Survey
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
Data releases
A first 4x4 degree tile based on the Science Demonstratoin Phase (SDP) data 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This has now been superceded by the DR1 release, which includes the area previously known as the SDP.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 161 sq deg of Hercshel imaging and associated catalogues (Valiente et al 2016) which list 120230 sources in the 5 Herschel bands - 100, 160, 250 ,350 and 500 micron). The catalogues include cross-ID information (Bourne et al 2016) based on the GAMA (Galaxy Mass and Assembly) survey (Driver et al. 2011).
The North Galactic Pole (NGP) and South Galactic Pole (SGP) fields together cover about 500 sq deg, and were releaseed as DR2. The maps are described in Smith et al. 2017. The submillimter catalogues are described in Maddox et al. 2018 and include 346894 sources in 5 photometric bands, which have a 4 sigma (including confusion noise) detection in any of the SPIRE bands. Furlanetto et al. 2018 describe optical identification from the SDSS DR10 catalogue and near-IR identification from a K-band deep catalogue obtained from UKIRT/WFCAM observations.