ALMA | ESO | 2016 Dec 21
[img3="The compound view of Arp 220: ALMA Band 5 (red) HST (blue/green). Credit: ALMA(ESO/NAOJ/NRAO)/NASA/ESA and The Hubble Heritage Team (STScI/AURA)"]https://cdn.eso.org/images/screen/eso1645a.jpg[/img3][hr][/hr]The Atacama Large Millimeter/submillimeter Array (ALMA) in Chile has begun observing in a new range of the electromagnetic spectrum. This has been made possible thanks to new receivers installed at the telescope’s antennas, which can detect radio waves with wavelengths from 1.4 to 1.8 millimetres — a range previously untapped by ALMA. This upgrade allows astronomers to detect faint signals of water in the nearby Universe.
ALMA observes radio waves from the Universe, at the low-energy end of the electromagnetic spectrum. With the newly installed Band 5 receivers, ALMA has now opened its eyes to a whole new section of this radio spectrum, creating exciting new observational possibilities. ...
It is ALMA’s unique location, 5000 metres up on the barren Chajnantor plateau in Chile, that makes such an observation possible in the first place. As water is also present in Earth’s atmosphere, observatories in less elevated and less arid environments have much more difficulty identifying the origin of the emission coming from space. ALMA’s great sensitivity and high angular resolution mean that even faint signals of water in the local Universe can now be imaged at this wavelength.
The Band 5 receiver, which was developed by the Group for Advanced Receiver Development (GARD) at Onsala Space Observatory, Chalmers University of Technology, Sweden, has already been tested at the APEX telescope in the SEPIA instrument. These observations were also vital to help select suitable targets for the first receiver tests with ALMA. ...
