arXiv 1111.27532011-11-11astro-ph.CO

合并系统NGC 1614的核PAH发射：环中环

The nuclear PAH emission of merger system NGC 1614: rings within rings

Petri Vaisanen, Vinesh Rajpaul, Albert A. Zijlstra, Juha Reunanen, Jari Kotilainen

备注：: 12 pages, 9 figures, accepted to MNRAS

摘要：

在研究富气体星系合并演化过程中，了解核恒星形成与核活动之间的相互作用是非常重要的。我们在这里提出了新的空间分辨L-波段积分场单位观测的内部kpc的明亮的红外星系NGC 1614。一个宽环的3.3 μ m的PAH发射被发现在一个距离约200 pc的核心。这个环与先前建立的一个由Pa_alpha和射电连续谱观测发现的恒星形成环重叠，但峰值在它之外，特别是如果使用PAH等效宽度确定的话。使用PAH发射和电离气体发射的特性，我们认为NGC 1614具有向外传播的恒星形成环，其中PAH发射的等效宽度定位于当前恒星形成的区域，该区域只是扩展到核外的分子气体中。核心本身显示了一个高度发光的，稍微分辨（在~80 pc）的L波段连续光源。我们没有发现活动星系核活动的证据，并排除了一个模糊的活动星系核使用L-波段诊断的存在。此外，我们发现可能的同伴星系档案HST/ACS成像。该系统的恒星形成和动力学特征与其第二次通过后的一次相对较大的合并一致。一个突出的问题是，像这样一个富含气体的高级合并，具有强烈的LIRG水平的核恒星爆发和主要合并的潮汐特征，还没有发展出一个活跃的核。

英文摘要：

It is important to understand the interplay between nuclear star-formation and nuclear activity when studying the evolution of gas rich galaxy mergers. We present here new spatially resolved L-band integral field unit observations of the inner kpc of the luminous IR galaxy NGC 1614. A broad ring of 3.3 um PAH emission is found at a distance of approximately 200 pc from the core. This ring overlaps with a previously established star-forming ring detected with Pa_alpha and radio continuum observations, but peaks outside it, especially if determined using the PAH equivalent width. Using the characteristics of the PAH emission and the ionised gas emission we argue that NGC 1614 features an outward propagating ring of star formation, where the equivalent width of the PAH emission localises the regions where the current star formation is just expanding into the molecular gas outward of the nucleus. The core itself shows a highly luminous, slightly resolved (at ~80 pc) L-band continuum source. We find no evidence of AGN activity and rule out the presence of an obscured AGN using L-band diagnostics. Furthermore, we detect the likely companion galaxy from archival HST/ACS imaging. The star formation and dynamical characteristics of the system are consistent with a relatively major merger just after its second passage. An outstanding question is how a gas-rich advanced merger such as this one, with strong LIRG level nuclear starburst and major merger-like tidal features, has not yet developed an active nucleus.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文