9th of May 2015 |
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GASS III, Parkes Galactic All Sky Survey, new data release |
by Peter Kalberla & Urmas Haud |
A new version of the Parkes Galactic All
Sky Survey (GASS) is available at
arXiv:1505.01011 (Kalberla & Haud 2015). Major improvements
are based on the use of HEALPIX for spatial gridding and the decomposition of
all HI profiles into Gaussian components with the aim to use the parameters
to identify and flag spectra that have been affected by instrumental effects
or radio frequency interference (RFI). Scanning effects, caused by correlator
failures, and remaining RFI could be removed. In addition, the baseline fitting
and subtraction was improved. The channel map, displayed above, shows as an example a clean picture of the large scale Galactic HI emission at a velocity of 4 km/s. Brightness temperatures TB < 100 K are displayed on a logarithmic scale. Numerous filaments are visible, including HI self absorption features in the Galactic center region. Credits: Peter Kalberla (Argelander-Institut für Astronomie, Bonn) and Urmas Haud (Tartu Observatory, Tõravere) |