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BICEP and Keck Array

Coordinates: 89°59′59″S 0°00′00″E / 89.999722°S 0°E / -89.999722; 0
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BICEP / Keck Array
Alternative namesBackground Imaging of Cosmic Extragalactic Polarization Edit this at Wikidata
Part ofAmundsen–Scott South Pole Station Edit this on Wikidata
Location(s)Antarctic Treaty area
Coordinates89°59′59″S 0°00′00″E / 89.999722°S 0°E / -89.999722; 0 Edit this at Wikidata
Wavelength150 GHz
Telescope styleRadio telescope
Websitewww.cfa.harvard.edu/CMB/keckarray
BICEP and Keck Array is located in Antarctica
BICEP and Keck Array
Location of BICEP / Keck Array
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Background Imaging of Cosmic Extragalactic Polarization (BICEP) is a cosmic microwave background (CMB) experiment. It aims to measure the polarisation of the CMB; in particular, measuring the B-mode of the CMB. It has had three generations of instrumentation, consisting of BICEP1, BICEP2 and the Keck Array.

Purpose

The purpose of the BICEP experiment is to measure the polarization of the CMB.[1] Specifically, it aims to measure the B-modes (curl component) of the polarization of the CMB.[2]

Instrumentation

BICEP operates from the Amundsen–Scott South Pole Station.[1]

The main properties of the BICEP instruments
Instrument Start End Frequency Resolution Number of detectors Refs
BICEP 2006 2008 100GHz 1.0 degrees [1][2]
150GHz 0.7 degrees [1]
BICEP2 512 [3]
Keck Array 2011 — 150GHz 2560 (2011-13)
1536 (2013-)		 [4][3]
2013 — 100GHz [4]
BICEP3 2014 — 100GHz 2560 [5]

BICEP1

The first BICEP instrument observed the sky at 100 and 150GHz with an angular resolution of 1.0 and 0.7 degrees. It had an array of 98 detectors, which were sensitive to the polarisation of the CMB.[1] The instrument was a prototype for future instruments; it started observing in January 2006[2] and ran until the end of 2008.[1]

BICEP2

The second generation instrument was BICEP2.[6]

Keck Array

The Keck Array consists of five polarimeters. The first three started observations in the Austral summer of 2010-11; another two started observing in 2012. All of the receivers observed at 150GHz until 2013, when two of them were converted to observe at 100GHz.[4] Each polarimeter consists of a refracting telescope (to minimise systematics), which are cooled by a pulse tube cooler to 4K, and a Focal Plane Arrays of 512 Transition edge sensors cooled to 250 mK, giving a total of 2560 detectors.[3]

The project was funded by $2.3 million from W. M. Keck Foundation, as well as funding from the National Science Foundation, the Gordon and Betty Moore Foundation, the James and Nelly Kilroy Foundation and the Barzan Foundation.[2]

BICEP3

BICEP3 will consist of 2560 detectors observing at 100GHz. It will be deployed in the 2014-15 Austral summer season.[5]

Observations

All three instruments have mapped the same part of the sky, around the South Celestial Pole.[1][3]

Collaboration

The institutions involved in the various instruments are Caltech, Cardiff University, University of Chicago, Harvard–Smithsonian Center for Astrophysics, Jet Propulsion Laboratory, University of Minnesota and Stanford University (all experiments); UC San Diego (BICEP1 and 2); National Institute of Standards and Technology (NIST) and University of British Columbia (BICEP2 and Keck Array); Case Western Reserve University (Keck Array) and University of Toronto (BICEP2, Keck Array and BICEP3).[7][8][9][10][2] The Keck Array project was led by Andrew Lange.[2]

Results

Rumours started in March 2014 that BICEP have detected B-modes from gravitational waves in the early universe. An announcement is due on the 17th March from Harvard–Smithsonian Center for Astrophysics.[11]

References

  1. ^ a b c d e f g "BICEP: Robinson Gravitational Wave Background Telescope". Caltech. Retrieved 2014-03-13.
  2. ^ a b c d e f "W.M. Keck Foundation Gift to Enable Caltech and JPL Scientists to Research the Universe's Violent Origin". Caltech.
  3. ^ a b c d "Instrument - Keck Array South Pole". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  4. ^ a b c "Keck Array South Pole". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  5. ^ a b "BICEP3". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  6. ^ "The BICEP2 CMB polarization experiment". 7741. Proceedings of SPIE. 2010: 11. doi:10.1117/12.857864. {{cite journal}}: Cite journal requires |journal= (help)
  7. ^ "BICEP1 Collaboration". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  8. ^ "Collaboration - BICEP2 South Pole". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  9. ^ "Collaboration - Keck Array South Pole". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  10. ^ "BICEP3 Collaboration". Harvard–Smithsonian Center for Astrophysics. Retrieved 2014-03-14. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  11. ^ "Gravitational waves: have US scientists heard echoes of the big bang?". The Guardian. 2014-03-14. Retrieved 2014-03-14. {{cite news}}: Cite has empty unknown parameter: |1= (help)
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