标题： 银河合并序列的HI、HII和R波段观测 显示英文标题

标题： H I, H II, and R-Band Observations of a Galactic Merger Sequence

摘要： 我们展示了对五个被认为处于合并渐进阶段的星系系统的中性氢分布的高质量孔径合成观测：Arp295、NGC4676、NGC520、NGC3921和NGC7252。 这些数据通过窄带H$\alpha$滤镜拍摄的宽视场图像以及深R波段表面照相术得到补充。 在早期阶段，大量的HI存在于星系盘内，恒星形成广泛存在。 电离气体发射通常呈现出从核区发出的羽毛状和弧状结构，这些区域可能是由相互作用引起的恒星爆发地点。 在最后阶段，残余体内部几乎没有或完全没有HI，可以看到潮汐物质向内移动。 这表明这些残余物在原子气体含量及其光度性质方面将演化为椭圆星系。 然而，NGC520的观测揭示了一个广泛的旋转气体盘，这表明也许一些合并不会摧毁前身星系的原子气体盘。 总体而言，在大半径处可以看到大量气体和星光。 由于这些物质在非常长的时间尺度上进化，它们可能会在数十亿年内留下可观察到的特征。 显示英文摘要

摘要： We present high-quality aperture synthesis observations of the neutral hydrogen distribution in a sample of five galactic systems believed to be involved in progressive stages of merging: Arp295, NGC4676, NGC520, NGC3921, and NGC7252. These data are supplemented by wide-field images taken through a narrow band Halpha filter, and by deep R-band surface photometry. In the early stages, large amounts of HI exist within the galactic disks and star formation is widespread. The ionized gas emission often takes on the appearance of plumes and arcs emanating from the nuclear regions, which are presumably the sites of interaction induced starbursts. In the final stages there is little if any HI within the remnant bodies, and tidal material is seen moving inward. This suggests that these remnants will evolve into elliptical galaxies in their atomic gas contents as well as their photometric properties. However the observations of NGC520 reveal an extensive rotating gaseous disk, suggesting that perhaps some mergers will not destroy the atomic gas disks of the progenitors. Overall, large quantities of both gas and starlight are seen at large radii. Since this material evolves on very long time scales, it may leave observable signatures for many Gyr.