论文标题
三个水母星系的紫外成像观测：中心的恒星形成抑制作用和脱落的尾巴中的恒星形成
Ultraviolet imaging observations of three jellyfish galaxies: Star formation suppression in the centre and ongoing star formation in stripped tails
论文作者
论文摘要
螺旋星系落入星系簇电位时会产生强大的RAM压力效应。结果，他们的气体被剥去形成延伸的尾巴，可以在其中发生恒星形成，从而使它们具有典型的水母外观。水母星系的紫外成像观测为了解剥落的尾巴中正在进行的恒星形成提供了机会。我们报告了水母星系JW39，JO60，JO194的紫外线观察结果，并与光学连续体和$ \ mathrm {h}α$的观测值进行了比较。我们检测到星系的磁盘和尾部的恒星形成结，发现它们的UV和H $α$通量良好相关。这些星系的光发射线比率图用于为每个区域识别由于恒星形成，衬里或两个现象的混合而导致的发射机制。发射线图中的星形区域与具有明显的紫外线通量的区域非常匹配。两个星系的中央区域（JW39，JO194）显示出紫外线的减少，这与发射线图中的复合材料或衬里区域一致。这里研究的星系表明在剥离的尾部中表现出明显的恒星形成，在中央区域被抑制的恒星形成，并提出了在水母星系中发生加速淬火的情况。
Spiral galaxies undergo strong ram-pressure effects when they fall into the galaxy cluster potential. As a consequence, their gas is stripped to form extended tails within which star formation can happen, giving them the typical jellyfish appearance. The ultraviolet imaging observations of jellyfish galaxies provide an opportunity to understand ongoing star formation in the stripped tails. We report the ultraviolet observations of the jellyfish galaxies JW39, JO60, JO194 and compare with observations in optical continuum and $\mathrm{H}α$. We detect knots of star formation in the disk and tails of the galaxies and find that their UV and H$α$ flux are well correlated. The optical emission line ratio maps of these galaxies are used to identify for every region the emission mechanism, due to either star formation, LINER or a mix of the two phenomena. The star-forming regions in the emission line maps match very well with the regions having significant UV flux. The central regions of two galaxies (JW39, JO194) show a reduction in UV flux which coincides with composite or LINER regions in the emission line maps. The galaxies studied here demonstrate significant star formation in the stripped tails, suppressed star formation in the central regions and present a possible case of accelerated quenching happening in jellyfish galaxies.
