Galaxy dynamics since z ~ 1

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Galaxy dynamics since z 1
GEPI, Obs. Paris F. Hammer, H. Flores, M. Puech
C. Balkowski LAM P. Amram MPE gt GEPI
M. Lehnert Stockholm Obs. G. Ostlin, T. Marquart
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B-band Tully Fisher relation its evolution
FDF
z lt 1 , studies with slits
Local TF (Verjeinhen 2001)

• Vogt et al, (1997) 0.1lt z lt1.0 ?
  ?MB0.5
• Simard Pritchet al (1998) ?
  ?MB2.0
• Barden et al. (2003) 19 Sp. (0.6ltzlt1.5)  ?
  ?MB1.1
• Ziegler et al, 2003 77 gal (0.1lt zlt 1.0) ?
  ?MB1.0

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K-band Tully Fisher relation its evolution
Local TF (Verjeinhen 2001)
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The multi-IFU mode of GIRAFFE
15 x
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Preliminary program (GTO, Paris)6 nights on
distant galaxies (PI H. Flores)
35 galaxies, 0.4 lt z lt 0.75 W0(OII)gt 15Å Tint
from 8 to 13hrs
gt 32 with enough pixels (6-18) with good
S/N(OII) (gt 6)
CFRS03.0488, z0.46, (3x2) Velocity field
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Also sigma maps
Provided by the absence of cross-talk between
individual spectra.
from Blais-Ouellete, Amram et al,
2002 (Fabry-Perot/Halpha)
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Also sigma maps
?pixel ?random_motions ? ?Vlarge_scale_motions
At low spatial resolution, dispersion maps of
rotating disks do show a peak in their center
Dispersion or ? map
Velocity map
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And we find rotating disks at z 0.6
Maps from Puech et al (2006a) Flores et al
(2006), astro-ph/0603562 0603563)
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but also  perturbed  rotations
Maps from Puech et al (2006a) Flores et al
(2006), astro-ph/0603562 0603563)
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and much complex kinematics
Maps from Puech et al (2006a) Flores et al
(2006), astro-ph/0603562 0603563)
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Could we have missed rotating disks at z 0.6 ?
Completness ALL available galaxies (with
redshift) with IABlt 22.5 and W0(OII)gt15A have
been observed within the GIRAFFE field gt no
bias expected Spatial resolution Several
galaxies have rhalf lt 0.5 arcsec in the
continuum, i.e. the size of the GIRAFFE pixel
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A simple test of the classification
We assume all galaxies to be rotating disks, i.e.
their large scale motions to be rotational We
can simply compared the derived ? maps to the
observed ones Amplitude ratio versus ? peak
distances
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A simple classification scheme
IFU 3x 2
?
Rotating disks (34 )
Perturbed rotation (22)

Complex kinematics (44)
?
Combined to photometric data MB MK
?Tully-Fischer relation
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Tully-Fischer relation at z 0.6 (K band)
VLT/GIRAFFE-IFUs Flores et al (2006, AA,
astro-ph/0603563)
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VLT/GIRAFFE-IFUs Flores et al (2006, AA,
astro-ph/0603563)
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Scatter is related to interlopers (non relaxed
kinematics)
VLT/GIRAFFE-IFUs Flores et al (2006, AA,
astro-ph/0603563)
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Tully-Fischer not evolving ?
Local TF (Verjeinhen 2001)
TF at z0.6 (Flores et al, 2006)
We need statistics !!!
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Galaxy kinematics at z 0.6 some numbers
A (small) complete sample of 35 galaxies IAB ?
22.5 W0(OII) gt 15A and 0.4 ? z ? 0.75 gt
representative of emission line galaxies at z
0.6 (MB lt -19.5)
- Simple classification using VFsigma HST
morphology rotating disks 31
perturbed/complex 60 undetermined 9
- Accounting for all IABlt 22.5 (i.e. including
quiescent E/S0/) gt we do find that 40 of
them are not relaxed systems
SOON a sample with 80 z0.6 galaxies
GIRAFFE/multiple IFUs good tool to study the VF
of distant galaxies
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some prospectives with SKA
To test TF evolution requires to go to z1 and
further, for catching galaxies with more
significant gas content
About 50 of today stars formed since z1 (Hammer
et al 2005) and 2 times more gas at z0.65 than
today (indirect estimate, Liang et al, 2006) gt
SKA to identify the gas origin for the star
formation (better than from just modelling)
z0 stellar TF / baryonic TF McGaugh 2005
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Some numbers
To sample large scale motions in individual
galaxies, requires 2-3 kpc up to z 1 (e.g.
Giraffe) gt is this feasible with SKA ? A need
to simulate the best/other configuration
(baseline/field) to be used with SKA
From van der Hulst et al (2004)
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Some other needs to prepare SKA
To have a full understanding of the
gas/star/total mass in the local universe
HI surveys (vflat M(HI) ) have still not the
coverage of SDSS (optical spectra images) and
of 2MASS (stellar masses) !
HI for SDSS-2MASS galaxies Chemin et al. (2007,
in preparation)
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Comparison with simulations

• a large fraction of on-going minor major
  mergers at z 0.6 ?
• perturbed VF minor mergers ?
• complex VF major mergers ?
• gt to be compared with
• hydrodynamical codes
• (coll. with Cox, Dekel,
• Primack et al)
• Puech s PhD thesis
• Simulations T. J. Cox

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Merger rates from imagery

• Morphologically-messed up things
• Close galaxy pairs
• Neither are perfect

From 1/3 (EB) to 3/4 (FH) merger per L galaxy,
since z 1
Bell et al. 06
Patton et al. 2002 Bundy et al. 2004 Le Fevre et
al. 2000 Conselice et al. 2003 Somerville et al.
in prep.

Consistent with 40 of on-going mergers (from
VF) at z0.6
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Conclusion
1- Since z0.4, galaxy dynamics is too complex to
be sampled by slits gt is this a definitive
claim ? 2- Requires multi-IFUs to sample gt 50
rotating disks (among gt 150 distant galaxies)
goal is to verify the absence of TF evolution 3-
High rate of merging (major/minor) or could this
be recovered by other scenarios (cold gas, Dekel
Birboim)? 4- To be compared with
gas/metal/SFR/stellar mass evolution gt another
clue of the disk rebuilding ?
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Merger or secular evolution ?
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Status of IMAGES

• Observations of half the targets with GIRAFFE
  FORS2
• all the tools well-designed (see Flores et al,
  Puech et al, 2006)
• further progress in estimating Vmax(comparison
  with FP data)
• Data reduction well in progress
• -most GIRAFFE datacubes reduced,
• FORS2 spectra reduced and analyses in progress
• First paper submitted (IMAGES1, Ravikumar et al)

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FLAMES/GIRAFFE on the UT2
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Comparison to local (Fabry-Perot)
- FP observations of 20 GHASP galaxies (Amram et
al, 2002) gt simulations of 60
data-cubes at different z gt
rotating disks are recovered - FP observations
of complex velocity fields
Perturbed/complex VFs are real!!