Starbursts

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Starbursts AGN Probing Feedback in
Galaxy Formation with GMT
Starbursts AGN Probing Feedback in
Galaxy Formation with GMT
Mike Dopita, RSAA, ANU
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Starburst Feedback at the Epoch of Galaxy
Formation
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The Madau Plot Translated
Epoch of Assembly of Massive Galaxies 1 lt z lt 6
c.f. Papovich, Thursday..
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Feedback from Massive Stars

• Controls the re-ionization of the Universe
• Determines the phase structure of the
  Interstellar Medium
• Triggers new star formation in starburst
  environments
• Controls the structural parameters of the disks
  of galaxies
• Produces galactic winds which enrich the
  intergalactic medium

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Condition to drive a Galactic Wind

• We need (at least) that the kinetic energy
  injection per unit area into a fraction of the
  disk gas will exceed its binding energy
• Star formation follows the Kennicutt (1998) Law
• So a wind becomes possible when
• Therefore, a wind is driven when
• Escape Velocity is Low (i.e. galaxy is small)
• Lifetime of Starburst is long
• Gas surface density is high

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Structure of a Superwind
Cooper, Bicknell Sutherland, RSAA astro-ph
0710.5437
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Density Evolution
Cooper, Bicknell Sutherland, RSAA astro-ph
0710.5437
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GMT Observations of Starburst-Powered
Protogalaxies

• Requires us to observe Lyman- break galaxies in
  the range 6 gt z gt 2.5 (1.0 lt t/Gyr lt 2.7).
• Star formation rates 50 - 500 solar masses /yr
• Sizes of objects 5 - 50 kpc.
• Resolution required 1 - 2 kpc (0.2 - 0.4 arc
  sec.) - This is fine!
• So, surface flux needed to see continuum 10-17
  erg cm-2 arc sec-2 This is easily within the
  range of the the GMT Optical (GMACS) and Near-IR
  (NIRMOS) Multi-slit spectrographs.
• We will be able to derive star formation rates
  metallicities for hundreds of of these objects in
  a single observing run.

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The Sub-mm Galaxies Hot Dust, Extreme
Star Formation Rates
Low and Intermediate Redshift Sequence
High Redshift Sequence (sub-mm Galaxies)
from Blain, Chapman, Smail Ivison 2004, ApJ,
611, 52
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Distant Radio Galaxies - Cores of
Protoclusters - AGN Driving the Transition to
Red-and-Dead Ellipticals
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Distant Protoclusters
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• Kurk, Pentericci, Röttgering, Miley Heckman
• Protocluster associated with radio galaxy at
  z4.1. D 2 Mpc
• Local over-density of galaxies 15
• M 1-2 x 1015 solar masses

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O III Galaxies around Radio Galaxy MRC 0316-257
(z3.13)
CIII 1937Å
1513Å
1513Å
CIII 1937Å
CIII 1937Å
1513Å
ACS Observations, Box 2x2 arc sec. 16x16 kpc
Maschietto et al. 2008 MNRAS, submitted
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Graphic from Huub Röttgering
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AGN Feedback- Expelling the ISM- The
Transition to red-and-dead
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Lyman-Alpha Halos around Radio Galaxies Massive
Galaxies in the Early Universe
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Feedback by AGN Jet Interaction
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Ly-Alpha Halos associated with Hi-z Radio
Galaxies are

• Luminous F 10-15 erg s-1 cm-2 or L 1044 erg
  sec-1
• Large up to 200 kpc across or 20 arc sec in
  diameter!
• Over 400 candidates remain unstudied.
• Such galaxies (and their radio-quiet
  counterparts) probably represent the dominant
  mode of star formation in the Universe at 4 gt z gt
  2

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4C 41.17 is forming 5000 solar masses of stars
per year, but the emission line spectrum is
shock-powered
Dey et al 1997, ApJ 490, 698
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Jet Hot-spot
Nucleus
Colour Ly-a Contours H-a
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The Expanding Shell of 4C 60.07Evidence for AGN
Feedback
Ly-Alpha Halos associated with Hi-z Radio
Galaxies are
Reuland et al. 2006 AJ
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Sphere of Influence of Black Hole (from Gemini
CoDR) - direct BH mass determination are just
out of reach of GMT
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Summary of the Role of GMT in HizRG
Proto-cluster Studies

• Optical Multi-object spectrograph (GMACS)
  Discover all the Ly-Alpha emitters in the
  field, measure velocity dispersions, luminosities
  clustering properties
• Near-IR Multi-object spectrograph (NIRMOS)
  Measure star formation rates from Balmer
  Lines and metallicities from other lines.
• Near-IR AO fed IFU (GMTIFS)
  Determine star formation rates,
  morphologies and velocity fields in both core of
  radio galaxy and in associated field galaxies

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The End