Core Collapse of Self-Interacting Dark Matter Halos Kimberly Boddy - - PowerPoint PPT Presentation

Core Collapse of Self-Interacting Dark Matter Halos

Kimberly Boddy 
 Johns Hopkins University

Searching for New Physics, Leaving No Stone Unturned University of Utah 5-10 August 2019

N-body Simulations

• Dark matter density halo profiles are cuspy and dense
• There are many more small halos than large ones
• Substructure is abundant and almost self-similar

Bullock & Boylan-Kolchin, Annu. Rev. Astron. Astrophys. (2017)

CDM-only!

Small-Scale Structure

Dwarf spheroidals LSBs Galaxy Clusters

small-scale structure puzzles arise in various systems: core-cusp, missing satellites, too-big-to-fail, diversity

Missing satellites

Buckley & Peter, Phys. Rept. (2018) Oh+, ApJ (2010)

Core-cusp

Boylan-Kolchin+, MNRAS (2012)

TBTF

Creasey+ (2017)

Diversity

SIDM Solution

1 c m

2

ê g 1 c m

2

ê g 1 c m

2

ê g . 1 c m

2

ê g s ê m = . 1 c m

2

ê g

10 50 100 500 1000 5000 1 10 102 103 104 Xv\ HkmêsL Xsv\êm Hcm2êg â kmêsL

Dwarfs LSBs Clusters

Kaplinghat, Tulin, Yu, PRL (2016)

Alleviate tensions?

Spergel and Steinhardt, PRL (2000) Rocha+, MNRAS (2013) Zavala+, MNRAS (2013)

Further investigations with SIDM+baryons are ongoing

Yes! Use semi-analytic methods. Gravothermal evolution.

Can we understand SIDM halo evolution without needing to run N-body simulations?

In globular clusters:

✦ Lynden-Bell and Eggleton (1980)

In SIDM halos:

✦ Balberg, S. Shapiro, Inagaki (2002); Ahn, P

. Shapiro (2004); Koda, P . Shapiro (2011)

Millennium-II, Boylan-Kolchin+ (2009)

• Mass conservation

• Hydrostatic equilibrium

• Laws of thermodynamics

• Heat conduction

Gravothermal Evolution

∂L ∂r = −4πr2ρν2 ✓ ∂ ∂t ◆

M

ln ✓ν3 ρ ◆ ∂(ρν2) ∂r = −GMρ r2 ∂M ∂r = 4πr2ρ L 4πr2 = −κ∂T ∂r

Two time scales:

td = H ν = (4πρG)−1/2 tr = λmfp aν = σ/m aρν

Gravothermal Evolution

• Mass conservation

• Hydrostatic equilibrium

• Laws of thermodynamics

• Heat conduction


∂L ∂r = −4πr2ρν2 ✓ ∂ ∂t ◆

M

ln ✓ν3 ρ ◆ ∂(ρν2) ∂r = −GMρ r2 ∂M ∂r = 4πr2ρ

∆ri Li Mi, νi

L 4πr2 = −κ∂T ∂r = −3 2abν ⇣ σ m ⌘  a ⇣ σ m ⌘2 + b C 4πG ρν2 −1 ∂ν2 ∂r

500 1000 1500 2000 2500 3000

r [pc]

35.0 37.5 40.0 42.5 45.0 47.5

v3D [km/s]

σm = 0.1 cm2/g σm = 0.5 cm2/g σm = 1 cm2/g σm = 5 cm2/g σm = 10 cm2/g Pippin CDM

Calibration

102 103 104

r [pc]

103 102 101 100

ρ [M/pc3]

σm = 0.1 cm2/g σm = 0.5 cm2/g σm = 1 cm2/g σm = 5 cm2/g σm = 10 cm2/g Pippin CDM

Matching densities works well across a range

• f cross sections

Matching velocity dispersions is more problematic

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499) Simulation reference: Elbert+, MNRAS (2015)

Central Density

100 101 102

˜ t (= t/t0)

101 102 103

˜ ρc (= ρc/ρs)

σm = 0.1 cm2/g σm = 0.5 cm2/g σm = 1 cm2/g σm = 5 cm2/g σm = 10 cm2/g σm = 50 cm2/g σm = 100 cm2/g

250 300 350 400

t−1 ∼ (σ/m)rsρ3/2

s

initial NFW profile

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 0 (t = 0 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 0 (t = 0 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 1 (t = 0.3 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 0 (t = 0 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 1 (t = 0.3 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 53 (t = 13.5 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 0 (t = 0 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 1 (t = 0.3 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 53 (t = 13.5 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 351 (t = 90 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 0 (t = 0 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 1 (t = 0.3 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 53 (t = 13.5 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 351 (t = 90 Gyr)

Density 3D Velocity Dispersion Positive Luminosity Negative Luminosity

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

10−3 10−2 10−1 100 101 102

˜ r (= r/rs)

10−9 10−6 10−3 100 103 106

˜ ρ (= ρ/ρs), ˜ L (= L/L0)

˜ t = 374.56 (t = 95.7 Gyr)

0.2 0.4 0.6 0.8 1.0

√ 3 ˜ v (= √ 3 v/v0)

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

Tidal Truncation

5 10

t [Gyr]

101 100 101

ρc [M/pc3]

σm = 5 cm2/g TNFW rt = rs TNFW rt = rs after 3Gyr NFW

100 101 102

˜ t (= t/t0)

101 102 103

˜ ρc (= ρc/ρs)

TNFW rt = rs TNFW rt = 3rs NFW

0.1 1 10

σm [cm2/g] corresponding to t = 13 Gyr

ρNFW = ρs (r/rs)[1 + (r/rs)2] ρtrunc = ρNFW × ( 1 r < rt

1 (r/rt)5

r > rt

Nishikawa, KB, Kaplinghat (arXiv: 1901.00499)

In progress: BH formation

Halo Survivability

Phat ELVIS Simulation

Kelley+, MNRAS (2019)

Prediction for SIDM: ✦ Core collapse phase may help subhalos survive infall ✦ High central densities Accelerated collapse from: ✦ Dissipative DM
 Essig+ (1809.01144) ✦ Baryonic potential
 (ongoing with Kaplinghat and Necib)

Simulations with Infall

Sameie, Yu, Sales, Vogelsberger, Zavala (1904.07872)

Can obtain wide diversity of halo profiles

Zavala, Lovell, Vogelsberger, Burger (1904.09998)

Kahlhoefer, Kaplinghat, Slatyer, Wu (1904.10539)

Simulations with Infall

Field halos Satellites (long period orbit) Satellites (short period orbit)

high concentration low concentration Recall:

c200 = r200/rs

ρs ∝ c3

200

ln(1 + c200) − c200/(1 + c200) t−1 ∝ (σ/m)rsρ3/2

s

TBTF Revisited

Kaplinghat, Valli, Yu (1904.04939)

Outlook

Drlica-Wagner+ (incl. KB) (1902.01055)