Author: Esan Mouli Ghosh, Kapteyn Astronomical Institute, University of Groningen (eghosh@astro.rug.nl) + GUSTO team
The 158 [C II] μm and 205 μm [N II] atomic fine-structure lines are powerful tracers of star formation activity. [C II] is the brightest FIR line and traces different phases of the ISM like H II regions, photodissociation regions (PDRs), diffuse ionised gas (DIG), warm and cold neutral media and molecular clouds. [N II] line, which traces the ionised medium from DIG and H II regions, can resolve highly and weakly ionised sources of the [C II] line emission. The Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) mission recently completed a 57-day stratospheric flight over Antarctica collecting unprecedented wide-field spectral maps of [C II] and [N II] line emissions at km/s spectral resolution.
Our study of the GUSTO data will start with analysis of [C II] line data alongside archival mid-infrared 8 μm polycyclic aromatic hydrocarbon (PAH) and far-infrared 70 μm dust emission. Comparative analysis with similar studies of star-forming regions such as Orion will lead to insights into the radiative heating and feedback processes. We expect to identify bubbles, protrusions, and expanding gas structures caused by stellar winds and radiation pressure. The high velocity resolution of the GUSTO data is crucial to reveal kinematic gas structures such as expanding shells resulting from mechanical feedback.
Further, we will compare star-forming regions in the Milky Way and the Large Magellanic Cloud like N158–N160 and N11. We will use PDR models which will enable us to create maps of parameters like gas density and radiation field. Mass estimates of ionised, atomic, and molecular gas phases will be determined by fitting CO, HI, [C II], and [N II] line intensities using RADEX models to constrain star formation rates and star formation efficiencies. In the future, we plan to use ALMA and JWST to zoom into small scale structures.