论文标题
根据PAH排放估算星系中的分子气体含量
Estimating Molecular Gas Content in Galaxies from PAH Emission
论文作者
论文摘要
多环芳烃（PAHS）的发射是星系中恒星形成活性的常用指标，也有可能充当有效的分子气体经验示踪剂。我们使用具有空间分辨的中红外Spitzer光谱，多波长光学和中红外成像的19个附近星系样品，以及毫米级干涉测量CO（1-0）地图，以研究将PAH发射作为经验代理到经验代理到估计分子气体的可行性。 PAH发射与我们的星形星系样本和低亮度活性银河系核样本探测的各种环境中的子KPC尺度上的CO发射密切相关。观察到的紧密相关可能是PAHS对弥漫性星际气体加热的结果，使我们能够从PAH发射的亮度中得出经验校准，从而估算出{\ sim} 0.2-0.25 dex的总散射。对PAH发射敏感的中红外带（例如，Spitzer/Irac4和Wise/W3过滤器）也可以用作为此目的的高效替代品。
Emission from polycyclic aromatic hydrocarbons (PAHs), a commonly used indicator of star formation activity in galaxies, also has the potential to serve as an effective empirical tracer of molecular gas. We use a sample of 19 nearby galaxies with spatially resolved mid-infrared Spitzer spectroscopy, multi-wavelength optical and mid-infrared imaging, and millimeter interferometric CO(1-0) maps to investigate the feasibility of using PAH emission as an empirical proxy to estimate molecular gas mass. PAH emission correlates strongly with CO emission on sub-kpc scales over the diverse environments probed by our sample of star-forming galaxies and low-luminosity active galactic nuclei. The tight observed correlation, likely a consequence of photoelectronic heating of the diffuse interstellar gas by the PAHs, permits us to derive an empirical calibration to estimate molecular gas mass from the luminosity of PAH emission that has a total scatter of only {\sim} 0.2 - 0.25 dex. Mid-infrared bands sensitive to PAH emission (e.g., the Spitzer/IRAC4 and WISE/W3 filters) can also be used as a highly effective substitute for this purpose.
