This interface allows you to extract HI profiles from the GASS and the LAB survey. The profiles are generated on the fly from the original databases using a weighted interpolation with a Gaussian kernel.
The effective beamsize (used for both GASS and LAB) includes telescope beam and beam smearing due to interpolation. The beam for the GASS is 14.4 arcmin (64m Parkes telescope), while for the LAB it is 36 arcmin for declinations > -27.5 deg (25m Dwingeloo telescope) and 30 arcmin for declinations < -27.5 deg (30m Villa Elisa telescope).
Due to interpolations the minimum effective FWHM beam is 16 arcmin for the GASS, 40 arcmin for the LAB for declinations > -27 deg and 35 arcmin for declinations < -27 deg. This implies for the profiles a different FWHM beam if you select an effective beamsize < 36 arcmin. If you want to compare the calculated column densities, the FWHM needs to be taken into account. Expected uncertainties are in each case at a 2-3% level (about 1% scale uncertainty and 1% for uncertainties in the correction for stray radiation). Additional contributions may be due to noise, residual baseline errors, and RFI (causing occasionally scale errors for the LAB). Column densities are calculated for -400 < v < 400 km/s.
GASS profiles calculated before 2013-02-08 accidentally got shifted by one channel to negative velocities. FITS maps are not affected by this bug. If necessary, please recalculate your profiles.
Please note: For GASS the third data release is used. GASS III is an update data release and has improved corrections for instrumental effects. Also for GASS III the brightness temperatures were scaled down by a factor 0.96 to be consistent with the Dwingeloo and Effelsberg brightness temperature scales.
If you use data products in your research or publications, please reference the following:
Kalberla, P.M.W. and Haud, U. (2015) A&A 578, A78 (Highlight: Gass: The Parkes Galactic All-Sky Survey. III)
Kalberla, P.M.W., McClure-Griffiths, N.M., Pisano, D. J. Calabretta, M. R., Ford, H. Alyson, Lockman, Felix J., Staveley-Smith, L., Kerp, J., Winkel, B., Murphy, T., Newton-McGee, K. (2010) A&A, 512, A14 (Highlight: Gass: The Parkes Galactic All-Sky Survey. II)
McClure-Griffiths, N. M.; Pisano, D. J.; Calabretta, M. R.; Ford, H. Alyson; Lockman, Felix J.; Staveley-Smith, L.; Kalberla, P. M. W.; Bailin, J.; Dedes, L.; Janowiecki, S , Gibson, B.K., Murpy, T., Newton-McGee, K. (2009) ApJS, 181, 398 (http://adsabs.harvard.edu/abs/2009ApJS..181..398M)
Data from the first data release are available at http://www.atnf.csiro.au/research/GASS/index.html
When refering to the LAB Survey, please use the following reference:
Kalberla, P.M.W., Burton, W.B., Hartmann, Dap, Arnal, E.M., Bajaja, E., Morras, R., & Pöppel, W.G.L. (2005), A&A, 440, 775 (http://adsabs.harvard.edu/abs/2005A%26A...440..775K)
Depending on the region of the sky being studied, please cite, in addition to the Kalberla et al. (2005) reference, also the appropriate source of the material used:
Observers were Dap Hartmann and W.B. Burton (Leiden University) for the Dwingeloo telescope, and E.M. Arnal, E. Bajaja, J.J. Larrarte, R. Morras, and W.G.L. Pöppel (Argentine Institute for Radio Astronomy) for the Villa Elisa telescope. Correction for stray radiation and combination of the data by P.M.W. Kalberla (Bonn University).
Webinterface created by Peter Kalberla