Speaker
Description
The ultra-diffuse nature of the Intergalactic Medium (IGM) makes it inherently difficult to resolve at high spatial resolution in simulations. Typical cosmological simulations are resolution limited by large box sizes (L > 50 Mpc) used to capture accurate statistical properties of large-scale structure, while higher-resolution zoom-in simulations rarely focus on the IGM. Thus, few simulations to date resolve IGM gas at sub-kpc scales, leaving potentially important scales for gas physics unresolved. We present semi-idealized simulations of cosmic sheet collapse at higher resolutions than previously explored to study the substructure and characteristics of IGM gas. We introduce a small 1D density perturbation to the initial conditions, allowing us to use small box volumes (L = 4-8 cMpc) to resolve IGM gas at kpc scales. We confirm previous work suggesting the IGM is inherently multiphase due to cooling-based instabilities causing fragmentation. We explore how IGM multiphase fragmentation manifests with both changing resolution and sheet-virial mass/temperature. With increasing resolution, we observe enhanced neutral hydrogen column densities through the cosmic sheet. Similar to subgrid-feedback physics, the unknown effects of resolution-limited cooling instabilities represent a fundamental limitation in our understanding of diffuse baryons in the universe. We aim to quantify this phenomenon and its broader implications for Lyman limit system statistics and the Lyman-alpha forest.
| Primary Theme | Hot gas to cold gas |
|---|---|
| Secondary Theme | Diffuse to dense structures |
| Presenter's Name | Charles Willard |
| Presenter's Email Address | [email protected] |
| Keywords | Intergalactic Medium, Multiphase Gas, Cooling Instabilities, Neutral Hydrogen, High-Resolution Simulations |
| Recording Permission | YES |
| Virtual Audience Permission | YES |
| Photography Permission | YES |
| If your talk is not accepted for a contributed talk, would you be interested in presenting a fireslide/lightning talk? | Yes |
| If your fireslide/lighting talk is not accepted, would you be interested in presenting a poster? | Yes |
Authors
External references
- 25070027
- 201106ca-72fe-466c-b8fc-7da52f7ba760
