1. The Evolution of Gas in Galaxies End of Thesis Colloquium Philip Lah

2. Chair of Supervisory Panel: Frank Briggs (ANU) Supervisory Panel: Jayaram Chengalur (NCRA) Matthew Colless (AAO) Roberto De Propris (CTIO) Erwin De Blok (UCT) With Assistance From: Michael Pracy (ANU)

3. Talk Outline Introduction HI 21-cm emission, galaxies and star formation the cosmic star formation rate density and the cosmic HI density high redshift HI 21-cm emssion observations and the coadding technique Current Observations with the HI coadding technique HI in star-forming galaxies at z = 0.24 HI in galaxies around Abell 370, a galaxy cluster at z = 0.37 Future Observations with SKA pathfinders using ASKAP and WiggleZ using MeerKAT and zCOSMOS ideas on the evolution of gas in galaxies

4. Talk Outline Introduction HI 21-cm emission, galaxies and star formation the cosmic star formation rate density and the cosmic HI density high redshift HI 21-cm emssion observations and the coadding technique Current Observations with the HI coadding technique HI in star-forming galaxies at z = 0.24 HI in galaxies around Abell 370, a galaxy cluster at z = 0.37 Future Observations with SKA pathfinders using ASKAP and WiggleZ using MeerKAT and zCOSMOS ideas on the evolution of gas in galaxies

5. Talk Outline Introduction HI 21-cm emission, galaxies and star formation the cosmic star formation rate density and the cosmic HI density high redshift HI 21-cm emssion observations and the coadding technique Current Observations with the HI coadding technique HI in star-forming galaxies at z = 0.24 HI in galaxies around Abell 370, a galaxy cluster at z = 0.37 Future Observations with SKA pathfinders using ASKAP and WiggleZ using MeerKAT and zCOSMOS ideas on the evolution of gas in galaxies

6. HI 21-cm Emission

7. Neutral atomic hydrogen creates 21-cm radiation proton electron

8. Neutral atomic hydrogen creates 21-cm radiation

9. Neutral atomic hydrogen creates 21 cm radiation

10. Neutral atomic hydrogen creates 21-cm radiation

11. photon

12. Neutral atomic hydrogen creates 21-cm radiation decay half life ~10 million years (3  10 14 s)

13. HI 21-cm Emission From Galaxies

14. Galaxy M33: optical

15. Galaxy M33: HI 21-cm emission

16. Galaxy M33: optical and HI

17. Galaxy M33: optical

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

19. Galaxy HI mass vs Star Formation Rate

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

21. The Star Formation Rate Density of the Universe

22. Star Formation Rate Density Evolution Compilation by Hopkins 2004

23. The HI Gas Density of the Universe

24. HI Gas Density Evolution Not a log scale

25. HI Gas Density Evolution Zwaan et al. 2005 HIPASS HI 21cm Rao et al. 2006 DLAs from MgII absorption Prochaska et al. 2005 & 2009 DLAs Lah et al. 2007 coadded HI 21cm

26. HI 21cm Emission at High Redshift

27. HI 21cm emission at z > 0.1 Zwaan et al. 2001 WSRT 200 hours

28. HI 21cm emission at z > 0.1 Verheijen et al. 2004 VLA 80 hours

29. HI 21cm emission at z > 0.1 Verheijen et al. 2007 WSRT 180 & 240 hours

30. HI 21cm emission at z > 0.1 Catinella et al. 2007 Arecibo 2-6 hours per galaxy

31. HI 21cm emission at z > 0.1 Lah et al. 2007 coadded GMRT 81 hours Lah et al. 2009 coadded GMRT 63 hours

32. Coadding HI signals

33. RA DEC Radio Data Cube Frequency HI redshift

34. Coadding HI signals RA DEC Radio Data Cube Frequency HI redshift positions of optical galaxies

35. Coadding HI signals frequency flux

36. Coadding HI signals frequency flux z2 z1 z3 z1, z2 & z3 optical redshifts of galaxies

37. Coadding HI signals velocity z1 z2 z3 flux z1, z2 & z3 optical redshifts of galaxies

38. Coadding HI signals velocity z1 z2 z3 flux velocity Coadded HI signal z1, z2 & z3 optical redshifts of galaxies

39. Current Observations - HI coadding

40. Giant Metrewave Radio Telescope

44. Anglo-Australian Telescope

45. multi-object, fibre fed spectrograph 2dF/AAOmega instrument

46. The Fujita galaxies H  emission galaxies at z = 0.24

47. The Fujita Galaxies Subaru Field 24’ × 30’ narrow band imaging  Hα emission at z = 0.24 look-back time ~3 billion years (Fujita et al. 2003, ApJL, 586, L115) 348 Fujita galaxies 121 redshifts using AAT GMRT ~48 hours on field DEC RA

48. Star Formation Rate Density Evolution Compilation by Hopkins 2004

49. Star Formation Rate Density Evolution Compilation by Hopkins 2004 Fujita et al. 2003 value

50. Coadded HI Spectrum

51. HI spectrum all Fujita galaxies coadded HI spectrum using 121 redshifts - weighted average raw

52. HI spectrum all Fujita galaxies coadded HI spectrum using 121 redshifts - weighted average raw binned M HI = (2.26 ± 0.90) ×10 9 M 

53. The HI Gas Density of the Universe

54. HI Gas Density Evolution Lah et al. 2007 coadded HI 21cm

55. Galaxy HI mass vs Star Formation Rate

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

57. HI Mass vs Star Formation Rate at z = 0.24 line from Doyle & Drinkwater 2006 all 121 galaxies

58. HI Mass vs Star Formation Rate at z = 0.24 line from Doyle & Drinkwater 2006 42 bright L(Hα) galaxies 42 medium L(Hα) galaxies 37 faint L(Hα) galaxies

59. Abell 370 a galaxy cluster at z = 0.37

60. Galaxy Clusters and HI gas

61. Galaxy Cluster: Coma

62. Nearby Galaxy Clusters Are Deficient in HI Gas

63. HI Deficiency in Clusters Def HI = log(M HI exp. / M HI obs) Def HI = 1 is 10% of expected HI gas expected gas estimate based on optical diameter and Hubble type interactions between galaxies and interactions with the inter-cluster medium removes the gas from the galaxies Gavazzi et al. 2006

64. Why target moderate redshift clusters for HI gas?

65. Why target moderate redshift clusters? at moderate redshifts the whole of the galaxy cluster core and its outskirts are within the field of view of a radio telescope (nearby this not the case – one has to target individual galaxies in clusters one by one) around a cluster there are many more galaxies that lie within a single telescope pointing than for a typical field pointing the Butcher-Oemler effect

66. Why target moderate redshift clusters? at moderate redshifts the whole of the galaxy cluster core and its outskirts are within the field of view of a radio telescope (nearby this not the case – one has to target individual galaxies in clusters one by one) around a cluster there are many more galaxies that lie within a single telescope pointing than for a typical field pointing the Butcher-Oemler effect

67. Why target moderate redshift clusters? at moderate redshifts the whole of the galaxy cluster core and its outskirts are within the field of view of a radio telescope (nearby this not the case – one has to target individual galaxies in clusters one by one) around a cluster there are many more galaxies that lie within a single telescope pointing than for a typical field pointing the (Harvey) Butcher-Oemler effect

68. The Butcher-Oemler Effect Redshift, z Blue Fraction, f B

69. The Butcher-Oemler Effect Redshift, z Blue Fraction, f B Abell 370

70. Abell 370 a galaxy cluster at z = 0.37

71. Abell 370, a galaxy cluster at z = 0.37 Abell 370 cluster core, ESO VLT image large galaxy cluster of order same size as 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 HI z = 0.35 to 0.39 look-back time ~4 billion years

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

73. 3σ extent of X-ray gas R 200  radius at which cluster 200 times denser than the general field

74. Coadded HI Mass Measurements

75. HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies Inner RegionsOuter Regions The galaxies around Abell 370 are a mixture of early and late types in a variety of environments.

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

77. HI mass 324 galaxies 219 galaxies 105 galaxies 94 galaxies 168 galaxies 156 galaxies 110 galaxies 214 galaxies HI deficient 11 blue galaxies within X-ray gas

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

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

80. HI Density Comparisons

81. Inner Cluster Region Outer Cluster Region HI density Whole Redshift Region z = 0.35 to 0.39

82. cluster redshift Distribution of galaxies around Abell 370

83. Inner Cluster Region HI density Outer Cluster Region Whole Redshift Region z = 0.35 to 0.39

84. cluster redshift Distribution of galaxies around Abell 370 within R 200 region

85. HI density Outer Cluster Region Inner Cluster Region Whole Redshift Region z = 0.35 to 0.39

86. Galaxy HI mass vs Star Formation Rate

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

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

89. HI Mass vs Star Formation Rate in Abell 370 81 blue [OII] emission galaxies line from Doyle & Drinkwater 2006 87 red [OII] emission galaxies Average

90. Future Observations - HI coadding with SKA Pathfinders

91. SKA – Square Kilometer Array both South Africa and Australia are currently building SKA pathfinder telescopes to strengthen their case for site selection the SKA pathfinder telescopes will also do interesting science SKA promises both high sensitivity with a wide field of view possible SKA sites – South Africa and Australia

92. SKA – Square Kilometer Array both South Africa and Australia are currently building SKA pathfinder telescopes to strengthen their case for site selection the SKA pathfinder telescopes will also do interesting science SKA promises both high sensitivity with a wide field of view possible SKA sites – South Africa and Australia (RFI quiet areas)

93. SKA – Square Kilometer Array both South Africa and Australia are currently building SKA pathfinder telescopes to strengthen their case for site selection the SKA pathfinder telescopes will also do interesting science SKA promises both high sensitivity with a wide field of view possible SKA sites – South Africa and Australia (RFI quiet areas)

94. The SKA pathfinders

95. ASKAP

96. MeerKAT South African SKA pathfinder

97. ASKAP and MeerKAT parameters ASKAPMeerKAT Number of Dishes 30 (36)80 Dish Diameter 12 m Aperture Efficiency 0.8 System Temp. 50 K30 K Frequency range 700 – 1800 MHz500 – 2500 MHz Instantaneous bandwidth 300 MHz512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg 2 1.2 deg 2 4.8 deg 2 Maximum Baseline Length 2 (6) km10 km

98. ASKAP and MeerKAT parameters ASKAPMeerKAT Number of Dishes 30 (36)80 Dish Diameter 12 m Aperture Efficiency 0.8 System Temp. 35 K30 K Frequency range 700 – 1800 MHz500 – 2500 MHz Instantaneous bandwidth 300 MHz512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg 2 1.2 deg 2 4.8 deg 2 Maximum Baseline Length 2 (8) km10 km

99. ASKAP and MeerKAT parameters ASKAPMeerKAT Number of Dishes 30 (36)80 Dish Diameter 12 m Aperture Efficiency 0.8 System Temp. 35 K30 K Frequency range 700 – 1800 MHz500 – 2500 MHz Instantaneous bandwidth 300 MHz512 MHz Field of View: at 1420 MHz (z = 0) at 700 MHz (z = 1) 30 deg 2 1.2 deg 2 4.8 deg 2 Maximum Baseline Length 2 (8) km10 km z = 0.4 to 1.0 in a single observation z = 0.2 to 1.0 in a single observation

100. single telescope pointing, assumes no evolution in the HI mass function Light grey 30 dishes T sys = 50 K Dark grey 45 dishes T sys = 35 K MeerKAT ~4 times more sensitive but smaller field of view (Johnston et al. 2007) z = 0.45 to 1.0 one year observations (8760 hours) Simulated ASKAP HI detections

101. Coadding HI with the SKA Pathfinders Optical Redshift Surveys

102. 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 < 1.00.1 < z < 1.2 Survey Timeline2006 to 20102005 to 2008 n z by survey end200,00020,000

103. 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 < 1.00.1 < z < 1.2 Survey Timeline2006 to 20102005 to 2008 n z by survey end200,00020,000

104. 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 < 1.00.1 < z < 1.2 Survey Timeline2006 to 20102005 to 2008 n z by survey end200,00020,000

105. WiggleZ and ASKAP

106. WiggleZ field data as of May 2009 z = 0.45 to 1.0 ASKAP Field of View Area 30 deg 2 square ~10 degrees across

107. ASKAP & WiggleZ 100hrs n z = 7009

108. ASKAP & WiggleZ 100hrs n z = 7009

109. ASKAP & WiggleZ 100hrs n z = 7009

110. ASKAP & WiggleZ 1000hrs n z = 7009 Can break up observations among multiple WiggleZ fields

111. zCOSMOS and MeerKAT

112. zCOSMOS field data as of March 2008 z = 0.2 to 1.0 7118 galaxies MeerKAT beam size at 1420 MHz z = 0 MeerKAT beam size at 1000 MHz z = 0.4 square ~1.3 degrees across

113. MeerKAT & zCOSMOS 100hrs n z = 4627 ~65 per cent of zCOSMOS galaies are star-forming, blue, disk- dominate galaxies (Mignoli et al. 2008)

114. MeerKAT & zCOSMOS 100hrs n z = 4627

115. MeerKAT & zCOSMOS 100hrs n z = 4627

116. MeerKAT & zCOSMOS 1000hrs n z = 4627

117. HI Science with SKA Pathfinders at High Redshift

118. Why is there a dramatic evolution in the Cosmic Star Formation Rate Density and only minimal evolution in the Cosmic HI Gas Density?

119. SFRD & HI density Evolution Star Formation Rate Density Evolution HI Density Evolution

120. Evolution of HI Gas in Galaxies log(SFR)  log(M HI ) SFR = a (M HI ) m  HI =  M HI SFRD =  SFR SFRD = a ×  (M HI ) m m ~ 1.7 at z = 0 (Doyle & Drinkwater 2006) Vol

121. Evolution of HI Gas in Galaxies log(SFR)  log(M HI ) SFR = a (M HI ) m  HI =  M HI SFRD =  SFR SFRD = a ×  (M HI ) m m ~ 1.7 at z = 0 (Doyle & Drinkwater 2006) Vol

122. Evolution of HI Gas in Galaxies log(SFR)  log(M HI ) SFR = a (M HI ) m  HI =  M HI SFRD =  SFR SFRD = a ×  (M HI ) m m ~ 1.7 at z = 0 (Doyle & Drinkwater 2006) Vol

123. Evolution of HI Gas in Galaxies log(SFR)  log(M HI ) SFR = a (M HI ) m  HI =  M HI SFRD =  SFR SFRD = a ×  (M HI ) m m ~ 1.7 at z = 0 (Doyle & Drinkwater 2006) Vol

124. Evolution of HI Gas in Galaxies log(SFR)  log(M HI ) SFR = a (M HI ) m  HI =  M HI SFRD =  SFR SFRD = a ×  (M HI ) m m ~ 1.7 at z = 0 (Doyle & Drinkwater 2006) Vol

125. Testing Ideas on HI Gas Evolution

126. Generated HI Mass Functions Integrated HI density = current value (~5×10 7 M  Mpc -3 ) Integrated SFRD = maximum value observed (~0.3 M  yr -1 Mpc -3 ) z = 0 HI mass function

127. Generated HI Mass Functions Integrated HI density = twice current value (~10 8 M  Mpc -3 ) Integrated SFRD = maximum value observed (~0.3 M  yr -1 Mpc -3 ) z = 0 HI mass function

128. Integrated HI density = current value (~5×10 7 M  Mpc -3 ) Integrated SFRD = maximum value observed (~0.3 M  yr -1 Mpc -3 ) SFR = a (M HI ) m current values Varying Galaxy SFR-HI Gas Relationship

129. Observational Evidence

130. Downsizing the bulk of the stellar populations of the most massive galaxies formed at early times (Heavens et al. 2004, Thomas et al. 2005 & others) the sites of active star formation shift from the high-mass galaxies at earliest times to the lower-mass galaxies at later periods (Cowie et al. 1996, Gunzman et al. 1997 & others) high mass galaxies with active star formation  highest HI gas content? SKA pathfinders observations test hypotheses

131. Downsizing the bulk of the stellar populations of the most massive galaxies formed at early times (Heavens et al. 2004, Thomas et al. 2005 & others) the sites of active star formation shift from the high-mass galaxies at earliest times to the lower-mass galaxies at later periods (Cowie et al. 1996, Gunzman et al. 1997 & others) high mass galaxies with active star formation  highest HI gas content? SKA pathfinders observations test hypotheses

132. Downsizing the bulk of the stellar populations of the most massive galaxies formed at early times (Heavens et al. 2004, Thomas et al. 2005 & others) the sites of active star formation shift from the high-mass galaxies at earliest times to the lower-mass galaxies at later periods (Cowie et al. 1996, Gunzman et al. 1997 & others) high mass galaxies with active star formation  highest HI gas content? SKA pathfinders observations test hypotheses

133. Downsizing the bulk of the stellar populations of the most massive galaxies formed at early times (Heavens et al. 2004, Thomas et al. 2005 & others) the sites of active star formation shift from the high-mass galaxies at earliest times to the lower-mass galaxies at later periods (Cowie et al. 1996, Gunzman et al. 1997 & others) high mass galaxies with active star formation  highest HI gas content? use SKA pathfinders observations to test hypotheses

134. Bonus Material

135. Two Unusual Radio Continuum Objects in the Field of Abell 370

136. 1.The DP Structure

137. Single RC Single Radio Contiuum Source

138. Double RC Double Radio Contiuum Source

139. The DP Structure GMRT image resolution ~3.3 arcsec at 1040 MHz Peak flux = 1.29 mJy/Beam Total flux density ~ 23.3 mJy 60 arcsec across

140. The DP Structure V band optical image from ANU 40 inch WFI 60 arcsec across

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

142. The DP Structure Optical as Contours

143. The DP Structure Galaxies all at similar redshifts z ~ 0.3264

144. The DP Group

145. ~167 Mpc difference between cluster Abell 370 and DP group in commoving distance NOT related objects group well outside GMRT HI redshift range The DP Group Abell 370 DP Group

146. DP Structure Galaxy 4 – source of DP Structure The DP Group

147. 10 arcmin square box ~2800 kpc at z = 0.326 galaxy group/small cluster

148. Explaining the Structure

149. DP 1 a galaxy

150. DP 2 pair of radio jets

151. DP 3

152. DP 4

153. DP 5 galaxy moving through intercluster medium

154. DP 6

155. DP 7

156. DP 8 currently I have the radio jets orientated along page with respect to the observer

157. DP 9 changing orientation of the radio jets with respect to the observer

158. DP 10

159. DP 11

160. 2. A Radio Gravitational Arc?

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

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

163. 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

164. 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)

165. 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

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

167. Radio Arc Optical as Contours

168. Conclusion

169. one can use coadding with optical redshifts to make measurement of the HI 21-cm emission from galaxies at redshifts z > 0.1 using this method the cosmic neutral gas density at z = 0.24 (look-back time of ~3 billion years) has been measured and the value is consistent with that from damped Lyα measurements galaxy cluster Abell 370 at z = 0.37 (look-back time of ~4 billion years) has significantly more gas than similar clusters at z ~ 0 the SKA pathfinders ASKAP and MeerKAT can measure the HI 21-cm emission from galaxies out to z = 1.0 (look-back time of ~8 billion years) using the coadding technique with existing optical redshift surveys Conclusion