We present a case study of the tidal interaction between low-mass star-forming galaxies initially found in the Sloan Digital Sky Survey (SDSS) images and further analyzed with SDSS spectroscopy and UV GALEX photometry. With a luminosity of Mr = ?17.7 mag and exhibiting a prominent tidal filament, UGC 6741 appears as a scaled down version of massive gas-rich interacting systems and mergers. The stellar disk of the smaller companion, UGC 6741_B, which is three times less massive, has likely already been destroyed. Both galaxies, which are connected by a 15 kpc long stellar bridge, have similar oxygen abundances of 12 +log(O/H)~8.3. Several knots of star-forming regions are identified along the bridge, some with masses exceeding ~107 M . The most compact of them, which are unresolved, may evolve into globular clusters or ultra compact dwarf galaxies. This would be the first time progenitors of such objects are detected in mergers involving dwarf galaxies. UGC 6741 currently has the color and star formation properties of blue compact dwarf galaxies (BCDs). However, analysis of its surface photometry suggests that the galaxy lies within the scaling relations defined by early-type dwarf galaxies (dEs). Thus, UGC 6741 appears as a promising system for studying the possible transformation of BCDs into dEs, possibly through a merger episode. The frequency of such dwarf–dwarf mergers should now be explored.
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机译：我们介绍了一个案例研究，该案例最初是在斯隆数字天空测量（SDSS）图像中发现的低质量恒星形成星系之间的潮汐相互作用，并进一步通过SDSS光谱学和UV GALEX光度法进行了分析。 UGC 6741的发光度为Mr =？17.7 mag，并显示出显着的潮汐细丝，是大规模富气相互作用系统和合并的按比例缩小版本。较小伴侣的星盘UGC 6741_B的质量要小三倍，可能已经被破坏了。这两个由15 kpc长的恒星桥连接的星系具有相似的氧丰度12 + log（O / H）〜8.3。沿桥梁识别出数个恒星形成区域，其中一些质量超过〜107 M。其中最紧密的，尚未解决的可能演化为球状星团或超紧凑的矮星系。这将是在涉及矮星系的合并中首次检测到此类物体的祖先。 UGC 6741当前具有蓝色紧凑矮星系（BCD）的颜色和恒星形成特性。但是，对其表面光度法的分析表明，该星系位于早期类型的矮星系（dEs）定义的缩放关系之内。因此，UGC 6741似乎是一个有前途的系统，用于研究可能通过合并事件将BCD转换为dE的可能性。现在应该探讨这种矮人兼并的频率。
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