1. The 6dF Galaxy Survey Design and Goals Matthew Colless The 6dFGS Workshop AAO, Sydney, 30-31 May 2002

2. Goals of the workshop To provide a clear view of the current state of play. To clarify the desired scientific outcomes. To refine the survey plan and operations. To enthuse participants in the survey! How? by sharing information and discussing plans regarding all aspects of the survey: – samples, observations, data reductions… – science, data releases, survey management…

3. Workshop program - Thursday Parker Saunder s Colless Watson

4. Workshop program - Friday Sadler Stavely- Smith

5. Workshop participants

6. The 6dF Galaxy Survey Three components to the survey…  A NIR-selected redshift survey of the local universe.  A peculiar velocity survey using D n -  distances.  Redshift surveys of other ‘interesting’ source samples. Strategic issues… – differentiation: what does the 6dFGS offer that is not offered by the 2dFGRS, SDSS or other surveys? – impact: what survey characteristics are required in order to maximize the scientific impact of each component? – timeliness: how quickly must the survey be carried out in order to achieve its goals in a timely manner?

7. The main redshift survey - goals To measure the luminosity function of NIR-selected galaxies (i.e. the stellar mass function of collapsed structures) and its variation with local environment and spectral type. To map the local galaxy distribution (esp. close to the Galactic equator). To quantify the small- and large-scale clustering of galaxies weighted by stellar mass, and so constrain the scale-dependence of the biasing of the galaxies with respect to the dark matter. To measure the power spectrum of galaxy clustering on very large scales, comparable to the scales achieved by the 2dFGRS and SDSS. To construct a large, all-sky, volume-limited sample of early-type galaxies as the basis for the peculiar velocity survey. To provide a fundamental redshift catalogue for future work.

8. The 2dF Galaxy Redshift Survey 221,283 galaxy redshifts 5% sky coverage, z  0.3

9. SDSS redshift survey Aim: ~ 10 6 galaxy z’s So far: ~ 200,000 z’s 25% sky coverage ugriz photometry

10. Advantages - sky coverage 2,000  10,000  17,000 

11. Selection in the NIR (J,H,K) minimizes extinction effects of extinction - galaxies can be selected over |b|>10°. NIR luminosity is very closely correlated with total stellar mass, and so yields the stellar mass function. log (M stars /h -2 M  ) Advantages - NIR selection Optical selection is biased towards late-type, star- forming galaxies - NIR selection is thus better for the D n -  sample.

13. Galaxies with redshifts  Galaxies without redshifts  The 2MASS Redshift Survey N(K<12.2) = 116401 N(gals, z) = 32331 N(gals, no z) = 36474

14. LSS and cosmology from z-surveys

15. The peculiar velocity survey - goals To map in detail the density and peculiar velocity fields over half the local volume out to 15,000 km/s. To provide additional constraints on cosmological models, and better measurements of fundamental parameters, from statistics of these fields. To study the ages, metallicities and star-formation histories of early-type galaxies over a wide range of masses and environments.

16. The local density and velocity fields PSCz predicted velocity field (15,000 galaxies) 6dFGS observed velocity field (15,000 galaxies)

17. 10 2 peculiar velocities with infinite precision 10 2 peculiar velocities with 20% precision… 10 3 peculiar velocities with 10% precision… 10 3 peculiar velocities with 5% precision Problem: the cosmic + measurement variance on a single measured bulk motion on any scale is large - 90% c.i. is greater than model differences. Bulk motions and cosmology Solution: measure rms bulk motions on a range of scales using surveys of large volumes. Plots: show constraints on rms bulk motion at different scales for surveys with different numbers of groups of objects and precision of pec.vel.s for groups.

18. Additional targets, additional science To extend the scientific grasp of the survey and make the fullest use of this opportunity for whole-sky redshift surveys, the astronomical community was invited to supply additional targets of special interest. The AT programs include targets from the following sources: – 2MASS NIR sky survey – DENIS NIR sky survey – SuperCosmos galaxy catalogues – ROSAT All-Sky Survey (RASS) – HI Parkes Sky Survey (HIPASS) – IRAS Faint Source Catalogue (FSC) – NVSS and SUMSS radio surveys – Hamburg-ESO QSO survey See talks to follow by: Koribalski, Drinkwater, Sadler, Wakamatsu, Cutri and Francis.

19. 6dF positioner and spectrograph Watson

20. Target samples 15 different samples Merge target lists and identify common objects Find objects with existing redshifts Set relative priorities Choose tiling of fields to optimize completeness and uniformity Saunders

21. Target density and survey tiling Campbell

22. Observed 6dFGS fields Saunders

24. The redshift distribution PredictedObserved

25. Survey progress - 2dF and 6dF 6dFGS fields 1500 1360 1200 900 600 300 0 Semester 01A 01B 02A 02B 03A 03B 04A 04B 05A 05B