PART II The Parameters of Galaxy Formation Darren Croton Centre - - PowerPoint PPT Presentation

▶
part ii the parameters of galaxy formation
SMART_READER_LITE
LIVE PREVIEW

PART II The Parameters of Galaxy Formation Darren Croton Centre - - PowerPoint PPT Presentation

Mar 20, 2023 280 likes •635 views

PART II The Parameters of Galaxy Formation Darren Croton Centre for Astrophysics and Supercomputing Swinburne University dcroton@astro.swin.edu.au Lets recap... The skeleton The flesh Schmidt law star formation

slide-1
SLIDE 1

PART II The Parameters of Galaxy Formation

Darren Croton Centre for Astrophysics and Supercomputing Swinburne University dcroton@astro.swin.edu.au

slide-2
SLIDE 2

Let’s recap...

slide-3
SLIDE 3

The skeleton The flesh

slide-4
SLIDE 4
slide-5
SLIDE 5
slide-6
SLIDE 6
slide-7
SLIDE 7
  • Schmidt law star formation
  • SFR dependent SN winds
  • satellite gas stripping
  • morphological transformation
  • assembly through mergers
  • starbursts through mergers
  • Magorrian relation BH growth
  • jet & bubble AGN feedback

Croton et al. 2006

slide-8
SLIDE 8

z=0 dark matter

slide-9
SLIDE 9

z=0 galaxy light

slide-10
SLIDE 10

Physical consequences

AGN SN AGN

Croton et al. 2006

(∝mBHσ3) (∝SFR)

slide-11
SLIDE 11

$20 z=1 $30 z=2 $40 z=3

slide-12
SLIDE 12

AGN SN

slide-13
SLIDE 13

AGN SN

slide-14
SLIDE 14

Our model is only as good as the questions we ask For systems with infinite levels of complexity, our model can never be “correct”

slide-15
SLIDE 15

What can semi-analytics actually tell us about galaxy formation?

slide-16
SLIDE 16

Example 1: Void galaxies

slide-17
SLIDE 17

Croton et al. 2005

2dFGRS

slide-18
SLIDE 18

Croton & Farrar (2008)

The Millennium Simulation semi-analytic galaxy formation model

slide-19
SLIDE 19

So what’s special about early-type void galaxies?

Halo mass function in different environments

Croton & Farrar (2008)

slide-20
SLIDE 20

Example 2: BH growth - mergers or secular?

slide-21
SLIDE 21

Merger driven growth

During the merger some fraction of the cold gas is driven onto the black hole

ΔmBH ~ 0.03 mR mcold

slide-22
SLIDE 22

merger driven growth

black hole-bulge

Haring & Rix 2005

slide-23
SLIDE 23

Secular driven growth

As the stellar disk becomes unstable, some fraction of the cold gas is dragged inward to accrete onto the black hole

ΔmBH ~ 0.01 mcold

slide-24
SLIDE 24

merger driven growth disk instability driven growth

black hole-bulge

Haring & Rix 2005

slide-25
SLIDE 25

merger driven growth disk instability driven growth

luminosity function

slide-26
SLIDE 26

merger driven growth disk instability driven growth

environment LFs

slide-27
SLIDE 27
slide-28
SLIDE 28

The down and dirty

slide-29
SLIDE 29

Semi-analytics (mostly) assume:

  • the cosmology is correct
  • local correlations extend to higher redshift
  • the baryon fraction is universal
  • halo properties determine galaxy properties
  • ...
slide-30
SLIDE 30

Semi-analytics are at the mercy of:

  • the IMF
  • stellar population models
  • the quality of constraining observations
  • the quality of the underlying simulation
  • ...
slide-31
SLIDE 31

Croton et al. 2006, 2012 (in prep.)

slide-32
SLIDE 32

The exact values of the parameter choices are (mostly) meaningless

slide-33
SLIDE 33

Let’s now look at some code...

slide-34
SLIDE 34

...and the story continues in the next lecture with “The universe in the cloud”