Reference Calibration for Precision Dark Energy Measurement

用于精密暗能量测量的参考校准

• 批准号: 341310-2012
• 负责人: Albert, Justin
• 金额: $ 1.82万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=572228
• 关键词: Reference; Calibration; Precision; Dark; Energy

Uncertainties on photometric standards now constitute the dominant uncertainty on our knowledge of dark energy. Additionally, they constitute a significant systematic for measurements of stellar population in galaxy cluster counts, and upcoming photometric redshift surveys measuring growth of structure. There are prospects for improvement in uncertainties from standard star flux, but the traditional techniques of measurement of stellar flux from above the atmosphere suffer from basic and inherent problems: the variability of all stellar sources, and the difficulty of creating a precisely calibrated, cross-checked, and stable platform for observation above Earth's atmosphere. We are undertaking a program of research to understand and profoundly reduce the many astrophysical and cosmological uncertainties due to photometry. Presently, together with colleagues at Toronto, McGill, NRC-INMS, and U.S. institutions, we have designed and constructed payloads for high-altitude balloons containing both monochromatic light sources and radiometric calibration. Our balloon flights have begun to overfly observatories, starting with our initial test flight in New Hampshire in August 2011, and continuing with a campaign of flights over the Univ. of New Mexico campus observatory and Mt. Hopkins in Arizona in 2012, and the following year with the CTIO and Las Campanas observatories in Chile. We have constructed and are the responsible party for the payload optics, including the light source, integrating sphere, and regulated power supply. As well as our initial free-flying balloon payload, both a teststand, and a calibrated payload on a tethered weather balloon, are taking data on an optical table and with the new 32" UVic telescope observatory, respectively. Together with an RTI grant with Canadian colleagues submitted separately, we presently request funding for an MSc student to analyze the data from the overflights, as well as from our calibrated lightsource observations at UVic. The longer-term goals of the program are calibrated sources on a nanosatellite, as well as on a controlled high-altitude miniature blimp, to fly directly "in front of" SNIa, and allow observatories across the world to reach the then-technology-limited precision of 0.01% photometry.

现在，对光度标准的不确定性构成了我们对黑能的知识的主要不确定性。 此外，它们构成了星系簇计数中恒星种群的测量以及即将进行的光度红移调查测量结构生长的重要系统。标准星通量不确定性的前景可以改善不确定性，但是从大气上方的恒星通量测量的传统技术却遭受了基本和固有的问题：所有恒星来源的可变性，以及创建精确校准，交叉检查和稳定平台以观察地球大气层的难度。 我们正在进行一项研究计划，以理解并深刻地减少由于光度法引起的许多天体物理和宇宙学不确定性。目前，我们与多伦多，McGill，NRC-INM和美国机构的同事一起设计并构建了有效载荷，用于具有单色光源和辐射校准的高空气球。我们的气球航班已经开始过度过度的天文台，从2011年8月在新罕布什尔州的初始测试飞行开始，并继续进行了一场比赛。在2012年，新墨西哥州的校园天文台和霍普金斯山（Mt. Hopkins）于2012年，第二年与智利的CTIO和LAS Campanas天文台一起。 我们已经构建了有效载荷光学元件的责任方，包括光源，集成球体和受监管的电源。 As well as our initial free-flying balloon payload, both a teststand, and a calibrated payload on a tethered weather balloon, are taking data on an optical table and with the new 32" UVic telescope observatory, respectively. Together with an RTI grant with Canadian colleagues submitted separately, we presently request funding for an MSc student to analyze the data from the overflights, as well as from our calibrated lightsource对uvic的观察。该程序的长期目标是在纳米卫星上的校准来源，以及在“ SNIA”前“直接飞行”，并允许全球观察者在世界范围内飞行。