Faraday Rotation (FR) and Interplanetary Scintillation (IPS) Case Studies Using the LOw Frequency ARray (LOFAR)
Tuesday, 16 December 2014
We present an update on the progress made using the LOw Frequency ARray (LOFAR) next-generation radio telescope for space-weather related activities – namely observations of interplanetary scintillation (IPS) and the first tests of observing heliospheric Faraday rotation (FR). The former has been used for half a century for heliospheric science and much progress has been made in recent years for using IPS in space weather science and forecasting. The latter, typically an astrophysical technique that uses pulsars and extragalactic radio sources to study the Galactic magnetic field, is now being investigated for heliospheric studies. The determination of heliospheric FR, combined with observations of IPS, can provide essential information on the Sun’s extended magnetic-field structure out into the inner heliosphere, especially when also combined with other forms of remote-sensing/heliospheric imaging data, and in-situ measurements. Here, we will present recent observations of IPS using LOFAR, including preliminary highlights from the first LOFAR joint IPS and heliospheric FR science campaign and investigate pathways for determining Bzfrom, and an overview of the potential of, such observations. LOFAR is an interferometric phased-array radio telescope that can be used to observe between 10 MHz (depending on ionospheric conditions) and 240 MHz, and consists of many relatively-low-cost antennas. These antennas are organised into ‘stations’ located in an area of ~100km diameter in the Netherlands, with additional international stations spread across central and western Europe with several more in the planning stages.