Wallaby and SKA HI surveysLister Staveley-Smith

Outline

•

HI surveys with SKA pathfinders–

Wallaby/HI science

–

Wallaby design study•

simulations •

techniques

•

SKA phase 1–

science coordination

Outline

•

HI surveys with SKA pathfinders–

Wallaby/HI science

–

Wallaby design study•

simulations •

techniques

•

SKA phase 1–

science coordination

LMC

•

.

Stars & ionised gas (Smith; CTIO)

HI (Kim et al., Staveley- Smith et al.; ATCA/PKS)

•

.LMC/SMC optical (Mellinger)

LMC/SMC HI Parkes (Bruens)

Dark and tidal galaxies

Duc & Bournaud (2008)

•

‘Dark’

galaxy VirgoHI21 detected in HIJASS observations (Davies et al. 2004).

•

Minchin et al. (2005) claim lack of stars (inc.HST) and high rotation velocity suggestive of true dark galaxy.

•

Other observations (Kent et al. 2007) and models (Bekki

et al. 2005; Duc

& Bournaud

2008) suggestive of tidal interaction.

•

ALFALFA Virgo results (Kent et al.)

Simulations

‘Cold’ gas (blue) flowing into a galaxy at z=3 (Agertz, Teyssier & Moore 2009)

Wallaby (WIDEBAND ASKAP L-BAND LEGACY ALL-SKY BLIND SURVEY)

Wallaby: summary

•

A-rated ASKAP Survey Science Proposal

•

Design study phase

•

Angular resolution: 30 arcsec

•

Area: 3π

•

Bandwidth: 300 MHz (z=0 to 0.26)

•

Frequency resolution: 18.3 kHz (4 km s-1)

•

RMS flux density (0.1 MHz): 0.7 mJy/beam

•

RMS column density sensitivity (0.1 MHz): 1.7x1019

cm-2

•

Cube volume: 330 TB (uv

data 50 PB)

ASKAP01

Dave De Boer/CSIRO

Wallaby: Simulated sky and redshift distribution (Beutler)

500,000 galaxies

The Local Volume HI Survey (LVHIS)B. Koribalski, A. Lopez-Sanchez, E. Kirby, E. van Eymeren,

L. Staveley-Smith, E. de Blok, J. Ott, N. Bonne, Jerjen

Science aims

•

Local Group–

MW halo

–

low-mass galaxies•

Galaxy properties in different environments

–

HI mass function–

Understanding star formation

•

Cosmology–

SkyMapper

Tully-Fisher/SN1A dark matter map

–

Baryon oscillations at z=0

Leo T: a transitional dwarf galaxy in the Local Group

Irwin et al. 2007; Ryan-Weber et al.

2008

GMRT 30” resolution(same as WALLABY)

Local Group velocity function: the missing satellite problem

(Simon & Geha

2007)

Keck spectroscopy of 8 new SDSS Milky Way satellites

Outline

•

HI surveys with SKA pathfinders–

Wallaby/HI science

–

Wallaby design study•

simulations •

techniques–

HI survey wedding cake

•

SKA phase 1–

science coordination

Simulated

HI skies (Zwaan)

Wallaby30,000 deg2

Dingo30deg2

Wallaby simulation: confusion not a problem; non-uniform noise might be.

•

30 deg2

•

32 (ideal) beams

•

30 antennas

•

2 km baseline

•

8 hrs

•

92.5 kHz (20 km s-1)

•

SKADS-SAX input catalogue (Obreschkow et al.)

ASKAP computing group

Cosmic Web predictions Duffy, Schaye

et al. (OWLS collaboration)

See also Popping et al. (2009); Crain et al.; GIMIC

log Σ

HI (cm-2)

H+

50 h-1 Mpc

2014

2018log Σ

H (cm-2) H0

OWLS simulation of baryonic Tully-Fisher relation at z=0 & 2 (Scrimgeour

& Duffy)To

tal M

bar[M

]

Vmax

[km/s]

z = 0z = 2

BTF slope shallower at higher z

•

Feedback: AGN, SNI, SNII

•

Stellar evolution

•

Radiative

cooling/heating

Outline

•

HI surveys with SKA pathfinders–

Wallaby/HI science

–

Wallaby design study•

simulations •

techniques

•

SKA phase 1–

science coordination

Stacking n-dimensional images

Shifte.g. using a catalogued source position

Stretche.g. to account for psf

or cosmology

Summationor other statistic

121 galaxy GMRT stack: galaxies at z=0.24

Lah

et al. (2007)

Deep HI integrations by stacking Delhaize

•

systematics•

confusion noise

•

Observe region with optical redshift coverage

•

Shift-and-add (stack) HI spectra

A stacked HI signal at z=0.1 with Parkes

(GAMA9 field; Delhaize et al.)

randomized catalogue

Evolution of Ω(HI)

Freudling, Staveley-Smith 10

Outline

•

HI surveys with SKA pathfinders–

Wallaby/HI science

–

Wallaby design study•

simulations •

techniques

•

SKA phase 1–

science coordination

SKA Phase 1 definition

•

Science case (Carilli & Rawlings 2004)–

science justification

•

Design Reference Mission (SWG 2009)–

science requirements

•

Science prioritization (SPDO)–

key projects (“sharpening the SKA science case”)

Pathfinder HI Survey Coordination Committee (PHISCC)

•

Role–

Discuss HI pathfinder surveys on ASKAP/MeerKAT/WSRT-

Apertif

–

key projects and coordination

•

Current Membership–

ICRAR, CASS–

UCT–

Astron–

Simulation (Oxford)–

SPDO and US observers

•

Meetings–

Groningen (June 2009)–

Bunker Bay (Oct 2010)–

Arniston

(May 2010)

Blind HI survey wedding cake

•

All-Sky (40,000 deg2)–

Wallaby (ASKAP) + Apertif (WSRT) + FAST–

500,000 galaxies out to z=0.26

•

Medium Deep (1000-5000 deg2)–

SDSS (Apertif)

•

Deep (60-200 deg2)–

Dingo (ASKAP)–

100,000 galaxies out to z=0.4–

150 deg2 (GAMA/GAMA2 regions)

•

Ultra-deep (2-30 deg2)–

Dingo (30 deg2 out to z=0.4)–

Asseghai/MeerKAT (4 deg2 out to z=1.4)–

[eVLA (clusters at z<0.4)]

ASKAP

Apertif

MeerKAT

Summary

•

Wallaby design study–

in progress:

•

science simulations (hydro, semi-analytic)•

telescope simulations (ASKAP computing group; WSRT)•

deep HI studies (AUDS, stacking); also GMRT, WSRT–

soon:

•

source-finding & parameterisation

(CASS; ICRAR)•

detailed survey design•

BETA commissioning

•

SKA phase 1 definition–

input from Wallaby science and simulations; PHISCC

Parkes

ASKAP

ASKAP