the instrument
DESCRIPTION
The Instrument. 13 90-cm Cassegrain antennas 78 baselines 6-meter platform Baselines 1m – 5.51m 10 1 GHz channels 26-36 GHz HEMT amplifiers (NRAO) Cryogenic 6K, Tsys 20 K Single polarization (R or L) Polarizers from U. Chicago Analog correlators 780 complex correlators - PowerPoint PPT PresentationTRANSCRIPT
2The Cosmic Background Imager – Aspen, June 2003
The Instrument
• 13 90-cm Cassegrain antennas– 78 baselines
• 6-meter platform– Baselines 1m – 5.51m
• 10 1 GHz channels 26-36 GHz– HEMT amplifiers (NRAO)
– Cryogenic 6K, Tsys 20 K
• Single polarization (R or L)– Polarizers from U. Chicago
• Analog correlators– 780 complex correlators
• Field-of-view 44 arcmin– Image noise 4 mJy/bm 900s
• Resolution 4.5 – 10 arcmin
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CBI Deep Fields 2000
Deep Field Observations: •3 fields totaling 4 deg^2•~115 nights of observing•Data redundancy strong tests for systematics
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Mosaic Field Observations• 3 fields totaling 40 deg^2• ~125 nights of observing• ~ 600,000 uv points covariance matrix 5000 x 5000
CBI 2000 Mosaic Power Spectrum
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SZE Angular Power SpectrumSZE Angular Power Spectrum
•Smooth Particle Hydrodynamics (5123) [Wadsley et al. 2002]
•Moving Mesh Hydrodynamics (5123) [Pen 1998]
•143 Mpc 8=1.0
•200 Mpc 8=1.0
•200 Mpc 8=0.9
•400 Mpc 8=0.9
[Bond et al. 2002]
Dawson et al. 2002
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SZE with CBI: z < 0.1 clusters
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Calibration using Jupiter
• Old uncertainty: 5%• 2.7% high vs. WMAP Jupiter• New uncertainty: 1.3%• Ultimate goal: 0.5%
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49
Future plans
CBI 2000+2001 Results
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CBI 2000+2001 and WMAP
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CBI 2000+2001, WMAP, ACBAR
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The CMB From NRAO HEMTs
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weak prior: t > 1010 yr 0.45 < h < 0.9 m > 0.1
LSS prior: constraint on amplitude of 8 andshape of eff (Bond et al. Ap.J. 2003)
CBI + COBECBI + COBE
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weak prior: t > 1010 yr 0.45 < h < 0.9 m > 0.1
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CBI Polarization
• CBI instrumentation– Use quarter-wave devices for linear to circular conversion– Single amplifier per receiver: either R or L only per element
• 2000 Observations– One antenna cross-polarized in 2000 (Cartwright thesis)– Only 12 cross-polarized baseline (cf. 66 parallel hand)– Original polarizers had 5%-15% leakage– Deep fields, upper limit ~8 K
• 2002 Upgrade– Upgrade in 2002 using DASI polarizers (switchable)– Observing with 7R + 6L starting Sep 2002– Raster scans for mosaicing and efficiency– New TRW InP HEMTs from NRAO
Ka-band Receiver
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Frequency (GHz)
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CBI-Pol 2002-2003 Projections
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The CBI Collaboration
Caltech Team: Tony Readhead (Principal Investigator), John Cartwright, Alison Farmer, Russ Keeney, Brian Mason, Steve Miller, Steve Padin (Project Scientist), Tim Pearson, Walter Schaal, Martin Shepherd, Jonathan Sievers, Pat Udomprasert, John Yamasaki.Operations in Chile: Pablo Altamirano, Ricardo Bustos, Cristobal Achermann, Tomislav Vucina, Juan Pablo Jacob, José Cortes, Wilson Araya.Collaborators: Dick Bond (CITA), Leonardo Bronfman (University of Chile), John Carlstrom (University of Chicago), Simon Casassus (University of Chile), Carlo Contaldi (CITA), Nils Halverson (University of California, Berkeley), Bill Holzapfel (University of California, Berkeley), Marshall Joy (NASA's Marshall Space Flight Center), John Kovac (University of Chicago), Erik Leitch (University of Chicago), Jorge May (University of Chile), Steven Myers (National Radio Astronomy Observatory), Angel Otarola (European Southern Observatory), Ue-Li Pen (CITA), Dmitry Pogosyan (University of Alberta), Simon Prunet (Institut d'Astrophysique de Paris), Clem Pryke (University of Chicago).
The CBI Project is a collaboration between the California Institute of Technology, the Canadian Institute for Theoretical Astrophysics, the National Radio Astronomy Observatory, the University of Chicago, and the Universidad de Chile. The project has been supported by funds from the National Science Foundation, the California Institute of Technology, Maxine and Ronald Linde, Cecil and Sally Drinkward, Barbara and Stanley Rawn Jr., the Kavli Institute,and the Canadian Institute for Advanced Research.