Square Kilometre Array

The Square Kilometre Array ( SKA short ) is under development as a radio telescope, which will have a total collecting area of ​​approximately one square kilometer. It will operate over a wide frequency range; by its size will be increased by 50 times over other radio telescopes sensitivity. For the evaluation of high performance computers and data long distance networks with a capacity requires that surpasses today's global Internet traffic. The SKA will be the sky can search thousands of times faster than before. With receiving stations that are situated away from a center to a distance of 3000 km, it will generate extremely high-resolution images of the sky. The SKA will be built in South Africa and Australia, where the best views are guaranteed on the galactic center and minimal radio interference. The construction of the SKA will start in 2016 with a budget of 1.5 billion euros to 2019 to receive the first data and to be in full operational readiness in 2023.

The SKA is operated by a collaboration of 19 countries. The researchers hope to find answers to fundamental questions about the origin and evolution of the universe.

• 4.1 MeerKAT
• 4.2 Australian SKA Pathfinder
• 4.3 LOFAR
• 4.4 Allen Telescope Array
• 4.5 Square Kilometre Array Design Study
• 4.6 Technology Development Project
• 4.7 MWA

Description

The SKA will combine signals received by thousands of small radio antennas. Due to the large spatial distance of up to 3000 km, it is possible so to simulate a huge radio telescope, which has an extremely high sensitivity and angular resolution. The SKA will also cover a very large field of view (FOV, field - of-view ), with the goal of 200 square degrees at frequencies below 1 GHz and more than 1 square degree (about 5 moon slices) at higher frequencies. An innovation is the simultaneous use of multiple VOCs using phased array technology. Thus, the speed is significantly improved with patterns and allowing different users to simultaneously observe different parts of the sky. The combination of very large FOV with high sensitivity exploration of the universe is being revolutionized.

In the first two phases, a continuous coverage of 70 MHz to 10 GHz is ensured. In a third phase expansion to 30 GHz is planned.

With a single antenna design can not be received sense of the entire frequency range from 70 MHz to 10 GHz (over two decades). Therefore, the SKA will have three types of antenna elements, SKA -low, mid and SKA- parabolic antennas.

The SKA will be divided into three regions:

Scientific objectives of the SKA

The SKA will be used as a highly flexible tool for answering a wide range of issues of fundamental physics, particle physics, astrophysics and cosmology. It is yet to explore unknown parts of the remote universe. The following research projects have been selected as the main fields of activity of the ASC:

Extreme tests of general relativity

Over more than 90 years of general relativity theory of Einstein has correctly predicted the results of all the experiments that have been developed for verifying it. Most of these tests, and the test string have been conducted with a radio astronomical methods. Astronomers will be able to use pulsars as cosmic gravitational wave detectors or in binary systems with black holes to explore the limits of the general theory of relativity as the behavior of space and time in regions with extreme space curvatures. This will provide information on new physical effects are obtained.

Galaxies, cosmology, dark matter and dark energy

The sensitivity of the SKA in the 21 -cm hydrogen line will allow to map billions of galaxies up to the limit of the visible universe. The large-scale structure of these galaxies allows conclusions on how galaxies formed and evolved. The distribution of hydrogen gas in the universe will show you where the first structures formed from the continuum, from which emerged galaxies and clusters. This quantitative conclusions about the effects of dark energy can be drawn.

Measurement of the "Dark Ages"; the first black holes and stars

The SKA will be able to examine the gap in the history of the universe, starting 300,000 years after the Big Bang, when the universe became transparent to radiation, and extends up to the time a billion years after the Big Bang, in which the first young galaxies light up. By measuring the primordial gas distribution, the SKA can understand how the universe was gradually brightens, when the first stars and galaxies formed and then developed.

Origin and evolution of cosmic magnetism

It is still not possible to answer simple questions about the origin and evolution of cosmic magnetic fields. But this place is known, an important component of the interstellar and intergalactic space Represents the SKA will clarify the shape of the cosmic magnetic field and its role in the evolution of the universe.

Discovering the unknown

History shows that many of the greatest discoveries were made unexpectedly. The unique sensitivity and versatility gives hope for new discoveries.

Locations

Possible locations for the SKA had to be located in uninhabited areas with very small artificial radio interference. After extensive testing, there were still two locations to choose from:

• Australia / New Zealand: The center is located at Boolardy (26 ° 59 ' S, 116 ° 32 ' E) in Western Australia 315 km north-east of Geraldton on a desert-like plain at an altitude of 460 meters above sea level. This area is located in the Mid- West Radio Quiet Zone, which was set up already for the Murchison Widefield Array ( MWA). The most remote stations are set up in New Zealand.
• South Africa: The center is located at ( 30.72113 ° S, 21.41113 ° E) at an altitude of 1000 meters above sea level in the area Karoo, in the arid Northern Cape Province, about 75 km north- west of Carnarvon, with distant stations in Ghana, Kenya Madagascar and Mauritius.

Compromise solution: a part of the majority of the parabolic antennas antennas for phases 1 and 2 and the SKA -mid array for Phase 2 will be built in South Africa: After a long contest between the two sites, the decision was made on 25 May 2012, a compromise solution the parabolic mirror for phase 1 and the SKA -low array for phases 1 and 2 in Australia and New Zealand.

Pathfinder arrays and development of technology

Many groups of scientists around the world are working to develop the technology required and the procedures which are to be used by the SKA. Some are listed below.

MeerKAT

MeerKAT is a project for 860 million Rand, which tested with an array of 50 or more parabolic antennas with 12 m diameter foundations for the technology of the SKA. KAT -7, a test environment from seven bowls near Carnarvon in the Northern Cape Province in South Africa will gain 2012 full functionality. The parabolic antennas are equipped with single wideband receivers for frequencies from 800 MHz to 8 GHz.

Australian SKA Pathfinder

The Australian SKA Pathfinder, short ASKAP, is a 100 - million -AU $ project with the goal to 2012 to form an array of 36 parabolic antennas with 12 m diameter and advanced phased array receiver arrays (with large FOV of 30 square degrees ). The frequency coverage to 700 MHz to 1.7 GHz. ASKAP will be established at the Australian site for the SKA, in Boolardy.

LOFAR

LOFAR is a 120 million euro expensive European project, planned and built by the institute ASTRON in the Netherlands, that builds a new array of antenna stations for low frequencies phased opening, spread all over Northern Europe and uses since 2011. Receiving data at low frequencies of 10 MHz to 240 MHz are passed directly to a central computer, where the superposition and evaluation can be made. LOFAR is currently developing basic processing techniques for the SKA crucial.

Allen Telescope Array

The Allen Telescope Array ( ATA) consists of innovative offset Gregory parabolic antennas with a diameter of 6.1 m, equipped with broadband receivers for 500 MHz to 11 GHz. Currently 42 elements into a functional array are connected together, with a planned expansion to 350 antenna elements. For the design of the satellite dishes special cheap production methods were tried.

Square Kilometre Array Design Study

The Square Kilometre Array Design Study, short SKADS, is a European project in the amount of 38 million euros, which developed a whole range of technologies and scientific studies in the context of the SKA. The focus of technical developments is high-frequency phase array for 300 MHz to 1 GHz. Such a fully electronic telescope provides a large number of simultaneous beams for the highest speeds with sky surveys.

Technology Development Project

The Technology Development Project, abbreviated TDP, is a 12 - million - dollar program of the United States in order to develop targeted for the SKA technologies for parabolic dishes and their integration. It is operated by a consortium of universities led by the Cornell University and is completed in 2012.

MWA

The Murchison Widefield Array is similar to LOFAR, a radio telescope for the frequency range up to 300 MHz synthetic aperture. For relevant technologies to be developed for the development of the SKA:

• Runtime controlled beam shaping with Antennenmatrizen from inexpensive dipole antennas
• Data collection and synchronization of a plurality of antenna groups
• FX technology, the receiver and Digitalisiererkomponenten.

The MWA is located at one of the possible locations for the SKA in Australia.

Schedule and funding

The SKA was originally conceived in the early 1990s by an international group, which was formed in 1994. 2000, the first " Memorandum of Agreement " was signed. Considerable energy has gone into the sequence in preparatory work, which culminated in PrepSKA 2008, with a full SKA design planned for 2012. Stage 1 is built from 2016 to 2019, after their completion a functional array can accommodate the first scientific operation. Phase 2 is performed in the terminal 2023, to reach the full sensitivity for frequencies up to 10 GHz.

The SKA budgeted 1.5 billion euros for phases 1 and 2 until 2023 it included 300 million euros for phase 1 by 2019. Intended is a division in equal parts to Europe, USA and the rest of the participating States. The European contribution is presumably can not be paid because the ASTRONET roadmap for European astronomy recommends the E-ELT with higher urgency 2017.

Member States

The SKA is funded by some states. The members are the Netherlands, Italy, Canada, New Zealand, the United Kingdom, the People's Republic of China and, since May 2012, Germany. Founding members founded 2011 " SKA organization" are Australia, the Netherlands, Italy, Canada, New Zealand, South Africa, the United Kingdom and the People's Republic of China.

In the Member States are several important ministries or areas. In Australia, the Institute for Innovation, Industry, Science and Research. In Canada, the national research body. In China, the National Astronomical Observatory and the Chinese Academy of Sciences. In Italy, the National Institute for Astrophysics. In New Zealand, the Ministry of Economic Development. In South Africa, there is the national natural science foundation. The United Kingdom provides the science and technology council for aid.