The 6dF Galaxy Redshift Survey: Status Report and Data Release 2 Heath Jones ANU/AAO Will Saunders AAO Mike Read Edinburgh Matthew Colless AAO 100,000 REDSHIFTS

The 6dF Galaxy Survey: The 6dFGS is designed to be the first of a new generation of combined z+v-surveys, combining…  NIR-selected redshift survey of the local universe  Peculiar velocity survey using FP distances  Additional redshift surveys of other ‘interesting’ source samples.

The 6dF Galaxy Survey: The 6dFGS is designed to be the first of a new generation of combined z+v-surveys, combining…  NIR-selected redshift survey of the local universe  Peculiar velocity survey using FP distances  Additional redshift surveys of other ‘interesting’ source samples. Survey strategy… survey whole southern sky with |b|>10° primary z-survey: 2MASS galaxies to K tot <12.75 secondary samples: H<13, J<13.75, r<15.6, b< additional samples: radio, X-ray, IRAS… v-survey: ~15,000 brightest early-type galaxies

Selection in the NIR (J,H,K) minimizes extinction effects of extinction - galaxies can be selected over |b|>10° Advantages - NIR selection

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 Cole et al (2001)

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. Advantages - Sky Coverage 2dFGRS SDSS The 6dFGS has 8x the sky coverage of the 2dFGRS and twice the coverage of SDSS.

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. Advantages - NIR selection The 6dFGS has 8x the sky coverage of the 2dFGRS and twice the coverage of SDSS. Traditionally, most redshift surveys have been optically selected and therefore favoured late-type galaxies. In contrast, the NIR selection of 6dFGS is biased towards the redder early-type galaxies needed for the Peculiar Velocity Survey.

Target Allocation SamplePriorityTotalSampling 2MASS K s < % 2MASS H < % 2MASS J < % SuperCosmos r F < % SuperCosmos b J < % Target allocation 92% or better for the primary and secondary samples. Number of Tiled Sources Number of Sources on Sky

Target Allocation SamplePriorityTotalSampling 2MASS K s < % 2MASS H < % 2MASS J < % SuperCosmos r F < % SuperCosmos b J < % Shapley % ROSAT All-Sky Survey % HIPASS (> 4-sigma) % IRAS FSC % Denis J < % Denis I < % 2MASS AGN % Hamburg-ESO Survey % NOAO-VLA Sky Survey % Target allocation 92% or better for the primary and secondary samples. Additional target samples extend science and fully exploit survey: 2MASS NIR sky survey DENIS NIR sky survey SuperCosmos galaxy catalogs ROSAT All-Sky Survey (RASS) HI Parkes Sky Survey (HIPASS) IRAS Faint Source Catalog (FSC) NVSS and SUMSS radio surveys Hamburg-ESO QSO survey

V grating:  = 5 – 6 A Q=1 - spectra of no value Q=2 - possible z value Q=3 - likely z value Q=4 - z value beyond doubt Q=5 - textbook example R grating:  = 9 – 12 A Q=1 - spectra of no value Q=2 - possible z value Q=3 - acceptable z value Q=4 - z value beyond doubt Q=5 - textbook example Q=6 - Galactic source <1% 0 % 5 % 7 % 77 % 11% DR 2:

The Observing/Redshifting Cycle Preparation, observing, reducing follows the lunar cycle 6dFGS

The Observing/Redshifting Cycle Preparation, observing, reducing follows the lunar cycle Redshifting takes place in the following lunation Survey results are updated/reported ~6 weeks after observation 6dFGS Mt STROMLO TELESCOPE

6dFGS 2nd Data Release: April 2005 DR2 Jan 2002 – October 2004 for public release  spectra; unique redshifts; 936 fields more redshifts (37163 more spectra) than DR1 6dFGS Online Database: Searchable using either SQL query commands or a WWW form Each source has its own multi-extension FITS file, including 6dF spectrum, brJHK imaging, redshift and photometric information The different target catalogues are also online, fully searchable and inter- linked

What’s New Since DR1 Data and database structure largely unchanged since DR1 Recent introduction of a QSO template for redshifting (~Aug 05 onwards) Introduction of Q=6 for confirmed Galactic spectra (formerly Q=2) Around 7% have disparate irreconcilable proximity and mag rankings Around 1% have no br match at all Recalibrated br SUPERCosmos photometry (BMAG, RMAG) and the preservation of the old selection magnitudes (BMAGSEL, RMAGSEL):

Median z for 6dFGS (z=0.05) is roughly half that of 2dFGRS and SDSS When complete, the population of 6dFGS galaxies at low redshifts will be on a par with the other surveys Number-Redshift Distribution

Redshift Maps: ~90k redshifts 2MASS

547 fields 595 fields 422 fields 1564 fields over southern sky with |b| >10  =   Survey Sky Coverage Observing strategy has been to cover the sky in thirds: (1) central strip; (2) equatorial strip; (3) southern polar cap. 6df

1564 fields over southern sky with |b|>10  =   Observing strategy has been to cover the sky in thirds: (1) central strip; (2) equatorial strip; (3) southern polar cap fields observed to date – 936 fields from January 02 to October 04 constituting the Second Data Release Survey Sky Coverage Number of Galaxy Redshifts Per Unit Area Number of Galaxy Redshifts + Failures + Remaining Per Unit Area 6dF+ ZCAT +2dF…

Survey Sky Coverage DR 2 (2005) DR 1 (2004)

90% of fields > 60% 80% of fields > 80% complete Number of 6dF Galaxy Redshifts Number of 6dF Galaxy z’s per field + Redshift Failures per field Breakdown of spectra extragalactic (85 %) stellar (3 %) HII regions,PNe (1%) failures (11 %) Field Completeness

6dFGS Second Data Release: Summary Jan 2002 – October 2004  spectra; unique redshifts; 936 fields Definitive 6dF Survey Paper (DR1):  Jones et al (2004), MNRAS 355, 747 DR2 paper  Jones et al, PASA 6dFGS Home  6dFGS Database  MOVED !