The Cosmos from the Outback

The MWA

A tile of MWA antennas. There will be 512 of these tiles deployed, for a total of 8,000 dual-polarization dipole antennas optimized for the 80-330 MHz frequency range. (Click to embiggen.)

A tile of MWA antennas. There will be 512 of these tiles deployed, for a total of 8,000 dual-polarization dipole antennas optimized for the 80-330 MHz frequency range. (Click to embiggen.)

Welcome to my MWA page — if you’ve come over from the 365 Days of Astronomy podcast site for August 14th, you’re probably looking for more information about MWA and other radio arrays.  The MWA is under construction in the Outback of Western Australia. You can follow its progress and background information at its newly constructed web site. There’ll you find science and technology information about MWA, as well as a video that contains more of my interview with Dr. Colin Lonsdale, who is heavily involved with the MWA.

Now, this is not just a hardware telescope — MWA depends heavily on software solutions to gather and correlate the immense amount of data the array units will collect every 24 hours.

The units in the array will not move or pivot as other radio arrays do — it will simply sit there and gather data, 24/7 for as long as its useful lifetime.  As I mentioned in the podcast, the MWA will perform a range of studies of astronomical objects and events.  There are three major projects that scientists will use the MWA to explore:  the detection and characterization of redshifted 21-centimeter neutral hydrogen signals from the Epoch of Reionization — the time in the early universe when the first light-emitting objects began to shine; a high-sensitivity survey of the dynamic radio sky (including such things as pulsars, the cores of radio-loud galaxies, and radio supernovae), and measurements of the Sun and the heliospheric plasma, including constraints on the magnetic field in coronal mass ejections (CMEs). This is science that has been difficult (if not impossible) to do at these frequencies before, and it should contain some interesting and surprising results.

MWA is not the first low-frequency array being built. The Low-Frequency Array (LOFAR) is being built (in Phase 1) in Europe  by ASTRON and a consortium of European nations. It has many of the same objectives as MWA, but works in a much noisier radio frequency environment.  The array has been taking data and scientists working with it are working around the radio-loud environment to refine and characterize what they’ve been seeing.

Individual antennas in the ALMA array. Courtesy the ALMA Observatory PIO. (Click to embiggen.)

Individual antennas in the ALMA array. Courtesy the ALMA Observatory PIO. (Click to embiggen.)

Of course, there are other radio arrays in existence — such as the world-famous Very Large Array in New Mexico, the Australia Telescope Compact Array, and many others.  There are at least two more being built — the most newsworthy one lately being the Atacama Large Millimeter Array (ALMA), going up in the high-altitude Chajnantor Plateau in the Atacama desert of Chile. ALMA is not a low-frequency array like the MWA — in fact, it will focus on the millimeter and submillimeter wavelengths — between radio and infrared waves to achieve its science objectives.

If all goes well with this humongous array, it should be up and fully operating in the next few years.

Finally, there’s the Square Kilometer Array (SKA).  Its site is still being determined, with candidates in South Africa and Australia leading the way. when it’s finally built, SKA will feature a collection of antennas placed in a square-kilometer-wide array, and it will work as a complement to the James Web Space Telescope and ALMA.  It’s an exciting time to be a radio astronomer, with the multiplicity of arrays in existence and coming online in the next decade or so.   As they say, stay tuned!

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