Integral Field Spectroscopy on Gemini Andrew Bunker (IoA, Cambridge) Euro3D Meeting July 2002 GMOS Gemini Multi-Object Spectrograph, optical IFU (Durham)

Gemini Integral Field Spectroscopy  Program with Gemini Observatory to demonstrate the power of IFUs (5+5 nights GMOS+CIRPASS)  Large interntational team (CIRPASS observations involve ~50 scientists) lead by Cambridge/Durham  Aimed at raising profile of IFU science in the Gemini community  Data made public in 2 months  Institute of Astronomy, Cambridge: Andy Bunker, Joanna Smith (PhD student), Richard McMahon, Gerry Gilmore & Ian Parry, Rob Sharp etc (CIRPASS team)  Durham: Richard Bower, Roger Davies etc & GMOS team  Gemini: Kathy Roth, Marianne Takamiya, Inger Jørgensen etc. (Director's discretionary time)

GMOS-IFU GEMINI-SOUTH GEMINI-NORTH June August 2002

IFU Science " Exquisitely sensitive to line emission redshifted between OH  Star formation at z>1 (H , [OIII]5007Å, H , [OII]3727Å)  Robust star formation rate measures down to 1M M /yr " Rotation curves, kinematics " Masses, extinction, metallicity  Nature of damped Lyman-  systems at high-z " Lensed galaxies/dark matter sub- clumping " Dynamics of dense Galactic stellar systems " Ages of young star clusters

GMOS Optical IFU Spectroscopy  Gemini-N June 2002: Andrew Bunker, Joanna Smith (IoA, Cambridge), Richard Bower (Durham) supported by Inger Jørgensen (Gemini)  3 good nights out of 5; 0.6" FWHM seeing, 0.2" fibres  Used `wide-field' 2-slit mode - 5"x7", use broad-band filters as order sorters  Used moderately high spectral resolution R~4000  100km/s resolution effective at working between sky lines, but (near) read-noise limit Targets - emission lines from:  z=1 lensed arc (kinematics)  z=1.2 3C radio galaxy (alignment effect etc.)  z=3 damped system & QSO (extended Lyman-  )

A z=1.2 radio galaxy 3C324  Extended blue light over >5", aligned with radio  3C radio galaxy z=1.2 deep HST im.  studied by Spinrad & Dickinson  evidence of a cluster  size well-suited to GMOS/CIRPASS  study emission lines [OII] & H-alpha (kinematics)

GMOS IFU Spectroscopy Gemini-N  3C324 z=1.21 radio galaxy - raw data Andrew Bunker (IoA, Cambridge) Euro3D Meeting July Å 8300Å

GMOS IFU Spectroscopy Gemini-N  3C324 z=1.21 radio galaxy - "reduced" 2D (still has sky & cosmics, but extracted fibres) Andrew Bunker (IoA, Cambridge) Euro3D Meeting July Å 8300Å

3C324 3-D data cube [OII]3727 structure has two velocity components at +/-400km/s Wavelength/velocity

z=1.03 lensed arc  z=1.03 Pello et al. (1992)  Good lens model for this cluster Abell2218  Reconstruct galaxy image  GMOS to study [OII]3727Å emission line  Spatially-resolved kinematics  Infer mass given lensing stretch 

z=1 arc 3D data cube [OII]3727Å doublet, ~300km/s velocity shift Wavelength/velocity

What is CIRPASS?  Near-infrared integral field unit  Built with UK government (PPARC) & private money by IoA Cambridge  Wavelengths  m (z, J, H): doubles range of Gemini IFU science  Working since June 2001 (passed Gemini benchmark test July 2001)  Fibre fed - sits on dome floor  490 spatial samples & variable image scales 0.05"-0.33" up to 5"x12" field  Large wavelength coverage (  =2200Å) at R~4000: great sensitivity between OH sky lines  Limiting line flux on Gemini ~2x ergs/sec/cm^2 (5  3 hours) 500 fibres IFU Instrument cryostat On dome floor

Damped Ly-  QSO Absorption Systems Bunker, Warren et al.

CIRPASS, GMOS and Gemini " Does CIRPASS have the sensitivity & throughput? 1 YES - at z~1 can reach sub-Milky Way star formation rates predicted by hierarchical formation " Is the IFU more efficient than long slit? 1 YES -for our spatially-extended targets " Can this science be done with GMOS IFU alone?  NO -requires IR for H  /[OIII]/H  z>1 • BUT coupling optical & near-IR integral field spectroscopy can act as a "science multiplier • We have used GMOS/IFU in June to hit many of the CIRPASS targets (metallicity & extinction)