Seite 1 von 31

Resolving (or Not) Multiphase Gas in Galaxy Outskirts and

the Cosmic Web in Cosmological Simulations

Nir Mandelker, Hebrew University of Jerusalem

Advances in Cosmology Through Numerical Simulations, MIAPP, May18 2022

With: Frank van den Bosch, Volker Springel, Freeke van de Voort, Joe Burchett, Iryna Butsky,

Daisuke Nagai, Peng Oh

Seite 2 von 31

The CGM/IGM – The Baryon Cycle

CGM: !"#$ < & < 1 − 2 !*+,

Circumgalactic medium

IGM: 1 − 2 !*+, < &

Intergalactic medium

Tumlinson, Peeples and Werk 2017

ISM: & < !"#$

Interstellar medium

Seite 3 von 31

The CGM/IGM – Reservoir for Baryons

and Metals

Most of baryons

and metals are

not in galaxies

Must be in

CGM/IGM

Cosmological

simulations must

resolve CGM/IGM

in addition to ISM

stars

Interstellar gas

Interstellar dust

Universal baryon fraction

Metal content inferred from SFH

Peeples et al. 2014

Tumlinson, Peeples & Werk 2017

Seite 4 von 31

Difficulty Resolving C/IGM Gas

!"#$

= 1.0×10*+⊙ !"#$ = 1.3×10.+⊙ !"#$ = 1.6×100+⊙

12344,678 = 31 pc 12344,678 = 11 pc 12344,678 = 3.3 pc

< 12344,<#4= >= 2.7 kpc < 12344,<#4= >= 1.6 kpc < 12344,<#4= >= 0.8 kpc

Nelson+16

AREPO Zoom-in simulations of ∼ 10DE+⊙ halos at z ∼ 2

Refinement typically quasi-Lagrangian (fixed mass)

à Cells get large in low density regions

Seite 5 von 31

Characteristic Scale for Cold Gas

McCourt et al 2018

See also:

Waters & Proga 2019a,b

Das et al 2021

Cooling length

!"##$ = &'("##$ ∼ 10pc×

/

0.02 3456

72

at 8 ∼ 109K

Wish to resolve ;<==; in CGM/IGM

!"##$ [cm]

e.g. Field 1965

Burkert & Lin 2000