Presentation on theme: "Integral Field Spectroscopy on Gemini Andrew Bunker (IoA, Cambridge) Euro3D Meeting July 2002 GMOS Gemini Multi-Object Spectrograph, optical IFU (Durham)"— Presentation transcript:
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 10-15 June 2002 4-9 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 10-15 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 2002 8000Å 8300Å [OII]3727Å @z=1.2
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 2002 8000Å 8300Å [OII]3727Å @z=1.2
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 Tully-Fisher @z=1?
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 0.9-1.8 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 ~2x10 -18 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)