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
- Generate ICs
- Integrate (\(N\)-nody)
- Select region of interest
- Trace back to ICs
- “Splice”
- 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
