168 results on '"Corey, Brian."'
Search Results
152. AAOA Healthcare offers private group benefit exchange to Washington employers with 'The Portfolio".
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Corey, Brian
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EMPLOYEE benefits ,MEDICAL care societies ,EMPLOYEE services ,TECHNOLOGY ,EMPLOYERS - Abstract
The article focuses on the move of the Affiliated Association of America (AAOA) Healthcare to launch "The Portfolio," which is the first Private Group Benefit Exchange in the Washington state. It says that the benefit exchange allows employers to continue providing their employees with group coverage of up to 24 benefit options. It adds that the technology platform is one of the advantages of the private exchange model.
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- 2014
153. Edison curator waxes nostalgic at UMass Lowell.
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Corey, Brian
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MUSEUM curators ,SOUND recording & reproducing ,ACOUSTICAL engineering ,TURNTABLES - Abstract
The article focuses on the issues concerning the history of sound recording technology tackled by Gerald Fabris, curator of the Edison Museum, at the University of Massachusetts (UMass) Lowell Student Section on March 11, 2009. Fabris traced the events that led to the development of wax, which is said to be the media choice for sound recording. He also described the relevance of placing instrumentalists around phonograph horn.
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- 2009
154. GET THE PICTURE.
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Corey, Brian
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SOCIAL media ,INSPIRATION ,INVESTORS - Abstract
The article focuses on the startup company Trover, a social media site based in Seattle, Washington. Trover chief executive officer (CEO) Jason Karas explains the features of the social media site. Topics discussed include the inspiration of Karas to start the company, investors of the company, and future plans for Trover.
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- 2014
155. MADE IN SEATTLE.
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Corey, Brian
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INVESTMENTS ,BUSINESS enterprises - Abstract
The article reports on a film project that aimed to encourage investment in the city of Seattle in Washington. Topics discussed include the film proposal put forward by producer Scott Berkun and the launching of a Kickstarter funding campaign for the project entitled We Make Seattle. The goal of the city government to encourage out-of-state talent to settle in the city is also mentioned.
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- 2014
156. A high reliability survey of discrete Epoch of Reionization foreground sources in the MWA EoR0 field
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Chen Wu, J. Riding, Frank H. Briggs, A. Roshi, Rachel L. Webster, S. K. Sethi, J. L. B. Line, S. M. Ord, Jonathan C. Pober, Adam P. Beardsley, N. Udaya Shankar, K. S. Srivani, Eric Kratzenberg, Andrew Williams, Pietro Procopio, Robert F. Goeke, Colin J. Lonsdale, M. Waterson, Gianni Bernardi, Roger J. Cappallo, Ian Sullivan, Bryna J. Hazelton, Bryan Gaensler, J. S. Dillon, Abraham Loeb, A. de Oliveira-Costa, Eric R. Morgan, Nichole Barry, T. Prabu, Steven Tingay, Alan E. E. Rogers, David Emrich, Benjamin McKinley, Brian E. Corey, Bartosz Pindor, Christopher L. Williams, Daniel A. Mitchell, D. L. Kaplan, P. Carroll, Alan R. Whitney, D. C. Jacobs, Judd D. Bowman, Lu Feng, A. R. Offringa, Jacqueline N. Hewitt, J. S. B. Wyithe, Abraham R. Neben, L. J. Greenhill, D. Oberoi, Hs. Kim, Stephen R. McWhirter, J. C. Kasper, Cathryn M. Trott, Miguel F. Morales, Aaron Ewall-Wice, Natasha Hurley-Walker, Emil Lenc, M. J. Lynch, Randall B. Wayth, Max Tegmark, S. Paul, Melanie Johnston-Hollitt, Ravi Subrahmanyan, Nithyanandan Thyagarajan, ITA, USA, AUS, Haystack Observatory, Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J, Corey, Brian E, de Oliveira Costa, Angelica, Dillon, Joshua Shane, Ewall-Wice, Aaron Michael, Feng, Lu, Goeke, Robert F, Hewitt, Jacqueline N, Kratzenberg, Eric W, Lonsdale, Colin John, McWhirter, Stephen R., Morgan, Edward H, Neben, Abraham Richard, Rogers, Alan E E, Tegmark, Max Erik, Whitney, Alan R, and Williams, Christopher Leigh
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Physics ,Spectral index ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010308 nuclear & particles physics ,media_common.quotation_subject ,FOS: Physical sciences ,Astronomy ,Astronomy and Astrophysics ,Murchison Widefield Array ,Astrophysics ,01 natural sciences ,Galaxy ,Flattening ,Space and Planetary Science ,Sky ,0103 physical sciences ,Dark Ages ,Calibration ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Reionization ,Astrophysics - Cosmology and Nongalactic Astrophysics ,media_common - Abstract
Detection of the epoch of reionization H i signal requires a precise understanding of the intervening galaxies and AGN, both for instrumental calibration and foreground removal. We present a catalogue of 7394 extragalactic sources at 182 MHz detected in the RA = 0 field of the Murchison Widefield Array Epoch of Reionization observation programme. Motivated by unprecedented requirements for precision and reliability we develop new methods for source finding and selection. We apply machine learning methods to self-consistently classify the relative reliability of 9490 source candidates. A subset of 7466 are selected based on reliability class and signal-to-noise ratio criteria. These are statistically cross-matched to four other radio surveys using both position and flux density information. We find 7369 sources to have confident matches, including 90 partially resolved sources that split into a total of 192 sub-components. An additional 25 unmatched sources are included as new radio detections. The catalogue sources have a median spectral index of −0.85. Spectral flattening is seen towards lower frequencies with a median of −0.71 predicted at 182 MHz. The astrometric error is 7 arcsec compared to a 2.3 arcmin beam FWHM. The resulting catalogue covers ∼1400 deg² and is complete to approximately 80 mJy within half beam power. This provides the most reliable discrete source sky model available to date in the MWA EoR0 field for precision foreground subtraction., National Science Foundation (U.S.) (AST-0847753), National Science Foundation (U.S.) (AST-1410484), National Science Foundation (U.S.) (AST-1506024)
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- 2016
157. A digital-receiver for the MurchisonWidefield Array
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Mervyn J. Lynch, David L. Kaplan, N. Udaya Shankar, Grant Hampson, Judd D. Bowman, S. Madhavi, Lincoln J. Greenhill, R. Koenig, T. Booler, W. Arcus, Justin C. Kasper, D. Pallot, Gianni Bernardi, Stephen M. Ord, Ludi deSouza, Alan R. Whitney, Gopalakrishna M R, Eric Kratzenberg, Frank H. Briggs, Edward H. Morgan, John D. Bunton, Melanie Johnston-Hollitt, Stuart Wyithe, David Emrich, David Herne, Daniel A. Mitchell, Jamie Stevens, Joseph Pathikulangara, S. E. Tremblay, D. Anish Roshi, P. A. Kamini, Thiagaraj Prabu, B. B. Kincaid, Joseph E. Salah, K. S. Srivani, Brian Crosse, Randall B. Wayth, Brian E. Corey, Mark Waterson, Robert J. Sault, Ravi Subrahmanyan, Andrew Williams, Miguel F. Morales, Avinash A. Deshpande, Ronald A. Remillard, Rachel L. Webster, Divya Oberoi, Christopher L. Williams, Alan E. E. Rogers, Jacqueline N. Hewitt, Roger J. Cappallo, Robert F. Goeke, Steven Tingay, Deepak Kumar, David G. Barnes, Bryna J. Hazelton, Russell McWhirter, Colin J. Lonsdale, ITA, USA, AUS, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Goeke, Robert F., Morgan, Edward H., Williams, Christopher Leigh, Hewitt, Jacqueline N., Remillard, Ronald Alan, Kratzenberg, Eric W., McWhirter, Stephen R., Cappallo, Roger J., Corey, Brian E., Kincaid, Barton B., Lonsdale, Colin John, Oberoi, Divya, Rogers, Alan E. E., Salah, Joseph E., and Whitney, Alan R.
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Murchison meteorite ,Optical fiber ,business.industry ,Computer science ,Bandwidth (signal processing) ,FOS: Physical sciences ,020206 networking & telecommunications ,Astronomy and Astrophysics ,Murchison Widefield Array ,02 engineering and technology ,Polarization (waves) ,01 natural sciences ,law.invention ,Analog signal ,Space and Planetary Science ,Observatory ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Computer hardware - Abstract
An FPGA-based digital-receiver has been developed for a low-frequency imaging radio interferometer, the Murchison Widefield Array (MWA). The MWA, located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia, consists of 128 dual-polarized aperture-array elements (tiles) operating between 80 and 300\,MHz, with a total processed bandwidth of 30.72 MHz for each polarization. Radio-frequency signals from the tiles are amplified and band limited using analog signal conditioning units; sampled and channelized by digital-receivers. The signals from eight tiles are processed by a single digital-receiver, thus requiring 16 digital-receivers for the MWA. The main function of the digital-receivers is to digitize the broad-band signals from each tile, channelize them to form the sky-band, and transport it through optical fibers to a centrally located correlator for further processing. The digital-receiver firmware also implements functions to measure the signal power, perform power equalization across the band, detect interference-like events, and invoke diagnostic modes. The digital-receiver is controlled by high-level programs running on a single-board-computer. This paper presents the digital-receiver design, implementation, current status, and plans for future enhancements., Comment: 14 pages, 7 figures
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- 2015
158. Serendipitous discovery of a dying Giant Radio Galaxy associated with NGC 1534, using the Murchison Widefield Array
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Steven Tingay, Alan E. E. Rogers, Divya Oberoi, Roger J. Cappallo, Jacqueline N. Hewitt, A. Roshi, U. Shankar, Thiagaraj Prabu, David Emrich, Melanie Johnston-Hollitt, Russell McWhirter, Gianni Bernardi, K. S. Srivani, Richard W. Hunstead, Judd D. Bowman, Luke Hindson, David L. Kaplan, A. R. Offringa, Colin J. Lonsdale, Elaine M. Sadler, Mark Waterson, Stephen M. Ord, Bryna J. Hazelton, Miguel F. Morales, Edward H. Morgan, Bryan Gaensler, Frank H. Briggs, Christopher L. Williams, Rachel L. Webster, Justin C. Kasper, Randall B. Wayth, Ravi Subrahmanyan, Ron Ekers, Brian E. Corey, Paul Hancock, Daniel A. Mitchell, Alan R. Whitney, Mervyn J. Lynch, Andrew Williams, Avinash A. Deshpande, Lincoln J. Greenhill, Natasha Hurley-Walker, Eric Kratzenberg, Robert F. Goeke, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J., Corey, Brian E., Goeke, Robert F., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Rogers, Alan E. E., Whitney, Alan R., Hewitt, Jacqueline N., Morgan, Edward H., Williams, Christopher Leigh, ITA, USA, and AUS
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Radio galaxy ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Luminosity ,Hubble sequence ,symbols.namesake ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Surface brightness ,010306 general physics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Luminous infrared galaxy ,Physics ,Astronomy ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Dust lane ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,symbols - Abstract
Recent observations with the Murchison Widefield Array at 185~MHz have serendipitously unveiled a heretofore unknown giant and relatively nearby ($z = 0.0178$) radio galaxy associated with NGC\,1534. The diffuse emission presented here is the first indication that NGC\,1534 is one of a rare class of objects (along with NGC\,5128 and NGC\,612) in which a galaxy with a prominent dust lane hosts radio emission on scales of $\sim$700\,kpc. We present details of the radio emission along with a detailed comparison with other radio galaxies with disks. NGC1534 is the lowest surface brightness radio galaxy known with an estimated scaled 1.4-GHz surface brightness of just 0.2\,mJy\,arcmin$^{-2}$. The radio lobes have one of the steepest spectral indices yet observed: $\alpha=-2.1\pm0.1$, and the core to lobe luminosity ratio is $, Comment: 12 pages, 7 figures, accepted MNRAS
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- 2015
159. The EoR sensitivity of the Murchison Widefield Array
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J. S. B. Wyithe, Robert F. Goeke, Edward H. Morgan, Mervyn J. Lynch, Steven Tingay, Alan E. E. Rogers, Ravi Subrahmanyan, David Emrich, Brian E. Corey, John D. Bunton, Melanie Johnston-Hollitt, B. B. Kincaid, Judd D. Bowman, Ron Remillard, Miguel F. Morales, A. Roshi, R. Koenig, Christopher L. Williams, Colin J. Lonsdale, Stephen R. McWhirter, Joseph Pathikulangara, David G. Barnes, Randall B. Wayth, David Herne, Daniel A. Mitchell, L. deSouza, Alan R. Whitney, Justin C. Kasper, K. S. Srivani, Rachel L. Webster, Jacqueline N. Hewitt, Mark Waterson, Stephen M. Ord, Roger J. Cappallo, Divya Oberoi, Robert J. Sault, Thiagaraj Prabu, Jamie Stevens, Joseph E. Salah, Andrew Williams, Avinash A. Deshpande, Shankar N. Udaya, Gianni Bernardi, Lincoln J. Greenhill, Eric Kratzenberg, David L. Kaplan, Bryna J. Hazelton, Bryan Gaensler, Adam P. Beardsley, W. Arcus, Frank H. Briggs, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J., Corey, Brian E., Goeke, Robert F., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Morgan, Edward H., Oberoi, Divya, Remillard, Ronald Alan, Rogers, Alan E. E., Salah, J. E., Whitney, Alan R., and Williams, Christopher Leigh
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Optics ,0103 physical sciences ,Astronomical interferometer ,Sensitivity (control systems) ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Reionization ,Physics ,010308 nuclear & particles physics ,business.industry ,Astrophysics::Instrumentation and Methods for Astrophysics ,Spectral density ,Astronomy and Astrophysics ,Redshift ,Space and Planetary Science ,Antenna (radio) ,Astrophysics - Instrumentation and Methods for Astrophysics ,Fiducial marker ,business ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Using the final 128 antenna locations of the Murchison Widefield Array (MWA), we calculate its sensitivity to the epoch of reionization (EoR) power spectrum of redshifted 21 cm emission for a fiducial model and provide the tools to calculate the sensitivity for any model. Our calculation takes into account synthesis rotation, chromatic and asymmetrical baseline effects, and excludes modes that will be contaminated by foreground subtraction. For the fiducial model, the MWA will be capable of a 14σ detection of the EoR signal with one full season of observation on two fields (900 and 700 h)., National Science Foundation (U.S.) (Grant AST CAREER-0847753), National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant AST-0908884), National Science Foundation (U.S.) (Grant PHY-0835713), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2012
160. The Murchison Widefield Array Correlator
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Justin C. Kasper, Jamie Stevens, Lu Feng, J. Riding, Martin Bell, Ron Remillard, J. S. B. Wyithe, Joseph E. Salah, A. Roshi, Rachel L. Webster, K. S. Srivani, Frank H. Briggs, Robert F. Goeke, Lincoln J. Greenhill, Natasha Hurley-Walker, Andrew Williams, A. Ewell-Wice, Emil Lenc, Gianni Bernardi, Divya Oberoi, M. Waterson, Bryna J. Hazelton, Avinash A. Deshpande, Pietro Procopio, Nadia Kudryavtseva, Steven Tingay, Alan E. E. Rogers, Eric Kratzenberg, Robert J. Sault, Eric R. Morgan, Stephen M. Ord, Stephen R. McWhirter, Miguel F. Morales, Colin J. Lonsdale, Alan R. Whitney, John D. Bunton, Brian E. Corey, David Emrich, Thiagaraj Prabu, Luke Hindson, Ravi Subrahmanyan, Joseph Pathikulangara, David L. Kaplan, A. R. Offringa, B. B. Kincaid, D. Pallot, Melanie Johnston-Hollitt, M. J. Lynch, Brian Crosse, Daniel C. Jacobs, S. E. Tremblay, L. deSouza, Bartosz Pindor, Judd D. Bowman, Randall B. Wayth, David Herne, Daniel A. Mitchell, R. Koenig, Benjamin McKinley, David G. Barnes, Jacqueline N. Hewitt, Roger J. Cappallo, N. Udaya Shankar, N. D. R. Bhat, W. Arcus, Michael A. Clark, Christopher L. Williams, ITA, USA, AUS, Haystack Observatory, Cappallo, Roger J., Corey, Brian E., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Rogers, Alan E. E., Salah, Joseph E., Whitney, Alan R., Ewall-Wice, Aaron Michael, Feng, Lu, Goeke, Robert F., Hewitt, Jacqueline N., Morgan, Edward H., Remillard, Ronald Alan, and Williams, Christopher Leigh
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FOS: Computer and information sciences ,Aperture ,FOS: Physical sciences ,Murchison Widefield Array ,02 engineering and technology ,01 natural sciences ,Signal ,law.invention ,Computational Engineering, Finance, and Science (cs.CE) ,Telescope ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Astronomical interferometer ,Computer Science - Computational Engineering, Finance, and Science ,Field-programmable gate array ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Physics ,business.industry ,020206 networking & telecommunications ,Astronomy and Astrophysics ,Interferometry ,Space and Planetary Science ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,Tera ,Computer hardware - Abstract
The Murchison Widefield Array (MWA) is a Square Kilometre Array (SKA) Precursor. The telescope is located at the Murchison Radio--astronomy Observatory (MRO) in Western Australia (WA). The MWA consists of 4096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays (FPGAs), and others by Graphics Processing Units (GPUs) housed in general purpose rack mounted servers. The correlation capability required is approximately 8 TFLOPS (Tera FLoating point Operations Per Second). The MWA has commenced operations and the correlator is generating 8.3 TB/day of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper we outline the correlator design, signal path, and processing elements and present the data format for the internal and external interfaces., Comment: 17 pages, 9 figures. Accepted for publication in PASA. Some figures altered to meet astro-ph submission requirements
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- 2015
161. The Murchison Widefield Array: solar science with the low frequency SKA Precursor
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R. Goeke, Rachel L. Webster, David Herne, Daniel A. Mitchell, Judd D. Bowman, Iver H. Cairns, Joseph Pathikulangara, Melanie Johnston-Hollitt, Andrew Williams, Alina-Catalina Donea, Bryan Gaensler, Steven Tingay, Avinash A. Deshpande, B. B. Kincaid, Lincoln J. Greenhill, Christina L. Williams, J. S. B. Wyithe, Colin J. Lonsdale, R. Duffin, Miguel F. Morales, Mark Waterson, R. Koenig, Edward H. Morgan, J. Kennewell, Bryna J. Hazelton, J. Stevens, A. Roshi, A. R. Whitney, Robert J. Sault, J. E. Salah, Randall B. Wayth, N. Udaya-Shankar, Ronald A. Remillard, Alan E. E. Rogers, Stephen M. Ord, Frank H. Briggs, S. R. McWhirter, W. Arcus, Divya Oberoi, David L. Kaplan, K. S. Srivani, Ravi Subrahmanyan, John D. Bunton, Mervyn J. Lynch, David Emrich, Justin C. Kasper, Ludi deSouza, Roger J. Cappallo, Jacqueline N. Hewitt, B. E. Corey, Gianni Bernardi, T. Prabu, E. Kratzenberg, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Tingay, S. J., Cappallo, Roger J., Corey, Brian E., Goeke, Robert F., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Morgan, Edward H., Remillard, Ronald Alan, Rogers, Alan E. E., Salah, J. E., Whitney, Alan R., and Williams, Christopher Leigh
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Murchison meteorite ,History ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,7. Clean energy ,Education ,Observatory ,0103 physical sciences ,010303 astronomy & astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,media_common ,Physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Computer Science Applications ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Sky ,Brightness temperature ,Hydrogen line ,Ionosphere ,Astrophysics - Instrumentation and Methods for Astrophysics ,Heliosphere - Abstract
The Murchison Widefield Array is a low frequency (80 – 300 MHz) SKA Precursor, comprising 128 aperture array elements (known as tiles) distributed over an area of 3 km diameter. The MWA is located at the extraordinarily radio quiet Murchison Radioastronomy Observatory in the mid-west of Western Australia, the selected home for the Phase 1 and Phase 2 SKA low frequency arrays. The MWA science goals include: 1) detection of fluctuations in the brightness temperature of the diffuse redshifted 21 cm line of neutral hydrogen from the epoch of reionisation; 2) studies of Galactic and extragalactic processes based on deep, confusion-limited surveys of the full sky visible to the array; 3) time domain astrophysics through exploration of the variable radio sky; and 4) solar imaging and characterisation of the heliosphere and ionosphere via propagation effects on background radio source emission. This paper concentrates on the capabilities of the MWA for solar science and summarises some of the solar science results to date, in advance of the initial operation of the final instrument in 2013., National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant CAREER-0847753), National Science Foundation (U.S.) (Grant PHY-0835713), National Science Foundation (U.S.) (Grant AST-0908884), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2013
162. The Murchison Widefield Array: The Square Kilometre Array Precursor at Low Radio Frequencies
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S. J. Tingay, R. Goeke, J. D. Bowman, D. Emrich, S. M. Ord, D. A. Mitchell, M. F. Morales, T. Booler, B. Crosse, R. B. Wayth, C. J. Lonsdale, S. Tremblay, D. Pallot, T. Colegate, A. Wicenec, N. Kudryavtseva, W. Arcus, D. Barnes, G. Bernardi, F. Briggs, S. Burns, J. D. Bunton, R. J. Cappallo, B. E. Corey, A. Deshpande, L. Desouza, B. M. Gaensler, L. J. Greenhill, P. J. Hall, B. J. Hazelton, D. Herne, J. N. Hewitt, M. Johnston-Hollitt, D. L. Kaplan, J. C. Kasper, B. B. Kincaid, R. Koenig, E. Kratzenberg, M. J. Lynch, B. Mckinley, S. R. Mcwhirter, E. Morgan, D. Oberoi, J. Pathikulangara, T. Prabu, R. A. Remillard, A. E. E. Rogers, A. Roshi, J. E. Salah, R. J. Sault, N. Udaya-Shankar, F. Schlagenhaufer, K. S. Srivani, J. Stevens, R. Subrahmanyan, M. Waterson, R. L. Webster, A. R. Whitney, A. Williams, C. L. Williams, J. S. B. Wyithe, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Goeke, Robert F., Lonsdale, Colin John, Cappallo, Roger J., Corey, Brian E., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., McWhirter, Stephen R., Morgan, Edward H., Remillard, Ronald Alan, Rogers, Alan E. E., Salah, J. E., Whitney, Alan R., and Williams, Christopher Leigh
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Physics ,Murchison meteorite ,Signal processing ,010308 nuclear & particles physics ,business.industry ,Bandwidth (signal processing) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Murchison Widefield Array ,01 natural sciences ,Electromagnetic interference ,Precision Array for Probing the Epoch of Reionization ,Optics ,Space and Planetary Science ,Observatory ,0103 physical sciences ,Radio frequency ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics - Abstract
The Murchison Widefield Array (MWA) is one of three Square Kilometre Array Precursor telescopes and is located at the Murchison Radio-astronomy Observatory in the Murchison Shire of the mid-west of Western Australia, a location chosen for its extremely low levels of radio frequency interference. The MWA operates at low radio frequencies, 80–300 MHz, with a processed bandwidth of 30.72 MHz for both linear polarisations, and consists of 128 aperture arrays (known as tiles) distributed over a ~3-km diameter area. Novel hybrid hardware/software correlation and a real-time imaging and calibration systems comprise the MWA signal processing backend. In this paper, the as-built MWA is described both at a system and sub-system level, the expected performance of the array is presented, and the science goals of the instrument are summarised., National Science Foundation (U.S.) (Grant AST CAREER-0847753), National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant AST-0908884), National Science Foundation (U.S.) (Grant PHY-0835713), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2013
163. The giant lobes of Centaurus A observed at 118 MHz with the Murchison Widefield Array
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Joseph Pathikulangara, W. Arcus, A. R. Offringa, Divya Oberoi, Ron Remillard, Jamie Stevens, Eric R. Morgan, L. deSouza, Melanie Johnston-Hollitt, Joseph E. Salah, Alan R. Whitney, David Emrich, Rachel L. Webster, D. A. Roshi, Colin J. Lonsdale, Bryna J. Hazelton, Gianni Bernardi, Bryan Gaensler, B. B. Kincaid, Roger J. Cappallo, K. S. Srivani, Stephen M. Ord, J. S. B. Wyithe, Christopher L. Williams, Ravi Subrahmanyan, Miguel F. Morales, Frank H. Briggs, Lincoln J. Greenhill, Benjamin McKinley, Justin C. Kasper, N. Udaya Shankar, Robert J. Sault, Eric Kratzenberg, Jacqueline N. Hewitt, R. Koenig, David L. Kaplan, Randall B. Wayth, Stephen R. McWhirter, David G. Barnes, Andrew Williams, Avinash A. Deshpande, Mark Waterson, M. J. Lynch, Robert F. Goeke, Ilana Feain, Brian E. Corey, Steven Tingay, Alan E. E. Rogers, David Herne, Daniel A. Mitchell, Thiagaraj Prabu, Judd D. Bowman, John D. Bunton, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J., Corey, Brian E., Goeke, Robert F., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Morgan, Edward H., Remillard, Ronald Alan, Rogers, Alan E. E., Salah, J. E., Whitney, Alan R., and Williams, Christopher Leigh
- Subjects
Active galactic nucleus ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Radio galaxy ,Astrophysics::High Energy Astrophysical Phenomena ,Centaurus A ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,X-shaped radio galaxy ,0103 physical sciences ,medicine ,Astrophysics::Solar and Stellar Astrophysics ,010306 general physics ,010303 astronomy & astrophysics ,Reionization ,Astrophysics::Galaxy Astrophysics ,Physics ,Astronomy ,Astronomy and Astrophysics ,Galaxy ,Lobe ,medicine.anatomical_structure ,Space and Planetary Science ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present new wide-field observations of Centaurus A (Cen A) and the surrounding region at 118 MHz with the Murchison Widefield Array (MWA) 32-tile prototype, with which we investigate the spectral-index distribution of Cen A's giant radio lobes. We compare our images to 1.4 GHz maps of Cen A and compute spectral indices using temperature–temperature plots and spectral tomography. We find that the morphologies at 118 MHz and 1.4 GHz match very closely apart from an extra peak in the southern lobe at 118 MHz, which provides tentative evidence for the existence of a southern counterpart to the northern middle lobe of Cen A. Our spatially averaged spectral indices for both the northern and southern lobes are consistent with previous analyses, however we find significant spatial variation of the spectra across the extent of each lobe. Both the spectral-index distribution and the morphology at low radio frequencies support a scenario of multiple outbursts of activity from the central engine. Our results are consistent with inverse-Compton modelling of radio and gamma-ray data that support a value for the lobe age of between 10 and 80 Myr., National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant PHY-0835713), National Science Foundation (U.S.) (Grant CAREER-0847753), National Science Foundation (U.S.) (Grant AST-0908884), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2013
- Full Text
- View/download PDF
164. Science with the Murchison Widefield Array
- Author
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Prabu Thiagaraj, John D. Bunton, Frank H. Briggs, R. Koenig, Colin J. Lonsdale, Gianni Bernardi, Jacqueline N. Hewitt, Robert F. Goeke, Lincoln J. Greenhill, K. S. Srivani, Anthea J. Coster, Melanie Johnston-Hollitt, A. Roshi, David G. Barnes, Eric Kratzenberg, Steven Tingay, Alan E. E. Rogers, Shea Brown, Adam J. Burgasser, Brian E. Corey, Lister Staveley-Smith, Randall B. Wayth, Ronald A. Remillard, Judd D. Bowman, Iver H. Cairns, Rachel L. Webster, Philip J. Erickson, Lisa Harvey-Smith, Bryan Gaensler, David Emrich, Edward H. Morgan, B. B. Kincaid, Mervyn J. Lynch, Bryna J. Hazelton, N. Udaya Shankar, S. Russell McWhirter, J. Stuart B. Wyithe, Robert J. Sault, Timothy Robishaw, Tara Murphy, Justin C. Kasper, W. Arcus, David Herne, Daniel A. Mitchell, Ludi deSouza, Joseph Pathikulangara, Ravi Subrahmanyan, Stephen M. Ord, Shami Chatterjee, Andrew Williams, Avinash A. Deshpande, Jamie Stevens, Lynn D. Matthews, Mark Waterson, Miguel F. Morales, Alan R. Whitney, Joseph E. Salah, David L. Kaplan, Christopher L. Williams, Divya Oberoi, Roger J. Cappallo, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J., Corey, Brian E., Coster, Anthea J., Erickson, Philip J., Goeke, Robert F., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, Matthews, Lynn D., McWhirter, Stephen R., Morgan, Edward H., Remillard, Ronald Alan, Rogers, Alan E. E., Salah, Joseph E., Whitney, Alan R., and Williams, Christopher Leigh
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Space weather ,7. Clean energy ,01 natural sciences ,Precision Array for Probing the Epoch of Reionization ,Cosmology ,law.invention ,Telescope ,law ,0103 physical sciences ,Angular resolution ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,media_common ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Sky ,Astrophysics of Galaxies (astro-ph.GA) ,Physics::Space Physics ,Ionosphere ,Astrophysics - Instrumentation and Methods for Astrophysics ,Geology ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives., National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant PHY-0835713), National Science Foundation (U.S.) (Grant CAREER-0847753), National Science Foundation (U.S.) (Grant AST-0908884), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2012
165. Low Frequency Observations of the Moon with the Murchison Widefield Array
- Author
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J. S. B. Wyithe, David L. Kaplan, A. R. Whitney, E. Kratzenberg, Divya Oberoi, Jacqueline N. Hewitt, David G. Barnes, John D. Bunton, Christina L. Williams, Mark Waterson, Miguel F. Morales, Roger J. Cappallo, N. Udaya Shankar, Stephen M. Ord, W. Arcus, Randall B. Wayth, Edward H. Morgan, Joseph Pathikulangara, Bryan Gaensler, R. Koenig, Ronald A. Remillard, Justin C. Kasper, Benjamin McKinley, Ludi deSouza, J. E. Salah, B. E. Corey, Robert J. Sault, Jamie Stevens, Bryna J. Hazelton, Ravi Subrahmanyan, Lincoln J. Greenhill, Gianni Bernardi, Alan E. E. Rogers, Mervyn J. Lynch, A. Roshi, T. Prabu, David Herne, Daniel A. Mitchell, K. S. Srivani, Rachel L. Webster, Judd D. Bowman, R. Goeke, Andrew Williams, Steven Tingay, Avinash A. Deshpande, B. B. Kincaid, David Emrich, Colin J. Lonsdale, Melanie Johnston-Hollitt, A. de Oliveira-Costa, Frank H. Briggs, S. R. McWhirter, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J., Corey, Brian E., Goeke, Robert F., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Morgan, Edward H., Remillard, Ronald Alan, Rogers, Alan E. E., Salah, J. E., Whitney, Alan R., and Williams, Christopher Leigh
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Frequency band ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Low frequency ,7. Clean energy ,01 natural sciences ,Radio spectrum ,Radio telescope ,0103 physical sciences ,010303 astronomy & astrophysics ,Reionization ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Astronomy and Astrophysics ,Interferometry ,Wavelength ,13. Climate action ,Space and Planetary Science ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
A new generation of low-frequency radio telescopes is seeking to observe the redshifted 21 cm signal from the epoch of reionization (EoR), requiring innovative methods of calibration and imaging to overcome the difficulties of wide-field low-frequency radio interferometry. Precise calibration will be required to separate the expected small EoR signal from the strong foreground emission at the frequencies of interest between 80 and 300 MHz. The Moon may be useful as a calibration source for detection of the EoR signature, as it should have a smooth and predictable thermal spectrum across the frequency band of interest. Initial observations of the Moon with the Murchison Widefield Array 32 tile prototype show that the Moon does exhibit a similar trend to that expected for a cool thermally emitting body in the observed frequency range, but that the spectrum is corrupted by reflected radio emission from Earth. In particular, there is an abrupt increase in the observed flux density of the Moon within the internationally recognized frequency modulated (FM) radio band. The observations have implications for future low-frequency surveys and EoR detection experiments that will need to take this reflected emission from the Moon into account. The results also allow us to estimate the equivalent isotropic power emitted by the Earth in the FM band and to determine how bright the Earth might appear at meter wavelengths to an observer beyond our own solar system., National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant AST-0908884), National Science Foundation (U.S.) (Grant PHY-0835713), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2012
- Full Text
- View/download PDF
166. Interferometric imaging with the 32 element Murchison Wide-field Array
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Andrew Williams, Mervyn J. Lynch, K. S. Srivani, A. R. Whitney, Avinash A. Deshpande, A. Vaccarella, Sheperd S. Doeleman, S. Madhavi, Colin J. Lonsdale, Miguel F. Morales, Mark Waterson, Judd D. Bowman, A. Schinkel, David Herne, Daniel A. Mitchell, David Emrich, Rachel L. Webster, Gabrielle Allen, R. G. Edgar, J. Stevens, William A. Coles, Eric R. Morgan, Stephen M. Ord, John D. Bunton, Deepak Kumar, David L. Kaplan, N. Udaya Shankar, Justin C. Kasper, Ludi deSouza, J. E. Salah, B. B. Kincaid, A. Roshi, P. A. Kamini, B. E. Corey, Christina L. Williams, Divya Oberoi, Jonathon Kocz, Steven Tingay, E. Kratzenberg, Gianni Bernardi, T. Prabu, Alan E. E. Rogers, Roger J. Cappallo, M. R. Gopalakrishna, R. Goeke, S. Gleadow, Lincoln J. Greenhill, E. Kowald, W. Arcus, Jacqueline N. Hewitt, Steven Burns, M. Matejek, Mark Derome, L. Benkevitch, Randall B. Wayth, Michael A. Clark, Frank H. Briggs, S. R. McWhirter, Joseph Pathikulangara, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Benkevitch, Leonid, Cappallo, Roger J., Corey, Brian E., Doeleman, Sheperd Samuel, Derome, Mark F., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Oberoi, Divya, Rogers, Alan E. E., Salah, Joseph E., Whitney, Alan R., Hewitt, Jacqueline N., Matejek, Michael Scott, Morgan, Edward H., and Williams, Christopher Leigh
- Subjects
Physics ,Spectral signature ,Field (physics) ,010308 nuclear & particles physics ,Epoch (reference date) ,business.industry ,media_common.quotation_subject ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Field of view ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Declination ,Radio telescope ,Optics ,Space and Planetary Science ,Sky ,0103 physical sciences ,Calibration ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,010303 astronomy & astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,media_common - Abstract
The Murchison Wide-Field Array (MWA) is a low-frequency radio telescope, currently under construction, intended to search for the spectral signature of the epoch of reionization (EOR) and to probe the structure of the solar corona. Sited in western Australia, the full MWA will comprise 8192 dipoles grouped into 512 tiles and will be capable of imaging the sky south of 40° declination, from 80 MHz to 300 MHz with an instantaneous field of view that is tens of degrees wide and a resolution of a few arcminutes. A 32 station prototype of the MWA has been recently commissioned and a set of observations has been taken that exercise the whole acquisition and processing pipeline. We present Stokes I, Q, and U images from two ~4 hr integrations of a field 20° wide centered on Pictoris A. These images demonstrate the capacity and stability of a real-time calibration and imaging technique employing the weighted addition of warped snapshots to counter extreme wide-field imaging distortions., National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant PHY-0835713), Australian Research Council (Grant LE0775621), Australian Research Council (Grant LE0882938), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), MIT School of Science
- Published
- 2010
- Full Text
- View/download PDF
167. A STUDY OF FUNDAMENTAL LIMITATIONS TO STATISTICAL DETECTION OF REDSHIFTED H I FROM THE EPOCH OF REIONIZATION
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Rachel L. Webster, Andrew Williams, Gianni Bernardi, Randall B. Wayth, A. Roshi, Bryan Gaensler, Frank H. Briggs, John D. Bunton, Colin J. Lonsdale, Robert J. Sault, Miguel F. Morales, K. S. Srivani, Jamie Stevens, Joseph E. Salah, Jacqueline N. Hewitt, N. Udaya Shankar, R. Koenig, Nithyanandan Thyagarajan, Melanie Johnston-Hollitt, S. Russell McWhirter, Stephen M. Ord, David L. Kaplan, David Herne, Bryna J. Hazelton, Edward H. Morgan, Daniel A. Mitchell, Joseph Pathikulangara, Mark Waterson, Roger J. Cappallo, Judd D. Bowman, Brian E. Corey, W. Arcus, Christopher L. Williams, Robert F. Goeke, Steven Tingay, Alan E. E. Rogers, Lincoln J. Greenhill, Eric Kratzenberg, Divya Oberoi, Prabu Thiagaraj, Alan R. Whitney, Mervyn J. Lynch, David Emrich, Ronald A. Remillard, B. B. Kincaid, J. Stuart B. Wyithe, Justin C. Kasper, Ludi deSouza, Ravi Subrahmanyan, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Cappallo, Roger J., Corey, Brian E., Goeke, Robert F., Hewitt, Jacqueline N., Kincaid, Barton B., Kratzenberg, Eric W., Lonsdale, Colin John, McWhirter, Stephen R., Morgan, Edward H., Remillard, Ronald Alan, Rogers, Alan E. E., Salah, Joseph E., Whitney, Alan R., and Williams, Christopher Leigh
- Subjects
Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Spectral density ,Astronomy and Astrophysics ,Murchison Widefield Array ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Noise (electronics) ,Redshift ,law.invention ,Telescope ,13. Climate action ,Space and Planetary Science ,law ,0103 physical sciences ,Sample variance ,Sensitivity (control systems) ,010303 astronomy & astrophysics ,Reionization ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
In this paper, we explore for the first time the relative magnitudes of three fundamental sources of uncertainty, namely, foreground contamination, thermal noise, and sample variance, in detecting the H I power spectrum from the epoch of reionization (EoR). We derive limits on the sensitivity of a Fourier synthesis telescope to detect EoR based on its array configuration and a statistical representation of images made by the instrument. We use the Murchison Widefield Array (MWA) configuration for our studies. Using a unified framework for estimating signal and noise components in the H I power spectrum, we derive an expression for and estimate the contamination from extragalactic point-like sources in three-dimensional k-space. Sensitivity for EoR H I power spectrum detection is estimated for different observing modes with MWA. With 1000 hr of observing on a single field using the 128 tile MWA, EoR detection is feasible (S/N >1 for k [< over ~] 0.8 Mpc[superscript –1]). Bandpass shaping and refinements to the EoR window are found to be effective in containing foreground contamination, which makes the instrument tolerant to imaging errors. We find that for a given observing time, observing many independent fields of view does not offer an advantage over a single field observation when thermal noise dominates over other uncertainties in the derived power spectrum., National Science Foundation (U.S.) (Grant AST-0457585), National Science Foundation (U.S.) (Grant PHY-0835713), National Science Foundation (U.S.) (Grant CAREER-0847753), National Science Foundation (U.S.) (Grant AST-0908884), United States. Air Force Office of Scientific Research (Grant FA9550-0510247), Smithsonian Astrophysical Observatory, MIT School of Science
- Published
- 2013
168. FIRST SPECTROSCOPIC IMAGING OBSERVATIONS OF THE SUN AT LOW RADIO FREQUENCIES WITH THE MURCHISON WIDEFIELD ARRAY PROTOTYPE
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Gabrielle Allen, Michael A. Clark, Roger C. Cappallo, Harish Vedantham, Alan R. Whitney, K. S. Srivani, John D. Bunton, J. Tuthill, Mark Derome, N. Udaya Shankar, Brian E. Corey, Mervyn J. Lynch, J. Stevens, Colin J. Lonsdale, Andrew Y. Ng, Judd D. Bowman, Iver H. Cairns, Mark Waterson, Gianni Bernardi, D. Thakkar, T. Prabu, Divya Oberoi, David Emrich, Lynn D. Matthews, R. Koeing, David L. Kaplan, Miguel F. Morales, Annino Vaccarella, Andrew Williams, Bryna J. Hazelton, Christopher L. Williams, David DeBoer, Joseph Pathikulangara, B. B. Kincaid, A. Roshi, M. Dawson, Robert J. Sault, Ravi Subrahmanyan, Errol Kowald, David Herne, Daniel A. Mitchell, L. Benkevitch, R. G. Edgar, Justin C. Kasper, Ludi deSouza, Randall B. Wayth, W. Arcus, Antony Schinckel, A. De Gans, Stephen M. White, P. A. Kamini, Edward H. Morgan, S. Madhavi, Lincoln J. Greenhill, Rachel L. Webster, S. Burns, Stephen M. Ord, Frank H. Briggs, Joseph E. Salah, Jacqueline N. Hewitt, Stephen R. McWhirter, David G. Barnes, T. Elton, Vasili Lobzin, Rachel Kennedy, Alan E. E. Rogers, M. R. Gopalakrishna, Robert F. Goeke, Jonathan Kocz, Steven Tingay, Haystack Observatory, MIT Kavli Institute for Astrophysics and Space Research, Oberoi, Divya, Matthews, Lynn D., Lonsdale, Colin John, Benkevitch, Leonid, Cappallo, Roger J., Corey, Brian E., Derome, Mark F., Kennedy, Rachel, Kincaid, Barton B., McWhirter, Stephen R., Rogers, Alan E. E., Salah, Joseph E., Whitney, Alan R., Morgan, Edward H., Williams, Christopher, Goeke, Robert F., and Hewitt, Jacqueline N.
- Subjects
Physics ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Murchison Widefield Array ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Solar radio ,Low frequency ,01 natural sciences ,Instantaneous phase ,Narrowband ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,0103 physical sciences ,Broadband ,Astronomical interferometer ,Radio frequency ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
We present the first spectroscopic images of solar radio transients from the prototype for the Murchison Widefield Array (MWA), observed on 2010 March 27. Our observations span the instantaneous frequency band 170.9-201.6 MHz. Though our observing period is characterized as a period of `low' to `medium' activity, one broadband emission feature and numerous short-lived, narrowband, non-thermal emission features are evident. Our data represent a significant advance in low radio frequency solar imaging, enabling us to follow the spatial, spectral, and temporal evolution of events simultaneously and in unprecedented detail. The rich variety of features seen here reaffirms the coronal diagnostic capability of low radio frequency emission and provides an early glimpse of the nature of radio observations that will become available as the next generation of low frequency radio interferometers come on-line over the next few years., Comment: 15 pages, 5 figures, accepted for publication in Astrophysical Journal Letters. Movies for figures 4 and 5 available at http://www.mwatelescope.org/info/mwa_proto.html
- Published
- 2011
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