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First Pulsar Detection With LOFAR Station
Dwingeloo, Holland (SPX) Jul 18, 2007 Astronomers from ASTRON and the University of Amsterdam successfully detected the pulsar PSR B0329+54 using the first LOFAR station, CS-01. The measurement took 15 minutes and used six of the prototype High Band Antennas (HBAs) that were recently installed at the "Core Station 1" field in Exloo, Drenthe, The Netherlands. The High Band Antennas operate at frequencies between 115-240 MHz. The search for the pulsar used 48 frequency bands in the range 170-230 MHz. The pulsar was observed in 44 of these 48 bands, indicating that the radio spectrum at the site is relatively clean, in line with earlier experiments with the Westerbork Synthesis Radio Telescope (WSRT). The results show that the technical performance of the High Band Antennas is excellent. With this experiment, all LOFAR subsystems have now been successfully verified in astronomical observations. Pulsars are rotating neutron stars with a diameter of only ~ 20 kilometer. They are the remnants of massive stars that have collapsed after they have used up all their nuclear fuel. These objects have extremely strong magnetic fields and emit radio-waves from their magnetic poles, just like the beam of a lighthouse. Ed van den Heuvel, astronomy professor at the University of Amsterdam, remarks: "It's fantastic to see that with only six antennas, which together are five hundred times less sensitive than the final LOFAR telescope, we can now already detect these pulsars! Last year, 40 years after the discovery of pulsars, observations with the Westerbork telescope finally gave some insights in the mechanism radio-pulsars use to generate their radio waves. It turned out that this mechanism will show itself most clearly at the low radio-frequencies that will be observed by LOFAR. Simulations predict that the full LOFAR will discover some thousand new pulsars, doubling the number of pulsars in the Northern hemisphere, and in addition, allowing us to study them in much more detail." This spring, LOFAR successfully passed an important milestone: the Critical Design Review of the technical project. On April 17-18, the design was presented to an independent review board. The advice of the board was to start vigorously with the construction of the first 20 LOFAR stations. Ultimately the ambition is to build 77 LOFAR stations, but funding still has to be secured for the final phase of 20 to 30 stations. The science team is also considering the option of deploying smaller stations at all targeted locations. In addition, there are now serious plans for the construction of 10 to 15 LOFAR stations elsewhere in Europe: six to nine in Germany, three in the UK, one in France and possibly also in Sweden, Poland, Ukraine and Italy. The first of these European LOFAR stations has been constructed already next to the 100-metre Effelsberg radio telescope near Bonn, Germany. The European LOFAR stations are an important extension for LOFAR. Combining stations at these large distances with those in the Netherlands will increase the spatial resolution of LOFAR images by a factor of 10. This is especially important for detailed studies of galaxies. Meanwhile, ASTRON's Radio Observatory is beginning to gear-up for the operational phase of LOFAR as an astronomical facility. Since 1970, the Radio Observatory has been responsible for the operations of the Westerbork Synthesis Radio Telescope (WSRT). The Radio Observatory will now assume a major role in maximising the scientific return from LOFAR, closely interacting with the international astronomical community and other users of the LOFAR infrastructure. After this summer, ASTRON's technical development team will hand over responsibility for the first LOFAR Station (CS01) to the Radio Observatory. Nineteen similar stations are to be deployed over the coming 18 months, and astronomical observations will increasingly ramp-up as each station comes on-line. Community Email This Article Comment On This Article Related Links ASTRON LOFAR Stellar Chemistry, The Universe And All Within It
Astronomers Find The Most Distant Known Galaxies
Pasadena CA (SPX) Jul 17, 2007Using natural "gravitational lenses", an international team of astronomers claim to have found a hint of a population of the most distant galaxies yet seen - the light we see from them today left more than 13 thousand million years ago, when the Universe was just 500 million years old. Team leader Professor Richard Ellis, Steele Professor of Astronomy at Caltech, will present images of these faint and distant objects in his talk on Wednesday 11 July at the "From IRAS to Herschel and Planck" conference at the Geological Society in London. |
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