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E-ELT VLT HARMONI – the first light integral field spectrograph for the E-ELT Niranjan Thatte On behalf of the HARMONI consortium Florence - 29 June 2013.

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Presentation on theme: "E-ELT VLT HARMONI – the first light integral field spectrograph for the E-ELT Niranjan Thatte On behalf of the HARMONI consortium Florence - 29 June 2013."— Presentation transcript:

1 E-ELT VLT HARMONI – the first light integral field spectrograph for the E-ELT Niranjan Thatte On behalf of the HARMONI consortium Florence - 29 June 2013

2 Outline  Capabilities of HARMONI  AO science + modes  Integral field + AO: an ideal marriage  Acquisition time / observing efficiency Florence - 29 June 2013

3 Outline  Capabilities of HARMONI  Difference in way of carving up parameter space.  Spatial pixel scales (and FoV)  Spectral coverage and resolving power  No ADC in science path  AO science + modes  Bright objects – SCAO: solar system targets (ref to Fraser’s talk), high contrast, type of coronagraph for no ADC, serendipitous faint object science  Faint objects – LTAO, optimal spaxel scale  Integral field + AO: an ideal marriage?  Strong variation of PSF with wavelength  PSF parameterisation  Need for PSF reconstruction  Acquisition time / observing efficiency Florence - 29 June 2013

4 Modular Construction Florence - 29 June 2013

5 For extended sources & optimal FoV For optimal sensitivity (faint targets) Best combination of sensitivity and spatial resolution 40 mas 20 mas10 mas Highest spatial resolution (diffraction limited) 4 mas 7 7 f f 2.5” × 5” 5” × 10” 1.25” × 2.5” 0.5” × 1.0” 128 × 256 spaxels at all scales

6 Wavelength Ranges & Resolving Powers BandsR V+R, I+z+J, H+K~4000 I+z, J, H, K~10000 Z, J_high, H_high, K_high~20000  Exploring adding simultaneous V-K coverage at R~500-1000  Re-assessing the need for high spectral resolving power at visible wavelengths (< 0.8 micron) Florence - 29 June 2013

7  Integral field spectrograph does not require ADC, as each narrow wavelength channel can be re-aligned in software to compensate for atmsopheric refraction  Blurring within long exposure cannot be compensated post-facto, but improving detector performance allows many shorter exposures to be co-added without penalty. No ADC required Florence - 29 June 2013

8 Wavelength Ranges & Resolving Powers Band min [µm] max [µm]  [Å/pixel] R H+K1.4502.4502.5003900 I+z+J0.8001.3601.4003857 V+R0.4700.8100.8503765 K1.9502.4501.2508800 H1.4601.8300.9258892 J1.0801.3600.7008714 I+z0.8201.0300.5258809 R0.6300.7900.4008875 V0.5000.6300.3258692 K high2.0902.3200.57519174 H high1.5451.7150.42519176 J high1.1701.2900.30020500 z0.8200.9100.22519222 R high0.6100.6800.17518428 V high0.5300.5900.15018666 Florence - 29 June 2013

9 Different Flavours of AO SCAO GLAOLTAO Or even degraded GLAO (NGS only) !!! Florence - 29 June 2013

10 Planets & Stars Stars & Galaxies Galaxies & Cosmology Contemporary Science Florence - 29 June 2013

11 5mas per pixel input10 mas HARMONI scale20 mas HARMONI scale40 mas HARMONI scale100 mas scale on VLT Florence - 29 June 2013

12 High-z Ultra-luminous IR Galaxies Survey 50 Spitzer candidate ULIRGs 1 4000 spectra, spaxels 5-40mas. @ 0.5 - 2.5 . H  in z=2 ULIRG Florence - 29 June 2013

13 Optimal Spaxel Scale Florence - 29 June 2013 15-20mas is optimal spaxel size for LTAO point sources Need to re-compute as a function of wavelength using 39m E-ELT, latest telescope PSFs, and HARMONI design

14 SCAO Provides significantly higher Strehl on-axis (70% v/s 48.5% in K band, median seeing) De-risk LTAO (complex, untested on sky) Key science themes –Characterisation of exo-planets detected by SPHERE / GPI –Detailed studies of outer Solar System (Jovian moons, Neptune, Uranus => see talk by Fraser Clarke Fri morning) –Serendipitous targets (high z galaxies, need ancillary data!) Florence - 29 June 2013

15 Spectroscopy at the Diffraction Limit Florence - 29 June 2013 56mas pupil size (grating physical size) 4mas anamorphic pupil size (ignoring diffraction) Instrument designed for coarse (seeing-limited) spaxels gives excellent performance at diffraction limited scales, even including slit diffraction.

16 High? Contrast with HARMONI  M4 actuator density similar to NACO & SINFONI on VLT, expect similar peak Strehl to SINFONI (~70% in K)  At these Strehl’s, benefit of coronagraph as a diffraction suppression system remains to be demonstrated  ADC would be needed to gain from coronagraph.  Apodizer, followed by large field stop (many λ /D) might work better.  Occulting bar to get around persistence / duty cycle issues  Looking into prism disperser for low R, wide band use.  ADI type operation possible, but co-rotate occulting bar? Florence - 29 June 2013

17 PSF effects Strong variation of PSF with wavelength Florence - 29 June 2013 Parameterize PSF (axi-symmetric) with a few parameters, which vary smoothly with wavelength => see Poster by S. Zieleniewski Allows quick computation of PSF at any wavelength, with high accuracy.

18 PSF Reconstruction Florence - 29 June 2013

19 10€ / second! Amortised cost of E-ELT 10x larger than VLT Need to optimise acquisition time / open-shutter efficiency of science instrument Eliminate –Background sky exposures –Need for telluric calibrators (on-sky) –PSF calibration observations –Blind offsets from reference stars (don’t use long slits!!) –Hunting for tip-tilt stars / NGS reference stars Florence - 29 June 2013

20 Field of View: size & sampling Variable sky & PSF  advantage to avoid mosaicing Typical single objects at z>1  128 x 20mas for short dimension of IFU Large objects (QSO hosts) or diffuse emission & stellar pops studies  largest possible FoV Linear size of spaxel (pc) Linear size of FoV (kpc) Florence - 29 June 2013

21 The E-ELT Florence - 29 June 2013

22 Choices of LGS Asterism Florence - 29 June 2013

23 New Developments (post Phase A)  Smaller telescope  Addition of SCAO capability  Visible cameras for all spectrographs (32000 spectra at all wavelengths)  Fixed format visible camera (TBC)  Explore simultaneous large wavelength coverage at low resolving power  Emphasis on high contrast performance Florence - 29 June 2013


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