Robust measurement of spatially resolved gas phase metallicity using FOGGIE simulations

by Ayan Acharyya (The John Hopkins University)

Wednesday 24 Apr 2024, 11:30 → 12:30 Europe/Rome

Sala Jappelli (Osservatorio Astronomico di Padova)

Regulating star-formation necessarily depends on regulating the flow of gas from which the stars would eventually form. The mechanisms that govern the complex gas flows within the galactic disk and across the disk-halo interface is therefore crucial ingredients for understanding the evolution of galaxies and their star-formation histories. An important diagnostic for such flows is the spatially resolved gas-phase metallicity distribution, including the metallicity gradient. Observations only ever capture a single snapshot of a galaxy's evolution, necessitating the need for time-domain simulations to interpret the evolution of those gradients.

Using the FOGGIE simulations we demonstrate that a high cadence (~few Myr) is indispensable for accurately tracking the metallicity gradient evolution, particularly at high-redshift (z). FOGGIE galaxies spend ~50% (~20%) of their time up to z=1 (z=0) outside the typical observational uncertainty away from the temporally smooth (~50 Myr) evolution -- which would be difficult to capture with lower cadence.

Additionally, we present a novel, non-parametric method of quantifying the metallicity distribution which is free from geometric assumptions. Therefore, our method is less susceptible to systematic uncertainties from the lens-model reconstruction employed in several high-z observations. We investigate how efficiently the our new method responds to metal-mixing stimuli, such as star-formation, mergers and outflows. Our models pave the way for interpreting upcoming JWST observations of high-z metallicity gradients.

 

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https://unipd.zoom.us/j/85273198731?pwd=V1ZiNE9ZWUN4ZTdIUzJsTFo0Z3U2Zz09
Meeting ID: 852 7319 8731
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