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WSRT mosaic for Apertif

Submitter: Mpati Ramatsoku; Davide Punzo; Marc Verheijen
Description: This movie shows the visualization of a mosaicked data cube that serves as a training set for forthcoming Apertif observations (Ramatsoku et al., in prep.), testing aspects of source finding, characterization and visualisation. A total of 230 HI sources were identified with a 3-sigma column density sensitivity of 6.4x10^19 cm^-2 at a velocity resolution of 16.5 km/s.

The mosaic is built from 35 individual WSRT pointings in a hexagonal grid, directed towards a region in the sky where a filament of the Perseus-Pisces Supercluster (PPScl) crosses the Zone-of-Avoidance - the obscuring plane of the Milky Way. HI observations, not affected by Galactic extinction, provide an excellent method to reveal the cosmic large scale structure that remains hidden at optical wavelengths and that is clearly discernable in the rotating cube.

The data cube visualised here covers a total sky area of 9.6 square degrees centered at R.A.=4h54m and Dec.=+45d11' with a bandwidth of 67 MHz covering recession velocities of 2,000-17,000 km/s. The cube comprises 2200x2200 spatial pixels and 1717 velocity channels. The angular and velocity resolutions are similar to an Apertif observation but the bandwidth represents only 22% of the instantaneous Apertif bandwidth. The slicer3D software was used to render this large cube and produce the movie.

Project PI: Prof.dr. R.C. Kraan-Korteweg, University of Cape Town

Full video of the mosaic can be found here:
zooming on one source (WEIN069):
Copyright: Mpati Ramatsoku; Davide Punzo; Marc Verheijen
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