An Expanding HI Photodissociated Region Associated with the Compact HII Region G213.880-11.837 in the GGD 14 Complex

追踪三叶星云中光解气体的层结构

Tracing the layers of Photodissociated gas in Trifid Nebula

基于[C II]和[O I]远红外谱线观测，分析了三叶星云中光解区的动力学结构，发现其壳层动量低于理论预测，揭示了电离前沿驱散气体导致的质量损失。

Ionized gas, molecules, and dust in Sh2-132

We analyze the various interstellar components of the HII region Sh2-132. The main stellar source is the double binary system that includes the Wolf-Rayet star WR153ab. We use radio continuum images at 408 and 1420 MHz, and HI 21cm line data taken from the Canadian Galactic Plane Survey, molecular observations of the 12CO(1-0) line at 115 GHz from the Five College Radio Astronomy Observatory, and available mid and far IR observations obtained with the MSX and IRAS satellites, respectively. Sh2-132 is composed of two shells showing radio continuum counterparts at both frequencies. The emission …

The nature of the interstellar medium of the starburst low-metallicity galaxy Haro11: a multi-phase model of the infrared emission

(abridged) Our goal is to describe the multi-phase ISM of the IR bright low-metallicity galaxy Haro 11, dissecting the photoionised and photodissociated gas components. We present observations of the mid- and far-IR fine-structure cooling lines obtained with the Spitzer/IRS and Herschel/PACS spectrometers. We use the spectral synthesis code Cloudy to methodically model the ionised and neutral gas from which these lines originate. We find that the mid- and far-IR lines account for ~1% of the total IR luminosity L_TIR. Haro 11 is undergoing a phase of intense star formation, as traced by the bri…

Star Formation and Molecular Gas in Extremely Metal-poor Galaxies: Insights from the Thermal Balance in the Neutral Gas

The apparent lack of cold molecular gas in blue compact dwarf (BCD) galaxies is at variance with their intense star-formation episode. The CO molecule, often used a tracer of H2 through a conversion function, is selectively photodissociated in dust-poor environments and, as a result, a potentially large fraction of H2 is expected to reside in the so-called CO-dark gas, where it could be traced instead by infrared cooling lines [CI], [CII], and [OI]. Although the fraction of CO-dark gas to total molecular gas is expected to be relatively large in metal-poor galaxies, many uncertainties remain d…