Visit the
Official CBI Homepage and the
CBI Publication Page (Caltech)
July 20, 2000 The nearby Volcan Lascar
underwent a major eruption last week, and was caught in the act by
Brian Mason and Tim Pearson! So far, this has not had an effect on
CBI operations. (©2000 Caltech/CBI).
NEW:The papers by Mason et al. and Sievers et
al. (2009) bringing together all the CBI CMB temperature anisotropy
data and foreground source measurements (with OVRO and GBT) are
available as preprints at
arXiv:0901.4540 (astro-ph)
and
arXiv:0901.4330 (astro-ph)
(2/5/09)
The paper J. Sievers et al. (2005)
"Implications of the Cosmic Background Imager Polarization Data" has
been completed, presenting results from the total of 2.5 years of CBI
polarization data.
See the preprint at
astro-ph/0509203. (9/8/05)
The CBI "high-ell" SZ Paper has finally
been published in the Astrophysical Journal (ApJ, 626, 12).
See the
CBI Publication Page. (6/2/05)
The CBI Polarization Paper reporting the
results from 2002-2004 has been published in
Science and is available as a preprint at
astro-ph/0409569.
(9/23/04)
Window functions, inverse Fisher matrices, bandpowers, and offsets for
log-normal approximation are available
here
for details! (7/10/02)
We held an NSF press
conference today for our first-year results. See also the
CBI press page
for details! The preprints are available
here.
(5/23/02)
The first CBI paper has been published in the March 1 ApJ Letters:
Padin et al. 2001, Astrophys. J. (Letters), 549, L1-L5. (3/1/01)
See the
CBI results page for extra information (likelhoods, etc) (2/21/01)
The first CBI paper has been accepted for publication in ApJ Letters.
See the preprint
on astro-ph (12/11/00)
Images of the eruption of Volcan Lascar as seen from the CBI
site are available! (7/20/00)
I am in Chile at the CBI site for a 3-week tour of duty - my first!
This first night observing went well, and it was clear most of the
night until clouds came about 4am. Lesson one - oxygen is good!
(5/5/00)
The DASI has seen
first light at the South Pole! (1/7/2000)
First light has been achieved with six antennas, four 1-GHz
correlators, giving an image of Jupiter. (11/1/99)
The CBI instrument has been shipped to Chile. (8/6/99)
Actual observing from Pasadena! With 6 antennas and 3 1GHz bands
opertational we observed calibrator sources and some short test scans
on clusters. The sources were clearly detected in spite of 83% humidity
and atmospheric temperatures of 40K at zenith! Martin Shepherds control
programs are easy to use and powerful - next step, the analyis software
to turn the uv-data into images. (4/2/99)
The drives are being installed on the mount. See
latest construction photographs. (6/10/98)
Installation of the sailcloth for the dome is nearly complete (4/15/98).
The elevation ball-screw is installed, and the mount
is nearly ready for the first pointing tests (3/27/98).
Be sure to see the
latest construction photos
The CBI dome is up! (2/15/98)
The official CBI website
at Caltech is now open (1/6/98)
The CBI antenna mount arrived at Caltech (12/1/97)
The Cosmic Background Imager (CBI) is an instrument designed to make images of the cosmic microwave background radiation and to measure its statistical properties on angular scales from 5 arc minutes to one degree (spherical harmonic scales from l = 3000 down to l = 300).
The CBI is a 13-element interferometer mounted on a 6.5 meter platform operating in ten 1-GHz frequency bands from 26 GHz to 36 GHz. The instantaneous field of view of the instrument is 44 arcmin and its resolution ranges from 4.5 to 10 arcmin. A 9-hour observation with the CBI will yield an image covering a 2 2 field with rms noise of 2.4 mJy, which for a 10 arcmin beam corresponds to Delta_T/T = 3 10-6 rms. This is considerably below the level predicted by current theories and found in recent observations.
The spectral capabilities of the CBI will be used to look for and separate diffuse foreground synchrotron, free-free, and dust emission from the interstellar medium in our Galaxy. Unresolved extragalactic sources will be measured with the 40 meter telescope at the Owens Valley Radio Observatory, and subtracted from the CBI images.
The CBI will also be a powerful instrument for observing the Sunyaev-Zel'dovich scattering of background radiation photons by the hot electrons in clusters of galaxies. Measurements of this effect can be used to study the properties of the hot cluster gas and the evolution of clusters, and to measure the Hubble constant directly.
The CBI will be completed early in 1998. After a few months of tests on the Caltech campus in Pasadena, it will be disassembled and shipped to Chile, where it will be installed at an altitude of 5000 meters. A high, dry site is essential in order to reach the required sensitivity levels in a reasonable observing time.
The Principal Investigator for the CBI project is Tony Readhead (Caltech), and the Project Scientist is Steve Padin (Caltech). Other Caltech team members include John Cartwright, Tim Pearson, Walter Schaal, Martin Shepherd, and John Yamasaki. Other collaborators include John Carlstrom, Mark Dragovan, and Bill Holzapfel (University of Chicago), Steven Myers (University of Pennsylvania), and Marshall Joy (NASA MSFC).
The construction of the CBI has been made possible by the generous support of the National Science Foundation (award AST-9413935), the California Institute of Technology, Ronald and Maxine Linde, and Cecil and Sally Drinkward.
Official CBI Homepage (Caltech)
OVRO CMB Programs (UPenn/Caltech)
OVRO Sunyaev-Zeldovich Effect Studies (UPenn/Caltech)
DASI Homepage (U Chicago)
VSA - The Very Small Array (Cambridge)
MAT - The Mobile Anisotropy Telescope (UPenn)Steven T. Myers