On the causal origin of the angular momentum and properties of DM halos & galaxies

With A. Pontzen & H. Peiris: 2012.02201, 2107.03407

Corentin Cadiou | JC Univers

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]

Linking cosmology to galaxy formation: the environment

Tillson+15

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

Cadiou+21c

[also Dekel & Birboim 06, Danovich+15]

Linking cosmology to galaxy formation: the environment

Environmental effects:

  • source of “pollution” in weak lensing surveys
    ⇒ intrinsic alignment
     
  • extra parameters in semi-analytical models
    ⇒ galaxy-halo correlation

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

Predicting angular momentum

“Tidal torque” prediction

\(N\)-body prediction

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 stem from different regions

Baryons more strongly bound
⇒ less prone to being ejected

[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?

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
  • Modify \(l(z=2)\)
  • Tracer particles
    Cadiou+19

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

+

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

+

\( R_{1/2} \)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

  • AM of baryons can be controlled!
  • ≠ effect on stars / baryons
  • Observables are impacted (significantly!)
  • Little AGN/SN global self-regulation
     
  • formation of blue nuggets?
  • co-evolution \(l - M_\bullet \)?
  • create “spin-flips”?
  • …

\( R_{1/2} \)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 0.66\)

\( l_0 \times 0.8\)

\( l_0 \times 1.2\)

\( l_0 \times 1.5\)

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!
    ⇒ good news for weak lensing predictions
    ⇒ also good news for my DiRAC project

     

  • but why do some objects grow their AM faster/slower?

The effect of environment on halo properties

The effect of environment on halo properties

Distance to filament

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

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

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 \(\Gamma\)

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 \(M_\mathrm{vir}\)?

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

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!
     

  • environmental effects can have dramatic impact on halo formation
    ⇒ 50% of concentration scatter due to env.
    ⇒ similar impact on galaxy formation?

Conclusion & outlook

Questions?

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

  • 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!
     

  • environmental effects can have dramatic impact on halo formation
    ⇒ 50% of concentration scatter due to env.
    ⇒ similar impact on galaxy formation?

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.