by Staff Writers
Paris (ESA) May 09, 2015
The AKARI space telescope's far-infrared all-sky image data are now available to researchers everywhere. The new all-sky maps have four to five times better spatial resolution than conventional far-infrared all-sky images, and include data at longer wavelengths.
AKARI, formerly known as ASTRO-F, is the second space mission for infrared astronomy from the Institute of Space and Astronautical Science (ISAS) of the Japanese Aerospace Exploration Agency (JAXA). It was realised with ESA participation.
AKARI's main objective was to perform an all-sky survey with better sensitivity, spatial resolution and wider wavelength coverage than IRAS, the Infrared Astronomical Satellite (IRAS) launched on 25 January 1983.
Although having been launched more than 30 years ago, the IRAS all-sky maps are still a standard resource for modern astronomers. Now, AKARI's maps improve on IRAS by a factor of four or five.
AKARI was launched on 21 February 2006. To achieve the sensitivity needed to make its maps, the telescope's detector had to be cooled to -271 C. Because the spacecraft could only carry 170 litres of coolant, this meant it had a limited lifetime.
During its 'cold' lifetime of 550 days it conducted the all-sky survey, observing more than 99% of the entire sky, with 1 to 1.5 arcminute resolution, in four wavelengths: 65, 90, 140 and 160 micrometers. This provides an excellent scientific legacy because these data also provide photometric information for about half a million sources.
Far-infrared light is the key wavelength range for investigating the formation of stars and planetary systems. It is emitted mostly from low-temperature dust and so reveals the distribution of the interstellar medium, as well as the processes of star formation within it.
In addition, the observations of various galaxies at far-infrared wavelengths allow scientists to explore the history of star formation in the Universe. Furthermore, closer examination of the distribution of the interstellar medium allows scientists to measure precisely cosmic background radiation, which is essential to investigate the origin of the Universe.
By combining AKARI data with data from ESA's other infrared space telescopes, ISO and Herschel, scientists can also look for variability in celestial sources.
The PACS instrument on Herschel covers a similar wavelength region to AKARI and achieved a greater spatial resolution in its observations. However, PACS was not designed to study the whole sky: it has observed some 7% of the sky at wavelengths of 70, 100 and 160 micrometers, compared with AKARI's 99% coverage, underlining how useful the new AKARI data will be.
The AKARI far-infrared all-sky image maps have been calibrated and prepared for public release by the research group of Dr Yasuo Doi, Assistant Professor at the Graduate School of Arts and Sciences, the University of Tokyo, and collaborators at the Institute of Space and Astronautical Science/JAXA, Tohoku University, University of Tsukuba, Rutherford Appleton Laboratory and the Open University (UK).
The full data sets can be accessed here
AKARI at ESA
Understanding Time and Space
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|