期刊論文
| 學年 | 114 |
|---|---|
| 學期 | 2 |
| 出版（發表）日期 | 2026-04-08 |
| 作品名稱 | Localized Deviations from the CO─Polycyclic Aromatic Hydrocarbon Relation in PHANGS-JWST Galaxies: Faint Polycyclic Aromatic Hydrocarbon Emission or Elevated CO Emissivity? |
| 作品名稱（其他語言） | |
| 著者 | Jaeyeon Kim; Adam K. Leroy; Karin Sandstrom; Sharon E. Meidt; Yu-Hsuan Teng; Miguel Querejeta; Eva Schinnerer; Susan E. Clark; Ryan Chown; Simon C. O. Glover; Daniel A. Dale; Dalya Baron; Jessica Sutter; Ashley T. Barnes; Jakob den Brok; Rupali Chandar; I-Da Chiang; Oleg V. Egorov; Kathryn Grasha; Ralf S. Klessen; Kathryn Kreckel; Eric W. Koch; Hannah Koziol; Lukas Neumann; Hsi-An Pan; Sophia K. Stuber; Tony D. Weinbeck; Thomas G. Williams |
| 單位 | |
| 出版者 | |
| 著錄名稱、卷期、頁數 | The Astrophysical Journal 1001(1) , p. 67 |
| 摘要 | Polycyclic aromatic hydrocarbon (PAH) emission is widely used to trace the distribution of molecular gas in the interstellar medium, exhibiting a tight correlation with CO(2–1) emission across nearby galaxies. Using PHANGS-JWST and PHANGS-Atacama Large Millimeter/submillimeter Array (ALMA) data, we identify localized regions where this correlation fails, with CO flux exceeding that predicted from 7.7 μm PAH emission by more than an order of magnitude. These outlier regions are found in 20 out of 70 galaxies and are located in galaxy centers and bars, without signs of massive star formation. We explore two scenarios to explain the elevated CO-to-PAH ratios, which can either be due to suppressed PAH emission or enhanced CO emissivity. We examine PAH emission in other bands (3.3 and 11.3 μm) and the dust-continuum-dominated bands (10 and 21 μm), finding consistently high CO-to-PAH (or CO-to-dust continuum) emission ratios, suggesting that 7.7 μm PAH emission is not particularly suppressed. In some outlier regions, PAH sizes and spectral energy distribution of the radiation differ slightly from nearby control regions with normal CO-to-PAH ratios, though without a consistent trend. We find that the outlier regions show higher CO velocity dispersions (ΔvCO). This increase in ΔvCO lowers CO optical depth and raises its emissivity for a given gas mass. Our results favor a scenario where shear along the bar lanes and shocks at the bar ends elevate CO emissivity, leading to the breakdown of the CO–PAH correlation. Future JWST spectroscopy and deep ALMA observations of CO isotopologues will provide critical tests of this scenario. |
| 關鍵字 | |
| 語言 | en |
| ISSN | |
| 期刊性質 | 國外 |
| 收錄於 | SCI |
| 產學合作 | |
| 通訊作者 | |
| 審稿制度 | 是 |
| 國別 | USA |
| 公開徵稿 | |
| 出版型式 | ,電子版 |
| 相關連結 |
機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/129237 ) |