Star formation in the massive cluster merger Abell 2744
Star formation in the massive cluster merger Abell 2744
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大质量星团合并 Abell 2744 中的恒星形成
DOI：
10.1093/mnras/stu868
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发表时间：
2014
影响因子：
4.8
通讯作者：
N.
中科院分区：
文献类型：
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作者：
Rawle;T. D.; Altieri;B.; Egami;E.; Perez-Gonzalez,P. G.; Richard;J.; Santos;J. S.; Valtchanov;I.; Walth;G.; Bouy;H.; Haines;C. P.; Okabe;N.
利用哈勃空间望远镜（HST）前沿场对最近星系团合并A2744（z= 0.308）中的恒星形成（SF）星系进行了全面研究。宽视场紫外-红外（UV-IR）成像能够直接限制53个星系团的总星星形成率（SFR），SFRUV+IR= 343 ± 10 M yr−1。在中心4弧分（1.1 Mpc）半径内，积分的SFR是完整的，得到总的SFRUV+IR= 201 ± 9 M yr−1。聚焦于被遮蔽的星星形成，这个核心区域的总SFRIR= 138 ± 8 M <$yr−1，质量标准化SFRIR = 11.2 ± 0.7 M <$yr− 1/1014 M <$yr，以及一小部分红外探测到的SF星系。总的来说，原子团在0.3处的原子团在红外特性（总SFRIR，TDustdistribution）上表现出明显的内在分散性，这显然与动力学状态无关：A2744与合并的子弹团有明显的不同，但与几个松弛的原子团相似。然而，在A2744中，我们确定了一条SF源的踪迹，包括水母星系，由于极端剥离（SFRUV/SFRIRup至3.3）而具有大量未被遮蔽的SF。尾迹的方向，以及从组成星系剥离的物质，表明星系团合并时经过的激波前沿是触发器。红外线和紫外线对星星形成的限制对于理解致密环境中的星系演化是至关重要的。
We present a comprehensive study of star-forming (SF) galaxies in theHubble Space Telescope(HST) Frontier Fieldrecent cluster merger A2744 (z= 0.308). Wide-field, ultraviolet–infrared (UV–IR) imaging enables a direct constraint of the total star formation rate (SFR) for 53 cluster galaxies, with SFRUV+IR= 343 ± 10 M⊙yr−1. Within the central 4 arcmin (1.1 Mpc) radius, the integrated SFR is complete, yielding a total SFRUV+IR= 201 ± 9 M⊙yr−1. Focusing on obscured star formation, this core region exhibits a total SFRIR= 138 ± 8 M⊙yr−1, a mass-normalized SFRIRof ΣSFR= 11.2 ± 0.7 M⊙yr−1per 1014M⊙and a fraction of IR-detected SF galaxies. Overall, the cluster population atz∼ 0.3 exhibits significant intrinsic scatter in IR properties (total SFRIR,Tdustdistribution) apparently unrelated to the dynamical state: A2744 is noticeably different to the merging Bullet cluster, but similar to several relaxed clusters. However, in A2744 we identify a trail of SF sources including jellyfish galaxies with substantial unobscured SF due to extreme stripping (SFRUV/SFRIRup to 3.3). The orientation of the trail, and of material stripped from constituent galaxies, indicates that the passing shock front of the cluster merger was the trigger. Constraints on star formation from both IRandUV are crucial for understanding galaxy evolution within the densest environments.