The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI - Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections

TLDR: The final data release of observations of 21 cm emission from Galactic neutral hydrogen over the entire sky, merging the Leiden/Dwingeloo Survey (LDS: Hartmann & Burton 1997, Atlas of Galactic Neutral Hydrogen) with the Instituto Argentino de Radioastronomia Survey (IAR: Arnal et al. 2000, AA and Bajaja et al., 2005, A&A, 440, 767) of the sky south of? =?25?, is presented in this article.

Abstract: We present the final data release of observations of ?21-cm emission from Galactic neutral hydrogen over the entire sky, merging the Leiden/Dwingeloo Survey (LDS: Hartmann & Burton 1997, Atlas of Galactic Neutral Hydrogen) of the sky north of ? = ?30? with the Instituto Argentino de Radioastronomia Survey (IAR: Arnal et al. 2000, AA and Bajaja et al. 2005, A&A, 440, 767) of the sky south of ? = ?25?. The angular resolution of the combined material is HPBW ? 0. ?6. The LSR velocity coverage spans the interval ?450 km s?1 to +400 km s?1, at a resolution of 1.3 kms?1. The data were corrected for stray radiation at the Institute for Radioastronomy of the University of Bonn, refining the original correction applied to the LDS. The rms brightness-temperature noise of the merged database is 0.07?0.09 K. Residual errors in the profile wings due to defects in the correction for stray radiation are for most of the data below a level of 20?40 mK. It would be necessary to construct a telescope with a main beam efficiency of ?MB >? 99% to achieve the same accuracy. The merged and refined material entering the LAB Survey of Galactic HI is intended to be a general resource useful to a wide range of studies of the physical and structural characteristices of the Galactic interstellar environment. The LAB Survey is the most sensitive Milky Way HI survey to date, with the most extensive coverage both spatially and kinematically.