Showing papers by "Edward L. Wright published in 2005"
TL;DR: The Wide-Field Infrared Survey Explorer (WISE) is a NASA MIDEX mission that will survey the entire sky in four bands from 3.3 to 23 microns with a sensitivity 1000 times greater than the IRAS survey as discussed by the authors.
Abstract: The Wide-field Infrared Survey Explorer (WISE), a NASA MIDEX mission, will survey the entire sky in four bands from 3.3 to 23 microns with a sensitivity 1000 times greater than the IRAS survey. The WISE survey will extend the Two Micron All Sky Survey into the thermal infrared and will provide an important catalog for the James Webb Space Telescope. Using 10242 HgCdTe and Si:As arrays at 3.3, 4.7, 12 and 23 microns, WISE will find the most luminous galaxies in the universe, the closest stars to the Sun, and it will detect most of the main belt asteroids larger than 3 km. The single WISE instrument consists of a 40 cm diamond-turned aluminum afocal telescope, a two-stage solid hydrogen cryostat, a scan mirror mechanism, and reimaging optics giving 5" resolution (full-width-half-maximum). The use of dichroics and beamsplitters allows four color images of a 47'x47' field of view to be taken every 8.8 seconds, synchronized with the orbital motion to provide total sky coverage with overlap between revolutions. WISE will be placed into a Sun-synchronous polar orbit on a Delta 7320-10 launch vehicle. The WISE survey approach is simple and efficient. The three-axis-stabilized spacecraft rotates at a constant rate while the scan mirror freezes the telescope line of sight during each exposure. WISE is currently in its Preliminary Design Phase, with the mission Preliminary Design Review scheduled for July, 2005. WISE is scheduled to launch in mid 2009; the project web site can be found at www.wise.ssl.berkeley.edu.
24 citations
Posted Content•
TL;DR: In this article, the authors used a digital filter designed to search for individual cosmic strings and found no evidence for them in the WMAP CMB anisotropies to a level of Δ T/T \sim 0.29$ mK.
Abstract: We report a search for signatures of cosmic strings in the the Cosmic Microwave Background data from the Wilkinson Microwave Anisotropy Probe. We used a digital filter designed to search for individual cosmic strings and found no evidence for them in the WMAP CMB anisotropies to a level of $\Delta T/T \sim 0.29$ mK. This corresponds to an absence of cosmic strings with $ G\mu \ga 1.07 \times 10^{-5}$ for strings moving with velocity $v = c/\sqrt{2}$. Unlike previous work, this limit does not depend on an assumed string abundance. We have searched the WMAP data for evidence of a cosmic string recently reported as the CSL-1 object, and found an ``edge'' with 2$\sigma$ significance. However, if this edge is real and produced by a cosmic string, it would have to move at velocity $\ga$ 0.94c. We also present preliminary limits on the CMB data that will be returned by the PLANCK satellite for comparison. With the available information on the PLANCK satellite, we calculated that it would be twice as sensitive to cosmic strings as WMAP.
21 citations
01 Mar 2005
TL;DR: In this paper, the authors used a digital filter designed to search for individual cosmic strings and found no evidence for them in the WMAP CMB anisotropies to a level of Δ T/T \sim 0.29$ mK.
Abstract: We report a search for signatures of cosmic strings in the the Cosmic Microwave Background data from the Wilkinson Microwave Anisotropy Probe. We used a digital filter designed to search for individual cosmic strings and found no evidence for them in the WMAP CMB anisotropies to a level of $\Delta T/T \sim 0.29$ mK. This corresponds to an absence of cosmic strings with $ G\mu \ga 1.07 \times 10^{-5}$ for strings moving with velocity $v = c/\sqrt{2}$. Unlike previous work, this limit does not depend on an assumed string abundance. We have searched the WMAP data for evidence of a cosmic string recently reported as the CSL-1 object, and found an ``edge'' with 2$\sigma$ significance. However, if this edge is real and produced by a cosmic string, it would have to move at velocity $\ga$ 0.94c. We also present preliminary limits on the CMB data that will be returned by the PLANCK satellite for comparison. With the available information on the PLANCK satellite, we calculated that it would be twice as sensitive to cosmic strings as WMAP.
14 citations
TL;DR: The Wide-Field Infrared Survey Explorer (WISE) is a NASA MIDEX mission that will survey the entire sky in four bands from 3.3 to 23 microns with a sensitivity 1000 times greater than the IRAS survey.
Abstract: The Wide-field Infrared Survey Explorer (WISE), a NASA MIDEX mission, will survey the entire sky in four bands from 3.3 to 23 microns with a sensitivity 1000 times greater than the IRAS survey. The WISE survey will extend the Two Micron All Sky Survey into the thermal infrared and will provide an important catalog for the James Webb Space Telescope. Using 1024x1024 HgCdTe and Si:As arrays at 3.3, 4.7, 12 and 23 microns, WISE will find the most luminous galaxies in the universe, the closest stars to the Sun, and it will detect most of the main belt asteroids larger than 3 km. The single WISE instrument consists of a 40 cm diamond-turned aluminum afocal telescope, a two-stage solid hydrogen cryostat, a scan mirror mechanism, and reimaging optics giving 5" resolution (full-width-half-maximum). The use of dichroics and beamsplitters allows four color images of a 47'x47' field of view to be taken every 8.8 seconds, synchronized with the orbital motion to provide total sky coverage with overlap between revolutions. WISE will be placed into a Sun-synchronous polar orbit on a Delta 7320-10 launch vehicle. The WISE survey approach is simple and efficient. The three-axis-stabilized spacecraft rotates at a constant rate while the scan mirror freezes the telescope line of sight during each exposure. WISE is currently in its Preliminary Design Phase, with the mission Preliminary Design Review scheduled for July, 2005. WISE is scheduled to launch in mid 2009; the project web site can be found at www.wise.ssl.berkeley.edu.
5 citations
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TL;DR: The infrared sky from space is the sum of a cosmic signal from galaxies, quasars, and perhaps more exotic sources; and foregrounds from the Milky Way and from the Solar System.
4 citations
TL;DR: The first year results of the Wilkinson microwave anisotropy probe have defined the baryonic and dark matter densities of the Universe as mentioned in this paper, but the dark energy content is not well determined by the CMB data alone.
1 citations
01 Jan 2005
TL;DR: The Widefield Infrared Survey Explorer (WISE) as discussed by the authors, launched in 2009, will survey the entire sky at 3.3, 4.7, 12, and 23 μm.
Abstract: Introduction: The Widefield Infrared Survey Explorer (WISE; Prof. Edward Wright of UCLA is the Principal Investigator), launching in 2009, will survey the entire sky at 3.3, 4.7, 12, and 23 μm [1], [2], [3]. With a sensitivity 500x better than IRAS at 12 and 23 μm and 500,000x better than COBE at 3.3 and 4.7 μm, WISE will open up new frontiers in galactic science. The WISE survey will extend the Two Micron All Sky Survey (2MASS) into the thermal infrared. Recent data from the Spitzer Space Telescope have shown the power and utility of mid-infrared observations for a wide range of problems in galactic science.
1 citations
01 Jan 2005
TL;DR: In this article, the authors discuss the techniques necessary to measure signals that are 100 million times smaller than the emission from the instrument and briefly describe results from experiments up to WMAP.
Abstract: The Cosmic Microwave Background (CMB) consists of photons that were last created about 2 months after the Big Bang, and last scattered about 380,000 years after the Big Bang. The spectrum of the CMB is very close to a blackbody at 2.725 K, and upper limits on any deviations from of the CMB from a blackbody place strong constraints on energy transfer between the CMB and matter at all redshifts less than 2 million. The CMB is very nearly isotropic, but a dipole anisotropy of ±3.346(17) mK shows that the Solar System barycenter is moving at 368 ±2 km/sec relative to the observable Universe. The dipole corresponds to a spherical harmonic index l = 1. The higher indices l≥ 2 indicate intrinsic inhomogeneities in the Universe that existed at the time of last scattering. While the photons have traveled freely only since the time of last scattering, the inhomogeneities traced by the CMB photons have been in place since the in- flationary epoch only 10−35 sec after the Big Bang. These intrinsic anisotropies are much smaller in amplitude than the dipole anisotropy, with ΔT ≤ 100 µK. Electron scattering of the anisotropic radiation field produces an anisotropic linear polarization in the CMB with amplitudes ≤ 5 µK. Detailed studies of the angular power spectrum of the temperature and linear polarization anisotropies have yielded precise values for many cosmological parameters. This paper will discuss the techniques necessary to measure signals that are 100 million times smaller than the emission from the instrument and briefly describe results from experiments up to WMAP.
01 Dec 2005
TL;DR: Joint Efficient Dark Energy Investigation (JEDI) as discussed by the authors is a candidate implementation of the NASA-DOE Joint Dark Energy Mission (JDEM), which will probe the effects of Dark Energy in three independent ways: (1) using Type Ia supernovae as cosmological standard candles over a range of distances.
Abstract: The Universe appears to be expanding at an accelerating rate, driven by a mechanism called Dark Energy. The nature of Dark Energy is largely unknown and needs to be derived from observation of its effects. JEDI (Joint Efficient Darkenergy Investigation) is a candidate implementation of the NASA-DOE Joint Dark Energy Mission (JDEM). It will probe the effects of Dark Energy in three independent ways: (1) using Type Ia supernovae as cosmological standard candles over a range of distances, (2) using baryon acoustic oscillations as a cosmological standard ruler over a range of cosmic epochs, and (3) mapping the weak gravitational lensing distortion by foreground galaxies of the images of background galaxies at different distances. JEDI provides crucial systematic error checks by simultaneously applying these three independent observational methods to derive the Dark Energy parameters. The concordance of the results from these methods will not only provide an unprecedented understanding of Dark Energy, but also indicate the reliability of such an understanding. JEDI will unravel the nature of Dark Energy by obtaining observations only possible from a vantage point in space, coupled with a unique instrument design and observational strategy. Using a 2 meter-class space telescope with simultaneous wide-field imaging (~ 1 deg, 0.8 to 4.2 μm in five bands) and multi-slit spectroscopy (minimum wavelength coverage 1 to 2 μm), JEDI will efficiently execute the surveys needed to solve the mystery of Dark Energy.