ASTRON performs first successful astronomical observations with a Focal Plane Array
ASTRON has performed the first successful astronomical observations with a so-called Focal Plane Array (FPA), installed on one of the fourteen dishes of the Westerbork telescope. Focal Plane Arrays are clusters of connected receivers and are the essence of the future APERTIF system (“APERture Tile In Focus”). This transformational FPA technology has been pioneered and brought to maturity by ASTRON, enabling a huge leap forwards for astronomy and the development of radio-sensor systems. The FPA system allows for a single telescope to observe in multiple directions at the same time, forming a continuous extended field of view which has not been possible before. Now, for the first time anywhere in the world, meaningful astronomical images have been made with this type of receiver at such a high frequency.
ASTRON is developing the APERTIF receiver system to enable extremely sensitive measurements of the whole sky with an unparalleled accuracy. The traditional horn antenna, located in the focus of each Westerbork telescope, will be replaced by a cluster of connected antennas, the Focal Plane Arrays, thus creating a radio ‘camera’ in every telescope. This will enlarge the instantaneous field of view of the telescope by at least ten times during one single observation. Astronomers can now collect much more information in a shorter period of time and from a larger area of the sky.
While enhancing the scientific productivity of existing facilities like the Westerbork telescope, the APERTIF system forms an important step towards a broad application of this innovative and promising FPA technology. The development of such a receiver system will play an important role in the international Square Kilometer Array (SKA) project, aimed at developing the world’s largest radio telescope, a hundred times more sensitive than existing instruments. APERTIF is made possible by a grant from the Investments NWO-Groot program.
For more information you can contact:
APERTIF project:
Wim van Cappellen, APERTIF project manager, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo – Phone: +31 (0)521 595 100. E-mail: cappellen@astron.nl
Marc Verheijen, APERTIF principal investigator, Kapteyn Instituut, Landleven 12 (Zernike building), 9747 AD Groningen; Tel: +31 (0)50-3634073, E-mail: M.A.W.Verheijen@astro.rug.nl
Tom Oosterloo, APERTIF principal investigator, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo – Phone: +31 (0)521 595 100. E-mail: oosterloo@astron.nl
ASTRON:
Prof. Mike Garrett, ASTRON General Director, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo; Phone: +31 (0)521-595 100; E-mail: garrett@astron.nl
Note to the editor:
The image belonging to the press release can be dowloaded from the website: http://www.astron.nl/press/270308.htm
Caption image: The picture shows one of the first images made with the prototype of the new APERTIF system. The image on the left shows the neutral hydrogen of the Andromeda nebula, also known as M31, the twin brother of our own Milky Way. M31 extends several degrees on the sky, which means that it appears almost ten times bigger than the full moon. This is much larger than the field of view of the current Westerbork telescope (the white circle on the picture). With the Focal Plane Arrays of APERTIF, simultaneously aimed in different directions at the sky, the largest part of M31 can be observed with one single observation of the telescope. The image on the left is the result of an observation that lasted only 6.7 seconds. Because the APERTIF prototype is only installed in one of the Westerbork dishes, the images are not yet very sharp. However, once most of the fourteen Westerbork dishes are equipped with Focal Plane Arrays, very sharp images can be obtained.
The image on the right also shows the distribution of atomic hydrogen in M31, on the same scale as on the left. This image has been made a few years ago with the Westerbork telescope, but without the Focal Plane Arrays. To make this image, 163 separate observations were necessary with all fourteen Westerbork dishes, a process that took many weeks. If every Westerbork dish had a system like APERTIF, the image on the right could be made in a few days with only a few observations.
