Planck: Herschels Smaller Sibling

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Planck Herschels Smaller Sibling

• Dave Clements
• Imperial College

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What is Planck?

• Planck is a primarily a CMB mission
• Operates from 857GHz (350?m) to 30GHz
• Two instruments
• HFI 100 - 857 GHz
• LFI 30 - 70 GHz
• Will survey the entire sky in 9 channels
• Includes polarization in several bands

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The Planck Satellite

• Primary 1.7x1.5m
• Primary WFE 10?m
• Lifetime 22 months
• Height 4.2m
• Launch date ?Aug? 2007
• Orbit L12
• Launch mass 1800kg
• Launch vehicle Ariane 5
• Microwave background survey mission

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What has Planck got to do with Herschel?

• Herschel and Planck will be launched together
• Go to the same orbit

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Planck Instruments

• Low Frequency Instrument (LFI)
• 30, 40, 70 GHz using HEMT receivers
• All channels polarisation sensitive
• High Frequency Instrument (HFI)
• 100, 143, 217, 353, 545, 857 GHz
• Polarization sensitivity at 100, 143, 217, 545
  GHz
• Uses NTD spider-web bolometers, similar to SPIRE

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The Goals of Planck

• Determine the CMB power spectrum from large to
  small scales with unprecedented accuracy
• Determine polarization effects in CMB

Stolyarov et al.
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Whats in it for Herschel

• To measure CMB anisotropy spectrum to the
  accuracy needed, all foregrounds and secondary
  anisotropies must be measured and removed
• Foregrounds include
• Thermal and nonthermal emission from our galaxy
• Dust emission in other galaxies
• S-Z effect from clusters
• Thus Planck will provide an all-sky catalog of
  submm sources
• It will be the IRAS for Herschels ISO
• Conducting the survey and followup at the same
  time

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CMB
Residuals
Stolyarov et al., 2004, MN, in press
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Planck Survey Basic Strategy

• Satellite rotates around earth-sun line
• Detectors point 95 deg. Away from sun
• Rotation scans 360 deg each minute
• Every hour shift rotation axis by 2.5
• Complete sky coverage in 6 months

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Strategy implications

• Coverage not uniform
• Ecliptic caps scanned most deeply
• All regions scanned more than once in complete 22
  month mission
• Detailed strategy still to be decided

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Sensitivity Goals

• CMB goals shown in figure
• ?T/T 1.7 ?K
• Corresponds to 9 - 40mJy detector noise

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Sensitivity for Foreground Surveys

• For foreground objects, sensitivity wont be that
  good
• Large beams (5 or bigger) gt confusion
• Galactic cirrus and CMB also contribute noise,
  maybe subtractable
• Final estimated sensitivity for best 10 sky for
  extragalactic surveys with (HFI)
• At 857 GHz (350 ?m), dominant noise is cirrus and
  confusion

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Planck Survey Simulation
Guiderdoni et al.
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Planck vs SPIRE
Guiderdoni et al.
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What Will Planck Find?

• 350?m flux limit of a few 100 mJy, vast majority
  will be local galaxies, known from IRAS PSC
• In LFI will find blazars, BLLacs, inverted
  spectrum sources (GPSs and related)
• Some small fraction will be rare high z,
  hyper-luminous or lensed dusty starbursts AGN
• Difficult to predict since they are rare events
• Search for these using colour-colour methods and
  comparison to IRAS, ASTRO-F all sky surveys

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Guiderdoni et al.
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Planck Catalog Releases

• The Early Release Compact Source Catalog
• Based on first Planck all-sky coverage
• Due out 22 months after launch
• Will not be as deep, accurate or reliable as
  final catalog
• Full survey complete 22 months after launch
• 1 year for final processing, 1 year proprietary
• Final catalog to public 46 months after launch

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Herschel-Planck Overlap Projects

• Follow up of unusual sources
• High z, odd SED, particular interesting subclass
  eg. ULIRGs/ HLIRGs, QSOs
• SZ clusters - to be found in large numbers
• Nonthermal sources with odd spectra
• The unexpected!
• Large shallow survey in ecliptic caps
• Deepest areas to be covered by Planck