Daily Image
27-08-2021
Continuum demos with the Dwingeloo telescope
| Submitter: | Tammo Jan Dijkema |
| Description: | For the summer opening of the Dwingeloo Telescope, we faced a little problem: the signal of the pulsar, which we usually use for demos, becomes increasingly drowned in radio interference. Reason to work on another demo, showing the bright continuum sources in the sky, in this case at 1.33 GHz. The set-up of the new demo is quite simple: every 0.5 seconds a GnuRadio flowchart spits out one number, which is plotted against the distance to various bright sources. Slewing (in azimuth) over a source thus shows how bright the source is. The image shows four bright sources: the Sun, Cassiopeia A (a supernova remnant 11,000 light years from us), Taurus A (the Crab nebula, a supernova remnant 6,500 light years from us) and Cygnus A (a radio galaxy over 700 million light years away). The observation of the Crab nebula shows higher noise, because the source was low and we also caught some ground noise. This image was built up live during a tour for new employees. Because the summer openings of the telescope happen regularly, this is also an opportunity to record some data over a somewhat longer time period. The data we recorded so far are collected on https://charon.camras.nl/public/continuumdata We have so far used this demo to capture continuum emission from the Sun, the Moon, Cassiopeia A, Cygnus A, the Crab Nebula and the Orion Nebula. Sometimes we manage to show four sources and the pulsar within a half-hour demo. The public seems to appreciate the large amount of slewing involved. |
| Copyright: | CC-BY-4.0 CAMRAS / Tammo Jan Dijkema |
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