3D spectrography V – Density waves in the inner regions of galaxies
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Transcript of 3D spectrography V – Density waves in the inner regions of galaxies
Padova 033D Spectrography
3D spectrography3D spectrography
V – Density waves in the innerV – Density waves in the inner
regions of galaxies regions of galaxies
Padova 033D Spectrography
DDensity ensity WWaves in aves in galaxiesgalaxies
Spirals
Bars
> 50% of grand-design
> 70% of spirals?
Lindblad, Lin & Shu (60’s)
Warps
Lopsidedness
All disk galaxies?
Very common
(Kamphuis et al. 91)
(Sancisi 76)
Padova 033D Spectrography
Role of Role of DDensity ensity WWavesaves
Torques Local density enhancements crowding,
shocks Angular momentum transfer Dynamical diffusion / heating
– Link with: Secular evolution?
Star formation, starbursts?– AGN?–
NGC 4314
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IDWIDW: Towards the centre: Towards the centre Shorter dynamical timescales !! Peaked density distributions (cusps, BHs) A priori lower fraction of dark matter (besides the BH), Axisymmetrisation? Importance of self-gravity
A few numbers:
100 pc 100 pc 10 1066 yrs at 100 km/s yrs at 100 km/s
• Duty cycle of an AGN? 107 – 108
yr
• Average Fueling rate? 0.001 – 1 Msun / yr
• Total mass used? 104-108 Msun
Padova 033D Spectrography
Epicycles and resonancesEpicycles and resonances
Natural frequency of the system: angular frequency
For a disk (potential ):
RR
R
V
VRR
RRR
c
c
2c
z
V
Ω
L
2
0 0et0th Ordre
Padova 033D Spectrography
Natural frequencies of the system:: circular frequency : radial epicyclic frequency
Epicycles and resonancesEpicycles and resonances
zzz
RRR
0
0
0
zz
Rt
RRR
02
2
0th Order
00
2
000
2
2
cos
03
00
tttRR
RR
RRRR
RzRR
zRR
For a disk (potential ):
Padova 033D Spectrography
Rotating with an angular velocity
Epicycles and resonancesEpicycles and resonances
0
2
22
22
2
0
4
4
zRRz
ABBR
R
Natural frequencies of the system:: circular frequency : radial epicyclic frequency
For a disk (potential ):
Padova 033D Spectrography
Epicycles and resonancesEpicycles and resonances
2:rotation Rigid
2:rotationFlat
:Keplerian
Natural frequencies of the system:: circular frequency : radial epicyclic frequency
For a disk (potential ):
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PrecessionPrecession
● Precession of elliptical orbits: / 2
Alignement Non Alignement
Structure with rigid rotation p if:
p / 2 = CTE
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Propagation, amplificationPropagation, amplification
CR
ILR
If Q > 1: evanescent waves
Potential is a superposition of spiral perturbations
j
jjjj RfmtitR exp,,
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Bars and angular Bars and angular momentummomentum
● Gas outside the CR
● Gas between the CR and l’ILR
OLR
ILR
Change of orientation of the orbits at the resonances :
gradual change for the gas
Padova 033D Spectrography
NGC 1068NGC 1068
Lai (CFHT, I + K + Br
N E
Padova 033D Spectrography
NGC 1068 with SAURONNGC 1068 with SAURON
NE
Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team
Padova 033D Spectrography
Modelling NGC 1068Modelling NGC 1068
• Mass model: NIR Photometry and Velocity curve• Stars and gas: ‘’Ringberg standards’’
Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team
Padova 033D Spectrography
Gas…Gas…
N E
Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team
Model
SAURON
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SAURON
Model
And stars…And stars…
N E
Coll.: K. Fathi, H. Wozniak, P. Ferruit, R. Peletier & the SAURON team
Padova 033D Spectrography
IDWIDW: Inner bars versus AGN?: Inner bars versus AGN?
The DEBCA project
NGC 1808(starburst)
H band
Emsellem, Greusard, Combes et al. 01, A&A 368, 52
ISAAC / VLTCO bandhead (2.3 m)
SDD
major minor
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NGC 3623 (Sa)
Gnd based Image 7' x 7' Stars
SAURON / WHT
SStellartellar DDispersion ispersion DDroprops in 2Ds in 2D
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Nuclear spiralsNuclear spirals
Regan & Mulchaey 99, AJ 117, 2676 (HST, WFPC2 / NICMOS)
1.6 m100 pc
Padova 033D Spectrography
IDWIDW: Inner spirals: Inner spirals
DSS 4’x4’
NGC 2974
E4 Vs = 1866 km/sD ~ 25 Mpc
Mdust ~ 1.5 106 Msun (IRAS)MHI ~ 8 108 Msun (Kim et al. 1988)MHII ~ 3 104 Msun (Buson et al. 1993)
Emsellem & Goudfrooij 03, MNRAS
Padova 033D Spectrography
NGC 2974
E(V - I)
WFPC2
[NII]+H
240 pcLRF
Emsellem & Goudfrooij 03, MNRAS
IDWIDW: Inner spirals: Inner spirals
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And the winner is …And the winner is …
Emsellem & Goudfrooij 03, MNRAS
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The inner bar: Integral Field The inner bar: Integral Field datadata
NGC 2974
TIGER – CFHT(3D Deconvolution)
Emsellem & Goudfrooij 03, MNRAS
V
Padova 033D Spectrography
NGC 3504NGC 3504: m=1 : m=1 modesmodes
NGC 3504
Optical
NIR
Combes et al.
PUEO / CFHT
WFPC2 / HST
OASIS / CFHT
I band
Coll.: Didier Greusard, Françoise Combes
arcsec
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PUEO/CFHT
WFPC2/HST
K
F606W
OASIS / CFHT
H [NII]
Vgas[OI]
NGC 3504
Coll.: Didier Greusard, Françoise Combes
NGC 3504NGC 3504: m=1 : m=1 modesmodes
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Berman 01, A&A 371, 476
gas flow model
Absorption map model
kpc
kpcar
csec
F814W
5 pc
arcsec
HRCAM
IDW: Towards the BH
M 31
STIS
Bulge & Nucleus
UV peak
Bacon, Emsellem, Monnet, et al. 1994, Emsellem & Combes 1997: Mbh = 7 107 Msun
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M31 – KepleriM31 – Kepleri an m=1an m=1
I V
OASIS / CFHT
N body simulation
Bacon, Emsellem, Combes, et al. 01, A&A 371, 409
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Summary - ConclusionsSummary - Conclusions• Density waves have an important role in redistributing the
dissipative component and reshaping the galaxy (nuclear disks) Resonances!!
• Density waves are present in the central regions of galaxies. nuclear bars versus central starbursts (cold system) nuclear spirals are common but have low amplitudes … nuclear m=1 modes may be common keplerian m=1 (M 31)
• The presence of gas is critical
• 3D spectrography is required (again…)
• Central starburst – AGN: evolution sequence?
• Time-scales! (fueling the nucleus, starburst, AGN, dynamical heating …)