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?
- AGN quenching
- 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
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 developed in Cadiou+21a
[AM prediction: described by tidal torque theory, White 84]
Time
DM angular momentum
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
\(\Delta x = 35\ \mathrm{kpc}\) - \(M_\mathrm{200c}(z=2) = 10^{12}\ \mathrm{M}_\odot\)
- 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
- Lower-AM in bulge ⇒ higher SMBH accretion?
- Formation of high-\(z\) “blue nuggets”
(compact & star forming)? - Origin of \(j_\mathrm{DM} \neq j_\mathrm{baryons}\)?
\( l_0 \times 1.2\)
\( l_0 \times 1.5\)
\( l_0 \times 0.66\)
\( l_0 \times 0.8\)
The effect of environment on halo properties
Past research
What if the galaxy had formed here instead?
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
\(1^\mathrm{st}\) 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]
[Sphinx project]
- Role of environment in setting spin
- Environmental-quenching
The effect of environment on halo properties
Proposed work
Summary
Summary
My research
Crosstalk theory \(\leftrightarrow\) simulations
Built interpretive framework to study origin of galaxy angular momentum
- Origin of AM?
- Translation in observable properties (morphology, disk size, spin)?
- Mitigation of intrinsic alignment in lensing surveys (Euclid)?
This postdoc
Interpretation of JWST/NirSPEC observations
- SMHR relation (COSMOS-Webb survey)
- Origin of high-\(z\) quiescent galaxies
Contribute to dev. models of BH seeding
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?