Beyond 6dF (what more can we do for you?)

Beyond 6dF(what more can we do for you?)

Anna Moore

Roger Haynes

Will Saunders + BJB

Fibre Positioner for Subaru/FMOS– Piezo ball-spine– 400 fibres– 0.5deg diam.

• 150mm Pick-and-place

– 0.9-1.8m

– Feed FMOS spectrograph

Steel Ball

Magnets

Spine

Counterweight

Echidna Ball-Spine

Moduleassembly

Top bridge

Fibre cover

Middle bridge

Fibre spines and piezo actuators

Module PCB

Module base

Echidna complete design

Single module

Example of fibre allocation to randomly scattered targets

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7mm spine deviation

90% success rate for random targets

Applications for Echinda

Gemini wide-field MOS (GWiMOS)– 1.5deg2 at prime focus

• Corrector design exists (400kg)• 0.5arcsec images (1” fibres)• 1.4m corrector

– 4000 fibres• Echidna fibre positioner• Fibre-spacing compatible with Subaru

– 10 more fibres, 10 larger area

Gemini wide-field

• US$20M project– Initial design already begun (NOAO/AAO)

• Opportunity to use AAO funds (A$2.5M) – Committed over 2002-05 as part of successful

bid to Aus. Govt to increase Gemini share– Build prototype to address ‘high-risk’ areas

• addressing >1000 fibres• patrolling field/reconfiguring times

Build prototype for use on UK Schmidt

Prototype Concept

Positioner– 2250 spines (15 arcmin patrol area)

• Slight lower packing than Echidna (s’graph limited)

– 60mm diameter (4 arcsec) – <10% vignetting over full 6o f.o.v.– Spine Tip Imager: ‘single shot’ for full field

• 5min reconfiguration time

Spectrograph

Concept– Based on KOSMOS concept– Single-beam Schmidt-Schmidt spectrograph

• Collimator f/2.25• Camera f/1.3

– VPH grating: R=10000– 2 x 2k x 4k CCD – 3 slits (750 fibres each)

• 1st order 845-870nm (grat=0.9)

• 2nd order 422-435nm (grat=0.8)

Schmechidna

• Total cost A$4M– Spectrograph: A$1.5M– Positioner: A$2.5M

• Purpose designed for stellar work

• IAB=15.5 R=104 S/N=30 in 1200s (S/N for 2nd order)

– 30 mins/field (inc. overheads)– 60% clear– 2000 objects/field (not limited by stellar density)

22000 objects per night (average)

Options

Option A

• No upgrade to existing system

Option B

• 6dF full upgrade: – new field plates + new spectrograph

Option C

• Schmechinda

Cost/benefit analysis

A6dF

B6dF+

CSchmechidna

Instrumentation - $2M $4M(A$1.5M)

Operations (5yr) $3M $3M $3M

# stars* 5.5x105 1.2x106 4.0x107

A$/star 5.5 4.1 0.18t(107 stars) 91yr 42yr 1.25yr

$(107 stars) $273M $128M $5M

*Fields/clear night: 5 (A), 8 (B), 18 (C) Ids/field: 100(A), 135(B), 2000(C) Fraction clear: 60% Resolution: 4000 (A,B) 10000(C)

DIVA survey (accessible from Australia): done in ~3yr

Futher Issues

• Schmechidna: medium technical risk– Echidna spine module already working– patrol camera innovative

• AAO ‘in kind’ contribution: $2.5M– only $1.5M outstanding instrumentation costs

• Room to increase S/N or mag. limit

– 107 stars in 5 years (S/N 50 or Ilim 16)

Further issues

• Survey using Schmechidna start in 2005/6?• Minimum of 107 stars by 2007 2010

– depending on survey parameters

• N. hemisphere: Kisochidna/KOSMOS??– Double cost– Double number of objects– Cover whole sky

Schmechidna All New Stellar Survey for Orbits, Uelocities, and Chemical Indices