The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI

Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections

¹ Radioastronomisches Institut der Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: pkalberla@astro.uni-bonn.de
² Sterrewacht Leiden, Postbus 9513, 2300 Leiden, The Netherlands
³ National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, Virginia 22903, USA e-mail: bburton@nrao.edu
⁴ Delft University of Technology, Postbus 5, 2600 Delft, The Netherlands e-mail: L.Hartmann@TBM.TUDelft.nl
⁵ Instituto Argentino de Radioastronomía, c.c. 5, (1894) Villa Elisa, Argentina e-mail: [bajaja;arnal]@iar.unlp.edu.ar; rimorras@isis.unlp.edu.ar; wpoeppel@iar.unlp.edu.ar
⁶ Facultad de Ciencias Astronómicas y Geofísicas, UNLP, Av. Paseo del Bosque, s/n, 1900 La Plata, Argentina

Received: 19 August 2004
Accepted: 3 March 2005

Abstract

We present the final data release of observations of λ21-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 δ = -30° with the Instituto Argentino de Radioastronomía Survey (IAR: Arnal et al. 2000, A&AS, 142, 35; and Bajaja et al. 2005, A&A, 440, 767) of the sky south of δ = -25°. The angular resolution of the combined material is HPBW ~ . The LSR velocity coverage spans the interval -450 km s^-1 to +400 km s^-1, at a resolution of 1.3 km s^-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  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  mK. It would be necessary to construct a telescope with a main beam efficiency of % to achieve the same accuracy. The merged and refined material entering the LAB Survey of Galactic H i 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 H i survey to date, with the most extensive coverage both spatially and kinematically.