R. Perley, P. Napier, J. Jackson, B. Butler, B. Carlson, D. Fort, P. Dewdney, B. Clark, R. Hayward, S. Durand, M. Revnell, M. McKinnon
备注:
Added journal reference: published in Proceedings of the IEEE, Special Issue on Advances in Radio Astronomy, August 2009, vol. 97, No. 8, 1448-1462 Six figures, one table
In almost 30 years of operation, the Very Large Array (VLA) has proved to be a remarkably flexible and productive radio telescope. However, the basic capabilities of the VLA have changed little since it was designed. A major expansion utilizing modern technology is currently underway to improve the capabilities of the VLA by at least an order of magnitude in both sensitivity and in frequency coverage. The primary elements of the Expanded Very Large Array (EVLA) project include new or upgraded receivers for continuous frequency coverage from 1 to 50 GHz, new local oscillator, intermediate frequency, and wide bandwidth data transmission systems to carry signals with 16 GHz total bandwidth from each antenna, and a new digital correlator with the capability to process this bandwidth with an unprecedented number of frequency channels for an imaging array. Also included are a new monitor and control system and new software that will provide telescope ease of use. Scheduled for completion in 2012, the EVLA will provide the world research community with a flexible, powerful, general-purpose telescope to address current and future astronomical issues.
A search for narrowband technosignatures from LTT 3780 with the Allen Telescope Array and the Karl G. Jansky Very Large Array
SETI Institute(SETI研究所);Berkeley SETI Research Center, University of California, Berkeley(加州大学伯克利分校伯克利SETI研究中心);Department of Physics and Astronomy, University of New Mexico(新墨西哥大学物理与天文系);National Radio Astronomy Observatory(美国国家射电天文台);Institute of Astronomy, University of Cambridge(剑桥大学天体物理研究所);Breakthrough Listen, University of Oxford, Department of Physics(牛津大学物理系突破聆听计划);Mydon Solutions (Pty(Mydon解决方案公司)
BEaTriX, expanded X-ray beam facility for testing modular elements of telescope optics: an update
本文介绍了BEaTriX(Beam Expander Testing X射线设备)设计的最新进展,BEaTriX是一种将在INAF/OAB实现的X射线设备,它将产生一束扩展的、均匀的和平行的软X射线。BEaTriX将用于对大型X射线光学器件的X射线聚焦模块进行功能测试,例如用于ATHENA X射线观测站的模块,使用硅孔光学器件(SPO)作为基线技术,并使用塌陷玻璃光学器件(SGO)作为可能的替代技术。在X射线中执行测试提供了对由工业连续生产的光学模块进行原位波长质量控制的优点,从而执行具有最佳角分辨率的模块的选择,并且在SPO的情况下,还存在直接在X射线下对准抛物线和双曲线堆叠以使像差最小化的有趣的可能性。然而,为了测量预期达到约4角秒的角分辨率的反射镜元件,需要发散度低于2角秒的平行光束,因为ATHENA对整个望远镜的要求是5角秒。在模块化光学器件的典型孔径上的这种低发散将需要将X射线源定位在几公里长的真空管中。相比之下,BEaTriX将足够紧凑(5 m x 14 m),可以容纳在小型实验室中,将产生60 mm x 200 mm宽的扩展X射线光束,其特征在于非常低的发散度(1.5 arcsec HEW)、强极化、高均匀性和X射线能量可在1.5 keV和4.5 keV之间选择。在这项工作中,我们描述了BEaTriX布局,并显示性能模拟的X射线能量为4.5千电子伏。
Distributed image reconstruction for very large arrays in radio astronomy
Laboratoire Joseph-Louis Lagrange(约瑟夫-路易·拉格朗日实验室);Université de Nice Sophia-Antipolis(尼斯索菲亚·安提波利斯大学);CNRS(法国国家科学研究中心);Observatoire de la Côte d’Azur(蔚蓝海岸天文台)
The Role of Radio Observations in Studies of Infrared-Bright Galaxies: Prospects for a next-generation Very Large Array
今天的大部分恒星质量是在宇宙还不到现在年龄的一半时在星系中形成的(即,$1 \lesssim z \lesssim 3$)。虽然这可能标志着星系演化最关键的时期之一,但我们目前还没有一个关于这个时期星系盘内冷分子气体的径向范围和分布以及相关恒星形成的清晰图像。这样的观测对于正确估计这些星系将气体转化为恒星的效率以及解释控制这种效率的各种能量过程至关重要。长波长(即,远红外到无线电)观测对于穿透与尘埃、红外明亮星系相关的高水平消光至关重要,这些星系在这些时期驱动恒星质量组装。在这篇文章中,我们将讨论如何下一代甚大阵列将采取变革性的一步,我们的理解星系形成和演化提供的能力,同时研究的相对分布分子气体和恒星形成的sub-kpc尺度不受尘埃的大人口的典型星系在早期宇宙探测未来的远红外空间任务。