Lister Staveley-Smith

2

Australian SKA Pathfinder (ASKAP)

2

• Radio interferometer – 36 ×12-m dishes

• CSIRO Phased Array Feed (PAF) technology: 36 beams

• Frequency range 700 to 1800 MHz

• Instantaneous bandwidth 300 MHz

• Maximum baseline 6 km

• SKA precursor on a radio-quiet site

• Wallaby (HI) and EMU (continuum) are the two key survey science projects

3

4

MurchisonShire

Netherlands

5

Boolardy Station

Population density (people/km2)

GAMA 2017, ICRAR

0.0001

0.0100

1.0000

100.0000

7

Wallaby goals

GAMA 2017, ICRAR

• Local Group/Volume

• Understanding Galaxies

• Cosmology

• Legacy

8

Environmental suppression

GAMA 2017, ICRAR

Notransition(gas-bearing)galaxieswithin300kpcofMilkyWay:

• strippingorionization?

(Westmeieretal.2015;Spekkensetal.2014)

gas-richgaspoor

DISTANCEFROMMILKYWAY

GASRICH

NESS

9

ASKAP Wallaby

GAMA 2017, ICRAR

• Local Group/Volume

• Understanding Galaxies

• Cosmology

• Legacy

10

Gas accretion onto galaxies

GAMA 2017, ICRAR

NGC891:Oosterloo,Fraternali&Sancisi(2007)

EBHIS:Kerpetal.(2016)

11

ASKAP Wallaby

GAMA 2017, ICRAR

• Local Group/Volume

• Understanding Galaxies

• Cosmology

• Legacy

12

Redshift-space distortions

GAMA 2017, ICRAR

HI optical

Beutler

13

ASKAP Wallaby

GAMA 2017, ICRAR

• Local Group/Volume

• Understanding Galaxies

• Cosmology

• Legacy

Comparison with other HI surveys

Area 3π 2.8π 0.7πRedshift 0- 0.26 0- 0.04 0- 0.06rms20km/s 0.7mJy/beam 13mJy/beam 1.5mJy/beamRes 30arcsec,4km/s 15arcmin,18km/s 3.5arcmin,5km/sNdet 500,000 5,000 30,000

GAMA 2017, ICRAR

Wallaby=WidefieldASKAPL-bandLegacyAll-skyBlindsurveYPIs:B.S.Koribalski&LStaveley-Smith

Den

sity

of S

pect

ra (N

/deg

2 )

Area (deg2)

2 Orders of Magnitude Improvement

Existing SurveyLimit

Meyer

SKA pathfinder HI surveys:

15

16

Synergies

GAMA 2017, ICRAR

DINGO

WALLABY

Duffy,Gerstmann

17

Spherical cap tiling (Robotham)

2016 PHISCC Cape Town 17

18

Sensitivity images (Robotham)

2016 PHISCC Cape Town 18

Rawtilepattern– max/min=2.3 4-ptdither– max/min=1.2

19

Wallaby timeline

GAMA 2017, ICRAR

• Sept 2014: commissioning science with BETA (6 antennas)

• Oct 2016: early science commenced with 12 antennas, 48 MHz

• Dec 2016: bandwidth increased to 192 MHz

• Sept 2017: bandwidth increased to 240 MHz

• Oct 2016: 16 antennas

• Apr 2018: 36 ASKAP antennas expected

• Dec 2018: full survey begins

GAMA 2017, ICRAR

FirstASKAPBETA+Wallabysciencepaper(Serraetal.2015)

IC1459group

21

Wallaby timeline

GAMA 2017, ICRAR

• Sept 2014: commissioning science with BETA (6 antennas)

• Oct 2016: early science commenced with 12 antennas, 48 MHz

• Dec 2016: bandwidth increased to 192 MHz

• Sept 2017: bandwidth increased to 240 MHz

• Oct 2016: 16 antennas

• Apr 2018: 36 ASKAP antennas expected

• Dec 2018: full survey begins

Early Science (ES) focus: environment

GAMA 2017, ICRAR

Preprocessinginandoutsidegroups

WallabySWG3pre-processingworkshop –SwinburneMarch8-10(KilbornandWong)

19groups

Kilborn+09

Whendidgalaxieslosetheirgas?

Early Science progress

GAMA 2017, ICRAR

ESdataisvirtuallyidenticaltotheWallabymainsurveydatainresolutionandsensitivity

WALLABY ES fields

GAMA 2017, ICRAR

Westmeier

WALLABY/DINGO workflow

GAMA 2017, ICRAR

ES1 coverage

GAMA 2017, ICRAR

ES1NGC7232fieldandbeampatternoncolouredDSS

IC5201

IC 5201 in the NGC 7232 group

NGC7232group

GAMA 2017, ICRAR

credit:Whiting,Lee-Waddell,Madrid

NGC 7162/A in the NGC 7232 group

GAMA 2017, ICRARCredit:TristanReynolds

ES3 coverage

GAMA 2017, ICRAR

ES3Doradofieldandbeampatternoncoloured DSS

6deg

Dorado group

GAMA 2017, ICRAR

NGC1566

NGC1596

NGC1602

10% depth images from Dorado

GAMA 2017, ICRAR

NGC1596NGC1602

NGC1566

Credit:Egali,Kleiner,Rhee1night 1-3nights

NGC 1566: Slicer

GAMA 2017, ICRAR

Jonghwan Rhee

33

Summary

GAMA 2017, ICRAR

• Wallaby science has started (4+2 ES fields - same area, resolution and sensitivity as ASKAP-36)

• Initial science focus: pre-processing in group environment

• Wallaby is zero-redshift, all-sky ‘anchor’ for high-z studies – most O/IR synergy with TAIPAN, SkyMapper, VISTA, VST, LSST

• Expected completion 2020/21

34

Parameterizing ΛCDM + testing GR

GAMA 2017, ICRAR

2MTFvelocitypowerspectrum(2062galaxieswithTFdistances)+Planck:Howlett etal.(2017)