Infrared instruments for a 2.5m telescope at Dome C

Transcription

1 Infrared instruments for a 2.5m telescope at Dome C A. Mora 1, C. Eiroa 1, D. Barrado y Navascués 2, M. L. García- Vargas 3, M. Maldonado 3, E. Sánchez-Blanco 3, C. Abia 4, P. Persi 5 1 Universidad Autónoma. Madrid. Spain 2 LAEX-CAB (INTA-CSIC). Madrid. Spain 3 FRACTAL-SLNE. Las Rozas. Spain 4 Universidad de Granada. Granada. Spain 5 Istituto di Astrofisica Spaziale e Fisica Cosmica.. Roma. Italy II Workshop ASTRID-RIA. September Madrid Motivation Outline Antarctica and Dome C Unique science cases NIR instrument MIR (& sub-mm) instrument Conclusions

2 Motivation Motivation Dome C: best NIR, MIR & sub-mm site Major step: a 2m-class telescope PILOT: Australian proposal for a telescope Lack of studies for the instruments Astrid project: conceptual design studies NIR: wide field camera MIR (& sub-mm): camera spectrograph Additional funds: acción complementaria Study finished. Reports available

3 Antarctica and Dome C Dome C and Concordia Third Antarctic Plateau summit 3200 m altitude, 75 S 123 E 1100 km inland Low temperature [-90ºC,-30ºC] Extremely dry: 200m m H 2 0 winter High atmospheric stability Seeing 35m Low scintillation (no aerosols) Clear skies (90% time fraction) Concordia Base: France-Italy

4 Dome C in the NIR Cold atmosphere during winter Thermal emission in Wien tail (KLM) reduced ~2 orders of magnitude K dark 2.30 m: sky emission ~ zodiacal light Telescope at Dome C is competitive with space Free atmosphere seeing ~ m telescope near diffraction limited in KLM Dry extended transmission in KLM Increased sky stability Exoplanet transits Dome C in MIR and sub-mm Extremely dry New windows from the ground MIR: Q m, sub-mm: 200 m Sky stability Mosaics in Q band, sub-mm noise Cold ~100x lower sky emission Q+ band Lenzen 2007 Durand et al. 2008

5 Unique science cases Unique science cases NIR-MIR: survey of star forming regions NIR-MIR: exoplanet secondary transits MIR: embedded protostars MIR: crystalline silicates MIR: H 2 galactic plane survey MIR-submm: solar flares

6 NIR-MIR unique science: Exoplanet secondary transits Thermal emission of hot jupiters detected at > 2m2 Star-planet flux ratio ~1-3 e-3 Dome C: low background + high stability + continuous observations Bands KLMN. Distant objects. Single telescope Multiwavelength approach: SED and bands planet physics Detection limits (pc): F5V (360 L, 190 M, 27 N) K5V (140 L, 69 M, 10 N) K Mooij & Snellen 2009 Charbonneau et al MIR unique science: Embedded protostars Class 0/I YSOs peak k in m m (T~30-70( K) SED fitting by models physical parameters Fluxes in m break degeneracies Follow up of WISE discoveries up to 5kpc Robitaille et al. 2007

7 NIR instrument NIR: conceptual design Telescope: PILOT 2.5m specifications, Good Wavefront Wavelength: m. Optimized for K dark and L Detector: 2x2 Mosaic Hawaii 2RG m m pixels Plate scale: 0.15 /pixel Nyquist sampling for KLM (diffraction limited) Nyquist sampling for zyjh with free atmosphere seeing ~0.36 Pseudo-Offner reflective design Inspired on Saunders et al. (2008) Compact, simple, robust and availability of pupil image Image quality: diffraction limited Field of view: 10.2 x10.2 x10.2

8 NIR: optical design NIR: optical quality Diffraction limited in JHKLM Plate scale optimized for K dark JH + good seeing drizzle Good quality pupil image Low distortion

9 NIR: mechanical design Total mass: ~750 kg Base unit: Teledyne Hawaii 2RG pix 18 m m pixels Sensitive: m 2x2 mosaic, as used by VLT/HAWK-I Alternatives do exist PILOT plate scale matched to Hawaii Phase B definition NIR: detectors

10 MIR (& sub-mm) instrument MIR: conceptual design Telescope: PILOT 2.5m specifications Optimized for Q window (17-40 m) Three detectors: active one selected by rotating mirror blue arm 8-25 m Raytheon Aquarius 1 Mpix Si:As IBC detector. Plate scale 0.86 /pixel. Field of view: 14.6 x14.6 x14.6 red arm m DRS 256x256 Si:Sb BIB detector. Plate scale 1.4 /pixel. Field of view: 6.1 x6.1 x6.1 sub-mm m Four 12x12 mm PACS-like bolometer arrays. Field of view: 11.4 x11.4 x11.4 Shared optics. Different entrance window Diffraction limited performance for 17+ m Low resolution MIR spectroscopy: / ~

11 MIR: optical design MIR: optical quality Collimation quality at 17 m Image quality at 17 m Spot size diagram Distortion grid diagram

12 MIR: mechanical design Cryostat diameter ~1.8m. Total mass: 1200 kg MIR: detectors Blue arm: Raytheon Aquarius Si:As IBC 1 Mpix 30 m m pixels Red arm: DRS Si:Sb BIB 256x m m pixels PMIRC Typical QE for DRS detectors Sub-mm: half PACS blue focal plane

13 Conclusions Conclusions Conceptual design finished Unique science cases NIR & MIR instruments are feasible Restrictions on telescope (e.g. chopping, weight) Main conclusions in prep.. Reports available on request The way forward Phase B study: telescope and instruments Not an easy task: access to Concordia and the telescope, funding, partners, schedule Further progress depends on previous factors

14 Extra slides

15 Domo C: el entorno Domo C: base Concordia

16 Emisión atmosférica Mejora hasta dos órdenes de magnitud (T, aerosoles) Lenzen 2007 Estabilidad atmosférica Muy alta estabilidad en la meseta antártica Fotometría de alta precisión (un orden de magnitud) Domo C se prevé mejor que el Polo Sur Estabilidad en banda N. Polo sur Estabilidad en banda N. Camberra Smith & Harper 1998

17 NIR-MIR unique science: Star forming regions full survey NIR (KLM): subestellar and planetary mass objects Mid infrared: N, Q, Q+. Very young embedded objects Dome C vs JWST & SOFIA Full coverage Dome C vs Spitzer & WISE ~5x spatial resolution Dome C vs VISTA ~2x spatial resolution Much deeper at 2 m Sensitive from L onwards Chamaeleon dark clouds. Cambrésy 1999 MIR unique science: Crystalline silicates Sillicates become crystalline in high temperature environments (e.g. protoplanetary disks, PNe) Crystalline features are best observed in m (avoid blending with amorphous population and PAHs) Observation of nearby protoplanetary disks (~200 pc) Kessler-Silacci et al. 2006

18 MIR unique science: Galactic plane survey in H 2 Fundamental rotational lines lie in the MIR S(1) 17.0 m m and S(2) 12.3 m m are observable Galactic plane survey. Sensitivity S(1): 140K, S(2): 165 K Lawrence et al (submitted) MIR & sub-mm unique science: Solar flares THz rising tail in solar flare spectra sub-mm & MIR Physical mechanism is unknown PMIRC: images in m m and m MIR 2.5m resolution: one order of magnitude better Kaufmann et al Lawrence et al (submitted)

19 MIR: H 2 spectro-imaging Ge, ZnSe etalons interference filters Similar devices for calibration in VLT/VISIR Circular field of view: 14.6 diameter Scanning through sky 3D data cube V V ~ km/s from centre to border Appropriate for the Galactic Plane Galactic centre: several filters or low n MIR: blue arm image sensitivity Good, but the real gain is the stability!

20 MIR: red arm image sensitivity MIR: spectral sensitivity vs Spitzer/IRS Sofia and Dome C only