English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Aims: Temperature uncertainties plague our understanding of abundancevariations within the ISM. Using the PHANGS-MUSE large program, we develop andapply a new technique to model the strong emission lines arising from HIIregions in 19 nearby spiral galaxies at ~50 pc resolution and infer electrontemperatures for the nebulae. Methods: Due to the charge-exchange coupling ofthe ionization fraction of the atomic oxygen to that of hydrogen, theemissivity of the observed [OI]6300/Ha line ratio can be modeled as a functionof gas phase oxygen abundance (O/H), ionization fraction (f_ion) and electrontemperature (T_e). We measure (O/H) using a strong line metallicitycalibration, and identify a correlation between f_ion and[SIII]9069/[SII]6716,6730, tracing ionization parameter variations. Results: Wesolve for T_e, and test the method by reproducing direct measurements ofT_e([NII]5755) based on auroral line detections to within ~600 K. We apply thischarge-exchange method of calculating T_e to 4,129 HII regions across 19PHANGS-MUSE galaxies. We uncover radial temperature gradients, increasedhomogeneity on small scales, and azimuthal temperature variations in the disksthat correspond to established abundance patterns. This new technique formeasuring electron temperatures leverages the growing availability of opticalintegral field unit spectroscopic maps across galaxy samples, increasing thestatistics available compared to direct auroral line detections.

A physically motivated `charge-exchange method' for measuring electron temperatures within HII regions