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PAPERBACK price:$15.00 add to cart Rights & Permissions Free PDF Access Sign in to download PDF book and chapters Free Resources PDF SUMMARY PDF Report Brief Display this book on your site! Related Titles Panel Reports--New Worlds, New Horizons in Astronomy and Astrophysics Astronomy and Astrophysics in the New Millennium:Panel Reports Other Related Titles The Atacama Large Millimeter Array (ALMA): Implications of a Potential Descope (2005) Committee on Astronomy and Astrophysics (CAA) Board on Physics and Astronomy (BPA) Space Studies Board (SSB) Citation Manager Export the bibliographic data for this book in your chosen format Web Search Builder Use this book's key terms to search within this book, across our collection, or across the Web. Skim This Chapter Skim this chapter and use this chapter's key terms to search within this book. Reference Finder Paste in your own text to find books that relate to your topic. Citation Manager . "5 Minimum Number of Antennas." The Atacama Large Millimeter Array (ALMA): Implications of a Potential Descope. Washington, DC: The National Academies Press, 2005. Please select a format: Page 21   E-mail Share on facebook Facebook Share on delicious Delicious Share on stumbleupon Stumble Share on twitter Twitter More Sharing ServicesMore The following HTML text is provided to enhance online readability. Many aspects of typography translate only awkwardly to HTML. Please use the page image as the authoritative form to ensure accuracy. 5 Minimum Number of Antennas Millimeter and submillimeter observations are very important to contemporary astronomy. No better defense of this proposition is needed than the list of advances in the 15 years that have elapsed since the 1991 astronomy and astrophysics decadal survey was written. Nonetheless it is legitimate to ask at what point a descoped telescope would fail to sustain support in the highly competitive environment for new facilities today. This committee’s answer, inevitably somewhat subjective, is based on the performance measures presented in Table 1. Table 1 shows, for example, that a 30-antenna array has only 3 to 4 times the sensitivity of Plateau de Beure at wavelengths longer than 1 millimeter and would not have ALMA’s potential enormous mosaicing speed advantage at high frequency over that of the Submillimeter Array (SMA), which is the one other high-altitude facility capable of observing at 900 GHz. The committee concludes that a 40-antenna array would retain ALMA’s strong support within the general astronomical community. However, the rapid decline in imaging capability that would result with a further reduction below 40 antennas would erode this support. Page 21 Front Matter (R1-R14) Summary (1-2) 1 Introduction (3-6) 2 Technical Performance Specifications (7-12) 3 Performance Degradation (13-16) 4 The Threshold for Transformational Science (17-20) 5 Minimum Number of Antennas (21-22) Appendix A: Letter of Request (23-28) Appendix B: ALMA Level-1 Science Requirements (29-32)

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The Atacama Large Millimeter Array: Implications of a Potential Descope 5 Minimum Number of Antennas Millimeter and submillimeter observations are very important to contemporary astronomy. No better defense of this proposition is needed than the list of advances in the 15 years that have elapsed since the 1991 astronomy and astrophysics decadal survey was written. Nonetheless it is legitimate to ask at what point a descoped telescope would fail to sustain support in the highly competitive environment for new facilities today. This committee’s answer, inevitably somewhat subjective, is based on the performance measures presented in Table 1. Table 1 shows, for example, that a 30-antenna array has only 3 to 4 times the sensitivity of Plateau de Beure at wavelengths longer than 1 millimeter and would not have ALMA’s potential enormous mosaicing speed advantage at high frequency over that of the Submillimeter Array (SMA), which is the one other high-altitude facility capable of observing at 900 GHz. The committee concludes that a 40-antenna array would retain ALMA’s strong support within the general astronomical community. However, the rapid decline in imaging capability that would result with a further reduction below 40 antennas would erode this support.

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imaging performance