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""Evolutionary Map of the Universe"", or EMU, is a large project which will use the new ASKAP telescope to make a census of radio sources in the sky. EMU is expected to detect about 70 million radio sources .〔Norris, R.P., et al., EMU: Evolutionary Map of the Universe, PASA (2015), Volume 28, Issue 2, pp. 215-248. http://adsabs.harvard.edu/abs/2011PASA...28..215N〕 compared to the 2.5 million radio sources currently known, most of which were detected by the NRAO VLA Sky Survey. Most of these radio sources will be galaxies millions of light years away, many containing massive black hole, and some of the signals detected will have been sent less than half a billion years after the Big Bang, which created the Universe 13.7 billion years ago. Unlike the NVSS, which mainly detected Active Galactic Nuclei, the greater sensitivity of EMU means that about half the galaxies detected will be star-forming galaxies. EMU's primary science driver is to try to understand how the stars and galaxies were first formed, and how they evolved to their present state. The census of 70 million galaxies detected by EMU will represent galaxies in all their different stages of evolution, so that they can be placed in sequence, enabling the study of how their properties change as they evolve. EMU will be able to probe star forming galaxies up to a redshift of about 1, Active Galactic Nuclei to the edge of the Observable Universe, and will undoubtedly uncover new classes of object. EMU was chosen (with WALLABY) as one of the two highest-ranked proposals for ASKAP from an initial field of 39 expressions of interest .〔Johnston, S, et al., Science with ASKAP. The Australian square-kilometre-array pathfinder, Experimental Astronomy (2008), Volume 22, p. 151. http://adsabs.harvard.edu/abs/2008ExA....22..151J〕 EMU is an international project, and the EMU team consists of about 300 astronomers in 21 countries. In addition to planning and conducting the radio survey itself, the EMU project also includes * Key Science Projects, which will deliver the key science goals from EMU. These include Galaxy Evolution, Cosmology, Galaxy Clusters, the Galactic Plane, and Radio Stars.〔Umana, G. et al., SCORPIO: a deep survey of radio emission from the stellar life-cycle, MNRAS (2015), Volume 454, p. 902. http://adsabs.harvard.edu/abs/2015MNRAS.454..902U〕 * Development Projects, which are developing and optimising the tools needed to generate the science from the EMU data. These include source extraction,〔Hopkins, A. et al., The ASKAP/EMU Source Finding Data Challenge, PASA (2015), in press. http://adsabs.harvard.edu/abs/2015arXiv150903931H〕 cross-identification with multi-wavelength catalogues,〔Fan, D. et al., Matching radio catalogues with realistic geometry: application to SWIRE and ATLAS, MNRAS (2015), 451, 1299. http://adsabs.harvard.edu/abs/2015MNRAS.451.1299F〕 and redshift determination. One such development project has resulted in the creation of the Radio Galaxy Zoo citizen science project.〔Banfield, J. et al., Radio Galaxy Zoo: host galaxies and radio morphologies derived from visual inspection, MNRAS (2015), 453, 2326. http://adsabs.harvard.edu/abs/2015MNRAS.453.2326B〕 * Collaboration Projects, which develop and maintain collaborations with other large survey projects such as Meerkat-Mightee, MWA-GLEAM, LOFAR, SkyMapper, WISE, and eRosita. * The (WTF project ), which will mine the EMU data for unexpected discoveries that are not included in the science goals. ==Technical Overview== EMU is a radio sky survey project which will use the new ASKAP telescope to make a deep (~10 microJy rms) radio continuum survey covering the entire Southern Sky as far North as declination +30°. It will have about 40 times the sensitivity, and six times the resolution, of the NVSS”, and will also be more sensitive to extended diffuse emission, because of the short baselines built into the ASKAP array. EMU will survey the entire sky visible from the ASKAP telescope in 30 square degree fields. Each field will be surveyed over the 300 MHz band from about 1110 to 1410 MHz, in 1 MHz channels, delivering both spectral shapes and, through the POSSUM 〔Gaensler, B. et al., Survey Science with ASKAP: Polarization Sky Survey of the Universe's Magnetism (POSSUM), Bulletin of the American Astronomical Society (2010), Vol. 42, p.515. http://adsabs.harvard.edu/abs/2010AAS...21547013G〕 project, all four Stokes parameters and rotation measures. The data will be processed in near-real-time by the ASKAP pipeline processor. After the processed data have been approved for quality control by the EMU team, they will be placed in the public domain. The ''radio components'' will then be grouped into ''radio sources'', and where possible cross-matched with other multiwavelength data. They will then be placed into the ''EMU value-added catalogue'' (EVACAT) which will be available only to members of the EMU team for some proprietary period before being released into the public domain. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Evolutionary Map of the Universe」の詳細全文を読む スポンサード リンク
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