A NEAR-INFRARED MULTIPLE-OBJECT INTEGRAL-FIELD

SPECTROMETER FOR THE VLT

The Science Case

Matt Lehnert, MPE

Distant Galaxy Science Distant Galaxy Science DriversDrivers

• 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 1 2 3 4 5 6 7 8 >9

Mg B

G Band

4000Å

Lyα

He II

[OII]

Hβ

[OIII]

Hα

CaT

Iz-bands: 0.80-1.05 µmJ band: 1.05-1.37 µmH band: 1.45-1.85µmK band: 1.95-2.50 µm

SFR, extinction, dynamics

metallicity, dynamics

extinction, metallicity

SFR, metallicity, density

Pop III/AGN

Reionization, escape fraction

Stellar populations

V(r,), (r,), v, Mvirial, fline(r,)

J/M,vrot/σ etc. – not with photometry or slitlets

Spatially-Resolved Spatially-Resolved PropertiesProperties

vrot/ =f(M, z) &

J/M = f(M, z)

Mergersvs.

Infall

dM/dt =f(M, r, z)

Superwinds&

Self-regulation

[O/H]=f(M, r, z)

Local Universe Science Local Universe Science DriversDrivers

• 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? Arethe 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-Diagnostic lines in the Near-IRIR

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: CO-bandheads in the H and K bands, SiI, MgI (in the K and z-band), CaI, Bracket and Paschen lines in absorption, the Calcium triplet in the z-band, etc

Galaxy Number CountsGalaxy Number Counts

Förster-Schreiber et al. (2004) and (2006)

K Selected GalaxiesK Selected Galaxies

Daddi et al. (2004)

… highly efficient way of selecting distant galaxies …

for 20 < K < 22, z>1.4 …about 4 sources arcmin-2

over 53 arcmin2 … KMOS FOV

zz1-3 Star-Forming Galaxies1-3 Star-Forming GalaxiesPopulating 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 LBGsClustering of z~3 LBGs

Steidel et al. (2000)

3.06<zspec<3.12 (24)

“Narrow band excess” (72)

“Giant Ly blob” (2)

… 162 objects that are likely to be associated …

Likely Sensitivity of Likely Sensitivity of KMOSKMOS

In 8 hrs integration (1 night):

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

BX galaxy at z=2.2101

Sensitivity Comparison in I/z Sensitivity Comparison in I/z bandsbands

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 – Galaxies in Pieces – Standard ModelStandard Model

Dark matter distribution on100s kpc scale.

Abadi et al. (2002)

Gill et al. (2004)

Merger TreeMerger Tree

Frenk, Baugh, & Cole (1996)

Ultimately:Spiral Elliptical

smooth vs complex … angular momentum … dissipative vs. non-dissipative collapse

Angular momentum Angular momentum problemproblem

Steinmetz & Navarro (2000)

Galaxies have JDisk ≈ JHalo

SPH plus N-body predict J that is too low

Formation of Disks in Formation of Disks in Mergers?Mergers?

Gas-rich mergers plus vigorous feedback

Robertson et al. (2005)

Predicts enough angular momentum, but needs robust feedback to keep disk from collapsing …

No BH

BH

Disk formation – Disk formation – accretion?accretion?

forms individual clumps of ~few x 109 M which coalesce to form a bulge in a few dynamical times …

In highly dissipative accretion/collapse, disks are very unstable …

Immeli et al. (2004)

~Gyr

~6 kpc

Early insights: ELS ‘62, Silk (1977), Binney (1977), Ostriker & Rees (1977)

Disk formation – accretionDisk formation – accretion

… properties appear similar to model predictions … but which model …

Elmegreen & Elmegreen (2005)

Clumpy galaxies in the UDF …

170

-170

2343-610

300

400

200

-170

170

SSA22-MD41

0

170

250

500

100

300

FWHM-200

200

v1623-663

2346-482-110

110 200330

-60

1623-528

60

60 180

320-60

Velocity fields of z~2 Velocity fields of z~2 GalaxiesGalaxies

Förster Schreiber, Genzel, Lehnert et al. (2006)

In best cases: 2-D velocity field is smooth and consistent with orbital motion – rotating disks?

evidence for evidence for high high μμKK, , metal-rich metal-rich stellar stellar population population at the at the dynamical dynamical center of center of BX610BX610

Q2343-BX610 Hα [NII]

line-free K-continuum [NII]/Hα

Range 0.25 - 0.55

Förster Schreiber et al. (2006)

≈dynamical center

Puech et al. (2006)

MergersMergers

Image Velocity map Dispersion map

z~2 galaxy

Model “analogued”

Model “original”

Dark Matter Mass and Dark Matter Mass and Angular momentumAngular momentum

If rotational support, compared to dark matter halos implies

(Mo, Mao &White ‘98):

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)

z~2

Förster Schreiber, Genzel, Lehnert et al. (2006)

Summary of z~2-3 Galaxy Summary of z~2-3 Galaxy ResultsResults

• <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 scenarioEmphasizing the role of gas accretion… and larger samples!!!!

LBGs at z>5

BDF1:10 z=5.774 8191.8Ǻ

8083.0ǺBDF2:19 z=5.645

7315.5ǺBDF1:18 z=5.017

8351.4ǺBDF1:19 z=5.870

7362.0ǺBDF1:26 z=5.056

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 …… KMOS can be used to investigate their complex morphologies …

R>3000 important for both night sky subtraction, HeII, and identifying source as Ly emission

R=3200

Stars in the Galactic Center

10”(0.39 pc)

0

1

2.04 2.06 2.08 2.10 2.12 2.14 2.16 2.18 2.20

IRS16 SW (Ofpe/LBV)

wavelength (m)

-0.1

0

0.1

2.05 2.10 2.15 2.20 2.25 2.30 2.35 2.40

IRS16SE2 (WN5/6)

wavelength (m)

0

1

2

3

4

1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4

IRS10 EE (K5 Ia/b)

wavelength (m)

1.5

3.0

4.5

6.0

7.5

1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4

IRS10 EE (M7/8 III)

wavelength (m)

0

0.1

0.2

2.0 2.1 2.2 2.3 2.4

IRS3 (WC 5/6)

wavelength (m)

0.9

1.0

1.1

1.2

1.3

2.12 2.14 2.16 2.18

S2 (O8/9 V)

3D spectroscopy critical in removing nebular emission and absorption from stellar resonance and recombination lines

KMOSKMOS3-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.