Impact of Lyman Alpha Pressure on Metal-Poor Dwarf Galaxies Taysun - - PowerPoint PPT Presentation

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impact of lyman alpha pressure on metal poor dwarf
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Impact of Lyman Alpha Pressure on Metal-Poor Dwarf Galaxies Taysun - - PowerPoint PPT Presentation

Apr 17, 2023 781 likes •967 views

Kimm et al. (2018, MNRAS, 475, 4617) Impact of Lyman Alpha Pressure on Metal-Poor Dwarf Galaxies Taysun Kimm (Cambridge Yonsei University) in collaboration with Jeremy Blaizot (Lyon) P LyA Martin Haehnelt (Cambridge) Joki Rosdahl

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SLIDE 1

Impact of Lyman Alpha Pressure 


  • n Metal-Poor Dwarf Galaxies

PLyA

in collaboration with Jeremy Blaizot (Lyon) 
 Martin Haehnelt (Cambridge) 
 Joki Rosdahl (Lyon) 
 Thibault Garel (Lyon) 
 Leo Michel-Dansac (Lyon) 
 Harley Katz (Oxford) 
 Romain Teyssier (Zurich)

Taysun Kimm (Cambridge ➡ Yonsei University)

Kimm et al. (2018, MNRAS, 475, 4617)

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SLIDE 2

Tokyo 30/March/2018 2

Ubiquitous Outflows in LBGs at z~2 (Steidel+10)

  • bserver

M82: local starburst

Red (0.3-1.1 keV); 3x106-107K Green (0.7-2.2 keV); 7x106-2x107K 
 Blue (2.2-6 kev); 2x107-6x107K (Credit: Chandra)

Heckman+(15; z~0 local starburst)

Common feature of SFRs - Outflows

Introduction

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SLIDE 3

Tokyo 30/March/2018 3

Lyman alpha profile on cloud scales

Radiation-Hydrodynamic simulations of a 
 turbulent cloud with 
 Mcloud=106Msun , SFE=1% Kimm, Blaizot et al. (in prep)

Introduction

c.f. Neufeld (90;91); Zheng+(02); Verhamme et al. (06,12); 
 Dijkstra et al. (06); Gronke & Dijkstra (15)

recombination+collisional radiation

Post-processing with RASCAS (Jeremy Blaizot’s talk)

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SLIDE 4

Tokyo 30/March/2018 4

Scattering of LyA photons transfers momentum to the surroundings

Momentum transfer Optical depth to LyA is huge! Why do we care?

Lya pressure

Multiplication factor See also Dijkstra & Loeb (08), Smith et al. (16)

Kimm, Cen, Devriendt+(15)

Solution to the Over-cooling problem at high z?

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SLIDE 5

Tokyo 30/March/2018 5

Scattering of LyA photons transfers momentum to the surroundings

Dust-free

Dusty

Dust-to-metal ratio: Remy-Ruyer+(14) Multiplication factor

Lya pressure

See also Dijkstra & Loeb (08), Smith et al. (17)

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Tokyo 30/March/2018

Momentum budget from Lya pressure

6

Lya pressure

Lya SNe LyC Photo-ionization heating Lyman alpha pressure

  • The momentum from Lya is comparable or more significant than that of SNe
  • Lya pressure is advantageous from a computational viewpoint as well
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Tokyo 30/March/2018

Radiation-hydrodynamic simulations of an isolated disk

7

Lya pressure

MDMH~1010 Msun Z=0.02 Zsun Mstar= 2x108 Msun Mgas=1.7x108 Msun

Simulation set-up Input physics

RAMSES-RT (Teyssier 02; Rosdahl+13)

  • Thermo-turbulent star formation scheme (Kimm+17)
  • Momentum-conserving SNe (Kimm & Cen 14, Kimm+15)

  • Non-equilibrium photo-chemistry with H2 (Katz,Kimm+17)
  • Photo-ionisation heating (Rosdahl+13)
  • Direct radiation pressure (Rosdahl+13)
  • RP by reprocessed IR photons (Rosdahl & Teyssier 15)
  • Photoelectric heating on dust (Kimm+17)

  • Lya pressure (Kimm+18)

Max Resolution: 2 - 5 pc

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SLIDE 8

Tokyo 30/March/2018

Radiation-hydrodynamic simulations of an isolated disk

8

Lya pressure

PhotoHeating+Direct Radation Pressure +IR Pressure
 +SN explosions + Lya Pressure

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SLIDE 9

Tokyo 30/March/2018

Radiation-hydrodynamic simulations of an isolated disk

9

Lya pressure

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SLIDE 10

Tokyo 30/March/2018

Where does Lya operate?

10

Lya pressure

  • Requirement for strong Lya pressure

  • Luminous ionizing source

  • Large NHI density


→ around young stars → interrupt SF quickly (<5Myr)

  • Effective MF ~ 200-300 in dense regions
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SLIDE 11

Tokyo 30/March/2018

Cluster Formation with LyA Feedback

11

Lya pressure

  • Fewer clusters form and survive when strong radiation feedback is present


(caution: cluster formation in HD simulations…) [see also Abe & Yajima 18]

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Tokyo 30/March/2018

Star formation histories of a gas-rich, metal-poor dwarf

12

Lya pressure

R+SN R+SN+Lya R+Lya

  • Suppression of Star formation



 Lya < SN < SN+Lya

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Tokyo 30/March/2018

Weaker outflows with Lya pressure

13

Lya pressure

  • Mass-loading factor is decreased
  • Outflows become cooler and slower

With Lya pressure w/o Lya w/ Lya

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SLIDE 14

Tokyo 30/March/2018

A picture with strong radiation feedback

14

Lya pressure

Less coherent Supernova Feedback Strong Radiation Feedback Coherent Supernova Feedback No or Weak Radiation Feedback

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SLIDE 15

Tokyo 30/March/2018

Weaker outflows with Lya pressure

15

Lya pressure

  • Mass-loading factor is decreased
  • Outflows become cooler and slower

With Lya pressure w/o Lya w/ Lya

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SLIDE 16

Tokyo 30/March/2018

Summary

16

  • LyA photons resonantly scatter with HI, and impart 100-300 times more momentum 


than the single-scattering case (LLya/c) in the metal-poor regime

  • Isolated gas-rich, metal-poor dwarf galaxy test:

  • Total stellar mass : suppressed by a factor of ~2

  • weaker outflows (mass loading~a few at 0.2 Rvir)

  • Star clusters are more difficult to form and survive -> important for GC formation





  • Strong RP does not necessarily lead to stronger outflows (due to self-regulated SF)

  • (Partial) Solution to the over-cooling problem in galaxy formation simulations