The Impact of Reionization on Dwarf Galaxies Oliver Elbert James - - PowerPoint PPT Presentation

▶

Oct 08, 2022 174 likes •357 views

The Impact of Reionization on Dwarf Galaxies Oliver Elbert James Bullock Jose Oorbe Alex Fitts Mike Boylan-Kolchin Image: wikipedia Absolute Basics First H, then He Completes by z = 6-10 (Probably) Caused by Pop III stars

SLIDE 1

The Impact of Reionization

n Dwarf Galaxies

Oliver Elbert

James Bullock  Jose Oñorbe Alex Fitts Mike Boylan-Kolchin Image: wikipedia

SLIDE 2

Absolute Basics

First H, then He
Completes by z = 6-10
(Probably) Caused by Pop III stars
Minor impact on “large” galaxies

SLIDE 3

What About Small Galaxies?

Wheeler, Elbert +2015 5 3 2 0.5 0.25 Redshift 2 6 8 Age (Gyr) 10 12 4 Cumulative SFH Simulated Classical Dwarfs Simulated UFDs 1010 109 Mhalo (Msun) 103 104 105 106 M* (Msun) UFD

SLIDE 4

UFDs are UV Quenched

But what about larger dwarfs?

1 2 3 4

Time [Gyr]

103 104 105

Cumulative Stellar Mass [M] Normal Reionization No Reionization

109 M⊙

SLIDE 5

Large Sample to Explore

Suite of 12 dwarf galaxies

Fitts, Elbert +2016

z M* Suite of 12 dwarf galaxies, same halo mass DMO + Hydro sims

SLIDE 6

Classical Dwarfs Can Be Affected

Fitts, Elbert +2016

SLIDE 7

Uncertainty in Reionization History

Oñorbe+2016

Use simulations to explore!

SLIDE 8

108 109 1010

Mvir [M]

102 103 104 105 106 107 108

M? [M] Early Reionization Late Reionization

Dwarfs Strongly Affected

SLIDE 9

108 109 1010

Mvir [M]

102 103 104 105 106 107 108

M? [M] Early Reionization Late Reionization

Dwarfs Strongly Affected

In 109 M⊙ halos: more than 2x more galaxies larger M*

SLIDE 10

108 109 1010

Mvir [M]

102 103 104 105 106 107 108

M? [M] Early Reionization Late Reionization

Dwarfs Strongly Affected

In 109 M⊙ halos: more than 2x more galaxies larger M* At 1010 M⊙: More similar M* No guarantee of more or less star formation!

SLIDE 11

Suppression Mass Threshold Fixed

Halos become UV suppressed around 3-5 x 109 M⊙

108 109 1010

Mvir [M]

1 3 6 9 12 14

Youngest Stellar Age [Gyr] Early Reionization Late Reionization

SLIDE 12

Still Significant for Classical Dwarfs

2 4 6 8 10 12 14

Time [Gyr]

105 106 107 108

Cumulative Stellar Mass [M] Early Reionization Late Reionization

1010 M sun

SLIDE 13

2 4 6 8 10 12 14

Time [Gyr]

105 106 107

Cumulative Stellar Mass [M] Early Reionization Late Reionization

2 4 6 8 10 12 14

Time [Gyr]

104 105 106

Cumulative Stellar Mass [M] Early Reionization Late Reionization

2 4 6 8 10 12 14

Time [Gyr]

105 106 107

Cumulative Stellar Mass [M] Faucher Giguere 09 Onorbe Late

Still Significant for Classical Dwarfs

2 4 6 8 10 12 14

Time [Gyr]

105 106 107 108

Cumulative Stellar Mass [M] Early Reionization Late Reionization

2 4 6 8 10 12 14

Time [Gyr]

104 105 106 107 108

Cumulative Stellar Mass [M] Faucher Giguere 09 Onorbe Late

2 4 6 8 10 12 14

Time [Gyr]

105 106 107

Cumulative Stellar Mass [M] Early Reionization Late Reionization

SLIDE 14

2 4 6 8 10 12 14

Time [Gyr]

0.25 0.5 0.75 1.0

Cumulative Star Formation History Early Reionization Late Reionization

2 4 6 8 10 12 14

Time [Gyr]

0.25 0.5 0.75 1.0

Cumulative Star Formation History Early Reionization Late Reionization

2 4 6 8 10 12 14

Time [Gyr]

0.25 0.5 0.75 1.0

Cumulative Star Formation History Faucher − Giguere 09 Onorbe Late

2 4 6 8 10 12 14

Time [Gyr]

0.25 0.5 0.75 1.0

Cumulative Star Formation History Faucher − Giguere 09 Onorbe Late

2 4 6 8 10 12 14

Time [Gyr]

0.25 0.5 0.75 1.0

Cumulative Star Formation History Early Reionization Late Reionization

Still Significant for Classical Dwarfs

2 4 6 8 10 12 14

Time [Gyr]

0.25 0.5 0.75 1.0

Cumulative Star Formation History Faucher − Giguere 09 Onorbe Late

SLIDE 15

Conclusions

Reionization is complicated:
Quenches UFDs
Mh~4 x 10

9 seems like threshold for this

Changing reionizing strength may move this?
Later reionization gives more galaxies
Smallest “classical “ dwarfs near Okamoto-like suppression mass
Can explain potential quenched field dwarfs
Even above this, SFH is impacted
Factor ~2 change in M*, variety of formation times
Dwarfs are snowflakes too, each responds in its own way

SLIDE 16

Thank You

SLIDE 17

This slide intentionally left blank

SLIDE 18

UV Feedback

Fitts, Elbert +2016

Heat input from Reionization

~20,000 K