Corentin Cadiou

Interview for postdoc @ LASTRO/EPFL

16-19 PhD at Institut d'Astrophysique de Paris
“The impact of the large-scale structures of the Universe on dark matter halo and galaxy formation”. Supervisors: C. Pichon and Y. Dubois.

19-now Postdoc on ERC at University College London
Working with A. Pontzen and H. V. Peiris
(ERC: “Tracing galaxy evolution in the early universe”).

6 authored or co-authored papers
+ 8 contributed articles

(simulation, theory)

PI of a $10\ \mathrm{Mcpu\,hr}$-allocation
co-I in EDGE2.0 & Vintergatan 2 ($40\ \mathrm{Mcpu\,hr}$ each)

Short curriculum

Research project

The origin of galaxy properties

[L. Cortese; SDSS.]

[Dubois+16]

AGN no AGN

How to explain morphological diversity at fixed mass?

Feedback processes (AGN & SN)
Different assembly (my project)

[L. Cortese; SDSS.]

[Dubois+16]

AGN no AGN

How to explain morphological diversity at fixed mass?

How to explain environmental effects?

spin alignment to be mitigated in Euclid
extra parameter in models?

The origin of galaxy properties

The origin of angular momentum

Past research

$z=0$

$ z = 100$

Genetically modified angular momentum

$z=0$

$ z = 100$

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

[AM prediction: described by tidal torque theory, White 84]

$z=0$

$ z = 100$

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

Genetically modified angular momentum

Further described in Cadiou+21a

[AM prediction: described by tidal torque theory, White 84]

Time

DM angular momentum

Time

Angular momentum of individual regions can be controlled all the way to $z=0$

The origin of angular momentum

Current & proposed work

Baryon angular momentum

Simulations (10Mh @ DiRAC):

Resolve disk height
$\Delta x = 35\ \mathrm{pc}$
$M_\mathrm{200c}(z=2) = 10^{12}\ \mathrm{M}_\odot$
RAMSES
SF + AGN & SN feedback (à la New-Horizon)
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

Total of ~ 50 simulations

$ l_0 \times 1.2$

$ l_0 \times 1.5$

$ l_0 \times 0.66$

$ l_0 \times 0.8$

A.M. of the baryons in $R_\mathrm{vir}$

PRELIMINARY

Mock edge-on star maps

Same $M_{200c}, M_\star$ & early assembly history

Proposed work

Lower-AM ⇒ bulge ⇒ higher SMBH accretion?
Morphology-AGN relation
≠scenarios ⇒ relate SMHR to assembly
COSMOS-Webb JWST survey
Can a high-$z$ galaxy be turned quiescent?
Rarity of massive quiescents, simulate them

$ l_0 \times 1.2$

$ l_0 \times 1.5$

$ l_0 \times 0.66$

$ l_0 \times 0.8$

The effect of environment on halo properties

Past research

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

Further described in Cadiou+21b

$1^\mathrm{st}$ application: 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)

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

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

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

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

$1^\mathrm{st}$ application: origin of DM halo concentration

Same halo in 10× different environments

Repeat experiment for 7 halos (70 realisations in total)

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

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

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

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

50% of fluctuations due to environment

$1^\mathrm{st}$ application: origin of DM halo concentration

The effect of environment on halo properties

Proposed work

The effect of environment on halo properties

Proposed work

[Sphinx project]

Proposed work

Role of environment in setting spin
Contrib. to Euclid weak-lensing mocks
Environmental quenching
effects beyond mere density?
Different effect on DM vs baryons
source of scatter in SMHR?

The effect of environment on halo properties

Summary

My research

Crosstalk theory $\leftrightarrow$ simulations

Testbench of galactic angular momentum & environment

AM ⇒ interpret IFU/spectro
WEAVE, NIRSpec / MOONS, 4MOST
assembly ⇒ kinematics ⇒ observables
morphology, disk size, spin, BH mass
origin of intrinsic alignment
lensing surveys Euclid

This postdoc

Interpret observations (NirSPEC):

Morphology-AGN relation
SMHR relation COSMOS-Webb survey
Origin of high-$z$ quiescent galaxies
etc.

Contribute to new models of BH/AGN:

BH seeding, early SMBH growth

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

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

[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?

Corentin Cadiou

Interview for postdoc @ LASTRO/EPFL

Short curriculum

Research project

The origin of galaxy properties

The origin of galaxy properties

The origin of angular momentum

Genetically modified angular momentum

Genetically modified angular momentum

Genetically modified angular momentum

DM angular momentum

DM angular momentum

The origin of angular momentum

Baryon angular momentum

Proposed work

The effect of environment on halo properties

The “splicing” technique

\(1^\mathrm{st}\) application: origin of DM halo concentration

\(1^\mathrm{st}\) application: origin of DM halo concentration

\(1^\mathrm{st}\) application: origin of DM halo concentration

The effect of environment on halo properties

The effect of environment on halo properties

Proposed work

The effect of environment on halo properties

Summary

Summary

My research

This postdoc

The effect of environment on halo properties

The causal origin of DM halo concentration

Splicing in 1D

Splicing in 1D

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

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