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The Galaxy as seen by RAVE
L. Veltz, O. Bienaymé & A. Just
Outline Model Observations Structure Kinematics Metallicity
Model Cigal
i => isothermal components
k => absolute magnitudes
Equation of stellar statistics:
Our modelOur model
Gravitation
alPotential
density distribution
velocitydispersion
€
Φ(z) = 2πG Σ0( z2 + D2 −D) + ρ eff z2
( )
Vertical gravitational potential:
self-consistentself-consistent
The analysis of the Galactic Disk structure relies on:
• Star counts
• Proper motions
• Radial velocities
2massComplete within
5 to 15.4 magnitudes
UCAC23 to 7 mas.y-1
within 6 to 14 magnitudes
RAVEInternal error of 2 km.s-1
Our samples Our samples
Fit the observations
Count Radial velocity
Proper motions
Kinematics distribution function
Thin disk Thic
k disk
Dwarf/Giant separation
Absolute magnitudes:
Sub-giants
MK=-0.89
MK=-0.17
Dwarfs MK=4.15
Clump giantsMK=-1.61
Color selectionColor selection
2mass-MSX-Hipparcos
HR diagram
Dwarf/Giant separation
Giants Dwarfs
Subgiants
Selection of dwarfs
Giants
Dwarfs
Subgiants
Dwarf/Giant separation
Dwarf/Giant separation
Giants Dwarfs
Subgiants
Dwarf/Giant separation
Giants Subgiants Dwarfs
hyp.: all stars are Dwarfs
Photometric distance
Observations versus Model
Thin/thick disk
transition
Thick disk
45 Km/s
Thin disk
15-20 Km/s
photometric distance (pc)
Scaleheight
Scale-height
Thin disk
Thick disk
Thin disk:
hz=225 ± 10 pc
Thick disk:
hz=1048 ± 36 pc
thick/
thin=8%
Scalelength
hR=2500pc
hR,1=1800pc & hR,2=2800pc
Kinematics
Selection of dwarfs
Selection of dwarfs
Selection of dwarfs
Selection of dwarfs
Dispersion-color
Dispersion-color
B-V <=> J-K
Dispersion-color
Dispersion - color
Dispersion vs distance
sigW-col (distance)
Metallicity
SDSS - RAVE
Metallicity
Metallicity-dispersion
Conclusions
Results
Kinematical decomposition Clear separation between the thin
and the the thick disk Separation of dwarfs/giants Determination Scale height /length Kinematics function of Z Metallicity
Space kinematics
