LOCAL INSTABILITY SIGNATURES IN ALMA OBSERVATIONS OF DENSE GAS IN NGC 7469
LOCAL INSTABILITY SIGNATURES IN ALMA OBSERVATIONS OF DENSE GAS IN NGC 7469
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DOI：
10.1088/2041-8205/806/2/l34
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发表时间：
2015-06
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影响因子：
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通讯作者：
K. Fathi;T. Izumi;A. Romeo;Sergio Mart'in;M. Imanishi;E. Hatziminaoglou;S. Aalto;D. Espada;
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作者：
K. Fathi;T. Izumi;A. Romeo;Sergio Mart'in;M. Imanishi;E. Hatziminaoglou;S. Aalto;D. Espada;
我们基于对致密气体示踪剂的 ALMA 观测和 165 × 132 pc 的合成光束，对发光红外 Seyfert 1 主机 NGC 7469 中的盘稳定性和局部不稳定性尺度进行了前所未有的测量。虽然我们确认非圆周运动对于重新分布该星系中致密的星际气体并不重要，但我们发现了令人信服的证据，表明致密气体是研究其高质量恒星形成环形结构起源的合适示踪剂。我们导出的盘稳定性参数 ?> 解释了厚盘结构，并且其值在发现强烈恒星形成的半径处低于统一值。此外，我们推导了特征不稳定尺度 λ c ?> 并发现我们测量的~180 pc 的尺度与高分辨率图像中看到的年轻和大质量星团的单个复合体的典型尺寸之间存在惊人的一致性。
We present an unprecedented measurement of the disk stability and local instability scales in the luminous infrared Seyfert 1 host, NGC 7469, based on ALMA observations of dense gas tracers and with a synthesized beam of 165 × 132 pc. While we confirm that non-circular motions are not significant in redistributing the dense interstellar gas in this galaxy, we find compelling evidence that the dense gas is a suitable tracer for studying the origin of its intensely high-mass star-forming ringlike structure. Our derived disk stability parameter ?> accounts for a thick disk structure, and its value falls below unity at the radii in which intense star formation is found. Furthermore, we derive the characteristic instability scale λ c ?> and find a striking agreement between our measured scale of ∼180 pc and the typical sizes of individual complexes of young and massive star clusters seen in high-resolution images.