E-ELT VLT

HARMONI – the first light integral field

spectrograph for the E-ELT

Niranjan ThatteOn behalf of the

HARMONI consortium

Florence - 29 June 2013

Outline

Capabilities of HARMONI

AO science + modes

Integral field + AO: an ideal marriage

Acquisition time / observing efficiency

Florence - 29 June 2013

Modular Construction

Florence - 29 June 2013

For extended sources &

optimal FoV

For optimal sensitivity

(faint targets)

Best combination of sensitivity and spatial resolution

40 mas

20 mas 10 mas

Highest spatial

resolution (diffraction

limited)

4 mas

7f

2.5” × 5”

5” × 10”

1.25” × 2.5”

0.5” × 1.0”

128 × 256 spaxels at all scales

Wavelength Ranges & Resolving Powers

Bands RV+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

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

Different Flavours of AO

SCAOGLAO LTAO

Or even degraded GLAO (NGS only) !!!Florence - 29 June 2013

Planets & Stars

Stars & Galaxies

Galaxies & Cosmology

Contemporary Science

Florence - 29 June 2013

5mas per pixel input 10 mas HARMONI scale 20 mas HARMONI scale 40 mas HARMONI scale 100 mas scale on VLT

Florence - 29 June 2013

High-z Ultra-luminous IR Galaxies

Survey 50 Spitzer candidate ULIRGs 1<z<2.5

Detect & characterise nuclear disks & rings

Measure shocks, winds, interaction with IGM

Measure dynamical masses

Distribution of dust

Modes of star formation Measure rotation, masses, dust

content, stellar pops & FPRequires: diffraction limited R > 4000 spectra, spaxels 5-40mas. @ 0.5 - 2.5.

H in z=2 ULIRG

Florence - 29 June 2013

Optimal Spaxel Scale

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0 20 40 60 80 100 120 1400

1000

2000

3000

4000

5000

6000LTAO sensitivity @ R=4000, K=23, 42m E-ELT

Spaxel size [mas]

Exp

tim

e f

or

SN

R=

10

Analysis from Phase A (S. Arribas)

• 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

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

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.

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

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.

PSF Reconstruction

Florence - 29 June 2013

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

starsFlorence - 29 June 2013