Past Experience and Vision for ELT Instruments · •Meteorites c. Miles Padgett Probe the Universe by measuring photons: 3 ... 4 x 4 Raytheon VIRGO detectors 2048 x 2048 pixels each

Past Experience and Vision for ELT Instruments

Colin Cunningham

Director, UK ELT Programme

Royal Observatory Edinburgh

2

• Photon emission

• Absorption

• Eclipses

• Gravitational lensing

• Angles - astrometry

• Doppler shift → dynamics of galaxies → Dark Matter

• Measure properties of E-M radiation::

– Intensity

• Spatial

• Temporal

– Wavelength (Energy)

– Amplitude & Phase

– Polarisation

– Orbital Angular Momentum?

We can also measure or collect:

• Neutrinos

• Gravitational Waves

• Cosmic rays (particles)

• Meteorites

c. Miles Padgett

Probe the Universe by

measuring photons:

3

• Photon emission

• Absorption

• Eclipses





– Intensity

• Spatial

• Temporal



– Polarisation


c. Miles Padgett


measuring photons:

Imaging

4

• Photon emission

• Absorption

• Eclipses





– Intensity

• Spatial

• Temporal



– Polarisation



measuring photons:

Spectroscopy

Evolution of Instrument Requirements

UKIRT: IRCAM 1 1986

VLT: KMOS 2011

Cameras: VISTA

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IR Camera for the VISTA TelescopeIR CAMERAVISTA telescope: Largest dedicated IR survey in the world – 4m class

Location is ESO‟s Cerro Paranal site in Chile

IR Camera

• At focus of F/3 telescope.

• Field of view 1.65 degrees.

• Up to 7 spectral bands.

• M ~ 20 at Ks wavelength (2 microns) in 15 minute exposures.

• Pixel size : 0.34 arcsecs

• Cold front baffle, cryostat length ~2.5m

– for low background, to be similar to telescope (self-emissivity,

~4% in Ks-band)

Poster prepared by: IR Camera team, contact A K Ward or M CaldwellFurther information: www.roe.ac.uk/atc/projects/

Baffle tube•Di-chroic coating to absorb

incoming stray-light (2um), but

reflect window heat.

•Long tube, for non-re-imaged

cold baffle

LensBarrel„field corrector‟ for wide

FOV

Cryostat-Window

~ 1m diameter

Closed Cycle

Coolers x3

Auto-guider & Wave-

Front Sensors Telescope &

camera aberrations, flexures

corrected by Active Optics

Low order: movement of M2.

High order: actuators in M1 cell

Science detectors focal plane array

4 x 4 Raytheon VIRGO detectors

2048 x 2048 pixels each

Filter Wheel - 1.4m diameter

Up to 7 science filter arrays

Utility filters

High-order sensor optics

VISTA Telescope with the IR Camera

VISTA Primary Mirror

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Silica Lens & Barrel

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Camera Window

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Removing the effects of the atmosphere with Adaptive Optics

Space Ground

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Adaptive Optics System

Wavefront Sensor Deformable Mirror

Beam splitter

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Impact of Adaptive Optics: exoplanets

HR 8799: 140 light years away, 1.5 times the size of our Sun and five times more luminous

Gemini North adaptive

optics image shows two of

the three confirmed planets

• ~7 Jupiter-mass planet

orbiting at about 70 AU

• ~10 Jupiter-mass planet

orbiting the star at about 40

AU

Keck AO follow-up AO image

showing a third planet!

© Gemini & Keck Observatories

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Adaptive Optics: The Galactic Centre

ESO VLTGenzel et al., 2003

Axel Mellinger

Adaptive Optics & Speckle Imaging

Supermassive Black Hole with mass of ~ 3 million Suns

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Spectroscopy: elements and

dynamics

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Long Slit Spectrometer

Slit aligned

on objectCollimator Dispersing

ElementCamera

X

Y

Y

Detector

array

a

b

c

3rd June 2003Smart Optics Forum 21

Integral Field Spectroscopy: 3D data cube

Image: Stephen

Todd, ROE and

Douglas Pierce-

Price, JAC

Field before

slicing

Pseudo-slit

Slicing mirror (S1)

Spectrogram

Pupil mirrors

(S2)

To spectrograph

Field optics

(slit mirrors S3)

From telescope

and fore-optics

Focal

plane

Integral Field

Spectroscopy:

Image Slicer

Jeremy Allington-Smith

Most distant Galaxy ever

observed?• Only 600 million years old (a

redshift of 8.6)

– light has taken over 13 billion

years to reach us!

• Integral Field Spectroscopy allows

measurement of spectral lines at

any point in the image

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Spectroscopy of a

(bright) candidate

z=8.6 Lyman-α Emitter

(Lehnert et al 2010)

14.8 hours on VLT with

SINFONI

3rd June 2003Smart Optics Forum 24

Multi-Object Spectroscopy

KMOS: 24 IFUs

Pick-off arms under test

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Why do we want to go from VLT

to ELT?

Discovery Potential

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Contemporary Science cases

Synergy with other facilities

Discovery potential

E-ELT excels in collecting power and angular resolution

42m telescope with Adaptive Optics will deliver

5.25✕ better angular resolution (1/D)

750✕ faster exposure time (1/D4)

than existing 8m telescopes

HST8m42m E-ELT

Unprecedented sensitivity and angular

resolution

Prepare for the unexpected….

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E-ELT Instruments

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Phase A Instrument Studies

EAGLE Multi-Integral Field (IFU), near-IR spectrometer

EPICS Imager/spectro-polarimeter for exo-planets

HARMONI Diffraction-limited, near-IR IFU

METIS Mid-IR (5-30μm) imager & spectrometer

OPTIMOS Seeing-limited high-multiplex spectrograph(s)

CODEX Ultra-high-resolution optical spectrograph

MICADO Near-IR, high-resolution imaging camera

SIMPLE Near-IR, high-resolution spectrograph

AO-relays MAORY (MCAO relay) & ATLAS (LTAO relay)

UK

in

vo

lve

d

E-ELT Science Objectives

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Contemporary

Science cases


Discovery potential

Planets & Stars

• From Giant to terrestrial planets: detection, imaging, spectral characterisation of their atmospheres

• Circumstellar Disks

Stars & Galaxies• Imaging and spectroscopy of extragalactic resolved stellar populations• The nature of black holes and active galactic nuclei

Galaxies & Cosmology• Detecting First-light• The physics of the highest redshift galaxies• A dynamical measurement of the expansion of the universe

E-ELT Science Objectives

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Contemporary

Science cases


Discovery potential

CODEXHARMONI

MICADO

SIMPLE

World-leading UK Technology

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Integral Field Spectroscopy

Multiplexed Spectroscopy

Adaptive Optics

HARMONI

333333

Stars & Galaxies•

Galaxies & Cosmology

First-light: The

physics of the

highest redshift

galaxies

V

z ~ 4 50 mas pixels

z=0 rotating disk simulations (M. Puech)

42-m, 10-hr integration, MOAO (MCAO)

Key Spec: IFU

spectroscopy on 20

objects simultaneously

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• Multi-Object Adaptive Optics

(MOAO)

• Correct small sub-fields across

a 5 arcmin field

• Extensive MOAO research in

the UK and France

EAGLE Adaptive Optics

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CANARY

MOAO on-sky demonstrator

• Using the existing Rayleigh laser guide star (LGS) on the

William Herschel Telescope in La Palma

• 10:1 Scale model of E-ELT

• Demonstrate MOAO in the EAGLE configuration on-sky

• Improve real-time control techniques

• Advance calibration techniques

The EAGLE instrument

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EAGLE Optical Paths

20 channels

with built in

Multi-object

Adaptive

Optics

TAS: Target Acquisition System

POS: Pick-off system

TRAMS: Target Re-imaging and

Magnification System

ISS: Integral Field Unit

Spectrograph System

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Pick-off Mirror positioning

Robots

Starbugs (AAO) Starpicker (UK ATC, CSEM, ASTRON)

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Micro Autonomous Positioning System

(MAPS)Hermine Schnetler (UK ATC) & William Taylor (Univ Edinburgh)

4040

Planets & Stars

&

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Key Spec: ultra-high

contrast ~10-9

• Over 400 planets found by radial velocity method

– How common are systems like ours?

– How do planetary systems form?

• Needs direct detection:

– Measure mass, orbit, temperature, composition

• Simulations of photon-limited case (idealised) show rocky planets detectable to 5-10 parsecs (16-32 light years)

• 377 stars within 10 parsecs

10-810-7

10-9

10-5

10-910-10

Simulated image courtesy of EPICS team

4141

Planets & Stars

&

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CODEX

Three-planet model of the Gliese 581

radial-velocity variations:

Top panel: 15 Earth-mass planet orbiting

close to the star (5-day period)

Middle panel: 5 Earth-mass planet in the

habitable zone

Lower panel: evidence for a third, 8 Earth-

mass planet with a period of 84 days

Stefan Udry, Geneva

Key Specs: RV stability:

2 cm/s over 30 years

R= 120,000

4242

Planets & Stars

&

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• Circumstellar disks

• Physical and Chemical Properties

of Exoplanets

Key Spec: Diffraction

limited ~10 mas in mid-IR

4343

Stars & Galaxies•


HARMONI

•Physics of high red shift

galaxies

• Resolved stellar populations

in elliptical galaxies

•Studies of black holes and

active galactic nuclei (AGN)

Key Spec: Diffraction limited IFU ~

4mas in Near IR

4444

Stars & Galaxies•

MICADO

HARMONI

• E-ELT can resolve individual stars in galaxies beyond our own Local Group

• Imaging in densely crowded fields in the Virgo cluster (65M light years away)

• Spectroscopy to 15-30M light years, Sculptor/Leo groups or further

– Kinematics

– Chemical composition

Two stars in Sculptor (3Mpc) with different

metallicities (Tolstoy et al 2001)

E-ELT Simulation by J. Liske

10hr K-band; LTAO

1 a

rcsec

HST image of NGC 253 (Sculptor group)

454545

•


CODEX

• Is Dark Energy accelerating the expansion of the Universe?

• E-ELT can measure acceleration directly, in real time

• Fundamentally different probe

– dynamical vs geometrical –current measurements rely on supernova „standard candles‟

by J

oh

n W

eb

b

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Measuring Cosmic Dynamics

Joe Liske, ESO

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Joe Liske, ESO

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Joe Liske, ESO

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Measuring the redshift drift requires:

• E-ELT

• High-resolution, extremely stable spectrograph:

CODEX

• ~20 yr long spectroscopic monitoring campaign.

t = 106 years!

Joe Liske, ESO

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Frequency CombT

hom

as U

dem

(MP

Q)

Extreme stability enabled by the frequency comb:

Optical or NIR laser producing a train of monochromatic femtosecond light

pulses

Produces a spectrum of evenly spaced delta-functions (frequency comb)

whose absolute wavelengths are known to a precision limited only by the

atomic clock that controls the pulse repetition rate

LIMITATIONS OF CURRENT

INSTRUMENT DESIGNS

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OH Sky Lines

• Big limitation on sensitivity from the

ground

Night sky near-IR spectrumP Rousselot et al,

Astron. & Astrophys. 354, 1134 (2000)

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Size of

seeing-limited

ELT instruments

WFOS Wide

Field Optical

Spectrograph

– 8m diam

x 9m long

– Size of an

4m

telescope!Deimos

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SOLUTION: Photonic devices?

• Devices developed for communications and industrial instrumentation are being investigated for Astronomy:

– Bragg Gratings

– Photonic (crystal) fibres

– Waveguide Beam combiners

• These technologies could be combined with an integrated detector to make compact integrated spectrometers, with built-in suppression of sky-lines

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Fibre v. conventional

spectrometer

The fibre array spectrometer has 5x the spectral resolution

of the conventional dispersive spectrometer – or is 5x

smallerRobert R. Thomson, Ajoy K. Kar, and Jeremy Allington-Smith Vol. 17, No. 3 / OPTICS EXPRESS

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Ultrafast laser inscription (ULI)Robert Thomson at Heriot Watt Univ

Video of ULI in progress

• Unique fabrication capabilities:

- 3D optical waveguides

- Micro-optics, -mechanics and -fluidics

• ULI is material flexible

• ULI is a direct-write technologyR. R. Thomson et al, Opt. Express

15, 11691 (2007)

Integrated Spectrograph

PIMMS: Joss Bland-Hawthorn (Sydney)

Direct-write waveguides: Robert Thomson (Heriot-Watt) 57

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Photonics and Smart Optics

Toolkit• 3D Fibre mode converters

• OH suppression waveguides

• Integrated spectrometers

• Robotic positioners

• The ultimate multi-object spectrometer?– A swarm of 1000 integrated spectrometers, mounted on

micro-robots and patrolling a wide field

– Would enable fast surveys of faint galaxies to generate a statistically complete picture of galaxy formation and evolution

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Headline Science Impact of E-ELT

Instruments

• Direct detection of a “Super Earth”

10-810-7

10-9 10-5

10-9

10-10

V

z ~ 4 50 mas pixels

z=0 rotating disk simulations (M. Puech)

42-m, 10-hr integration, MOAO (MCAO)

• Direct measurement of the expansion rate

of the Universe

• Understanding of galaxy formation in the

early Universe

EAGLE ANIMATION

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EAGLE

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Documents

Past Experience and Vision for ELT Instruments · •Meteorites c. Miles Padgett Probe the Universe by measuring photons: 3 ... 4 x 4 Raytheon VIRGO detectors 2048 x 2048 pixels each