A%20long%20time%20ago%20in%20a%20galaxy%20far,%20far%20away......the%20mysteries%20of%20the%20formation%20of%20supermassive%20radio%20galaxies%20began

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A long time ago in a galaxy far, far
away......the mysteries of the formation of
supermassive radio galaxies began

• Dr Julia Bryant
• SIfA, University of Sydney

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Radio galaxies
Super-massive black hole
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Hierarchical galaxy formation
Credit Michael Warren, Theoretical
Astrophysics Los Alamos National Laboratory
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Finding high-redshift radio galaxies (HzRGs)
Fainter ----gt
Further awayearlier
Closerlater
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Highest mean SFR
Feulner et al. 2005
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Electromagnetic spectrum
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Finding HzRGs
Photometric redshifts of cluster members

• USS
• radio
• selection

Wide-field multi-band imaging
K-band imaging
Spectra of host galaxy
Identify larger-scale structures that the HzRGs
live in.
9.4
Can we find the progenitors of low redshift
clusters?
Bryant et al. 2009
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HzRGs in proto-clusters

• Low redshift radio galaxies in clusters have
  extreme rotation measures (RM)
• Polarization p.a. ?
• ??0 RM?2

• High RM gt1000rad/m2
• Dense hot magnetized cluster gas

• Overdensities of surrounding star forming
  galaxies

Direct imaging of cluster members is difficult.
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PANIC images with ATCA contours
J1045-3838 K17.2
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PANIC images with ATCA contours
J1510-3528 K20.20 Z2.937 SI-1.35 S(1384)45mJy
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Z2.2 Spiderweb Galaxy

• Radio 8GHz (red), Optical Hubble image,
• VLT Ly-alpha blue contours (Miley et al. 2006)

1 parsec 3 x 1013 Km
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Conclusion

• A long time ago in a galaxy far, far away a
  1012 Msol galaxy with a supermassive black hole
  was forming.
• 10 Gyrs later, we are using radio, optical and
  infrared imaging and spectroscopy to determine
  the role of the environment in accelerating the
  evolution of the most massive galaxies in the
  Universe.