Daily Image
01-03-2010
Looking beyond 3C61.1
| Submitter: | Sarod Yatawatta |
| Description: | Observations of 3C61.1 using the LOFAR highband system provides an interesting opportunity to study the complexities of the structure of 3C61.1. Moreover, it also gives a glimpse of the large field of view observable by LOFAR. Starting from the location of 3C61.1, we zoom out the image, extending our field of view until the image size is 8x8 degrees. At a resolution of 4 arc seconds, this yields an image of more than 50 million pixels in size. A multitude of sources can be seen all around the image. In order to improve the dynamic range of the image, not only do we have to have a good model for the central source, but also we have to subtract the off axis sources satisfactorily. As seen from the closeups of some off axis sources, traditional CLEAN based algorithms do a feeble job in removing artifacts due to variations of the point spread function (PSF) over the field. On the other hand, subtraction in the uv (visibility) plane performs much better. This is the path taken by Meqtrees/BBS in calibrating LOFAR data. |
| Copyright: | ASTRON |
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