1. Neutral Hydrogen Gas in Star Forming Galaxies at z=0.24 Philip Lah Frank Briggs (ANU) Jayaram Chengalur (NCRA) Matthew Colless (AAO) Roberto De Propris (CTIO) Michael Pracy (ANU) Erwin de Blok (ANU)

2. Background

3. Star Formation Rate Subaru Field  Hα Spectroscopy  Hα Narrow Band Imaging  UV (with no dust correction)

4. HI redshift Zwaan et al. 2005 HIPASS HI 21cm Rao et al. 2006 Prochaska et al. 2005

5. HI look back

6. HI 21cm Emission at High Redshift

7. Previous highest redshift HI Westerbork Synthesis Radio Telescope (WSRT) Netherlands Abell 2218 z = 0.18 integration time 36 days, Zwaan et al. 2001 Very Large Array (VLA) Abell 2192 z = 0.1887 integration time ~80 hours, Veheijen et al. 2004

8. Giant Metrewave Radio Telescope

9. GMRT Antenna Positions

10. GMRT Collecting Area 30 dishes of 45 m diameter GMRT Collecting Area  21 × ATCA  15 × Parkes  6.9 × WSRT  3.6 × VLA

11. Method of HI Detection RA DEC Radio Data Cube pick out HI signal using optical redshifts coadd faint signals to make measurement

12. The Subaru Field - H  emission galaxies

13. Subaru Field RA DEC 24’ × 30’ Fujita et al. 2003 narrow band imaging - H  emission flux used 2dF to get optical redshifts

14. Subaru Field Data GMRT Obs Time Frequency Observed z Look Back Time RMS per channel 80.5 hours 1150 MHz 0.242.8 Gyr ~130  Jy Primary Beam Size ResolutionChannel Width Number of Channels ~29’ ~3’’32.6 kms -1 2 × 128

15. Subaru Galaxies - B magnitude Thumbnails 10’’ sq Ordered by H  luminosity

16. Subaru Galaxies - redshifts Thumbnails 10’’ sq Ordered by H  luminosity

17. Redshift histogram Subaru Narrow Band Filter FWHM (120 Å) GMRT HI freq range 2dF (& AAOmega) redshifts

18. HI spectrum all 121 redshifts Neutral Hydrogen measurement M HI = (1.47 ± 0.89) ×10 9 M 

19. HI redshift mine all used the Fujita et al. 2003 H  Luminosity function for volume calculation comparable error to low z DLA measurements but required less observing effort (no need lots of HST time)

20. Radio Continuum in the Subaru Field

21. Deepest GMRT Image Sub field 12’ × 12’ RMS ~ 16  Jy several hundred continuum sources some with optical counterparts

22. Sullivan et al. 2003 Sullivan et al. 2001 H  Luminosity vs. 1.4 GHz Luminosity & UV Luminosity vs. 1.4 GHz Luminosity

23. Halpha vs. RC line from Sullivan et al. 2001 10’ × 10’

24. Conclusions measured the neutral gas density at z=0.24 with similar accuracy to the DLA method – with plenty of room for improvement made the current deepest GMRT continuum image the H  emission - radio continuum correlation for star forming galaxies seems to hold true at z=0.24

25. The End

27. Additional Slides

28. HI redshift mine all taking into account narrow band (H  ) filter shape – brighter galaxies will be seen over a larger volume

29. Model no error

30. model

31. UV Plane

32. Fuzzy RC Integrated Flux = 17.035  0.077 mJy

33. Fuzzy B galaxy UGC 05849 at redshift z=0.026045