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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