Daily Image
17-10-2014
Gravitational lensing at the highest angular resolution
| Submitter: | John McKean |
| Description: | The poster above won 2nd prize in the Astronomy Pretty Poster Pageant (APPP) 2014. All entries are available for editing and outreach purposes within ASTRON. Gravitational lensing is the deflection of light from a distant background object (the source) by an intervening mass distribution (the lens). If the surface mass density of the lens is sufficiently high, then multiple images of the background source, which are often highly magnified and distorted, are produced. The gravitational lensing phenomena is beautifully illustrated in this global very long baseline interferometry image of MG J0751+2716 at redshift 3.2. Here, the extended background radio source is highly distorted into several images, some of which are stretched to form large gravitational arcs. Never before has such high angular resolution of extended arcs been seen before, which highlights the excellent sensitivity that can be achieved with VLBI arrays today (a collecting area that is about 10 per cent of the proposed SKA). The image was made from a 18 hour observation with an array that included 10 stations from the EVN, 10 stations from the VLBA and the GBT. The image noise is about 10 uJy / beam and the resolution is about 2 x 7 mas. The maximum image separation of the arcs is about 1 arcsecond. |
| Copyright: | John McKean / EVN / VLBA-GBT (NRAO) |
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