PHANGS-JWST First Results: Destruction of the PAH Molecules in H II Regions Probed by JWST and MUSE
學年 111
學期 2
出版(發表)日期 2023-02-16
作品名稱 PHANGS-JWST First Results: Destruction of the PAH Molecules in H II Regions Probed by JWST and MUSE
著者 Oleg V. Egorov; Kathryn Kreckel; Karin M. Sandstrom; Adam K. Leroy; Simon C. O. Glover; Brent Groves; J. M. Diederik Kruijssen; Ashley. T. Barnes; Francesco Belfiore; F. Bigiel; Guillermo A. Blanc; Médéric Boquien; Yixian Cao; Jérémy Chastenet; Mélanie Chevance; Enrico Congiu; Daniel A. Dale; Eric Emsellem; Kathryn Grasha; Ralf S. Klessen; Kirsten L. Larson; Daizhong Liu; Eric J. Murphy; Hsi-An Pan; Ismael Pessa; Jérôme Pety; Erik Rosolowsky; Fabian Scheuermann; Eva Schinnerer; Jessica Sutter; David A. Thilker; Elizabeth J. Watkins; Thomas G. Williams
著錄名稱、卷期、頁數 The Astrophysical Journal Letters 944(2)
摘要 Polycyclic aromatic hydrocarbons (PAHs) play a critical role in the reprocessing of stellar radiation and balancing the heating and cooling processes in the interstellar medium but appear to be destroyed in H ii regions. However, the mechanisms driving their destruction are still not completely understood. Using PHANGS–JWST and PHANGS–MUSE observations, we investigate how the PAH fraction changes in about 1500 H ii regions across four nearby star-forming galaxies (NGC 628, NGC 1365, NGC 7496, and IC 5332). We find a strong anticorrelation between the PAH fraction and the ionization parameter (the ratio between the ionizing photon flux and the hydrogen density) of H ii regions. This relation becomes steeper for more luminous H ii regions. The metallicity of H ii regions has only a minor impact on these results in our galaxy sample. We find that the PAH fraction decreases with the Hα equivalent width—a proxy for the age of the H ii regions—although this trend is much weaker than the one identified using the ionization parameter. Our results are consistent with a scenario where hydrogen-ionizing UV radiation is the dominant source of PAH destruction in star-forming regions.
關鍵字 Polycyclic aromatic hydrocarbons;H II regions;Interstellar dust;Astrophysics - Astrophysics of Galaxies
語言 en_US
ISSN 2041-8213
期刊性質 國外
收錄於 SCI
國別 USA
出版型式 ,電子版

機構典藏連結 ( )