Neutral Hydrogen Gas in Abell 370, a Galaxy Cluster at z = 0.37 NCRA 17 th July 2008 Philip Lah

Collaborators: Jayaram Chengalur (NCRA) Michael Pracy (ANU) Frank Briggs (ANU) Matthew Colless (AAO) Roberto De Propris (CTIO)

Giant Metrewave Radio Telescope

Talk Outline Introduction evolution in clusters & star formation rate density vs redshift HI 21-cm emission & the HI coadding technique review of current HI measurements at z > 0.1 Abell 370, a Galaxy Cluster at z = 0.37 HI in Abell 370 star formation in Abell 370 two unusual radio continuum objects around Abell 370 Future Observations with SKA pathfinders using ASKAP and WiggleZ using MeerKAT and zCOSMOS

Evolution in Galaxy Clusters

Galaxy Cluster: Coma

Butcher-Oemler Effect Butcher-Oemler Effect increasing fraction of blue galaxies in clusters with redshift nearby clusters neutral hydrogen gas deficient

The Cosmic Star Formation Rate Density

SFRD vs z Hopkins 2004

HI Gas and Star Formation Neutral atomic hydrogen gas cloud (HI) molecular gas cloud (H 2 ) star formation

Neutral Atomic Hydrogen (HI) 21-cm Emission

Neutral atomic hydrogen creates 21 cm radiation proton electron

Neutral atomic hydrogen creates 21 cm radiation

photon

Neutral atomic hydrogen creates 21 cm radiation

HI 21cm Emission at High Redshift

HI 21cm emission at z > 0.1 single galaxy at z =  WSRT 200 hours (Zwaan et al. 2001, Science, 293, 1800) single galaxy at z =  VLA ~80 hours (Verheijen et al. 2004,in IAU Symposium Vol 195, p. 394) two galaxy clusters at z = and z =  WSRT 420 hours  42 galaxies detected  HI gas masses 5  10 9 to 4  M  (Verheijen et al. 2007, ApJL, 668, L9) galaxies with redshifts z = 0.17 to 0.25 observed with Arecibo  detected 26 from 33 observed  HI gas masses (2 to 6)  M  (Catinella et al. 2007, in IAU Symposium Vol 235, p. 39)

HI 21cm emission at z > 0.1 single galaxy at z =  WSRT 200 hours (Zwaan et al. 2001, Science, 293, 1800) single galaxy at z =  VLA ~80 hours (Verheijen et al. 2004,in IAU Symposium Vol 195, p. 394) two galaxy clusters at z = and z =  WSRT 420 hours  42 galaxies detected  HI gas masses 5  10 9 to 4  M  (Verheijen et al. 2007, ApJL, 668, L9) galaxies with redshifts z = 0.17 to 0.25 observed with Arecibo  detected 26 from 33 observed  HI gas masses (2 to 6)  M  (Catinella et al. 2007, in IAU Symposium Vol 235, p. 39)

HI 21cm emission at z > 0.1 single galaxy at z =  WSRT 200 hours (Zwaan et al. 2001, Science, 293, 1800) single galaxy at z =  VLA ~80 hours (Verheijen et al. 2004,in IAU Symposium Vol 195, p. 394) two galaxy clusters at z = and z =  WSRT 420 hours  42 galaxies detected  HI gas masses 5  10 9 to 4  M  (Verheijen et al. 2007, ApJL, 668, L9) galaxies with redshifts z = 0.17 to 0.25 observed with Arecibo  detected 26 from 33 observed  HI gas masses (2 to 6)  M  (Catinella et al. 2007, in IAU Symposium Vol 235, p. 39)

HI 21cm emission at z > 0.1 single galaxy at z =  WSRT 200 hours (Zwaan et al. 2001, Science, 293, 1800) single galaxy at z =  VLA ~80 hours (Verheijen et al. 2004,in IAU Symposium Vol 195, p. 394) two galaxy clusters at z = and z =  WSRT 420 hours  42 galaxies detected  HI gas masses 5  10 9 to 4  M  (Verheijen et al. 2007, ApJL, 668, L9) galaxies with redshifts z = 0.17 to 0.25 observed with Arecibo  detected 26 from 33 observed  HI gas masses (2 to 6)  M  (Catinella et al. 2007, in IAU Symposium Vol 235, p. 39)

HI 21cm emission at z > 0.1 our group using the GMRT measured the coadded HI signal from 121 star forming galaxies at z = 0.24 (look-back time ~3.8 Gyr)  GMRT ~48 hours on field  weighted average M HI = (2.26 ± 0.90) ×10 9 M  (Lah et al. 2007, MNRAS, 376, 1357)

Abell 370 a Galaxy Cluster at z = 0.37

Abell 370, a galaxy cluster at z = 0.37 large galaxy cluster of order same size as Coma optical imaging ANU 40 inch telescope spectroscopic follow- up with the AAT GMRT ~34 hours on cluster

Abell 370 – R band images Thumbnails 10’’ sq 324 galaxies with useful redshifts (z~0.37) ordered by observed R band magnitudes

Abell 370 galaxy cluster 324 galaxies 105 blue (B-V  0.57) 219 red (B-V > 0.57) Abell 370 galaxy cluster

3σ extent of X-ray gas R 200  radius at which cluster 200 times denser than the general field

redshift histogram 324 useful redshifts

redshift histogram 324 useful redshifts GMRT sideband frequency limits

Galaxy Sizes I want galaxies to be unresolved. For the galaxies at z = 0.24 I used an estimate of the HI size from the optical properties of spiral and irregular field galaxies and the smoothed radio data. Major Complication!! The Abell 370 galaxies are a mixture of early and late types in a variety of environments.

Galaxy Sizes I want galaxies to be unresolved. For the galaxies at z = 0.24 I used an estimate of the HI size from the optical properties of spiral and irregular field galaxies and the smoothed radio data. Major Complication!! The Abell 370 galaxies are a mixture of early and late types in a variety of environments.

HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies

HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies

HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies

HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies

HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies

HI all spectrum all Abell 370 galaxies neutral hydrogen gas measurement using 324 redshifts – large smoothing M HI = (6.6 ± 3.5) ×10 9 M 

HI Flux – All Galaxies

HI blue outside x-ray gas blue galaxies outside of x-ray gas measurement of neutral hydrogen gas content using 94 redshifts – large smoothing M HI = (23.0 ± 7.7) ×10 9 M 

HI Flux – Blue Galaxies Outside X-ray Gas

Comparisons with the Literature

Average HI Mass Comparisons with Coma

Abell 370 and Coma Comparison 214 galaxies 324 galaxies 110 galaxies

Abell 370 and Coma Comparison 214 galaxies 324 galaxies 110 galaxies

Abell 370 and Coma Comparison 214 galaxies 324 galaxies 110 galaxies

HI Density Comparisons

HI density field

HI density - inner regions of clusters within 2.5 Mpc of cluster centers

HI Mass to Light Ratios

HI mass to optical B band luminosity for Abell 370 galaxies Uppsala General Catalog Local Super Cluster (Roberts & Haynes 1994)

HI Mass to Light Ratios HI mass to optical B band luminosity for Abell 370 galaxies Uppsala General Catalog Local Super Cluster (Roberts & Haynes 1994)

Galaxy HI mass vs Star Formation Rate

Galaxy HI Mass vs Star Formation Rate HIPASS & IRAS data z ~ 0 Doyle & Drinkwater 2006

HI Mass vs Star Formation Rate in Abell 370 all 168 [OII] emission galaxies line from Doyle & Drinkwater 2006 Average

HI Mass vs Star Formation Rate in Abell blue [OII] emission galaxies line from Doyle & Drinkwater red [OII] emission galaxies Average

Star Formation Rate from [OII] and radio continuum emission

radio continuum emission produced from relativistic electrons moving in magnetic field of the galaxy - synchrotron radiation relativistic electrons produced by supernova remnants, what remains after the death of massive, short-lived stars in theory - number of supernova remnants related to star formation rate in galaxy in practice - empirical relationship - agrees with other star formation rate indicators Radio Continuum – Star Formation Connection

Radio Continuum vs. [OII] Star Formation Rate all 168 [OII] emission galaxies line from Bell 2003 Average

Radio Continuum vs. [OII] Star Formation Rate line from Bell blue [OII] emission galaxies 87 red [OII] emission galaxies Average

Two Unusual Radio Continuum Objects in the field of Abell 370

1.The De Propris Structure

Example Radio Continuum Jet

The De Propris Structure FIRST image 60 arcsec across VLA at 1.4 GHz Resolution ~5 arcsec

The De Propris Structure GMRT image resolution ~3.3 arcsec at 1040 MHz Peak flux = 1.29 mJy/Beam Total flux density ~ 23.3 mJy

The De Propris Structure V band optical image from ANU 40 inch WFI

The De Propris Structure Radio contours at 150, 300, 450, 600, 750, 900 & 1150  Jy/beam RMS ~ 20  Jy

The De Propris Structure Optical as Contours

The De Propris Structure Galaxies all at similar redshifts z ~

The De Propris Group

~167 Mpc difference between cluster Abell 370 and De Propris group in comoving distance NOT related objects group well outside GMRT HI redshift range The De Propris Group Abell 370 De Propris Group

De Propris Structure Galaxy 4 – source of De Propris Structure The De Propris Group

10 arcmin square box ~2800 kpc at z = galaxy group/small cluster galaxies moving through intra-group medium of hot ionised gas ionised gas pushes radio jet bending it back on itself to create the strange shape

2. A Radio Gravitational Arc?

Radio Arc V band optical image from ANU 40 inch Abell 370 cluster 8 arcmin square

Radio Arc V band optical image from ANU 40 inch Abell 370 cluster 8 arcmin square

Radio Arc V band optical image from ANU 40 inch image centred on one of the two cD galaxies near the centre of the Abell 370 cluster 50 arcsec square

Radio Arc optical image from Hubble Space Telescope optical arc in Abell 370 was the first detected gravitational lensing event by a galaxy cluster (Soucail et al. 1987)

Radio Arc GMRT image resolution ~3.3 arcsec at 1040 MHz Peak flux = 490  Jy/Beam cD galaxy Peak flux = 148  Jy/Beam Noise ~20  Jy noise

Radio Arc Radio contours at 80, 100, 120, 140, 180, 220, 260, 320, 380 & 460  Jy/beam RMS ~ 20  Jy

Radio Arc Optical as Contours

Future Observations - HI coadding with SKA Pathfinders

SKA – Square Kilometer Array final site decision by 2012?? – money will be the deciding factor both South Africa and Australia are building SKA pathfinder telescopes to strengthen their case for site selection – also do science SKA promises both high sensitivity with wide field of view possible SKA sites – South Africa and Australia

Why South Africa and Australia?

Population Density – India

Population Density – South Africa

Population Density – Australia

Radio Interference Frequency (Hz)

The SKA Pathfinders

ASKAP

MeerKAT South African SKA pathfinder

ASKAP and MeerKAT parameters ASKAPMeerKAT Number of Dishes 4580 Dish Diameter 12 m Aperture Efficiency 0.8 System Temp. 35 K30 K Frequency range 700 – 1800 MHz700 – 2500 MHz Instantaneous bandwidth 300 MHz512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg deg deg 2 Maximum Baseline Length 8 km10 km

ASKAP and MeerKAT parameters ASKAPMeerKAT Number of Dishes 4580 Dish Diameter 12 m Aperture Efficiency 0.8 System Temp. 35 K30 K Frequency range 700 – 1800 MHz700 – 2500 MHz Instantaneous bandwidth 300 MHz512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg deg deg 2 Maximum Baseline Length 8 km10 km

ASKAP and MeerKAT parameters ASKAPMeerKAT Number of Dishes 4580 Dish Diameter 12 m Aperture Efficiency 0.8 System Temp. 35 K30 K Frequency range 700 – 1800 MHz700 – 2500MHz Instantaneous bandwidth 300 MHz512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg deg deg 2 Maximum Baseline Length 8 km10 km z = 0.45 to 1.0 in a single observation z = 0.2 to 1.0 in a single observation

single pointing assumes no evolution in the HI mass function (Johnston et al. 2007) MeerKAT - will detect galaxies easier - more sensitive - but in a single pointing will end up with fewer total detections due to smaller field of view z = 0.45 to MHz to 700 MHz one year observations (8760 hours) Simulated ASKAP HI detections

What I could do with the SKA pathfinders using optical coadding of HI if you gave them to me TODAY.

WiggleZ and zCOSMOS WiggleZzCOSMOS Instrument/TelescopeAAOmega on the AATVIMOS on the VLT Target Selection ultraviolet using the GALEX satellite optical I band I AB < 22.5 Survey Area 1000 deg 2 total 7 fields minimum size of ~100 deg 2 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < < z < 1.2 Survey Timeline2006 to to 2008 n z by survey end176,00020,000 n z in March 2008~62,000~10,000

WiggleZ and zCOSMOS WiggleZzCOSMOS Instrument/TelescopeAAOmega on the AATVIMOS on the VLT Target Selection ultraviolet using the GALEX satellite optical I band I AB < 22.5 Survey Area 1000 deg 2 total 7 fields minimum size of ~100 deg 2 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < < z < 1.2 Survey Timeline2006 to to 2008 n z by survey end176,00020,000 n z in March 2008~62,000~10,000

WiggleZ and zCOSMOS WiggleZzCOSMOS Instrument/TelescopeAAOmega on the AATVIMOS on the VLT Target Selection ultraviolet using the GALEX satellite optical I band I AB < 22.5 Survey Area 1000 deg 2 total 7 fields minimum size of ~100 deg 2 COSMOS field single field ~2 deg 2 Primary Redshift Range 0.5 < z < < z < 1.2 Survey Timeline2006 to to 2008 n z by survey end176,00020,000 n z in March 2008~62,000~10,000

WiggleZ and ASKAP

WiggleZ field data as of March 2008 z = 0.45 to 1.0 ASKAP beam size Diameter 6.2 degrees Area 30 deg 2 ~10 degrees across

ASKAP & WiggleZ 100hrs n z = 3887

ASKAP & WiggleZ 100hrs n z = 3887

ASKAP & WiggleZ 100hrs n z = 3887

ASKAP & WiggleZ 1000hrs n z = 3887

zCOSMOS and MeerKAT

zCOSMOS field data as of March 2008 z = 0.2 to galaxies MeerKAT beam size at 1420 MHz z = 0 MeerKAT beam size at 1000 MHz z = 0.4 square ~1.3 degrees across

MeerKAT & zCOSMOS 100hrs n z = 3559

MeerKAT & zCOSMOS 100hrs n z = 3559

MeerKAT & zCOSMOS 100hrs n z = 3559

MeerKAT & zCOSMOS 1000hrs n z = 3559

Conclusion

Abell 370 a galaxy cluster at z = 0.37 has significantly more gas than similar clusters at z ~ 0 despite this fact, galaxies in regions of higher density within Abell 370 have less gas than galaxies located in regions of lower density, the same trend seen in nearby clusters there are two unusual radio continuum structures in the field of Abell 370 – a twisted radio jet and a possible radio gravitational arc 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 redshift surveys Conclusion

Additional Slides

RFI – 950 MHz mobile phones Field of view small – 45 m dishes bandpass small 32 MHz – upgrade coming but will not soon work for all dishes simultaneously longer baselines resolve HI in galaxies Why not GMRT?