1. The 6dF Galaxy Survey - The Target Samples Will Saunders Anglo-Australian Observatory

2. UK Schmidt has huge AΩ, ~ AAT/2dF or SLOAN Galaxy source counts inversely with brightness => same number of accessible targets per unit time for given AΩ Schmidt has unique ability to cover whole sky So ideal for wide field, shallow samples, in particular new wavebands or techniques. And also ideal for peculiar velocities. 6dF coincides with first imaging and first NIR sky surveys - 2MASS, DENIS. Ending of photographic era allows large fraction of UKST time to go to 6dF Why 6dFGS

3. Instrumental parameters 1K x 1K chip - limited by existing spectrograph Focus 3-4 pixels fwhm over chip few hundred spectral resolution elements R>1000 resolution desirable for z-survey, imperative for D n -σ Coverage 3900A-7500A desired - z=0 H,K to z=0.1 Hα. => require 2 grating setups per field. 3 x 20min 600V 4000A-5600A @ 5-6A fwhm 3 x 10min 316R 5400A-8400A @ 9-12A fwhm 40 mins overhead between fields (changing field plate, flats and arcs, slewing, acquisition) => max 4-5 frames/night

4. Overall survey parameters: 4 year hard limit for UKST funding (to June 2005). Button size + plate scale => twice over coverage 2 x 17,000 deg 2 / 25 deg 2 =1400 fields 18 nights x 13 lunations x 4 years x 75% 6dFGS x 50% clear x 4 fields/night = 1400 fields 1400 fields x 130 targets/field = 180,000 spectra reserve 10,000 for z-survey reobservation, 10,000 for D n -σ reobservation => 160,000 observable targets.

5. The K s -selected sample 1 2MASS (2 Micron All-Sky Survey) covers whole sky in J,H,K s Very shallow, large pixels. Confusion limited in Plane. K s ideal place to study Large Scale Structure - Old stellar population - constant mass-to-light ratio Small external extinction Small internal extinction But need total magnitudes from low S/N data on extended objects.

6. K cor magnitudes 2MASS gives reliable isophotal magnitudes K 20 - comparable depth to 2dF for most galaxies. can easily determine average surface brightness within this isophote μ K20. 2MASS gives total magnitude K tot - noisy but OK at high latitude can use K 20, μ K20 + simple model to estimate total magnitude, compare with K tot Final estimator K cor = K 20 - min(1.5 e (1.25(μK20 -20)), 0.5) Robust to confusion noise Statistical error ~ 0.11 m Overall systematic error << 0.1 m Possible biases at 0.05 m level vs galaxy profile No extinction correction to the correction!

8. The K s -selected sample 2 Final selection: K cor < 12.75 m extended sources |b|>10° δ < 0° A V < 5 m (protostellar sources) => 120,000 targets Early-type dominated Median redshift z~0.06 Tail to z~0.18

11. The peculiar velocity survey Whole new scale of peculiar velocity survey - can rewrite rules All spectra in principal good enough resolution and wavelength coverage for D n -σ Limited by S/N, ellipticity, linewidth, redshift, spectral type? Can reobserve suitable galaxies with marginally poor S/N (or alibi) Aim for S/N = 20/A at MgB Photometry from K s May want to set selection criteria at this meeting

12. Additional Samples 1 If covering whole sky, can include smaller samples along for the ride, especially if lower completeness is required (cf 2dFGRS/ 2dF quasar survey). Also, small numbers of additional targets in other bands can lead to large complete samples, useful for eg comparing clustering vs waveband. Samples agreed from early planning were: H,J-selected 2MASS galaxies to make complete samples ~100,000 in each: final limits Hcor < 13.0m, Jcor < 13.75m DENIS I,J -selected galaxies to Jkron < 13.85m, Ikron < 14.85m, for the 35% of of the sky for which DENIS data is reduced SUPERCOSMOS-selected galaxies with |b|>20 to rF<15.6m, bJ<16.75

13. Additional Samples 2 In addition, the AAO made a call for additional targets in late 2000. This led to a large number of smaller additional samples being included: All IRAS FSC galaxies with |b|>20, S/N > 6 ROSAT All Sky Survey quasars with bJ<18.5 m HI Parkes All Sky Survey galaxies with ambiguous optical identification 2MASS-selected red AGN candidates with J-K s > 2 Hamburg-ESO objective prism quasar candidates Quasar candidates from the VLA NVSS survey} Sources from the SUMSS survey with b J < 18.5 m 1000 galaxies to complete the Durham/UKST survey, 1- in-3 to b J < 17.5 m Galaxies in the Shapley supercluster to r F <16.0 m

14. ID sample weight total distinct unique observe 1 2m_K1275 8/7 118648 118642 15724 112827 7 scos_R156 6/2 63059 9140 1099 8225 8 scos_B1675 6/2 65779 9598 8555 8638 126 fsc_b20r19 6/2 22769 10805 9868 9725 113 RASS_final 6/2 3409 2929 2573 2636 3 2m_H1300 6/2 93965 2308 1146 2077 4 2m_J1375 6/2 98593 2537 2265 2283 119 hipass4sig 6/2 1151 823 810 741 78 durukst 6/2 1145 466 463 419 90 shapley 6/2 1328 945 936 851 6 denisI1485 5/2 22907 4846 3165 4119 5 denisJ1385 5/2 22631 2285 2259 1942 116 6df2magnid_b19r18 4/2 2260 2131 2090 1705 129 hes 4/2 3846 3538 3462 2830 130 nvss 4/2 4460 4334 3051 3467 125 sumss 3/2 13172 4514 4514 2708 totals 539122 179841 61980 165194