A NEAR-INFRARED MULTIPLE-OBJECT INTEGRAL-FIELD SPECTROMETER FOR THE VLT The Science Case Matt Lehnert, MPE Distant Galaxy Science Drivers • Growth and dynamics of intermediate redshift clusters -- How do cluster galaxies grow and evolve? When was the morphology density put into place? What’s the role of “dry” vs. “wet” mergers? Can we see differences between cluster and field galaxies at high redshifts? • Dynamics of intermediate and high redshift galaxies -- How do galaxies grow? Why were galaxies “downsized”? Gas accretion quasi-adiabatically or through merging? What is the source of angular momentum? Does it grow linearly with time? How did mass surface density evolve? • Gas phase metal abundances and absorption lines in distant galaxies – What is the evolution of mass and metallicity? How was the ISM polluted with metals? Early enrichment? Metal distribution -- Is this consistent with “inside-out” galaxy formation models? • Evolution of AGN – What is the relationship between the growth of BHs and growth of galaxies? Did this happen in “fits, stops, and starts”? z Lyα He II [OII] 1 2 3 4 5 6 7 Pop III/AGN SFR, metallicity, density extinction, metallicity [OIII] metallicity, dynamics 4000Å G Band Mg B CaT >9 Reionization, escape fraction Hβ Hα 8 SFR, extinction, dynamics Iz-bands: 0.80-1.05 µm J band: 1.05-1.37 µm Stellar populations H band: 1.45-1.85µm K band: 1.95-2.50 µm Spatially-Resolved Properties vrot/ =f(M, z) & J/M = f(M, z) Superwinds & Self-regulation V(r,), (r,), v, Mvirial, fline(r,) Mergers vs. Infall [O/H]=f(M, r, z) dM/dt =f(M, r, z) J/M,vrot/σ etc. – not with photometry or slitlets Local Universe Science Drivers • Stellar populations in the MW and other nearby galaxies. When did the disk form in other galaxies? What is the relationship between metallicity and dynamics for individual stars and clusters? What is the age and metallicity distribution of the stars in, for example, the GC. • The dynamics of merging/interacting and star-bursting galaxies. Do the compact young clusters have the same ages as the background stars? Are the clusters long-lived? What fraction of the star-formation is in clusters? What about metallicity versus age – what is the mixing time scale for metals? • The properties of stars embedded in their natal molecular cloud. What is the initial mass function? What is the impact of the stars on the surrounding nebula? IFUs are crucial for removing the nebular emission from stellar recombination lines. Diagnostic lines in the Near-IR Ionization: [SiVI] and other highly ionized forbidden lines for AGN, Bracket and Paschen lines in emission, various HeI lines, H2 vib-rotational lines for X-ray heating and PDR diagnostics, etc. Shocks: H2 vib-rotational lines, FeII lines, etc. Ages, surface gravities, and temperatures of stars: CObandheads in the H and K bands, SiI, MgI (in the K and zband), CaI, Bracket and Paschen lines in absorption, the Calcium triplet in the z-band, etc Galaxy Number Counts Förster-Schreiber et al. (2004) and (2006) K Selected Galaxies … highly efficient way of selecting distant galaxies … for 20 < K < 22, z>1.4 … about 4 sources arcmin-2 over 53 arcmin2 … KMOS FOV Daddi et al. (2004) z1-3 Star-Forming Galaxies Populating the “redshift desert” z=1.5-3.5 SFR20-60 M yr-1 [M/H] 0.8[M/H] Selects only actively star-forming galaxies! Steidel et al. (2004) Clustering of z~3 LBGs 3.06<zspec<3.12 (24) “Narrow band excess” (72) “Giant Ly blob” (2) … 162 objects that are likely to be associated … Steidel et al. (2000) Likely Sensitivity of KMOS In 8 hrs integration (1 night): BX galaxy at z=2.2101 5 limits for compact galaxies and between OH lines are: J~22, H~21.2, K~19.4 … but with SINFONI, in 3 hours, at ~0.5” seeing, for … FH1.7x10-16 ergs s-1 cm-2 Ks=19.2 5σ in 1 hour for SINFONI of: K~18.4 & FH4x10-17 ergs s-1 cm-2 µH4x10-17 ergs s-1 arcsec-2 3 hours of total integration time Sensitivity Comparison in I/z bands KMOS has better sensitivity, better sampling, 3-D capability, and comparable or higher multiplex, and is more flexible … Stoichiometry for Cd1-yZnyTe Galaxies in Pieces – Standard Model Dark matter distribution on 100s kpc scale. Gill et al. (2004) Abadi et al. (2002) Merger Tree Ultimately: Spiral Elliptical Frenk, Baugh, & Cole (1996) smooth vs complex … angular momentum … dissipative vs. non-dissipative collapse Angular momentum problem Galaxies have JDisk ≈ JHalo SPH plus N-body predict J that is too low Steinmetz & Navarro (2000) Formation of Disks in Mergers? Gas-rich mergers plus vigorous feedback No BH BH Robertson et al. (2005) Predicts enough angular momentum, but needs robust feedback to keep disk from collapsing … Disk formation – accretion? Early insights: ELS ‘62, Silk (1977), Binney (1977), Ostriker & Rees (1977) In highly dissipative accretion/collapse, disks are very unstable … ~Gyr ~6 kpc Immeli et al. (2004) forms individual clumps of ~few x 109 M which coalesce to form a bulge in a few dynamical times … Disk formation – accretion Clumpy galaxies in the UDF … Elmegreen & Elmegreen (2005) … properties appear similar to model predictions … but which model … Velocity fields of z~2 Galaxies In best cases: 2-D velocity field is smooth and consistent with orbital motion – rotating disks? v 1623-663 FWHM 500 -200 300 200 SSA22-MD41 100 -170 170 0 250 170 2343-610 170 200 400 300 -170 2346-482 -110 200 110 1623-528 60 180 -60 -60 Förster Schreiber, Genzel, Lehnert et al. (2006) 330 60 320 evidence for high μK, metal-rich stellar population at the dynamical center of BX610 Q2343-BX610 Hα line-free K-continuum [NII] [NII]/Hα Range 0.25 - 0.55 ≈dynamical center Förster Schreiber et al. (2006) Mergers z~2 galaxy Model “analogued” Model “original” Image Velocity map Dispersion map Puech et al. (2006) Dark Matter Mass and Angular momentum If rotational support, compared to dark matter halos implies (Mo, Mao &White ‘98): z~2 Mhalo1011.7 (vc/180 kms-1)3 (1+z/3.2)-1.5 M jhalo102.8 0.05(vc/180 kms-1)2 (1+z/3.2)-1.5 km s-1 kpc • jdisk problem persists • vcircularvvirial since dynamical and clustering estimates are in rough agreement Abadi et al. (2003) Förster Schreiber, Genzel, Lehnert et al. (2006) Summary of z~2-3 Galaxy Results • • • • • <Mdyn> ~ few x 1010 M vcircular vvirial Σdyn ~ few x 109 M kpc-2 (Mdyn/Area½) Jz~2 ~ Jspirallocal, angular momentum “in place” v/σ and angular momentum may imply rapid accretion “inside-out” galaxy formation scenario Emphasizing the role of gas accretion … and larger samples!!!! LBGs at z>5 8191.8Ǻ BDF1:10 z=5.774 BDF2:19 z=5.645 BDF1:18 z=5.017 BDF1:19 z=5.870 BDF1:26 z=5.056 8083.0Ǻ 7315.5Ǻ 8351.4Ǻ 7362.0Ǻ HST VIz images of V-band “dropouts” S/N(Z)>5 S/N(I)>3 S/N(B)<3 I>26.3 V-I>1.7 (contaminants included) Median UV half-light-radii: 1kpc Night Sky Problem … gaps in the night sky are used for narrow band searches … … KMOS not a particularly good redshift machine … R=3200 … KMOS can be used to investigate their complex morphologies … R>3000 important for both night sky subtraction, HeII, and identifying source as Ly emission Stars in the Galactic Center 4 IRS3 (WC 5/6) IRS10 EE (K5 Ia/b) 0.2 3 0.1 2 1 0 0 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.0 2.4 2.1 2.2 2.3 2.4 wavelength (m) wavelength (m) 1 .3 IRS16SE2 (WN5/6) 0.1 S2 (O8/9 V) 1 .2 1 .1 0 1 .0 -0.1 2.05 2.10 2.15 2.20 2.25 2.30 2.35 0 .9 2.40 2 .1 2 2 .1 4 2 .1 6 2 .1 8 wavelength (m) 7.5 IRS10 EE (M7/8 III) IRS16 SW (Ofpe/LBV) 6.0 1 10”(0.39 pc) 4.5 0 3.0 1.5 1.6 1.7 1.8 1.9 2.0 2.1 wavelength (m) 2.2 2.3 2.4 2.04 2.06 2.08 2.10 2.12 2.14 2.16 2.18 2.20 wavelength (m) 3D spectroscopy critical in removing nebular emission and absorption from stellar resonance and recombination lines KMOS 3-D spectroscopy is crucial for studying in situ galaxy evolution; While emphasizing the distant galaxy science case, KMOS is flexible and can do a wide range of studies; The combination of large FOV, 2 dozen IFUs, and a flexible arm placement means that KMOS will be highly efficient at getting the most important targets in any science field; Will provide robust statistical samples w/ 3-D data.