SLIDE 1 Sergey Khoperskov1, Misha Haywood1, Paola Di Matteo1, Matt Lehnert2, Francoise Combes3
Star formation quenching in gas-rich barred galaxies
1GEPI, Observatoire de Paris, Meudon, France 2IAP, Paris, France 3LERMA, Observatoire de Paris, Paris, France
Khoperskov et al A&A accepted arXiv 1709.03604
SLIDE 2 Hogg et al. 2003
The color-magnitude diagram
SLIDE 3 Hogg et al. 2003
The color-magnitude diagram
Galaxy color bimodality
SLIDE 4 Hogg et al. 2003
The color-magnitude diagram
Blue cloud: star-forming, a lot of gas, spiral Galaxy color bimodality
SLIDE 5 Hogg et al. 2003
The color-magnitude diagram
Blue cloud: star-forming, a lot of gas, spiral Galaxy color bimodality Red sequence: non-star-forming, little gas
SLIDE 6
Color Magnitude
Evolution of galaxies
SLIDE 7
Color Magnitude
Evolution of galaxies
Secular evolution Gas consumption
SLIDE 8
Color Magnitude
Evolution of galaxies
Secular evolution Gas consumption Gas accretion
SLIDE 9
Color Magnitude
Evolution of galaxies
Secular evolution Gas consumption Gas accretion Quenching
SLIDE 10
Color Magnitude
Evolution of galaxies
Secular evolution Gas consumption Gas accretion Quenching
SLIDE 11
Color Magnitude
Evolution of galaxies
Secular evolution Gas consumption Gas accretion Quenching remove gas inefficient SF
SLIDE 12
Nearby quenching
SLIDE 13
Nearby quenching
SLIDE 14 CEM by Snaith et al 2015
Thick disk formation
Nearby quenching
SLIDE 15 Milky Way: ”quenching”
Rapid decrease of SFR
Snaith+ 2015 Haywood+ 2016
continuity in chemical evolution
After quenching: gas-rich disk
SLIDE 16
Nearby galaxies morphology
SLIDE 17
Nearby galaxies morphology
z~0: 60-70% of galaxies have a bar
SLIDE 18
Nearby galaxies morphology
z~0: 60-70% of galaxies have a bar N-body sims -> bar is a long-lived structure
SLIDE 19 CALIFA barred galaxies
“Quenching”
González Delgado+ 2017
MW
SLIDE 20
SLIDE 21
Most of disk galaxies quenched SF in the past
SLIDE 22
Most of disk galaxies quenched SF in the past A lot of galaxies are barred now
SLIDE 23
Most of disk galaxies quenched SF in the past A lot of galaxies are barred now Typically bar is a long-lived structure
SLIDE 24 N-body/hydro simulations
Isolated disk galaxies
- Gaseous disk (30 pc resolution)
- Radiative heating/cooling
- Star formation
- Initial thick stellar disk
- New born particles (0.5-4 106 particles)
- Stellar feedback (SNe, stellar evolution STARBURST’99)
- Dark matter halo (rigid or 0.5-1 107 particles)
- Models of gas rich galaxies (initially Mgas/Mstars ~ 0.5-1)
SLIDE 25 Unbarred galaxy. Star formation rate
Gas fraction f=1
SLIDE 26 Unbarred galaxy. Star formation rate
Gas fraction f=1
SLIDE 27 Unbarred galaxy. Star formation rate
Different radii
total Gas fraction f=1
SLIDE 28 Barred galaxy. Star formation rate
Gas fraction f=1
SLIDE 29 Barred galaxy. Star formation rate
Gas fraction f=1
SLIDE 30 Barred galaxy. Star formation rate
Different radii
total Gas fraction f=1
SLIDE 31
Star formation efficiency
Different radii SFE = SFR / Gas density
Barred galaxy Unbarred galaxy
SLIDE 32 Gas velocity dispersion
Barred galaxy Unbarred galaxy
Different radii
bar formation time scale
SLIDE 33
Gas velocity dispersion
SLIDE 34
Gas velocity dispersion
Bar rotation
SLIDE 35
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
SLIDE 36
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
SLIDE 37
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
SLIDE 38
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
dust lines
SLIDE 39
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
SLIDE 40
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
SLIDE 41 Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
Gas (partially) lose angular momentum gas LOS velocity stellar density
SLIDE 42
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
Velocity gradient
SLIDE 43
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
Velocity gradient
SLIDE 44
Gas velocity dispersion
Bar rotation Gas (supersonic) flow
Shock wave(!)
Velocity gradient Kelvin-Helmholtz- type instability High gas velocity dispersion
SLIDE 45
SFR Gas density SFE
SLIDE 46 Before the bar formation
Kennicutt-Schmidt relation. Gas-rich galaxy
Gas surface density
Whole disk
SLIDE 47 After the bar formation
Gas surface density
Whole disk
Kennicutt-Schmidt relation. Gas-rich galaxy
SLIDE 48 After the bar formation
Gas surface density
Whole disk
Flattening of the KS relation in the central regions
Kennicutt-Schmidt relation. Gas-rich galaxy
SLIDE 49 Kennicutt-Schmidt relation
Whole disk 5<r<10 kpc <5 kpc
A prediction to be checked with observations of high-redshift, or local gas-rich galaxies.
Gas-rich galaxy
SLIDE 50
- For 10% bar amplitude and M_gas/M_stars ~ 1.0:
SFR suppressed by a factor of 10 during 1 Gyr
- Bar -> turbulent motions
- Within the bar size gas vel. dispersion + 10−25 km s−1
- SFE (in highly turbulent gas) is less efficient
- Factor of 5-10 in comparison to unbarred
Conclusions
- agreement with Milky Way star formation quenching
episode
more details on arXiv 1709.03604
