Simulating our Universe
Andreas Burkert (Munich)The Golden Age of Astrophysics
What is the structure of the Universe?
How did it form and how does it evolve?
How did life form in the Universe?
Are we alone in the Universe?

The Golden Age of Computational Astrophysics
What is the structure of the Universe?
How did it form and how does it evolve?
How did life form in the Universe?
Are we alone in the Universe?

The Golden Age of Computational Astrophysics
What is the structure of the Universe?
How did it form and how does it evolve?
How did life form in the Universe?
Are we alone in the Universe?

• The Universe is far from equilibrium, non-linear and self-organized• The Universe itself and its ingredients are emergent structures thatconnect processes on very different spatial scales and cannot be
understood in isolation

Self consciousness

15 million degrees

The Energy of Life
H

He6400 degrees

Simulating Stellar Structure and Evolution(Hayashi, Nishida, Hoshi&Sugimoto 1962; Hofmeister, Kippenhahn&Weigert 1964)• Costs: 3 million $, corresponding today to 20 million $• Processing speed: 100 Kflops• RAM: 32 kB• Punching cardsIBM 7090

Simulating Stellar Structure and Evolution(Hayashi, Nishida, Hoshi&Sugimoto 1962; Hofmeister, Kippenhahn&Weigert 1964)• Costs: 3 million $, corresponding today to 20 million $• Processing speed: 100 Kflop/s• RAM: 32 kB• Punching cards

Thomas, 1967

Simulating Stellar Structure and Evolution(Hayashi, Nishida, Hoshi&Sugimoto 1962; Hofmeister, Kippenhahn&Weigert 1964)• Costs: 3 million $, corresponding today to 20 million $• Processing speed: 100 Kflop/s• RAM: 32 kB• Punching cards

Thomas, 1967

Simulating our Solar System

Simulating our Solar System

Kepler’s laws

2 is orderpr=
1 + e cos ϕ
What determines a ?

J. Kepler
1571-1630

Ta=( yrs )( AU )
23

Simulating our Solar System

3 is complexity

2 is order

J. Kepler
1571-1630

Hut+1983

Neptune

Uranus2 is order

J. Kepler
1571-1630

Simulating our Solar System
The Nice model (Morbidelli+05)

3 is complexity

Neptune

Uranus2 is order

J. Kepler
1571-1630

Simulating our Solar System
The Nice model (Morbidelli+05)

3 is complexity

Simulating the diversity of planetary systemsHHe

Dust+CNOHHeSimulating dust coagulation in turbulent protoplanetary disks(Umemura, M.; Ishihara, T.)(Ishihara+ 2018)

Simulating the growth and migration of giant gas planets(e.g. Kley+)

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

5 AU

n ≈ 102cm −3l ≈ 30lyl ≈ 10−5lyn ≈ 1024cm −3l ≈ 10−7ly800,000 km/h

Sun

200 Mio yrs

100 Billion
StarsOrder out of Self-organised, Turbulent Complexity
Molecular clouds are not spheroidal and not isolated.

105ly

10−5ly

M51

The Galactic Cycle of Life

Massive star

τsf =Mgas
SFRwinds

SupernovaStardust

The Puzzle of Star Formation

Gas reservoir:
Collapse time:

Observed:

93⋅10 M ⊙Expected star formation rateM⊙yr

3⋅106 yrs

1000

M⊙
3yr

Star formation timescale

109 yrs

The Puzzle of Star Formation
Maybe, our Milky Way
is unique!

M⊙yrM⊙
3yr

Star formation timescaleal3⋅106 yrs

1000

109 yrs

rsObserved:

3⋅10 M ⊙Expected star formation rateive

Collapse time:

9UnGas reservoir:

The Puzzle of Star Formation
But
All molecular clouds
are forming stars

0.3% of all clouds
form stars?

99.7% of all clouds
do not form stars

M⊙yr

M⊙
3yr

Star formation timescaleal3⋅106 yrs

1000

109 yrs

rs

Observed:

3⋅10 M ⊙Expected star formation rateive

Collapse time:

9UnGas reservoir:

The Puzzle of Star Formation
Feedback
0.3% of a cloudturns into stars

99.7% of a cloudis blown away

M⊙yr

M⊙
3yr

Star formation timescaleal3⋅106 yrs

1000

109 yrs

rs

Observed:

3⋅10 M ⊙Expected star formation rateiveCollapse time:

9UnGas reservoir:

KH Clouds, Birmingham

Star-Forming Filaments

TaurusKH Clouds, Birmingham

Turbulence and Filaments

Star Formation in Filaments(Heigl+ 17, 21, 22)

High-resolution zoom-in simulation of acollapsing, turbulent core

Disk Formation in the Center of the CoreDisk looks very similar to observations

AB Aurigaein polarized light(Boccaletti+20)

Multi-Scale Disk Feeding

Per-emb-2(Pineda+20)

Galaxy Evolution and Supermassive Black Holes (AGNs)(Ohsuga, K.; Umemura, M.; Wagner, A.; Yajima, H.; Asahina, Y; Ogawa, T.)

M51

Galaxy Evolution and Supermassive Black Holes (AGNs)(Ohsuga, K.; Umemura, M.; Wagner, A.; Yajima, H.; Asahina, Y; Ogawa, T.)Black hole shadow

510 ly10−3ly(Kawashima; Ohsuga+)

BH mergers andgravitational waves
Ohsuga+

M51(Umemura+)

Interstellar Turbulence Driven by AGN Feedback(Wagner, A.+)The Puzzle of Star Formation
Age: 10 Gyrs
Stellar mass loss
50% returnedto the ISM

Current star formation rate:

3Gas depletion rate:

M⊙yrM⊙
1.5yr

3 × 109 M⊙Gas depletion timescale

109 yrs
Depletion timescale

2 ⋅109 yrs

Takamizu, Y.
Credit: V. Springel,MPACosmic webGalaxies

Galaxy Formation and Evolution within the Cosmic Web
High-resolution cosmic structure formation

Yoshikawa, K.

Galaxy interaction and stripping

Mori,M.

High-resolution simulation of large-scale structure formation

Yajima,H.; Abe, M.; Inoue, S.; Fukushima, H.

Early Chemical Enrichment

Kirihara, Hasegawa, Umemura,Mori, Tomoaki

The Cosmic Flow of Life10−7ly10−7ly10−5ly10−5ly

107ly

102ly

102ly

106ly

105ly105ly