Spectral Line Data Analysis with LOFAR
The Low Frequency Array (LOFAR) represents a major step forward in exploring the low-frequency radio regime. With its unprecedented sensitivity, spatial and spectral resolution, frequency coverage and multi-beaming capability, LOFAR enables efficient surveys of the sky that will revolutionize the field of low-frequency spectral line studies. In this chapter we present a very brief overview of line spectroscopy at radio frequencies below 250 MHz. We focus our discussion on (Galactic) radio recombination lines from carbon that are prominently visible at these low frequencies and that provide an important tracer of the physical properties of the cold neutral medium. We briefly discuss the technical capabilities and calibration procedures of spectral line data as observed with LOFAR.
A lot of work by many people has gone into characterizing LOFAR for spectral line observations. JBRO would like to thank the Radio Observatory, the Software Group and the Astronomy Group at ASTRON for enabling and supporting these observations. In particular JBRO has had many fruitful discussions with G. Heald, J. Hessels and the Pulsar group, J. McKean, J. D. Mol and J. Romein on the topics addressed in this chapter. A special thanks also goes out to all the people that are part of the LOFAR-RRL group.
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