The electron density stratification in IC10: a low-metallicity galaxy
Abstract
Connecting the properties and the structure of the interstellar medium (ISM) with the properties of the ionizing sources is of fundamental importance to make a step forward in understanding galaxy evolution, driven by the interplay between the ISM and the stars. The study of the electron density distribution helps to infer the ISM structure and quantify the ionizing radiation escaping the ISM.
The electron density can be estimated using the line ratios of the same ion but different transitions. In this study, we used several infrared diagnostics, which are less affected by temperature fluctuations than other electron density tracers. Combining data from SOFIA/FIFI-LS, Herschel/PACS, and Spitzer/IRS, we estimated the electron density stratification for various star-forming regions of the low-metallicity irregular dwarf galaxy IC10. The low-metallicity environment of this nearby galaxy allows us to study in the detail the electron density structure in the 'chemically-young' environment that characterizes the high-z galaxies, the ionizing sources of the early universe. Our study shows that each line ratio traces a different gas component of the ionized gas. Moreover, the density values of the gas in closer proximity to the star cluster cover a wide range of values, while the density values of the second layer are almost constant for all of the regions investigated. This result suggests a correlation between the ionizing source and the density of the gas in closer proximity to it and that this correlation disappears moving farther from the ionizing source.- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- January 2023
- Bibcode:
- 2023AAS...24123504P