Galaxy Evolution and Supernovae from a Deep-Wide WFC3 Survey

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Galaxy Evolution and Supernovae from a Deep-Wide
WFC3 Survey

• WFC3 IR observations of 5 well-studied reference
  fields at high galactic latitude
• The GOODS fields
• Encompass the deepest fields from HST, Spitzer,
  Chandra, the VLA, and soon Herschel
• The Extended Groth Strip
• A small portion of the COSMOS field
• The UKIRT Ultradeep Survey Field
• Optimized for studies of galaxy evolution at
  z2-10
• Optimized for supernova cosmology

Theories crumble, but good observations never
fade. Harlow Shapley
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Merger of two similar proposals

• Sandy Fabers team proposed a wedding cake
  strategy with 2-orbit depth in the three
  non-GOODS fields, and 50 of GOODS to 15-orbit
  depth.
• Our team proposed to cover both GOODS fields to
  intermediate depth and to measure supernovae
  spectra and light curves. We also proposed UV
  observations for GOODS-N.
• The TAC liked the wedding cake, the supernova
  followup and the UV observations.
• Teams were merged and told to try to preserve
  these features.

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90 Co-investigators
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Supernova Cosmology

• Refine the only constraints we have on the time
  variation of w, on a path to more than doubling
  the strength of this crucial test of a
  cosmological constant by the end of HSTs life.

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Supernova Cosmology

• Obtain a direct, explosion-model-independent
  measure of the evolution of Type Ia supernovae as
  distance indicators at z gt 1.5, independent of
  dark energy.

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Supernova Cosmology

• Provide the first measurement of the SN Ia rate
  at zgt1.5 to distinguish between prompt and
  delayed SN Ia production and their corresponding
  progenitor models.

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Supernova Cosmology

• Refine the only constraints we have on the time
  variation of w, on a path to more than doubling
  the strength of this crucial test of a
  cosmological constant by the end of HSTs life.

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Supernova Cosmology
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Cosmic Dawn

• Greatly improve the estimates of the evolution of
  stellar mass, dust and metallicity at z 4-8 by
  combining WFC3 data with very deep Spitzer
  observations.

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Cosmic Dawn

• Improve by 10x the constraints on the bright
  end of the luminosity function at z7 and 8, and
  make z6 measurements robust using proper 2-color
  Lyman break selection.

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Cosmic Dawn

• Measure fluctuations in the near-IR background
  light, at sensitivities sufficiently faint and
  angular scales sufficiently large to constrain
  re-ionization models.

• Extragalatic background
• Integrated galaxy counts below previous detection
  limits form a lower EBL bound
• Gamma-Ray bursts (e.g Aharonian et al. 2005) form
  upper bound
• Direct detections are difficult due to the EBLs
  faint intensity
• Detections currently conflict

Bock et al. 2006
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WFC3 Fluctuation Measurements

• The large angle (? 1/30 ) peak (green curve)
  is a linear-theory prediction of clustering of
  reionization sources.
• Small scale power is sensitive to the slope and
  normalization of the luminosity function.
• large area surveys with WFC3 can (barely) reach
  large angle peak

Reionization Simulation from Trac and Cen 2007
Large ? ????? ????? Small ?
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Cosmic high-noon

• Test models for the co-evolution of black holes
  and bulges via the most detailed census of
  interacting pairs, mergers, AGN, and bulges,
  aided by the most complete and unbiased census of
  AGN from Herschel, improved Chandra observations,
  and optical variability.

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Cosmic high-noon

• Detect individual galaxy subclumps and measure
  their stellar mass, constraining the timescale
  for their dynamical-friction migration to the
  center leading to bulge formation.
• Reveal the presence of fully formed passively
  evolving bulges out to z gt 3, measure the
  bulge/disk ratio, and provide constraints on the
  relative ages of the bulge and disk populations.
• Measure the rest-frame optical morphologies of
  passive galaxies up to z2 and beyond, and
  combine with ACS data to quantify UV-optical
  color (age) gradients.

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Cosmic variance
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Observing strategy

• Wide fields
• 750 sq. arcmin
• 2/3 orbits J (debating F125W vs. F110W)
• 4/3 orbits H (F160W)
• Half the GOODS area covered this way
• GOODS Deep
• 130 sq. arcmin
• 12 orbit depth 444 in F105WF125WF160W
• At least 12 orbits new ACS F814W
• UV (GOODS-N)
• 70 sq. arcmin
• Primary science is Lyman-escape fractions at
  z2.5
• 31 ratio in F275WF336W leaning toward binning
  2x2

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Technical Issues

• We need to reprocess and stack all the existing
  ACS data on these fields (for high-z galaxies)
• With better geometric distortion corrections and
  astrometry than the original GOODS stacks
• With CTE corrections (Anderson algorithm?)
• Need alignment to WFC3 to within 0.1 pixel
• Correcting crosstalk for the EBL fluctuations
  project
• We are looking closely at image subtraction and
  galaxy morphology versus number size of dithers
• We need to worry about scattered earthshine for
  the CVZ orbits
• Persistence, blobs, etc. will be a challenge for
  the EBL fluctuations measurement.