We have developed a thermal-optical-mechanical model of a representative sunshield and telescope assembly, appropriate to 10-m class far-infrared large space telescopes such as SAFIR, SPECs, SPIRIT, and CMBPol. The model provides a tool... more
We have developed a thermal-optical-mechanical model of a representative sunshield and telescope assembly, appropriate to 10-m class far-infrared large space telescopes such as SAFIR, SPECs, SPIRIT, and CMBPol. The model provides a tool for sensitivity analysis for design parameters, including material properties and structural configuration, provides performance predictions, and has been used to direct technology development for large space telescope
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We report initial results from a new analysis method for data taken with the Python microwave background anisotropy experiment. The Python telescope performs a three-beam chop on the sky at multiple azimuth positions. The original... more
We report initial results from a new analysis method for data taken with the Python microwave background anisotropy experiment. The Python telescope performs a three-beam chop on the sky at multiple azimuth positions. The original analysis involved subtracting neighboring pairs of three-beam observations to produce a four-beam pattern on the sky. This talk generalizes the original analysis in three ways and presents preliminary results of a reanalysis of the previous Python data. First, we decompose the three-beam chop data into four independent modes. Two of these are signal modes which contain information from the sky. The other two are dark modes which have zero response to signals on the sky but non-zero response to instrumental effects. Second, we allow more general methods of combining three-point observations (at neighboring azimuth positions and/or from independent detectors) to produce synthesized n-point chopping patterns. Third, we synthesize n-beam chopping patterns which constitute optimal filters for estimating cosmological parameters. This work was supported by the National Science Foundation under a cooperative agreement with the Center for Astrophysical Research in Antarctica (CARA), grant number NSF OPP 89-20223, M.D.'s PYI grant NSF AST 90-57089, and the James S. McDonnell Foundation. CARA is a National Science Foundation Science and Technology Center.
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The Degree Angular Scale Interferometer (DASI) is a 13-element array of horns operating at 26 - 36 GHz designed explicitly to image anisotropy in the Cosmic Microwave Background radiation and to determine its angular power spectrum over... more
The Degree Angular Scale Interferometer (DASI) is a 13-element array of horns operating at 26 - 36 GHz designed explicitly to image anisotropy in the Cosmic Microwave Background radiation and to determine its angular power spectrum over the range 140 < l < 920. DASI was deployed sucessfully at the Amudsen-Scott South Pole station last austral summer (1999/2000) and is
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SAFIR is a large (10m-class), cold (4-10K) space telescope for wavelengths between 20μm and 1mm. It will provide sensitivity of a factor of a hundred or more over that of SIRTF and Herschel, leveraging their capabilities and building on... more
SAFIR is a large (10m-class), cold (4-10K) space telescope for wavelengths between 20μm and 1mm. It will provide sensitivity of a factor of a hundred or more over that of SIRTF and Herschel, leveraging their capabilities and building on their scientific legacies. Covering this scientifically critical wavelength regime, it will complement the expected wavelength performance of the future flagship endeavors JWST and ALMA. This vision mission will probe the origin of stars and galaxies in the early universe, and explore the formation of solar systems around nearby young stars. Endorsed as a priority by the Decadal Study and successive OSS roadmaps, SAFIR represents a huge science need that is matched by promising and innovative technologies that will allow us to satisfy it. In exercising those technologies it will create the path for future infrared missions. Efforts are underway to refine the scientific goals of the mission, explore promising approaches for it's architecture, and sharpen understanding about remaining technological challenges that will recommend optimal strategic investments. We show how SAFIR responds to the scientific challenges in the OSS Strategic Plan, and how the observatory can be brought within technological reach.
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The Degree Angular Scale Interferometer (DASI) is a compact cm-wave interferometer designed to image anisotropy in the Cosmic Microwave Background (CMB) and to measure its angular power spectrum. The power spectrum will be densely sampled... more
The Degree Angular Scale Interferometer (DASI) is a compact cm-wave interferometer designed to image anisotropy in the Cosmic Microwave Background (CMB) and to measure its angular power spectrum. The power spectrum will be densely sampled over the l range 160 to 710, corresponding to angular scales of 0.25 to 1.15 degrees. DASI consists of 13 elements. Each element consists of
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The Cornell Caltech Atacama Telescope (CCAT) is a 25 m diameter telescope that will operate at wavelengths as short as 200 microns. CCAT will have active surface control to correct for gravitational and thermal distortions in the... more
The Cornell Caltech Atacama Telescope (CCAT) is a 25 m diameter telescope that will operate at wavelengths as short as 200 microns. CCAT will have active surface control to correct for gravitational and thermal distortions in the reflector support structure. The accuracy and stability of the reflector panels are critical to meeting the 10 micron HWFE (half wave front error)
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SAFIR is a 10-meter, 4 K space telescope optimized for wavelengths between 20 microns and 1 mm. The combination of aperture diameter and telescope temperature will provide a raw sensitivity improvement of more than a factor of 1000 over... more
SAFIR is a 10-meter, 4 K space telescope optimized for wavelengths between 20 microns and 1 mm. The combination of aperture diameter and telescope temperature will provide a raw sensitivity improvement of more than a factor of 1000 over presently-planned missions. The sensitivity will be comparable to that of the JWST and ALMA, but at the critical far infrared wavelengths,
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To meet the 10 µm RMS half wavefront error requirement for the 25 m diameter Cornell Caltech Atacama Telescope (CCAT), active control of the approximately 200 primary mirror panels is required. The CCAT baseline design includes carbon... more
To meet the 10 µm RMS half wavefront error requirement for the 25 m diameter Cornell Caltech Atacama Telescope (CCAT), active control of the approximately 200 primary mirror panels is required. The CCAT baseline design includes carbon fiber aluminum honeycomb sandwich mirror panels. Distortions of the panels due to thermal gradients, gravity and the mounting scheme need to be taken
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The Experimental Probe of Inflationary Cosmology - Intermediate Mission (EPIC-IM) is a concept for the NASA Einstein Inflation Probe satellite. EPIC-IM is designed to characterize the polarization properties of the Cosmic Microwave... more
The Experimental Probe of Inflationary Cosmology - Intermediate Mission (EPIC-IM) is a concept for the NASA Einstein Inflation Probe satellite. EPIC-IM is designed to characterize the polarization properties of the Cosmic Microwave Background to search for the B-mode polarization signal characteristic of gravitational waves generated during the epoch of Inflation in the early universe. EPIC-IM employs a large focal plane
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We report the success of our first engineering run with Z-Spec, a new millimeter spectrograph on the 10m Caltech Submillimeter Telescope during the first week of June 2005. The bolometric instrument is indeed the first of its kind,... more
We report the success of our first engineering run with Z-Spec, a new millimeter spectrograph on the 10m Caltech Submillimeter Telescope during the first week of June 2005. The bolometric instrument is indeed the first of its kind, covering the atmospheric window from 187 to 310GHz at the spectral resolution of 250–400, and will provide a critical follow-up study for
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Measurements of the cosmic microwave background (CMB) radiation can reveal with remarkable precision the conditions of the Universe when it was approximately 400,000 years old. The three most fundamental properties of the CMB are its... more
Measurements of the cosmic microwave background (CMB) radiation can reveal with remarkable precision the conditions of the Universe when it was approximately 400,000 years old. The three most fundamental properties of the CMB are its frequency spectrum (which determines the temperature), and the fluctuations in both the temperature and polarization across a range of angular scales. The frequency spectrum has been well determined, and considerable progress has been made in measuring the power spectrum of the temperature fluctuations. But despite many efforts to measure the polarization, detection of this property of the CMB has hitherto been beyond the reach of even the most sensitive observations. Here we describe the Degree Angular Scale Interferometer (DASI), an array of radio telescopes, which for the past two years has conducted polarization-sensitive observations of the CMB from the Amundsen-Scott South Pole research station.