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HI in Galaxies at Redshifts 0.1 to 1.0: Current and Future Observations U sing Optical Redshifts for HI Coadding. Philip Lah. Deep Surveys of the Radio Universe with SKA Pathfinders.
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HI in Galaxies at Redshifts 0.1 to 1.0: Current and Future Observations Using Optical Redshifts for HI Coadding Philip Lah Deep Surveys of the Radio Universe with SKA Pathfinders
Collaborators:Frank Briggs (ANU) Jayaram Chengalur (NCRA) Matthew Colless (AAO)Roberto De Propris (CTIO)Michael Pracy (ANU)
Talk Outline Current Observations • HI in star forming galaxies at z=0.24 • HI in Abell 370, a galaxy cluster at z = 0.37 Future Observations • using ASKAP and WiggleZ • using MeerKAT and zCOSMOS
2dF/AAOmega instrument multi-object, fibre fed spectrograph
DEC RA The Fujita Galaxies Subaru Field 24’ × 30’ narrow band imaging Hα emission at z = 0.24 (Fujita et al. 2003, ApJL, 586, L115) 348 Fujita galaxies 121 redshifts using AAT GMRT ~48 hours on field
HI spectrum all Fujita galaxies neutral hydrogen gas measurement using 121 redshifts - weighted average MHI = (2.26 ± 0.90) ×109 M raw binned
The Cosmic Gas Density vs. Redshift my new point
Cosmic Neutral Gas Density vs. Time my new point
Abell 370 • large galaxy cluster at z = 0.37, of order same size of Coma similar cluster velocity dispersion and X-ray gas temperature • optical imaging ANU 40 inch telescope • spectroscopic follow-up with the AAT • GMRT ~34 hours on cluster
Abell 370 galaxy cluster Abell 370 galaxy cluster 324 galaxies with redshifts z = 0.345 to 0.387 105 blue galaxies 219 red galaxies
Abell 370 galaxy cluster Abell 370 galaxy cluster 3σ extent of X-ray gas R200 radius at which cluster 200 times denser than the general field
Galaxy Sizes For HI stacking I want the galaxies to be unresolved. For the Fujita galaxies I used an estimate of the HI size from the optical properties using information on nearby spiral and irregular field galaxies. Complication! The Abell 370 galaxies are a mixture of early and late types in a variety of environments. Solution I made multiple measurements of the galaxies HI mass using different smoothing sizes.
Galaxy Sizes For HI stacking I want the galaxies to be unresolved. For the Fujita galaxies I used an estimate of the HI size from the optical properties using information on nearby spiral and irregular field galaxies. Complication! The Abell 370 galaxies are a mixture of early and late types in a variety of environments. Solution I made multiple measurements of the galaxies HI mass using different smoothing sizes.
Galaxy Sizes For HI stacking I want the galaxies to be unresolved. For the Fujita galaxies I used an estimate of the HI size from the optical properties using information on nearby spiral and irregular field galaxies. Complication! The Abell 370 galaxies are a mixture of early and late types in a variety of environments. Solution I made multiple measurements of the galaxies HI mass using different smoothing sizes.
HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 156 galaxies 168 galaxies 104 galaxies 220 galaxies
HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 156 galaxies 168 galaxies 104 galaxies 220 galaxies
HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 156 galaxies 168 galaxies 104 galaxies 220 galaxies
HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 156 galaxies 168 galaxies 104 galaxies 220 galaxies
HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 156 galaxies 168 galaxies 104 galaxies 220 galaxies
HI spectra – Large Smoothing MHI = (6.6 ± 3.5) ×109 M MHI = (23.0 ± 7.7) ×109 M
HI Flux – All Galaxies 30 arcsec across ~150 kpc across
HI Flux – The Blue Galaxies Outside X-ray Gas 30 arcsec across ~150 kpc across
What I could do with the SKA pathfinders if you gave them to me TODAY.
ASKAP and MeerKAT parameters z = 0.4 to 1.0 in a single observation z = 0.2 to 1.0 in a single observation
WiggleZ field ~10 degrees across data as of March 2008 z = 0.1 to 1.0 ASKAP beam size Diameter 6.2 degrees Area 30 deg2
ASKAP & WiggleZ 100hrs nz = 5975
ASKAP & WiggleZ 100hrs nz = 5975
ASKAP & WiggleZ 100hrs nz = 5975
ASKAP & WiggleZ 1000hrs nz = 5975