ALMA at the SSE

A mosaic of all the "interferometered" people and objects at the ALMA Royal Society Summer Science Exhibition stand...

ALMA observes a ring around the bright star Fomalhaut

Although it is an ambitious scientific project activities on the ALMA site not only focus on building the world’s most advanced astronomical observatory but also on the historical and environmental aspects in this unique region. 

If not you should come down to the Royal Society Summer Science Exhibition and you can see what you would look like through the eyes of the worlds most power radio telescope.

If you have then take a look at our twitpic feed... as you could have uploaded the result for the whole world to see just like my hand:

Venus shortly before it moved in front of the Sun (the famous Venus transit) last month on June 5th. At that stage Venus was not visible through optical telescopes because its dark side was turned towards us. ALMA detects millimeter and submillimeter waves which are given off by the hot atmosphere of Venus (and of course even more strongly by the hot surface of the Sun). 

The Atacama Large Millimeter/sub-millimeter Array (ALMA) is an array of radio telescopes in the Atacama desert of northern Chile.

When ALMA is completed it will consist of:

a giant array of 12-m antennas with baselines up to 16 km

an additional compact array of 7-m and 12-m antennas to greatly enhance ALMA's ability to image extended targets

This is located on the Chajnantor plateau at 5000m altitude. Initially, it will observe at wavelengths in the range 3 mm to 400 μm (84 to 720 GHz).

The antennas can be moved around, in order to form arrays with different distributions of baseline lengths. More extended arrays will give high spatial resolution, more compact arrays give better sensitivity for extended sources.

Each antenna weighs: 115 tonnes! Moving these around at 5000m is not an easy feat. Two custom 28-wheel self-loading heavy haulers were developed. Each is 10 m wide, 20 m long and 6 m high, weighing 130 tonnes. They are powered by twin 500 kW diesel engines!

The ALMA antennas are designed and built to face very rough conditions. ALMA is located in one of the driest locations on the Earth but very occasionally snow can cover the site... 

ALMA (Atacama Large Millimeter/submillimeter Array) scientists have detected a galaxy that is 12.4 billion light-years away! This was detected via looking at the emission line of Nitrogen in the galaxy. At that distance we are looking at a time that is just 1.3 billion years after the big bang. This means that astronomers are able to see if there is any difference between the contents of galaxies not long after the big bang and now. The result of this work shows that the composition was already close to the elemental composition of the present Universe. Thus suggesting that intense star formation activities had occurred in the early Universe. 

More on this work can be found in the ALMA press release and if you fancy taking a read you can also freely download the science paper. 

... were currently putting the last touches to our Royal Society Summer Science Exhibition 2012 stand.. 

(picture by Sarah Graves)