Dirk Scholte

@dirkscholte.bsky.social

290 Followers 492 Following

Postdoc at The University of Edinburgh Institute for Astronomy | Galaxy Evolution | Previously PhD at UCL and science outreach at Jodrell Bank Observatory. 🇳🇱 in 🇬🇧

Green and red aurora over Arthur’s seat in Edinburgh
In this figure we show the comparison of electron temperature measurements based on the observed line ratios of emission lines of different ions (O++ on the x-axis and S++ on the y-axis). We show that measurements of the electron temperature based on these different ions are in fairly close agreement. (This is not necessarily the case for other ions that are not plotted here.)
We show a plot with the metallicity on the x-axis and nitrogen-to-oxygen ratio on the y-axis. The data in this figure shows a large scatter with the average N/O ratio constant at low metallicity and a rising N/O ratio at higher metallicity. In the top left corner of the figure we highlight a number of galaxies with low metallicity but high N/O abundance ratios. These galaxies have similar abundance patterns to extreme nitrogen emitters observed in the early Universe with JWST.
A plot showing the electron temperature (of the high ionisation zone) on the x-axis and metallicity on the y-axis. The data shows a strongly anti-correlated relation. The lowest metallicity galaxies are highlighted. These galaxies also have some of the highest electron temperatures. An inset plot shows the comparison of our metallicity measurements to other literature works for galaxies that have been observed by other surveys. This shows that our measurements are in good agreement.
Image of the night sky taken in Teide National park on Tenerife. Near the horizon the Andromeda galaxy is visible. Some of the Milky Way visible on the right hand side of image. Contours of the Roques de Garcia in the foreground.
The sun setting over Edinburgh, Scotland.
A picture of the Mayall 4-m telescope illuminated by moonlight beneath a starry night sky. The dome of the telescope is open.