1. 1 Spectroscopy behind PUEO NUI -diffraction limited imaging in the visible -high constrast imaging and coronography - => let's do (imaging) spectroscopy ! Jean-Louis Monin, LAOG with the help of G. Henri, C. Kahane, P.O. Petrucci … and many previous speakers !

2. 2 Competitors : - Subaru (200 electrodes) - Keck eXaoPI (104) - Keck precise AO (cf high dynamic range) - VLT PF What is the question ? HAR ? (of course) Wide field ? (already there) spectroscopy needed ? (you bet) Wavelength coverage ? (large, please) Sensitivity ? (more !) Worthwhile goal : obtain in the visible range the full HAR capability of a 4m telescope. This pleads for spectroscopy, as there are a lot of (atomic) observables in this wavelength range and spectroscopy history is (more) mature. Why and where ?

3. 3 Spectroscopy starts and goes along with imagery Better image quality / contrast / dynamic range will improve S/N ratio and spectral resolution on individual sources access to physical parameters in close associations access to even dimmer companions MOS LONG SLIT Focal plane "actual" 3D spectroscopy + Fabry Perot + imaging FTS (let's stay friends :-)

4. 4 Spectro imaging of CTTS with 3D spectroscopy : better than HST ! 6240 Å6620 Å

5. 5 Young stars in the optical - most of TTS are multiple stars - many Herbig stars have companions "High Angular Resolution" spectroscopy in the visible will help to caracterize the physical parameters of close companions in He / CTTS multiple systems : compared spectral types (cf. G. Duchêne) relative force of accretion (this talk) presence of jets / disks (cf. C. Dougados) evolution state of disks (cf. F. Ménard) high spectral resolution not mandatory (R ~ 1000) 400 Å 800 Å EW (H  ) = 22Å EW (H  ) = 147 Å

6. 6 4 321 5 6 4 3 2 1 5 6 HH PUEO / OASIS DD Tau (2 Å / px)

7. 7 0.20.05 0.1 ang. dist. (arcsec) Mathieu (1994) ARAA 32, 465 Separation distribution of PMS binary stars

8. 8 => 280 TTS (V - R ~1) V lim = 13 R = 12 (13.5) 50% K & V magnitudes of TTS and Herbig stars Still > 50 targets to begin with

9. 9 Other possible targets include : -AGN & QSO : cf. talk by P. Petitjean : high redshift, rotation curve (NIR ?), Lyman-alpha at high z ? - Evolved stars : at last, no one has presented this before ! 7 targets …

10. 10 Evolved stars : AGB, post AGB, planetary nebulae Frosty Leo Roddier et al., 1995 Red rectangle Planetary Nebulae K magnitude R magnitude A sample of 30 hot post AGB Fujii et al., 2002 AGB : cold, dusty environment -> mostly IR and radio spectrocopy (molecules) but … Asymmetrical evolution -> HAR + HSR See also Gauba et al., 2003 (astroph 0303320) MACAO first light !

11. 11 HST would be a competitor  3D spectroscopy (1) or MOS (2) ? CFHT need for another instrument  wide field MOS spectroscopy ? Keep the complexity reasonnable  a 'simple' (dedicated ?) instrument eg. with limited spectral resolution ? HAR + (limited) diameter (4m vs 8m)  stellar physics in the visible (3) ? One of the niche is high contrast  close companions (3D) caracterisation ?  need NIR range (4) ? Time scale 7-10 yrs  check lifetime of given scientific interest Discussion / conclusions (1) / (2) / (3) / (4) versus scientific drivers ?  (1) + (3) ! An instrumental niche ?More competitors ? (HST should still be there in 7 years)