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GEPI, Obs. Paris: F. Hammer, H. Flores, M. Puech & C. Balkowski LAM : P. Amram MPE ==> GEPI : M. Lehnert Stockholm Obs. : G. Ostlin, T. Marquart Galaxy dynamics since z ~ 1
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FDF Vogt et al, (1997) 0.1< z <1.0 M B ~0.5 Simard & Pritchet al (1998) M B ~2.0 Barden et al. (2003) 19 Sp. (0.6<z<1.5) M B ~1.1 Ziegler et al, 2003 77 gal (0.1< z< 1.0) M B ~1.0 z < 1, studies with slits B-band Tully Fisher relation & its evolution Local TF (Verjeinhen 2001)
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K-band Tully Fisher relation & its evolution Conselice et al (2005) KECK/LRIS (long slit) Conselice et al (2005) Local TF (Verjeinhen 2001)
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The multi-IFU mode of GIRAFFE 15 IFUs deployable over a 20 arcmin FoV R= 9000 / 22000 No cross-talk between fibers on the CCD 15 x
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35 galaxies, 0.4 15Å: T int from 8 to 13hrs ==> 32 with enough pixels (6-18) with good S/N(OII) (> 6) CFRS03.0488, z=0.46, (3’’x2’’)Velocity field Preliminary program (GTO, Paris) 6 nights on distant galaxies (PI: H. Flores) 1 2 3 4 1 2 3 4 5x5 linear interpolation R> 13000 at rest [OII] doublet In most cases the doublet is well resolved
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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) GIRAFFE pixel @ z=0.6 pixel = random_motions V large_scale_motions
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Also sigma maps… pixel = random_motions V large_scale_motions At low spatial resolution, dispersion maps of rotating disks do show a peak in their center Velocity map Dispersion or map
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And we find rotating disks at z ~ 0.6 HST/F814W Velocity field sigma map Maps from Puech et al (2006a) & Flores et al (2006), astro-ph/0603562 & 0603563)
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but also « perturbed » rotations HST/F814W Velocity fieldsigma map Maps from Puech et al (2006a) & Flores et al (2006), astro-ph/0603562 & 0603563)
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and much complex kinematics HST/F814WVelocity fieldsigma map 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 I AB 15A have been observed within the GIRAFFE field ==> no bias expected Spatial resolution: Several galaxies have r half < 0.5 arcsec in the continuum, i.e. the size of the GIRAFFE pixel But within the ionised gas region (OII): they have 11 GIRAFFE pixels (median value) with enough S/N(OII) (> 6) to be mapped HST/F814W OII hot pixels
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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 Complex VF Perturbed VF Rotat. disk VF ▲ █▲ █ ●
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▲ ● Rotating disks (34 %) IFU: 3’’x 2’’ Perturbed rotation (22%) █ Complex kinematics (44%) Combined to photometric data: M B & M K Tully-Fischer relation A simple classification scheme
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Conselice et al (2005) KECK/LRIS (long slit) Conselice et al (2005) Tully-Fischer relation at z ~ 0.6 (K band) VLT/GIRAFFE-IFUs Flores et al (2006, A&A, astro-ph/0603563)
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Complex VF Perturbed VF Disk-like VF ▲█▲█ ● Conselice et al (2005) KECK/LRIS (long slit) Conselice et al (2005) VLT/GIRAFFE-IFUs Flores et al (2006, A&A, astro-ph/0603563)
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Conselice et al (2005) KECK/LRIS (long slit) Conselice et al (2005) VLT/GIRAFFE-IFUs Flores et al (2006, A&A, astro-ph/0603563) Scatter is related to interlopers (non relaxed kinematics)
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Local TF (Verjeinhen 2001)TF at z=0.6 (Flores et al, 2006) Tully-Fischer not evolving ? We need statistics !!!
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Galaxy kinematics at z ~ 0.6: some numbers A (small) complete sample of 35 galaxies: I AB 22.5 ; W 0 (OII) > 15A and 0.4 z 0.75 ==> representative of emission line galaxies at z= 0.6 (M B representative of emission line galaxies at z= 0.6 (M B < -19.5) - Simple classification using VF+sigma+ HST morphology: rotating disks: 31%; perturbed/complex: 60%; undetermined: 9% - Accounting for all IAB< 22.5 (i.e. including quiescent E/S0/…): ==> we do find that ~ 40% of them are not relaxed systems GIRAFFE/multiple IFUs: good tool to study the VF of distant galaxies SOON: a sample with 80 z=0.6 galaxies
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some prospectives with SKA To test TF evolution requires to go to z=1 and further, for catching galaxies with more significant gas content z=0: stellar TF / baryonic TF McGaugh; 2005 About 50% of today stars formed since z=1 (Hammer et al 2005) and 2 times more gas at z=0.65 than today (indirect estimate, Liang et al, 2006) ==> SKA to identify the gas origin for the star formation (better than from just modelling)
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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) ==> 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 (v flat + 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 ? ==> 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 Morphologically-messed up things Close galaxy pairs Close galaxy pairs Neither are perfect Neither are perfect * 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. ~1/3 (EB) to 3/4 (FH) merger per L* galaxy, since z= 1 From ~1/3 (EB) to 3/4 (FH) merger per L* galaxy, since z= 1 ~ Consistent with ~ 40% of on-going mergers (from VF) at z=0.6 …
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Conclusion 1- Since z=0.4, galaxy dynamics is too complex to be sampled by slits ==> is this a definitive claim ? 2- Requires multi-IFUs to sample > 50 rotating disks (among > 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 ==> 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 V max (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 UT2MEDUSE, 132 mono-fibers, 1”.2 IFU, IFU, 3’’x2’’arrays 15 deployable IFUs ARGUS, ARGUS, 11”x7” array 3 modes
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FP velocity field ESO 400-G43 (Ostlin et al, 2001) Simulated Giraffe IFU observation (degraded spatial resolution, z=0.6) Perturbed/complex VFs are real!! - FP observations of 20 GHASP galaxies (Amram et al, 2002) ==> simulations of 60 data-cubes at different z ==> rotating disks are recovered - FP observations of complex velocity fields: Comparison to local (Fabry-Perot)
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