2013/09/18 by J. S. Farnes, David A. Green, D. A. Green +4 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #Radio Astronomy Observations and Technology #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1309.4646
10 pages, 7 figures. Conference Proceedings, "Magnetic Fields in the Universe IV", Playa del Carmen, Mexico, 2013
arxiv created 2013/09/18 · arxiv updated 2013/09/19
We present the first spectropolarimetric radio observations that apply Rotation Measure (RM) Synthesis to interferometric data from the Giant Metrewave Radio Telescope (GMRT) at 610 MHz. Spectropolarimetry requires measurement of a large number of instrumental systematics so that their effects can be calibrated - a technical problem that is currently being faced by the upcoming SKA pathfinders. Our fully-calibrated data allow for the peak Faraday depth and polarisation fraction to be measured for sub-mJy compact sources in the field of M51 at 610 MHz. The diffuse extended emission in the interacting galaxy pair is shown to be depolarised below the sensitivity limit. A survey of linear polarisation with the GMRT is now feasible and could be used to place constraints on the prevailing depolarisation mechanisms at low frequencies - improving polarised source count estimates and constraining the RM-grid observable with next generation facilities such as the SKA.