期宇宙中球状星团形成的重要场所。
We report evidence for dynamically significant rotation in the globular cluster systems of two luminous Virgo dwarf ellipticals, VCC1261 and VCC1528. Including previous results for VCC1087, the globular cluster systems of all three Virgo dwarf ellipticals studied in detail to date exhibit vrot/σlos>1. Taking the rotation seen in the globular clusters as a maximal disk rotation, and accounting for the possible fading of any hypothetical progenitor galaxy, we find all three dwarf elliptical galaxies (dEs) lie on the r-band Tully–Fisher relation. We argue that these data support the hypothesis that luminous dEs are the remnants of transformed disk galaxies. We also obtained deep, longslit data for the stars in VCC1261 and VCC1528. Both these galaxies show rapid rotation in their inner regions, with spatial scales of ∼0.5 kpc. These rotation velocities are surprisingly similar to those seen in the globular cluster systems. At larger radii, we see little rotation in the dEs themselves. Since our longslit data for Virgo dEs extend out to 1–2 effective radii (typical of deep observations), whereas the globular clusters extend out to 4–7 effective radii, we conclude that nondetections of rotation in many luminous dEs may simply be due to a lack of radial coverage in the stellar data, and that globular clusters represent singularly sensitive probes of the dynamics of dEs. Based on these data, we suggest that gas disks are significant sites of globular cluster formation in the early universe.