Corentin Cadiou

Online @ Hyderabad 10/07/24

How chaotic is galaxy formation?

Based on work by A. Storck, Z. Kocjan, E. Pichon-Pharabod

Cadiou, Pontzen & Peiris 21 · Cadiou, Pontzen +21 · Kocjan, Cadiou, Agertz, Pontzen 24 · Cadiou, Pichon-Pharabod+24

My interests:

Cosmic web
DM halo formation
Halo-galaxy connection
Cosmological accretion
Galaxy kinematics

and high-performance computing & visualisation

Intrinsic alignment measurement: Ganeshaiah Veena+ 19 · Alignment: M. Sachs

Neighbouring galaxies' shapes are aligned
(on the plane of the sky)

Intrinsic alignment

Baryon dominated?
No cosmo information?

Weak lensing

L.o.s. measurement of
dark matter density

⇒

Galaxy formation: the biased point of view of the spin

Stochastic spin: Vitviska+ 02, Beson+ 20
Spin prediction, Porciani+ 02

Spin: \[\lambda = \dfrac{j}{\sqrt{2}R_\mathrm{vir}V_{vir}}\]

Spin jumps at mergers
Distribution well reproduced by drawing mergers' parameters randomly
Theoretical predictions are, at best, inaccurate

First complication

$1\,\mathrm{dex}$!

“Mergers bring chaos”

Second complication

Let's be optimistic and assume we can predict DM spin

DM spin is not even a good predictor for the galaxy's!

TR: Jiang+ 19, BL: Rodriguez-Gomez+ 22

$\lambda_\mathrm{DM}$

Butterfly effect: Genel+ 19, see also Thiébaut+ 08

Third complication

Resimulating the same galaxy twice yields different results ⇒ galaxies are chaotic

But are galaxies truly chaotic?

How complex are galaxies?

Results from Cadiou+ 24a

1 How complex are galaxies?

Results from Cadiou+ 24a

1

Example of the S-curve:

2D manifold embedded in 3D

Compute $k$-nearest neighbors
→ edges of a graph

Draw a point
→ find shortest path to all others

Take a radius
count number of points, $p$ within $[r, r+\mathrm{d} r]$

$\Rightarrow p(r) \propto r^{D-1}$

$r$

$\#(<r)$

Actually $p(r)\propto \sin^{D-1}(r)$, Granata & Carnevalle 16

$\#(<r)$

COSMOS dataset

300,000 observed galaxies

Horizon-AGN

700,000 simulated galaxies

We have a method to measure
the intrinsic dimensionality of any dataset.

Magnitude measurements (not images!)
14 photometric wide-bands (u*, g, r, i, z, y, Y, J, H, Ks, B, V, IRAC CH1 & CH2)
+ 14 narrow-bands
SNR > 2
passive/active selection

Note: we are not working with images, but integrated magnitudes

COSMOS dataset

300,000 observed galaxies

Horizon-AGN

700,000 simulated galaxies

No more than $\sim 4$ independent parameters? (with comparable magnitudes)

See Disney 08 for even more controversial results, although with smaller statistics

Horizon-AGN

700,000 simulated galaxies

No more than $\sim 3$ independent parameters!

Galaxy formation is tightly constrained

Galaxies populate a 3D attractor?

$M$

$z$

$j$

With simulated noise

Without simulated noise

Is DM angular momentum chaotic?

Results from Cadiou+21, 22

2 Is DM angular momentum chaotic?

Results from Cadiou+21, 22

2

DM angular momentum

$z=0$

$ z = 100$

$z=0$

$ z = 100$

[White 84]

DM angular momentum

$z=0$

$ z = 100$

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

DM angular momentum

Time

Angular
momentum

DM angular momentum

✅ AM of fixed DM regions responds ~linearly (so is not chaotic!)

However, particle membership hence DM halo does not

Angular
momentum

Time

DM angular momentum

Halo AM is hard to predict

the usual culprit are mergers

Are mergers really
stochastic?

Results from Cadiou +24b

3

Based on the critical event theory (Cadiou +20)

We can make some reasonable predictions
of orbital spin of mergers

Given: tides + density peaks

Changes to tides at $z=100$, effect at $z<1$

tides ×0.5 ⇒ merger @ $z=0.7$

tides ×1.1 ⇒ merger @ $z=0.55$

tides ×1.2 ⇒ merger @ $z=0.5$

tides ×2 ⇒ merger @ $z=0.2$

How chaotic is baryonic
angular momentum?

Results from Cadiou +21a

4 How chaotic is baryonic
angular momentum?

Results from Cadiou +21a

4

Full hydro simulations
(RAMSES, New-Horizon model):

Resolved disk height
$\Delta x_\mathrm{min} = 35\ \mathrm{pc}$
$M_\mathrm{200c} = 10^{12}\ \mathrm{M}_\odot$
at $z=2$
SF, AGN, SN feedback
3 galaxies, 5× scenario each

$ j_0 \times 0.66$

$ j_0 \times 0.8$

$ j_0 \times 1.2$

$ j_0 \times 1.5$

$ j_0 \times 0.66$

$ j_0 \times 0.8$

$ j_0 \times 1.2$

$ j_0 \times 1.5$

$ j_0 \times 0.66$

$ j_0 \times 0.8$

See Cadiou+21a

INPUT: Changes to tides $z=\infty$

OUTPUT: Ang. mom
$z=2$

$ j_0 \times 0.66$

$ j_0 \times 0.8$

$ j_0 \times 1.2$

$ j_0 \times 1.5$

$ j_0 \times 0.8$

See Cadiou+21a

INPUT: Changes to tides $z=\infty$

OUTPUT: Ang. mom
$z=2$

Stellar angular momentum responds ~linearly
to large-scale tides

Gas + stars spAM

Stars spAM

Halo spAM

See Cadiou+21a

Halo and disk evolve separately,

this allows stellar AM to be ~linear despite halo AM not being

Gas + stars spAM

Stars spAM

Halo spAM

See Cadiou+21a

Special case: no massive satellite

Low tides

High tides

$\mathcal{B}\searrow$

$R_\mathrm{eff} \nearrow $

$v/\sigma\nearrow$

See Cadiou+21a

Impact of the cosmological-scale density on halo properties

Results from Cadiou +21b

5

What if the galaxy had formed here instead?

or here?

The “splicing” technique

Generate ICs
Integrate ($N$-body)
Select region of interest
Trace back to ICs
“Splice” the density
Integrate again

$t$

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

$\longleftarrow 50\,\mathrm{Mpc} \longrightarrow$

Splicing in 1D

Most likely field $f$ with

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

Mathematically, ${\color{green}f}$ is the unique solution that satisfies:

$ {\color{green}f(x)}= {\color{blue}a(x)},\qquad\qquad\qquad\forall x \in\Gamma$
minimizes \[\mathcal{Q} = ({\color{red}b}-{\color{green}f})^\dagger\mathbf{C}^{-1}({\color{red}b}-{\color{green}f}),\quad \forall x \not\in \Gamma \]

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

Impact of the cosmological-scale tides on halo properties

Results from Storck, Cadiou in prep.

6

Impact of the cosmological-scale tides on halo properties

Results from Storck, Cadiou in prep.

6

$\rho_\mathrm{i}, v_\mathrm{i}$

$\Lambda$CDM+baryon non-linear evolution

halo & galaxy properties

$\log\left|\dfrac{{\color{blue}\rho_\mathrm{i}} - \color{red}\rho_\mathrm{i}}{\sigma_\rho}\right|$

$\log\left|\dfrac{{\color{blue}v_\mathrm{i}} - \color{red}v_\mathrm{i}}{\sigma_v}\right|$

Issue : splicing the density does not fix the velocity & tides

Issue : splicing the density does not fix the velocity & tides

Solution: splice the potential

$\log\left|\dfrac{{\color{blue}\rho_\mathrm{i}} - \color{red}\rho_\mathrm{i}}{\sigma_\rho}\right|$

$\log\left|\dfrac{{\color{blue}v_\mathrm{i}} - \color{red}v_\mathrm{i}}{\sigma_v}\right|$

Remember $\nabla^2\phi = 4\pi G\rho$ so

\[\rho_n\propto\frac{\phi_{n+1}-2\phi_n+\phi_{n-1}}{\Delta x^2}\]

\[v_n\propto\frac{\phi_{n+1}-\phi_{n-1}}{2\Delta x}\]

Same halo (same initial tides + density)

forming closer and closer to filament

Repeat for 5 halos, 9 positions

Variation compared to mean value

For different quantities

spin alignment

shape alignment

Conclusions

The title might have been clickbait… but

On global scales galaxies aren't that complex: success of simulations
Actual complexity is on the order of 3 (mass, redshift, SFR?)
Tides determine merger orbital parameters & angular momentum accretion
Mergers are not stochastic/not rerolling the dice
Trickling down to galactic scale, which drives scaling relations
Galaxies are less stochastic than expected
Galaxy & DM spin sins are partially independent at the level of individual galaxies
Non-linear effects on halo shape and alignment are comparable to population-level
Crucial to investigate further the success of Euclid or LSST

Are galaxies chaotic?

Angular momentum:

Qualitatively understood
Abrupt changes with mergers
Crucial for galaxy formation + weak lensing

Corentin Cadiou

Porciani+02

Vitviska+02, Benson+20

Fall+80

Corentin Cadiou

Vitviska+02, Benson+20

Porciani+02

Fall+80

Angular momentum:

Qualitatively understood
Abrupt changes with mergers
Crucial for galaxy formation + weak lensing

Corentin Cadiou

Fall+80

Vitviska+02, Benson+20

Porciani+02

Angular momentum:

Qualitatively understood
Abrupt changes with mergers
Crucial for galaxy formation + weak lensing

Angular momentum:

Abrupt changes with mergers
Qualitatively understood
Crucial for galaxy formation + weak lensing

Corentin Cadiou

Fall+80

Vitviska+02, Benson+20

Porciani+02

What's the origin of angular momentum?
Are mergers truly stochastic?
How does it translate to galaxy properties?

See Cadiou+21a

based on genetic modifications: Roth+16, Rey&Pontzen 18, Stopyra+20

“Find the most likely $\Lambda$CDM realisation
that increases the torques by factor $f$”

This is actually done by minimizing $(\delta_\mathrm{new}-\delta_\mathrm{old})^\dagger \textbf{C}^{-1}(\delta_\mathrm{new}-\delta_\mathrm{old})$
with the constrains $\tau^{(i)}_\mathrm{new} = f \tau^{(i)}_\mathrm{old}, \quad i=x,y,z$

MEGATRON simulation

With Rey & Katz

Large volumes (TNG, HAGN, …)
- statistical results only
- relatively poor resolution
Small volumes & zoom-ins
- few formation scenarios
Genetically modified simulations

Large-scale torques control mergers deterministically
which controls secondary galaxy properties

… what happens to the gas?

Corentin Cadiou

Large-scale torques control mergers deterministically
which controls secondary galaxy properties

… what happens to the gas?

Corentin Cadiou

Most of re-alignment happens in the inner CGM $0.1\leq \displaystyle\frac{r}{R_\mathrm{vir}}\leq 0.3$

The longer gas remains in inner CGM, the more it realigns (with disk)

Corentin Cadiou

Tracers: Cadiou+19
Cadiou+21b, see also Danovich+15, Prieto+17

Tracking Lagrangian trajectories, comparing $\vec{j}$ to

$\parallel$ to direction @ $R_\mathrm{vir}$

$\perp$ to direction @ $R_\mathrm{vir}$

⚠️ Only looking at gas that will form stars eventually

Kocjan, Cadiou+24

Corentin Cadiou

Time $2R_\mathrm{vir}\rightarrow R_\mathrm{vir}/3$

Time $R_\mathrm{vir}/3 \rightarrow ⭐$

Angular momentum: bridging galaxy formation to cosmology

2 Spin $\leftrightarrow$ morphology

Romanowsky&Fall 12

Harrison+17

Hasan+23 (TNG)

3 Cosmic web $\leftrightarrow$ SFR

Kraljic+CC+19 (HAGN)

1 Cosmic web $\leftrightarrow$ spin

Ganeshaiah Veena+21

Corentin Cadiou

Angular momentum: bridging galaxy formation to cosmology

2 Spin $\leftrightarrow$ morphology

Romanowsky&Fall 12

Harrison+17

Hasan+23 (TNG)

3 Cosmic web $\leftrightarrow$ SFR

Kraljic+CC+19 (HAGN)

1 Cosmic web $\leftrightarrow$ spin

Ganeshaiah Veena+21

Corentin Cadiou

Why is the effect of the cosmic web at % level?
What's the arrow of causality?
CW ⇒ spin ⇒ morphology?
How stochastic is galaxy formation?

$z=0$

$ z = 100$

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

Tide $\nearrow$ delay merger

Tide $\searrow$ hasten merger

Corentin Cadiou

Corentin Cadiou

Cadiou+21b

So far, I've shown effect of linear perturbations on galaxy formation.

How to probe non-linear couplings?

Corentin Cadiou

Splicing technique Cadiou, Pontzen & Peiris 21

Extended by A. Storck

Corentin Cadiou

Splicing technique Cadiou, Pontzen & Peiris 21

Extended by A. Storck

Corentin Cadiou

See Anatole Storck's poster for more information!

Far

Halo (mis-)aligns itself to filament

Corentin Cadiou

Harrison+17 (KMOS, $z=1$)

Spiral galaxies $\leftrightarrow$ high $J_\star$

What's the arrow of causality?

Rodriguez-Gomez+22 (TNG)

Angular momentum: controls disk formation?

Tillson+15

Dekel&Birnboim 06

High-z:
most of mass + AM flow along filaments

How do we study these effects?

Large volumes

sample $p(M_\star, M_\mathrm{DM},\mathbf{J}, d_\mathrm{fil}, \dots)$

This talk

sample $p(\mathbf{J}|M_\star, M_\mathrm{DM}, d_\mathrm{fil}, \dots)$

Angular momentum: bridging galaxy to cosmology

Lower-zs:
intrinsic alignment problem

Angular momentum: where are we?

Porciani+02

Rodriguez-Gomez+22

Predictions for $j_\mathrm{DM}$ remain qualitative

$j_\mathrm{DM}-j_\mathrm{\star}$
weak correlation
(statistically strong)

Is $j_\mathrm{DM}$ chaotic or our theory poor?
Do $j_\mathrm{gal}$ retain memory of their environment?
How is AM transported to the disk?

1. Is $j_\mathrm{DM}$ chaotic or our theory poor?

First controlled experiment of testing tidal torque theory for individual halos

CC+21a, arXiv: 2012.02201

2. Do $j_\mathrm{gal}$ retain memory
of the environment?

3. How is AM transported
to the disk?

1. Is $j_\mathrm{DM}$ chaotic or our theory poor?

2. Do $j_\mathrm{gal}$ retain memory
of the environment?

First controlled experiment of angular momentum accretion on individual galaxies

CC+22, arXiv: 2206.11913

Main idea: stars are deeper in potential well so less sensitive to what happens at large scales

⇒ stellar Lagrangian patch should be more stable to perturbations

3. How is AM transported
to the disk?

1. Is $j_\mathrm{DM}$ chaotic or our theory poor?

2. Do $j_\mathrm{gal}$ retain memory
of the environment?

3. How is AM transported
to the disk?

CC+Pichon+Dubois, 21, arXiv: 2110.05384

Kocjan, CC in prep.

Dynamics of angular momentum

Realignment between…

…$3R_\mathrm{vir}$ and $R_\mathrm{vir}$

…$R_\mathrm{vir}$ and $R_\mathrm{vir}/3$

…$R_\mathrm{vir}$ and $R_\mathrm{vir}/10$

✅ Most of realignment happens in “CGM” ($\leq R_\mathrm{vir}/3$)

Mostly due to grav. torques (consistent with e.g. Danovich+15)

[CC+21]

$t_{1/3}$

$t_{\star}$

$T_\mathrm{max}$ between $2 R_\mathrm{vir}$ and $R_\mathrm{vir}/3$?

$\leq 3\times10^4\,\mathrm{K}$

Cold accretion

$\geq 5\times10^5\,\mathrm{K}$

Hot accretion

[Kocjan, CC+ in prep]

What happens in the CGM?

Ongoing work by Z. Kocjan

✅ Cold accretion is slow to form stars

Quick depletion right after merger

[Kocjan, CC+ in prep]

The effects of environment on halo properties

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

$ M_\mathrm{DM}(\text{node}) $ > $M_\mathrm{DM}(\text{fil}) $ >$M_\mathrm{DM}(\text{void})$, higher clustering
spins align with cosmic web ⇒ issue for weak lensing
$v/\sigma(\mathrm{fil})>v/\sigma(\mathrm{void})$ ⇒ bias in galaxy formation
….

The effects of environment on halo properties

Isotropic effects

Kaiser bias, cluster vs. groups, ...

From theory: $M\propto \int\mathrm{d}^3R\rho$

Mass regulated

An-isotropic effects

Intrinsic alignment, formation of disks?

From theory: $J \propto \int\mathrm{d}^3R \nabla \phi$

Angular momentum regulated?

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]

Note: vanishes at 1st order in a sphere

\[ \int_\Gamma \mathrm{d}^3{q}(\mathbf{q}-\mathbf{\bar{q}}) \times\nabla\phi = \int_{\partial\Gamma}\phi(q)(\mathbf{q}-\mathbf{\bar{q}})\times\mathrm{d}\mathbf{S}\]

Note: the following is a (poor) approximation:

\[ \mathbf{L} \propto \epsilon_{ijk} T_{jl}I_{lk},\quad\text{with \textbf{T} the tidal tensor and \textbf{I} the inertia tensor}\]

Ongoing work by Z. Kocjan

[Kocjan, CC+ in prep]

Filamentary accretion ~ Cold flow = $T \leq 10^5\mathrm{K}$ for $0.3R_\mathrm{vir} < r < 2R_\mathrm{vir}$

Not necessarily fast-track to star formation ⇒ lose connection to CW?

[Kocjan, CC+ in prep]

$M_\mathrm{DM}(z=2)\approx 10^{11}-10^{12} \mathrm{M_\odot}$

Ongoing work by Z. Kocjan

Ex Uno Plures: direct measure of the impact of the cosmic web on individual objects to shed light on their population statistics

Corentin Cadiou
The Co-evolution of the CW and Galaxies across Cosmic Time

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 $M_\mathrm{vir}$?

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?

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

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.

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
⇒ key to understand morphology

Galaxy formation in cosmology: the role of the environment

Environmental effects:

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

$ 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$

$ l_0 \times 1.2$

$ l_0 \times 1.5$

$ l_0 \times 0.66$

$ l_0 \times 0.8$

$ l_0 \times 1.2$

$ l_0 \times 1.5$

$ l_0 \times 0.66$

$ l_0 \times 0.8$

AM of baryons originates from initial conditions…
can be controlled…
and regulate galaxy morphology
Negligible AGN/SN global self-regulation

Galaxy formation

[L. Cortese; SDSS.]

[Dubois+16]

AGN no AGN

Origin of morphological diversity at fixed mass?

[L. Cortese; SDSS.]

[Dubois+16]

AGN no AGN

Origin of morphological diversity at fixed mass?

How to explain environmental effects?

[Kraljic+ in prep]

Galaxy formation

[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

[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?

How chaotic is galaxy formation? | Hyderabad

By Corentin Cadiou

How chaotic is galaxy formation? | Hyderabad

Presentation at Hyderabad (online)

How chaotic is galaxy formation?

Intrinsic alignment

Weak lensing

Galaxy formation: the biased point of view of the spin

First complication

Second complication

Third complication

How complex are galaxies?

1

How complex are galaxies?

1

COSMOS dataset

Horizon-AGN

We have a method to measure the intrinsic dimensionality of any dataset.

COSMOS dataset

Horizon-AGN

Horizon-AGN

Is DM angular momentum chaotic?

2

Is DM angular momentum chaotic?

2

DM angular momentum

DM angular momentum

DM angular momentum

DM angular momentum

DM angular momentum

Are mergers really stochastic?

3

How chaotic is baryonic angular momentum?

4

How chaotic is baryonic angular momentum?

4

Special case: no massive satellite

Impact of the cosmological-scale density on halo properties

5

The “splicing” technique

Splicing in 1D

Splicing in 1D

The causal origin of DM halo concentration

The causal origin of DM halo concentration

The causal origin of DM halo concentration

Impact of the cosmological-scale tides on halo properties

6

Impact of the cosmological-scale tides on halo properties

6

Conclusions

Are galaxies chaotic?

Angular momentum: bridging galaxy formation to cosmology

Angular momentum: bridging galaxy formation to cosmology

Angular momentum: controls disk formation?

Angular momentum: bridging galaxy to cosmology

Angular momentum: where are we?

1. Is \(j_\mathrm{DM}\) chaotic or our theory poor?

2. Do \(j_\mathrm{gal}\) retain memory of the environment?

3. How is AM transported to the disk?

1. Is \(j_\mathrm{DM}\) chaotic or our theory poor?

2. Do \(j_\mathrm{gal}\) retain memory of the environment?

3. How is AM transported to the disk?

1. Is \(j_\mathrm{DM}\) chaotic or our theory poor?

2. Do \(j_\mathrm{gal}\) retain memory of the environment?

3. How is AM transported to the disk?

Dynamics of angular momentum

What happens in the CGM?

The effects of environment on halo properties

The effects of environment on halo properties

Isotropic effects

An-isotropic effects

Predicting angular momentum

Ex Uno Plures: direct measure of the impact of the cosmic web on individual objects to shed light on their population statistics

The causal origin of DM halo concentration

Predicting angular momentum

Can we control baryonic angular momentum?

Temporary conclusions

Galaxy formation in cosmology: the role of the environment

Galaxy formation

Galaxy formation

The origin of high \(z\) angular momentum

The origin of high \(z\) angular momentum

The origin of high \(z\) angular momentum

The origin of high \(z\) angular momentum

We have a method to measure
the intrinsic dimensionality of any dataset.

Are mergers really
stochastic?

How chaotic is baryonic
angular momentum?

How chaotic is baryonic
angular momentum?

2. Do \(j_\mathrm{gal}\) retain memory
of the environment?

3. How is AM transported
to the disk?

2. Do \(j_\mathrm{gal}\) retain memory
of the environment?

3. How is AM transported
to the disk?

2. Do \(j_\mathrm{gal}\) retain memory
of the environment?

3. How is AM transported
to the disk?

Can we control baryonic
angular momentum?