Low-z CGM Absorption in the Mufasa Simulations Kate Storey-Fisher - - PowerPoint PPT Presentation

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Dec 02, 2023 115 likes •282 views

Low-z CGM Absorption in the Mufasa Simulations Kate Storey-Fisher (UWC, NYU) Romeel Dav (UWC, Edinburgh) What are the physical processes that shape the CGM on large (kpc) scales? What is the relation between the CGM and galaxy

SLIDE 1

Low-z CGM Absorption in the Mufasa Simulations

Kate Storey-Fisher (UWC, NYU) Romeel Davé (UWC, Edinburgh)

What are the physical processes that shape the CGM on large (kpc) scales?
What is the relation between the CGM and galaxy properties?

SLIDE 2

GIZMO-MUFASA

GIZMO: Gadget gravity+“meshless” hydro (Hopkins)
Grackle cooling+heating, including metals, non-equil primordial
Star formation (H2-based), minimal ISM pressure
9-metal chemical enrichment: Type II/Ia + AGB stars & heat
Kinetic decoupled winds (+ SN heating) based on FIRE scalings
Quenching via prevention of halo gas cooling in Mhalo>1012+0.48z M

Hopkins+15 z=2

z=0 z=1

25 Mpc/h

Projected neutral hydrogen

SLIDE 3

Mufasa’s new features vs. our previous sims in Ford+13,14,16

Mufasa

Gizmo: MFM
FIRE-based wind scalings
Thermal Mhalo-based quenching
30% SN-heated outflows
50% SNII yields (better MZR)
Very good MF & red sequence

Oppenheimer+Davé

Gadget-2: Old (EC) SPH
Mom + E-driven scalings
Kinetic M*-based quenching
Cold (~104K) outflows
Full yields (too high MZR)
Good MF, no RS

Davé+16,17,17b Davé+11a,11b

SLIDE 4

~300 HST

rbits total

COS-Halos+COS-Dwarfs

Detect: HI, OVI, CII, CIII, {CIV}, SiII, SiIII, SiIV , MgII (from Keck), … Shout out to X for pyigm!

SLIDE 5

COS-Halos matched sample

5 central galaxies per COS-Halo/Dwarf galaxy, 4 orientations (+/-x,y) Red/blue selected at sSFR=0.01 Gyr-1

SLIDE 6

Spectral generation

pygad: SPH-based analysis suite (B. Roettgers, MPA);

Absorption spectra + a whole lot more!

Fast, flexible, public (bitbucket.org/broett/pygad)
Self-shielding (Rahmati+13 αJν), damping wings.
Outputs τ-weighted T, ρ, Z for each ion.
Very good match to specexbin (our previous code).
Sum to get EW

, column within +/- 600 km/s

[no Voigt profile fitting – but see our Bayesian MCMC VP

fitter VAMP: github.com/christopherlovell/VAMP (in prep)]

Bernhard Roettgers

SLIDE 7

Mass Fraction in CGM Phases

SLIDE 8

Metal fraction in CGM Phases

Cool CGM dominates for SF galaxies WHIM (not hot) dominates for quenched galaxies

SLIDE 9

EW vs. impact parameter

OVI too low!

SLIDE 10

CIV in COS-Dwarfs

Mean is about right, scatter too small

SLIDE 11

EW Distribution

SLIDE 12

Covering fractions

SLIDE 13

Integrated Column per ∆z (±600 km/s)

Ford+16 dEW/dz dEW/dz

SLIDE 14

Physical conditions vs. IEion

SLIDE 15

Summary

Mufasa matches COS-Halos about as well our previous sims.
HI matches reasonably well, even for massive red galaxies.
Low ions (SiIV

,CIII) are low by x2-3 around blue galaxies, almost nonexistent around red galaxies.

Mid ion (CIV) from COS-Dwarfs is okay, but spread is small.
OVI low by x2-3 in integrated column (dNOVI/dz) or EW

. Weaker around red galaxies, as observed.

OVI shows strong ρ,Τ dependence on mass; other ions don’t.
Some discrepancies may be helped by metal-loaded outflows.
Origin of low ions around passive galaxies remains a puzzle!