Commissioning LOFAR for polarisation observations

调试 LOFAR 进行偏振观测

• 批准号: 159500861
• 负责人: Dr. Rainer Beck
• 金额: --
• 依托单位: Max-Planck-Institut für Radioastronomie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/159500861?language=en
• 关键词: Commissioning; LOFAR; polarisation; observations

Measuring linearly polarised radio emission at low frequencies and with a software telescope such as LOFAR opens exciting scientific prospects, but is technically challenging. The construction of non-moving telescope elements results in high instrumental polarization which varies with position on the sky and with distance from the beam center and needs appreciable correction efforts. Furthermore, Faraday rotation in the Earth's ionosphere is different for each direction and for each LOFAR station. The imaging software needs to account for all of these effects. Until now the distorting effects could be identified and analysed in this project. New calibration procedures were developed, leading to radio maps in total intensity. Polarised emission from several pulsars and from a region in the Milky Way was successfully detected.These commissioning efforts are to be continued and finalised over the next years. These efforts shall be conducted by the postdoc at the MPIfR, who should continue to lead these efforts and supervise the students from the other projects in technical issues. He should be supported by a new PhD student at AlfA who should develop calibration methods for polarisation, including corrections for instrumental polarisation and ionospheric Faraday Rotation.

用LOFAR这样的软件望远镜测量低频线偏振射电发射打开了令人兴奋的科学前景，但在技术上具有挑战性。非移动望远镜元件的构造导致仪器的高偏振，它随天空上的位置和离光束中心的距离而变化，需要可观的校正努力。此外，地球电离层的法拉第旋转在每个方向和每个LOFAR站都是不同的。成像软件需要考虑到所有这些影响。到目前为止，在这个项目中可以识别和分析扭曲效应。制定了新的校准程序，产生了总强度的无线电地图。来自几颗脉冲星和银河系某个区域的偏振辐射被成功探测到。这些调试工作将在未来几年内继续并最终完成。这些工作将由MPIfR的博士后进行，他应该继续领导这些工作，并在技术问题上监督其他项目的学生。他应该得到一名新的AlfA博士生的支持，该博士生应该开发偏振校准方法，包括仪器偏振和电离层法拉第旋转的校正。

项目成果

The LOFAR view of cosmic magnetism

• DOI: 10.1002/asna.201311894
• 发表时间: 2013-02
• 期刊: Astronomische Nachrichten
• 影响因子: 0.9
• 作者: R. Beck;James M. Anderson;G. Heald;A. Horneffer;M. Iacobelli;J. Koehler;D. Mulcahy;R. Pizzo;A. Scaife;O. Wucknitz;the team of the Lofar Magnetism Key Science Project-the-team-of-the-Lofar-Magnetism-Key-Science-Project-123206934

Subarcsecond international LOFAR radio images of the M82 nucleus at 118 MHz and 154 MHz

M82 核在 118 MHz 和 154 MHz 下的亚弧秒国际 LOFAR 射电图像

• DOI: 10.1051/0004-6361/201425089
• 发表时间: 2015
• 期刊: Astronomy and Astrophysics
• 影响因子: 6.5
• 作者: Varenius;Adebahr;Dettmar;Brüggen
• 通讯作者: Brüggen

FARADAY ROTATION MEASURE SYNTHESIS OF INTERMEDIATE REDSHIFT QUASARS AS A PROBE OF INTERVENING MATTER

• DOI: 10.3847/0004-637x/829/2/133
• 发表时间: 2016-03
• 期刊: The Astrophysical Journal
• 作者: Kwang Seong Kim;S. Lilly;F. Miniati;M. Bernet;R. Beck;S. O’Sullivan;B. Gaensler

Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes

• DOI: 10.1051/0004-6361/201220728
• 发表时间: 2013-03
• 期刊: Astronomy and Astrophysics
• 影响因子: 6.5
• 作者: C. Sotomayor-Beltran;C. Sobey;J. Hessels;G. D. Bruyn;A. Noutsos;A. Alexov;J. Anderson;A. Asgekar-A.-Asg

Future Observations of Cosmic Magnetic Fields with LOFAR, SKA and Its Precursors

未来利用 LOFAR、SKA 及其前体对宇宙磁场进行观测

• DOI: 10.1007/978-3-662-44625-6_1
• 发表时间: 2015