The Herschel ATLAS is the largest open time Key Project, with 600 hrs of time to survey a huge area of the sky: one eightieth in fact (a whopping 600 square degrees). This makes it the largest extragalactic survey with Herschel. H-ATLAS used both the PACS and SPIRE cameras which take pictures in infra-red and submillimetre light at wavelengths (colours) of 100um, 160um, 250um, 350um, & 500um. In our maps we detect approximately 400,000 galaxies from the nearby Universe out to redshifts of 6, when the Universe was less than a billion years old. This survey is the only truly unbiased way to measure the evolution of the dusty interstellar medium in galaxies in the past 5 billion years of cosmic history, optical surveys trace only starlight which is often distorted and hidden by dust and the dust emission from galaxies is also a way to measure their gas content, something which is very difficult to do in any other way for such a large, and unbiased sample of galaxies. Learning how the gas content of galaxies has been evolving over time is fundamental to understanding the processes of galaxy evolution - both growth of stellar mass, and transformation of morphology (colour and shape).
Current Status of the Survey
The survey is now complete. The area of sky covered is shown here
Science Demonstration Phase (SDP).
A first 4x4 degree tile was released in October 2010 as described in Rigby et al. 2011, Ibar et al. 2010, Pascale et al. 2011, Smith et al. 2011.
This has now been superceded by the DR1 release, which includes the area previously known as the SDP. The DR1 comprises 160 sq deg of Hercshel imaging and associated catalogues and cross-IDs from the equatorial fields which were also surveyed by the GAMA (Galaxy Mass and Assembly) survey (Driver et al. 2011).
Future data releases:
The NGP and SGP fields will be released to the public in July 2016, watch this space for further updates.