Daily Image
03-03-2010
Delay/fringe rate mapping on a German LOFAR baseline
| Submitter: | Olaf Wucknitz |
| Description: | As shown on the daily image of 4th Nov 2009, we can apply basic geometry to map delay/fringe rate spectra of observations on single baselines to positions on the sky and produce crude, low-resolution images in this way. On 12th Feb 2010, the first LOFAR observations with all three currently connected German stations (Effelsberg near Bonn, Tautenburg near Jena and Unterweilenbach near Munich) have produced fringes to and between all these stations. With three German stations we now have closure information that, in principle, allows us to calibrate and produce maps. Today's daily image shows a map produced from 2h of delay/rate spectra on the Effelsberg-Unterweilenbach baseline using the XX correlation of 40 subbands scattered between 44 and 55 MHz. The target source in the centre is 3C196 with about 150 Jy. In addition we see at least three other sources that are listed in the VLSS with 19 (A), 6 (B) and 17 Jy (C) at 74 MHz. But no, we are not planning to disconnect the German stations from the rest of the array to produce our own maps. An interferometer is more valuable than the sum of its parts, and the same is true for the combination of the Dutch and German subarrays. |
| Copyright: | public domain |
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