The Parkes Galactic All-Sky Survey (GASS) provides atomic hydrogen (HI) spectral line data with an angular resolution of 16 arcmin for the region south of δ = +1° over the Local Standard of Rest (LSR) velocity range -400 km/s to +500 km/s with a spectral resolution of 1 km/s. The rms noise over the velocity range is approximately 57 mK.
Data from the first GASS data release (McClure-Griffiths et al. 2009) are currently available in the form of spectra towards any position south of δ = 1°. These spectra are not corrected for stray radiation. Also available here FITS images of the total column density and estimates of the fraction of the total column density due to stray radiation.
With this form you can extract the complete spectrum (LSR velocity -400 km/s to +500 km/s) for any postion in the survey. Please be patient, requests can be slow.
Accepted input is Right Ascension and Declination (J2000) in decimal degrees (dd.d) or colon separated sexidecimal (hh:mm:ss.s or dd:mm:ss.s).
Here we provide images in Zenithal-Equal-Area (ZEA) projection of:
- map of rms in units of K: JPEG version or FITS version
- total column density, NHI, in units of cm−2: JPEG version or FITS version
- estimate of stray radiation as equivalent NHI, in units of cm−2: JPEG version or FITS version
When using any data from GASS, please use the following reference:
- McClure-Griffiths, N. M., Pisano, D. J., Calabretta, M. R., Ford, H. A., Lockman, F. J., Staveley-Smith, L., Kalberla, P. M. W., Bailin, J., Dedes, L., Janowiecki, S., Gibson, B. K., Murphy, T., Nakanishi, H. & Newton-McGee, K. 2009, ApJS, in press [Preprint]