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Precision Array For Probing The Epoch Of Reionization
The Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) is a radio interferometer funded by the National Science Foundation to detect 21 cm hydrogen (HI) fluctuations occurring when the first galaxies ionized intergalactic gas at around 500 Million years after the Big Bang. PAPER is a focused experiment aimed toward making the first statistical detection of the 21 cm reionization signal. Given the stringent dynamic range requirements for detecting reionization in the face of foregrounds that are five orders of magnitude brighter, the PAPER project is taking a carefully staged engineering approach, optimizing each component in the array to mitigate, at the outset, any potentially debilitating problems in subsequent data calibration and analysis. This staged approach addresses the observational challenges that arise from very-wide-field, high-dynamic-range imaging over wide bandwidths in the presence of transient terrestrial interference. PAP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald Backer
Donald C. Backer (November 9, 1943 – July 25, 2010) was an American astrophysicist who primarily worked in radio astronomy. Backer made important contributions to the understanding and study of pulsars (including the discovery of the first millisecond pulsar), black holes, and the epoch of reionization. Biography Backer was born in Plainfield, New Jersey. He attended Cornell University, where he earned a Bachelor's degree in engineering physics (B.E.P.) from Cornell University in June 1966. He received a Master of Science degree in radio astronomy from Manchester University in 1968, and then returned to Cornell to earn his doctorate in astronomy in May 1971. Backer then took post-doctoral positions first at NRAO in Charlottesville, Virginia (1971–1973), and then at NASA/GSFC in Greenbelt, Maryland (1973–1975). In 1975, Backer moved to the University of California, Berkeley as a research astronomer in the Radio Astronomy Laboratory, and became professor of astronomy at Berk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Science Foundation
The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health. With an annual budget of about $8.3 billion (fiscal year 2020), the NSF funds approximately 25% of all federally supported basic research conducted by the United States' colleges and universities. In some fields, such as mathematics, computer science, economics, and the social sciences, the NSF is the major source of federal backing. The NSF's director and deputy director are appointed by the President of the United States and confirmed by the United States Senate, whereas the 24 president-appointed members of the National Science Board (NSB) do not require Senate confirmation. The director and deputy director are responsible for administration, planning, budgeting and day-to-day operations of the foundation, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Line
The hydrogen line, 21 centimeter line, or H I line is the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms. This electromagnetic radiation has a precise frequency of , which is equivalent to the vacuum wavelength of in free space. This frequency falls below the microwave region of the electromagnetic spectrum, which begins at 3.0 GHz (10 cm wavelength), and it is observed frequently in radio astronomy because those radio waves can penetrate the large clouds of interstellar cosmic dust that are opaque to visible light. This line is also the theoretical basis of the hydrogen maser. The microwaves of the hydrogen line come from the atomic transition of an electron between the two hyperfine levels of the hydrogen 1 s ground state that have an energy difference of []. It is called the ''spin-flip transition''. The frequency, , of the quantum, quanta that are emitted by this transition between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reionization
In the fields of Big Bang theory and cosmology, reionization is the process that caused matter in the universe to reionize after the lapse of the " dark ages". Reionization is the second of two major phase transitions of gas in the universe (the first is recombination). While the majority of baryonic matter in the universe is in the form of hydrogen and helium, reionization usually refers strictly to the reionization of hydrogen, the element. It is believed that the primordial helium also experienced the same phase of reionization changes, but at different points in the history of the universe. This is usually referred to as helium reionization. Background The first phase change of hydrogen in the universe was recombination, which occurred at a redshift ''z'' = 1089 (379,000 years after the Big Bang), due to the cooling of the universe to the point where the rate of recombination of electrons and protons to form neutral hydrogen was higher than the reionizatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant university and the founding campus of the University of California system. Its fourteen colleges and schools offer over 350 degree programs and enroll some 31,800 undergraduate and 13,200 graduate students. Berkeley ranks among the world's top universities. A founding member of the Association of American Universities, Berkeley hosts many leading research institutes dedicated to science, engineering, and mathematics. The university founded and maintains close relationships with three national laboratories at Berkeley, Livermore and Los Alamos, and has played a prominent role in many scientific advances, from the Manhattan Project and the discovery of 16 chemical elements to breakthroughs in computer science and genomics. Berkeley is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Astronomy Laboratory
The Radio Astronomy Lab (RAL) is an Organized Research Unit (ORU) within the Astronomy Department at the University of California, Berkeley. It was founded by faculty member Harold Weaver in 1958. Until 2012, RAL maintained a radio astronomy observatory at Hat Creek, near Mt. Lassen. It continues to support on-campus laboratory facilities in Campbell Hall. From 1998 to 2012, the RAL collaborated with the SETI Institute of Mountain View California to design, build and operate the Allen Telescope Array (ATA). RAL has been central to the creation of several radio observatories, including: * Hat Creek Radio Observatory (HCRO), * the Allen Telescope Array (ATA), * the Berkeley-Illinois-Maryland Association (BIMA) array, * the Combined Array for Research in Millimeter-wave Astronomy (CARMA) array, * the Precision Array for Probing the Epoch of Reionization (PAPER) array Research Interests * Millimeter-wavelength interferometry * Very Long Baseline Interferometry * Low-frequency radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Radio Astronomy Observatory
The National Radio Astronomy Observatory (NRAO) is a federally funded research and development center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc. for the purpose of radio astronomy. NRAO designs, builds, and operates its own high-sensitivity radio telescopes for use by scientists around the world. Locations Charlottesville, Virginia The NRAO headquarters is located on the campus of the University of Virginia in Charlottesville, Virginia. The North American ALMA Science Center and the NRAO Technology Center and Central Development Laboratory are also in Charlottesville. Green Bank, West Virginia NRAO was, until October 2016, the operator of the world's largest fully steerable radio telescope, the Robert C. Byrd Green Bank Telescope, which stands near Green Bank, West Virginia. The observatory contains several other telescopes, among them the telescope that utilizes an equatorial mount uncommon for radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aaron Parsons
Aaron R. Parsons (born 1980) is an American astrophysicist who works primarily in the fields of radio astronomy instrumentation and experimental cosmology. Biography Parsons was born in 1980. He grew up in Rangely, Colorado and graduated simultaneously from high school and from Colorado Northwestern Community College with an AS degree in 1998. He majored in physics and mathematics at Harvard University, and graduated with a BA in 2002. After working as a development engineer at the UC Berkeley Space Sciences Lab from 2002 to 2004, Parsons entered graduate school at the University of California, Berkeley in astronomy, receiving his PhD in 2009 while holding a predoctoral research position at Arecibo Observatory in Puerto Rico. Parsons returned to UC Berkeley on an NSF postdoctoral fellowship in 2009. He was hired as an assistant professor in the Astronomy Department and in the Radio Astronomy Laboratory at UC Berkeley in 2011. Research Parsons is the Principal Invest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murchison Widefield Array
The Murchison Widefield Array (MWA) is a joint project between an international consortium of organisations to construct and operate a low-frequency radio array. 'Widefield' refers to its very large field of view (on the order of 30 degrees across). Operating in the frequency range 70–300 MHz, the main scientific goals of the MWA are to detect neutral atomic Hydrogen emission from the cosmological Epoch of Reionization (EoR), to study the sun, the heliosphere, the Earth's ionosphere, and radio transient phenomena, as well as map the extragalactic radio sky. It is located at the Murchison Radio-astronomy Observatory (MRO). Along with the Australian Square Kilometre Array Pathfinder (ASKAP), also at the MRO, and two radio telescopes in South Africa, the Hydrogen Epoch of Reionization Array (HERA) and MeerKAT, the MWA is one of four precursors to the international project known as the Square Kilometre Array (SKA). Development The MWA was to be situated at Mileura S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Academies Press
The US National Academies Press (NAP) was created to publish the reports issued by the National Academies of Sciences, Engineering, and Medicine, the National Academy of Engineering, the National Academy of Medicine, and the National Research Council. It publishes nearly 200 books a year on a wide range of topics in the sciences. The NAP's stated mission is seemingly self-contradictory: to disseminate as widely as possible the works of the National Academies of Sciences, Engineering, and Medicine, and to be financially self-sustaining through sales. This mission has led to great experimentation in openness regarding online publishing. The National Academy Press (as it was known in 1993) was the first self-sustaining publisher to make its material available on the Web, for free, in an open access model. By 1997, 1000 reports were available as sequential page images (starting with i, then ii, then iii, then iv...), with a minimal navigational envelope. Their experience up to 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Pennsylvania
The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universities by numerous organizations and scholars. While the university dates its founding to 1740, it was created by Benjamin Franklin and other Philadelphia citizens in 1749. It is a member of the Ivy League. The university has four undergraduate schools as well as twelve graduate and professional schools. Schools enrolling undergraduates include the College of Arts and Sciences, the School of Engineering and Applied Science, the Wharton School, and the School of Nursing. Among its highly ranked graduate schools are its law school, whose first professor wrote the first draft of the United States Constitution, its medical school, the first in North America, and Wharton, the first collegiate business school. Penn's endowment is US$20.7 billion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Kilometre Array
The Square Kilometre Array (SKA) is an intergovernmental international radio telescope project being built in Australia (low-frequency) and South Africa (mid-frequency). The combining infrastructure, the Square Kilometre Array Observatory (SKAO), and headquarters, are located at the Jodrell Bank Observatory in the United Kingdom. The SKA cores are being built in the southern hemisphere, where the view of the Milky Way galaxy is the best and radio interference at its least. Conceived in the 1990s, and further developed and designed by the late-2010s, when completed a total collecting area of approximately one square kilometre. It will operate over a wide range of frequencies and its size will make it 50 times more sensitive than any other radio instrument. If built as planned, it should be able to survey the sky more than ten thousand times faster than before. With receiving stations extending out to a distance of at least from a concentrated central core, it will exploit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
