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)
Current Observations Talk Outline 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
Current Observations - HI coadding
Giant Metrewave Radio Telescope
Giant Metrewave Radio Telescope
Anglo-Australian Telescope
2dF/AAOmega instrument multi-object, fibre fed spectrograph
The Fujita galaxies Hα emission galaxies at z = 0.24
The Fujita Galaxies Subaru Field 24! 30 DEC narrow band imaging H" emission at z = 0.24 (Fujita et al. 2003, ApJL, 586, L115) 348 Fujita galaxies 121 redshifts using AAT GMRT ~48 hours on field RA
Coadded HI Spectrum
Fujita galaxies neutral hydrogen gas measurement raw HI spectrum all using 121 redshifts - weighted average binned M HI = (2.26 ± 0.90)!10 9 M
The Cosmic Hydrogen Gas Density
my new point The Cosmic Gas Density vs. Redshift
my new point Cosmic Neutral Gas Density vs. Time
Abell 370 a galaxy cluster at z = 0.37
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 3# extent of X-ray gas R 200 radius at which cluster 200 times denser than the general field
The Measuring the HI signal
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.
The Average HI Mass Measurements
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 M HI = (6.6 ± 3.5)!10 9 M M HI = (23.0 ± 7.7)!10 9 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
Future Observations - HI coadding
What I could do with the SKA pathfinders if you gave them to me TODAY.
ASKAP and MeerKAT ASKAP parameters MeerKAT Number of Dishes 45 80 Dish Diameter 12 m 12 m Aperture Efficiency 0.8 0.8 System Temp. 35 K 30 K Frequency range 700 1800 MHz 700 10000 MHz Instantaneous bandwidth 300 MHz 512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg 2 30 deg 2 1.2 deg 2 4.8 deg 2 Maximum Baseline Length 8 km 10 km
ASKAP and MeerKAT ASKAP parameters MeerKAT Number of Dishes 45 80 Dish Diameter 12 m 12 m Aperture Efficiency 0.8 0.8 System Temp. 35 K 30 K Frequency range 700 1800 MHz 700 10000 MHz Instantaneous bandwidth 300 MHz 512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg 2 30 deg 2 1.2 deg 2 4.8 deg 2 Maximum Baseline Length 8 km 10 km
ASKAP and MeerKAT ASKAP parameters MeerKAT Number of Dishes 45 80 Dish Diameter 12 m 12 m Aperture Efficiency 0.8 0.8 System Temp. 35 K 30 K Frequency range 700 1800 MHz 700 10000 MHz Instantaneous bandwidth 300 MHz 512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) z = 0.4 to 1.0 in a single 30 observation deg 2 30 deg 2 z = 0.2 to 1.0 in a single 1.2 observation deg 2 4.8 deg 2 Maximum Baseline Length 8 km 10 km
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and WiggleZ zcosmos zcosmos Instrument/Telescope AAOmega on the AAT VIMOS on the VLT Target Selection Survey Area ultraviolet using the GALEX satellite 1000 deg 2 total 7 fields minimum size of ~100 deg 2 optical I band I AB < 22.5 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < 1.0 0.1 < z < 1.2 Survey Timeline 2006 to 2010 2005 to 2008 n z by survey end 176,000 20,000 n z in March 2008 ~62,000 ~10,000
WiggleZ and ASKAP
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 deg 2
ASKAP & WiggleZ 100hrs n z = 5975
ASKAP & WiggleZ 100hrs n z = 5975
ASKAP & WiggleZ 100hrs n z = 5975
ASKAP & WiggleZ 1000hrs n z = 5975
zcosmos and MeerKAT
zcosmos field MeerKAT beam size at 1420 MHz z = 0 MeerKAT beam size at 1000 MHz z = 0.4 ~1.3 degrees across data as of March 2008 z = 0.1 to 1.0
MeerKAT & zcosmos 100hrs n z = 7615
MeerKAT & zcosmos 100hrs n z = 7615
MeerKAT & zcosmos 100hrs n z = 7615
MeerKAT & zcosmos 1000hrs n z = 7615
Conclusion
Conclusion can use coadding with optical redshifts to make measurement of the HI 21 cm emission from galaxies at redshifts z > 0.1 the measured cosmic neutral gas density at z = 0.24 is consistent with that from damped Ly" measurements galaxy cluster Abell 370 at z = 0.37 has significantly amounts of neutral hydrogen gas the SKA pathfinders ASKAP and MeerKAT can measure significant amounts of HI 21 cm emission out to z = 1.0 using the coadding technique with existing optical redshift surveys