Evolution of disk galaxies

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CCAT survey of the GEMS Legacy field in ECDF-S
Shardha Jogee (UT Austin)
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CCAT survey the legacy GEMS/Extended CDF-S field
GEMS (Galaxy Evolution from Morphology and SEDs)
is the largest area 2-filter survey completed to
date with HST (Rix et al. 2004)
? Area 30x30 120 x HDF 78 x HUDF 5
x GOODS-S ? Filters F606W (V) , F850LP (z)
(26.8, 25.7 AB mag) 0.07 ? Has accurate
redshifts for 9000 galaxies out to z1.2
(Tback 8 Gyr) from Combo-17 (Wolf et al 2004)
dz/(1z) 0.02 for RVegalt24
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GEMS field ? Has HST, Spitzer (3.6 to 24 mu)
, and Chandra data providing optical-to-IR SEDs
morphology, SFRs, AGN for 9,000 galaxies
over z0.2-1.1 (Tback 2-8 Gyr) ? Is missing a
census of gas , dust, IR-to-summ SEDs which
CCAT can provide ? Has dec -28 and is
ideal for CCAT surveys and target follow-ups by
ALMA
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GEMS
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(No Transcript)
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Spitzer 3.6mm IRAC
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Courtesy P Gonzalez/ Spitzer GTO team
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CCAT survey of GEMS galaxies out to z1 Science
Goals
1. What causes the SFR density to decline by a
factor of 10 from z1 to 0 ?
a) Decline in cold gas content of galaxies ?
(CCAT) b) Decline in rate of minor
mergers ? c) Change in internal structure
(e.g., bars) and gas concentration ?
(HST/CCAT) d) Decline in rate of major mergers
? (ruled out from HST/Spitzer Bell et al 2005
Wolf et al 2004) e) Decline in gas accretion
rate from cosmological filaments ?
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z 0.2 T 12 Gyr
z0.5 or T8 Gyr
z0.7 or T7 Gyr
2. Constrain gas and mass assembly in
interacting galaxies at different lookback
times
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3. Constrain content and concentration of
gas/dust in young barred galaxies (Jogee et al.
2004) vs unbarred ones at z 0.4-1.1
(Tback4.5 to 8 Gyr).
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CCAT survey of GEMS galaxies out to z1

• 1) Continuum mapping at 200-850 micron
• - Assuming a mapping speed 0.5 sqarcmn/sec
• - Assuming sensitivity of 1 sigma (10-15 mJy)
  in 1 sec,
• - Can cover GEMS (900 sq arcmin) field in 4 hrs
  down to confusion limit of 3 mJy
• 2) Spectral estimates? In 10,000 seconds of
  integration time
• The CII 158 ?m line is detectable from
  galaxies with Lfar-IR 2 ?1010 L? at z 0.2 in
  the 200 ?m window and at 8 ?1010 L? at z 1.2
  in the 350 ?m window.
• The NII 205 ?m line is detectable from
  galaxies with Lfar-IR 2 ? 1010, at z 0.1, and
  1.6 ?1011 L? at z 0.7 in the 350 ?m window
• The NII 122 ?m line is detectable from
  galaxies with Lfar-IR 1.2 ? 1012 L? at z 0.64
  in the 200 ?m window.
• The CO(7-6) line is detectable from galaxies with
  Lfar 1.2 ? 1011 L? at z 0.22 in the 450 ?m
  window
• We could therefore pursue spectroscopic follow-up
  of many galaxies detected in the survey
• 3) Operate down to l lt 200 mu ?
• A galaxy with a diameter of 20 kpc has an
  angular size of 2.4 to 4.6 at z0.5-1.2.
• The high angular resolution (lt 2) and low
  confusion limit (0.04 mJy assuming 10
• beams/src at l lt 200 mu) will help to
  identify individual galaxies and reduce