MeerKAT, originally the Karoo Array Telescope, is a
radio telescope consisting of 64 antennas in the
Meerkat National Park, in the
Northern Cape of South Africa. In 2003, South Africa submitted an expression of interest to host the
Square Kilometre Array
The Square Kilometre Array (SKA) is an intergovernmental international radio telescope project being built in Australia (low-frequency) and South Africa (mid-frequency). The combining infrastructure, the Square Kilometre Array Observatory (SKA ...
(SKA) Radio Telescope in Africa, and the locally designed and built MeerKAT was incorporated into the first phase of the SKA. MeerKAT was launched in 2018.
Along with the
Hydrogen Epoch of Reionization Array
The Hydrogen Epoch of Reionization Array (HERA) is a radio telescope dedicated to observing large scale structure during and prior to the epoch of reionization. HERA is a Square Kilometre Array (SKA) precursor instrument, intended to observe t ...
(HERA), also in South Africa, and two
radio telescopes in
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
, the
Australian SKA Pathfinder
The Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Mid West region of Western Australia.
The facility began as a technology demonstrator for the i ...
(ASKAP) and the
Murchison Widefield Array
The Murchison Widefield Array (MWA) is a joint project between an international consortium of organisations to construct and operate a low-frequency radio array. 'Widefield' refers to its very large field of view (on the order of 30 degrees ac ...
(MWA), the MeerKAT is one of four precursors to the final SKA.
History
MeerKAT is a precursor for the SKA-mid array, as are the Hydrogen Epoch of Reionization Array (HERA), the Australian SKA Pathfinder (ASKAP) and the Murchison Widefield Array (MWA).
Description
It is located on the SKA site in the
Karoo, and is a pathfinder for SKA-mid technologies and science. It was designed by engineers within the
South Africa Radio Astronomy Observatory and South African industries, and most of the hardware and software was sourced in South Africa. It comprises 64 antennas, each 13.5m in diameter, equipped with cryogenic receivers. The antennas have positions for four receivers, and one of the three vacant positions will be filled by S-band receivers provided by the
Max Planck Institute for Radio Astronomy
The Max Planck Institute for Radio Astronomy (MPIfRA) (German: ''Max-Planck-Institut für Radioastronomie'') is located in Bonn, Germany. It is one of 80 institutes in the Max Planck Society (German: Max-Planck-Gesellschaft).
History
By com ...
(MPIfR). The array configuration has 61% of the antennas located within a 1 km diameter circle, and the remaining 39% distributed out to a radius of 4 km.
The receiver outputs are digitised immediately at the antenna, and the digital data streams are transported to the Karoo Array Processor Building (KAPB) via buried optical fibres. The antenna signals are processed by the Correlator/Beamformer (CBF) digital signal processor. Data from the CBF is passed on to the Science Processor computer cluster and disk storage modules. The MeerKAT antenna data is also made available to a number of user-supplied digital backends via the CBF, including pulsar and fast radio burst (FRB) search engines, a precision pulsar timing system, and a
SETI
The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other pl ...
signal processor. A time and frequency reference (TFR) system provides clock and absolute time signals required by the digitisers and other telescope subsystems. This TFR system comprises two hydrogen maser clocks, two rubidium atomic clocks, a precise crystal oscillator, and a set of GNSS receiver systems for time transfer with UTC.
The massive computing and digital signal-processing systems located at the KAPB are housed in a large shielded chamber (or
Faraday cage) to prevent radio signals from the equipment interfering with the sensitive radio receivers. The KAPB itself is partially buried below ground level to provide additional radio frequency interference (RFI) protection, and to provide temperature stability. The KAPB also houses a power conditioning facility for the entire site, including three diesel rotary UPS units that provide an uninterrupted power supply to the whole site.
A long-haul optical fibre transfers data from the KAPB to the Centre for High Performance Computing (CHPC) and SARAO office in Cape Town, and provides a control and monitoring link to the SARAO operations centre in Cape Town. Telescope data processing and reduction is executed on compute facilities provided by the MeerKAT SP systems, and on other high performance computer facilities provides by MeerKAT users.
Specifications
MeerKAT inaugurated in July 2018
consists of 64 dishes of 13.5 metres in diameter each with an offset
Gregorian configuration.
An offset dish configuration has been chosen because its unblocked aperture provides uncompromised optical performance and sensitivity, excellent imaging quality and good rejection of unwanted radio frequency interference from satellites and terrestrial transmitters. It also facilitates the installation of multiple receiver systems in the primary and secondary focal areas and is the reference design for the mid-band SKA concept.
MeerKAT supports a wide range of observing modes, including deep continuum, polarisation and
spectral line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...
imaging,
pulsar timing
Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty of ...
and transient searches. A range of standard data products are provided, including an imaging pipeline. A number of "data spigots" are also available to support user-provided instrumentation. Significant design and qualification efforts are planned to ensure high reliability to achieve low operational cost and high availability.
MeerKAT's 64 dishes are distributed over two components:
* A dense inner component containing 70% of the dishes. These are distributed in a two-dimensional fashion with a
Gaussian distribution with a mean dispersion of 300 m, a shortest baseline of 29 m and a longest baseline of 1 km.
* An outer component containing 30% of the dishes. These are also distributed in a two-dimensional Gaussian distribution with a mean dispersion of 2,500 m and a longest baseline of 8 km.
Construction schedule
![SKA site, South Africa 2014 47](https://upload.wikimedia.org/wikipedia/commons/c/cc/SKA_site%2C_South_Africa_2014_47.jpg)
To acquire experience in the construction of interferometric telescopes, members of the Karoo Array Telescope constructed the
Phased Experimental Demonstrator (PED) at the
South African Astronomical Observatory
South African Astronomical Observatory (SAAO) is the national centre for optical and infrared astronomy in South Africa. It was established in 1972. The observatory is run by the National Research Foundation of South Africa. The facility's funct ...
in
Cape Town
Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...
between 2005 and 2007.
During 2007, the eXperimental Development Model Telescope (XDM) was built at the
Hartebeesthoek Radio Astronomy Observatory
The Hartebeesthoek Radio Astronomy Observatory (HartRAO) is a radio astronomy observatory, located in a natural bowl of hills at Hartebeesthoek just south of the Magaliesberg mountain range, Gauteng, South Africa, about 50 km west of Johannes ...
to serve as a testbed for MeerKAT.
Construction of the MeerKAT Precursor Array (MPA – also known as KAT-7), on the site started in August 2009.
[
] In April 2010 four of the seven first dishes were linked together as an integrated system to produce its first interferometric image of an astronomical object. In Dec 2010, there was a successful detection of
very long baseline interferometry (VLBI) fringes between the Hartebeesthoek Radio Astronomy Observatory 26 m dish and one of the KAT-7 dishes.
Despite original plans to complete MeerKAT by 2012, construction was suspended in late 2010 due to budget restructure. Science Minister
Naledi Pandor
Grace Naledi Mandisa Pandor (née Matthews; born 7 December 1953) is a South African politician, educator and academic serving as the Minister of International Relations and Cooperation since 2019. She has served as a Member of Parliament (MP) ...
denied the suspension marked any setback to the SKA project or 'external considerations'. MeerKAT construction received no funding in 2010/11 and 2011/12. The 2012 South African National Budget projected that just 15 MeerKAT antennas would be completed by 2015.
The last of the
reinforced concrete foundations for the MeerKAT antennas was completed on 11 February 2014. Almost 5000 m
3 of concrete and over 570 tonnes of steel were used to build the 64 bases over a 9-month period.
MeerKAT is planned to be completed in three phases. The first phase will include all the antennas but only the first receiver will be fitted. A processing bandwidth of 750 MHz is available. For the second and third phases, the remaining two receivers will be fitted and the processing bandwidth will be increased to at least 2 GHz, with a goal of 4 GHz. With construction of all sixty-four MeerKAT antennas complete, verification tests have begun to ensure the instruments are functioning correctly.
Following this, MeerKAT will be commissioned in the second half of 2018 with the array then coming online for science operations.
Inauguration
On 13 July 2018, the Deputy President of South Africa,
David Mabuza
David Dabede "DD" Mabuza (born 25 August 1960) is a South African politician who has been deputy president of South Africa, Deputy President of South Africa since February 2018. He was the Deputy President of the African National Congress (ANC) f ...
, inaugurated the MeerKAT Telescope, and unveiled an image produced by MeerKAT that revealed unprecedented detail of the region surrounding the supermassive black hole at the centre of our Milky Way Galaxy.
The 64 MeerKAT antennas will be incorporated into Phase 1 of the SKA Mid Frequency Array once the 133 SKA dishes have been built and commissioned on the Karoo site, resulting in a total of 197 antennas for the SKA array. All of the infrastructure currently associated with MeerKAT will be transferred to the SKA array. The KAPB has the capacity to house the additional equipment required by SKA Mid.
Science objectives
The science objectives of the MeerKAT surveys are in line with the prime science drivers for the first phase of the
SKA
Ska (; ) is a music genre that originated in Jamaica in the late 1950s and was the precursor to rocksteady and reggae. It combined elements of Caribbean mento and calypso with American jazz and rhythm and blues. Ska is characterized by a walki ...
, confirming MeerKAT's designation as an SKA precursor instrument. Five years of observing time on MeerKAT have been allocated to leading astronomers who have applied for time to do research.
Site
The South African Department of Science and Technology, through the NRF and SARAO, has invested more than R760 million in infrastructure on the South African SKA site. The innovative design and engineering of the infrastructure established for MeerKAT, as well as the RFI-quiet environment, favourable physical site characteristics, and on-site technical expertise has positioned the site in the Karoo as an ideal location for other radio astronomy experiments.
The HERA (Hydrogen Epoch of Reionisation Array) radio telescope is one such instrument co-located at the South African SKA site. HERA is designed to detect, for the first time, radio signals from the very first stars and galaxies that formed early in the life of the universe. South African engineers and scientists are working with their colleagues at the University of California Berkeley in the US, and Cambridge University in the UK, to build HERA and exploit its unique and fundamental scientific capabilities.
Other experiments which have been constructed at the SA SKA site include PAPER (the Precision Array to Probe the Epoch of Ionisation) and the C-BASS (the C-Band All Sky Survey).
To ensure long term viability of the Karoo site for the MeerKAT and the SKA, and for other radio astronomy instruments, the South African Parliament passed the Astronomy Geographic Advantage Act, in 2007. The act gives the Minister of Science and Technology the authority to protect areas, through regulations, that are of strategic national importance for astronomy and related scientific endeavours.
Discoveries
In September 2019, an international team of astronomers using South Africa’s MeerKAT radio telescope discovered enormous balloon-like structures that tower hundreds of light-years above and below the centre of our galaxy.
South Africa and SKA science and technology
The experience gained by South African engineers in the design and construction of MeerKAT had been carried over to the SKA design, reducing risks and development costs. South African engineers within SARAO and South African industrial partners have participated in 7 of the 11 SKA engineering design consortia, contributing about 10% of the workforce in these internationally distributed consortia. The Infrastructure South Africa Consortium and the Assembly, Integration, Verification (AIV) Consortium have been led by SARAO, and there was South African participation in the DISH Consortium, Science Data Processor (SDP) Consortium, the Signal and Data Transport (SaDT Consortium), the Telescope Manager (TM) Consortium and the Mid-frequency Aperture Array Consortium. South African engineers have overseen the system engineering aspects of 5 of the consortia. SARAO has signed an MoU with the SKAO to provide resources to the Bridging Activities that will continue the development of SKA subsystems now that the consortia have concluded their work. Participation by South African industrial partners in previous consortium work and future Bridging Activities is facilitated by SARAO through the Financial Assistance Programme (FAP) funding initiative.
Scientists from SARAO and South African universities are well represented on the various SKA Science Working Groups (SWGs), with about 10% of the authors of papers in the SKA Science Book having South African institution affiliations. The MeerKAT Large Science Projects (LSPs) are closely aligned with the SKA science case, and there is a large membership overlap between the LSP teams and the associated SWGs.
Capacity development for radio astronomy in Africa
To create the required skills to design, construct and operate the SKA and MeerKAT telescopes, and to make optimal use of these radio telescopes for research, once commissioned, SARAO initiated a capacity development programme, in 2005. The programme is fully integrated into the operations of SARAO, and it is crafted to develop and retain the excellent researchers, engineers and artisans required to ensure that the MeerKAT and SKA will be successful in South Africa. To date the programme has provided more than 1000 scholarships and fellowships across all relevant academic levels, and for a range of relevant qualifications. The programme is coveted by academic colleagues from abroad because of its success in developing, from a low base, significant expertise in radio astronomy over the past 14 years.
African Very Long Baseline Interferometry Network (AVN)
The African Very Long Baseline Interferometry (VLBI) Network (AVN) is an important development towards building SKA on the African Continent. The AVN programme will transfer skills and knowledge in the SKA African partner countries (Botswana, Ghana, Kenya, Madagascar, Mauritius, Mozambique, Namibia, and Zambia) to build, maintain, operate and use radio telescopes.
MeerKAT will also participate in global VLBI operations with all major radio astronomy observatories around the world and will add considerably to the sensitivity of the global VLBI network. Further potential science objectives for MeerKAT are to participate in the
search for extraterrestrial intelligence and collaborate with
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
on downloading information from space probes.
See also
*
Australian Square Kilometre Array Pathfinder
The Australian Square Kilometre Array Pathfinder (ASKAP) is a radio telescope array located at Murchison Radio-astronomy Observatory (MRO) in the Mid West region of Western Australia.
The facility began as a technology demonstrator for the in ...
*
Hartebeesthoek Radio Astronomy Observatory
The Hartebeesthoek Radio Astronomy Observatory (HartRAO) is a radio astronomy observatory, located in a natural bowl of hills at Hartebeesthoek just south of the Magaliesberg mountain range, Gauteng, South Africa, about 50 km west of Johannes ...
*
Karoo
*
List of radio telescopes
This is a list of radio telescopes – over one hundred – that are or have been used for radio astronomy. The list includes both single dishes and interferometric arrays. The list is sorted by region, then by name; unnamed telescopes are in r ...
*
Precision Array for Probing the Epoch of Reionization
The Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) is a radio interferometer funded by the National Science Foundation to detect 21 cm hydrogen (HI) fluctuations occurring when the first galaxies ionized inte ...
*
South African Astronomical Observatory
South African Astronomical Observatory (SAAO) is the national centre for optical and infrared astronomy in South Africa. It was established in 1972. The observatory is run by the National Research Foundation of South Africa. The facility's funct ...
for optical astronomy in South Africa
*
Square Kilometer Array
The Square Kilometre Array (SKA) is an intergovernmental international radio telescope project being built in Australia (low-frequency) and South Africa (mid-frequency). The combining infrastructure, the Square Kilometre Array Observatory (SKA ...
References
External links
SKA South AfricaeXperimental Development Model (XDM) at HartebeeshoekYouTube: Square Kilometre Array
{{radio-astronomy
Astronomical observatories in South Africa
Buildings and structures in the Northern Cape
Karoo
Radio telescopes
Astronomy protected areas of South Africa
Square Kilometre Array
Telescopes under construction
Interferometric telescopes