Angular momentum acquisition at high \(z\)

With Y. Dubois & C. Pichon: 2110.05384

With A. Pontzen & H. Peiris: 2012.02201

Corentin Cadiou | ANR Segal

The formation of galaxies

[L. Cortese; SDSS.]

[Dubois+16]

AGN         no AGN

How to explain morphological diversity at fixed mass?

The formation of galaxies

[L. Cortese; SDSS.]

[Dubois+16]

AGN         no AGN

How to explain morphological diversity at fixed mass?

How to explain environmental effects?

[Kraljic+ in prep]

Tillson+15

High-\(z\), most of the gas + AM flows along filamentary structures…
connected to cosmic web

Cadiou+21c

Linking cosmology to galaxy formation: the environment

The origin of angular momentum

Predicting angular momentum

\(z=0\)

\( z = 100\)

Predicting angular momentum

\(z=0\)

\( z = 100\)

\[\mathbf{L}_\mathrm{lin.} \propto \int\mathrm{d}^3q(\mathbf{q}-\bar{\mathbf{q}})\times \nabla\phi\]

Position w.r.t. center

Velocity

[White 84]

Predicting angular momentum

\(z=0\)

\( z = 100\)

[Genetic modifications: Roth+16, see also Rey&Pontzen 18, Stopyra+20]

Predicting angular momentum

“Tidal torque” prediction

\(N\)-body prediction

Time

Predicting angular momentum

Accuracy of predicted AM

  • better than linear prediction* at \(z = 0\)
  • rises much later

*Tidal torque theory, see e.g. White 84

Predicting angular momentum

  • Angular momentum of individual regions can be predicted accurately.
  • AM of halos ⇒ requires boundaries of patch

\[\mathbf{L}_\mathrm{lin.} \propto \int\mathrm{d}^3q(\mathbf{q}-\bar{\mathbf{q}})\times \nabla\phi\]

[On patch boundaries: see Lucie-Smith+18]

Can we control baryonic
angular momentum?

Can we control baryonic
angular momentum?

Wechsler & Tinker 18

\({\color{red}M_\star} / M_\mathrm{h} \ll \Omega_b / \Omega_m \)
⇒ baryons & DM
originate from different regions

Baryons more strongly bound
⇒ less prone to being ejected

Baryon angular momentum

Simulations (9Mh @ DiRAC):

  • Resolve disk height
    \(\Delta x = 35\ \mathrm{kpc}\)
  • \(z \geq 2\), \(M_\mathrm{200c} = 10^{12}\ \mathrm{M}_\odot\)
  • SF + AGN & SN feedback (à la Horizon-AGN)
  • Modify \(l(z=2)\)
  • Tracer particles
    Cadiou+19

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

PRELIMINARY

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

+

Angular momentum of the baryons / stars within \(R_\mathrm{vir}\)

PRELIMINARY

  • AM of baryons can be controlled!
  • ≠ effect on stars / baryons
  • Little AGN/SN global self-regulation
  • Observables are impacted (significantly!)

\( R_{1/2} \)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

Stay tuned:

3 more galaxies

4 more scenarios with modified \(l(z=3\))

PRELIMINARY

Temporary conclusions

  • angular momentum is predictable

     

  • boundary of halos in the ICs is a hard problem
    ⇒ limits practicality of predictions (for now)

     

  • baryons appear to be simpler!

     

  • but… how come little effect of baryonic physics on baryonic AM?

Dynamics of AM of accreted gas: torques

$$ \frac{\mathrm{d} j}{\mathrm{d} t} = \tau_\mathrm{grav} + \tau_\mathrm{pressure} $$

,          and

\( {\color{gray}\tau_\mathrm{grav} }= -r\times\nabla \phi \)

From                  gradients

\( {\color{red}\tau_\mathrm{pressure}} = -r\times\nabla P/\rho \)

DM

stars

gas

pressure

Mean of norm \(\langle |\tau|\rangle\)

Pressure torques dominate

esp. in hot phase

Dynamics of AM of accreted gas: torques

DM

stars

gas

pressure

Tillson+15

Mean of norm \(\langle |\tau|\rangle\)

Norm of mean \(|\langle\tau\rangle|\)

Pressure torques dominate

esp. in hot phase

Gravitational torques dominate!

esp. in cold phase

Tillson+15

Norm of mean \(|\langle\tau\rangle|\)

Gravitational torques dominate!

esp. in cold phase

Ratio of torques \(\dfrac{|\langle\tau_\mathrm{g}\rangle|}{|\langle\tau_\mathrm{g}\rangle|+|\langle\tau_\mathrm{p}\rangle|}\)

Conclusion & outlook

Conclusion & outlook

  • angular momentum is predictable
     

  • boundary of halos in the ICs is a hard problem
    ⇒ limits practicality of predictions (for now)
     

  • baryons can be controlled!
    ⇒ good news for weak lensing predictions
        stay tuned!
     

  • AM kinematics in accreted gas is dominated by gravitational torques, esp. in cold flows!
    ⇒ “connection” with cosmic web is retained!
    ⇒ interesting physics happen in CW \(\leftrightarrow\) disk interface (CGM!)

Conclusion & outlook

Questions?
 

More infos in Cadiou+21a,b,c (2012.02201, 2107.03407, 2110.05384)

📧 c.cadiou@ucl.ac.uk           @cphyc         🔗 cphyc.github.io

  • angular momentum is predictable
     

  • boundary of halos in the ICs is a hard problem
    ⇒ limits practicality of predictions (for now)
     

  • baryons can be controlled!
    ⇒ good news for weak lensing predictions
        stay tuned!
     

  • AM kinematics in accreted gas is dominated by gravitational torques, esp. in cold flows!
    ⇒ do not expect to “lose connection” with cosmic web

The effect of environment on halo properties

What if the galaxy had formed here instead?

What if the galaxy had formed here instead?

or here?

The “splicing” technique

  1. Generate ICs
  2. Integrate (\(N\)-nody)
  3. Select region of interest
  4. Trace back to ICs
  5. “Splice”
  6. Integrate again

\(t\)

Splicing: equivalent of constraining field at all points in spliced region

The causal origin of DM halo concentration

\(M^{(1)}_{200\mathrm{c}}, c^{(1)}_\mathrm{NFW}, \dots\)

\(M^{(2)}_{200\mathrm{c}}, c^{(2)}_\mathrm{NFW}, \dots\)

\(M^{(\dots)}_{200\mathrm{c}}, c^{(\dots)}_\mathrm{NFW}, \dots\)

\(M^{(10)}_{200\mathrm{c}}, c^{(10)}_\mathrm{NFW}, \dots\)

Same halo in 10× different environments

Repeat experiment for 7 halos (70 realisations in total)

Same halo in 10× different environments

Repeat experiment for 7 halos (70 realisations in total)

\(M^{(1)}_{200\mathrm{c}}, c^{(1)}_\mathrm{NFW}, \dots\)

\(M^{(2)}_{200\mathrm{c}}, c^{(2)}_\mathrm{NFW}, \dots\)

\(M^{(\dots)}_{200\mathrm{c}}, c^{(\dots)}_\mathrm{NFW}, \dots\)

\(M^{(10)}_{200\mathrm{c}}, c^{(10)}_\mathrm{NFW}, \dots\)

The causal origin of DM halo concentration

Same halo in 10× different environments

Repeat experiment for 7 halos (70 realisations in total)

\(M^{(1)}_{200\mathrm{c}}, c^{(1)}_\mathrm{NFW}, \dots\)

\(M^{(2)}_{200\mathrm{c}}, c^{(2)}_\mathrm{NFW}, \dots\)

\(M^{(\dots)}_{200\mathrm{c}}, c^{(\dots)}_\mathrm{NFW}, \dots\)

\(M^{(10)}_{200\mathrm{c}}, c^{(10)}_\mathrm{NFW}, \dots\)

The causal origin of DM halo concentration

50% of population

The effect of environment on halo properties

Distance to filament

Kraljic+18 [see also Laigle15, Song+21,…]

The causal origin of DM halo concentration

$$\rho_\mathrm{DM}(r) = \frac{\rho_0}{\frac{r}{R_\mathrm{vir}/c} \left(1 + \frac{r}{R_\mathrm{vir}/c}\right)^2}$$

Wechsler+02

Origin of scatter at fixed \(M_\mathrm{vir}\)?

Splicing in 1D

Splicing in 1D

Most likely* field \(f\) with

  • same value in spliced region (\(a\)),
  • as close as possible outside (\(b\))

Mathematically \(f\) is solution of:

\( f= a\) in \(\Gamma\)

minimizes \(\mathcal{Q} = (b-f)^\dagger\mathbf{C}^{-1}(b-f) \) outside \(\Gamma\)

Verify that

\[\xi_\mathrm{lin}(r) \sim \left\langle {\color{green}\underbrace{\delta(x=d)}_\mathrm{in}} {\color{purple} \underbrace{\delta(x=d+r)}_\mathrm{out}}\right\rangle \]

is the same in spliced / ref simulation.

Verify that

\[\xi_\mathrm{lin}(r) \sim \left\langle {\color{green}\underbrace{\delta(x=d)}_\mathrm{in}} {\color{purple} \underbrace{\delta(x=d+r)}_\mathrm{out}}\right\rangle \]

is the same in spliced / ref simulation.

Verify that

\[\xi_\mathrm{lin}(r) \sim \left\langle {\color{green}\underbrace{\delta(x=d)}_\mathrm{in}} {\color{purple} \underbrace{\delta(x=d+r)}_\mathrm{out}}\right\rangle \]

is the same in spliced / ref simulation.

[Danovich+15]

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

II. Transport at constant AM

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

II. Transport at constant AM

III. Torque down in inner halo

The origin of high \(z\) angular momentum

[Danovich+15]

I. Torque with cosmic web

II. Transport at constant AM

III. Torque down in inner halo

IV. Mixing in inner disk & bulge

The origin of high \(z\) angular momentum

The origin of high \(z\) angular momentum

[Danovich+15]

IV. Mixing in inner disk & bulge

Fraction that ends up in disk vs. IGM?

Influence of galactic physics?

III. Torque down in inner halo

Origin of torque down (pressure or gravity)?

Loss of link with cosmic AM?

II. Transport at constant AM

Same evolution in cold/hot accretion modes?

I. Torque with cosmic web

Predict pre-accretion AM?

Alignment with environment?

The origin of high \(z\) angular momentum

[Danovich+15]

IV. Mixing in inner disk & bulge

Fraction that ends up in disk vs. IGM?

Influence of galactic physics?

III. Torque down in inner halo

Origin of torque down (pressure or gravity)?

Loss of link with cosmic AM?

See Cadiou+21c

II. Transport at constant AM

Same evolution in cold/hot accretion modes?

I. Torque with cosmic web

Predict pre-accretion AM?

Alignment with environment?

The origin of high \(z\) angular momentum

[Danovich+15]

IV. Mixing in inner disk & bulge

Fraction that ends up in disk vs. IGM?

Influence of galactic physics?

III. Torque down in inner halo

Origin of torque down (pressure or gravity)?

Loss of link with cosmic AM?

II. Transport at constant AM

Same evolution in cold/hot accretion modes?

I. Torque with cosmic web

Predict pre-accretion AM?

Alignment with environment?

Angular momentum acquisition at high redshift

By Corentin Cadiou

Angular momentum acquisition at high redshift

“SEGAL” talk, Wed. 15th December 2021

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