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VLT FLAMES Jeremy R. Walsh , ESO. Three modes: Medusa -132 single object fibres (+6-8 fibres to UVES) IFU – 15 x 20 spaxel IFU’s (2x3’’, 0.52’’) Argus – 14x22 IFU ( spaxel scales 0.52 or 0.30’’) Unique among IFU facilities in offering high spectral resolution (R~10000 & 30000).
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VLT FLAMES Jeremy R. Walsh, ESO Three modes: Medusa -132 single object fibres (+6-8 fibres to UVES) IFU – 15 x 20 spaxel IFU’s (2x3’’, 0.52’’) Argus – 14x22 IFU (spaxel scales 0.52 or 0.30’’) Unique among IFU facilities in offering high spectral resolution (R~10000 & 30000)
FLAMES Medusa and IFU modes 132 1.2’’ fibres over 28’ diameter field placed by OzPozpositioner IFUs deployable over field – 0.52’’spaxels
FLAMES Giraffe Two gratings Low Res 600 l/mm grating in low orders (2-5) High Res 316 l/mm grating in high orders (6-15) EEV 4kx2k detector with good blue sensitivity. Currently being changed to a red Sensitive CCD
FLAMES Giraffe - 2 22 HR modes R~19-47K (depending on order) and coverage 170-650Å
FLAMES Argus + Giraffe Simultaneous calibration lamp for high accuracy radial velocities (<50 ms-1) Use only if really required!
Tutorial Project Emission line spectroscopy of planetary nebulae to study the spatial structure of optical recombination lines (e.g. O++ +e- -> O+) OIII 4089Å [ORL] and collisionally excited lines (O++ + e- -> O++) [O III] 4363Å [CEL]
NGC 7009 Observed a region including the bright shell on the minor axis for spectroscopy in the L2 and L3 modes, coverage 3960 – 5070A to include bright H, He and [O III] lines and faint OII lines NGC 7009 imaged by WF/PC2 on HST with FLAMES/Argus overplotted
NGC 7009 L2 spectrum Hγ [O III] Text O III C II
NGC 7009 L2 analysis Fit the emission lines of interest with Gaussians for each spaxel and make maps of emission line flux (and error)
NGC 7009 L2 analysis Correct maps for extinction (from Hg/Hb) and produce line ratio maps.
NGC 7009 L2 analysis From line ratio maps determine electron density Ne (cm-3) from [Ar IV] 4711/4740Å and electron temperature Te (K) for [O III] 5007/4363Å
NGC 7009 L2 analysis From Te and Ne and line ratios to Hβ make maps of ionic abundances. Compare ORL and CEL abundance maps
NGC 7009 L2 analysis Analyse abundance gradients between ORL and CEL and the Abundance Discrpancy Factor (ADF) = ORL/CEL abundance ratio See Yiannis, T., Walsh, J. R. et al. 2008, MNRAS, 386, 22 for more
FLAMES Giraffe Data Reduction Two pipelines available: girBLDRS written by the Geneva Observatory group who were on the one of the Instrument Teams. Uses python and C to implement stand-alone pipes Gasgano (window based) or esorex (command line based) file organizer as version of the ESO Quality Control (running CPL with common C code to girBLDRS)