The Virginia Tech Spectral-Line Survey (VTSS)

The VTSS is a wide-field image survey of the Galaxy's warm ionized interstellar medium (a 10,000 K plasma). The survey is carried out using the Virginia Tech Spectral Line Imaging Camera (SLIC), specially designed for obtaining sensitive, arcminute-resolution, 10-degree wide images of the 6563Å H-alpha recombination line of hydrogen, and the [SII]6717,6731Å doublet emission of singly ionized sulfur. This survey will cover the northern hemisphere (declinations greater than -15 degrees).

The resolution of the map is 1.6' and units are Rayleighs (R).

The Continuum-Corrected H-alpha images are produced by a process including the alignment and subtraction of a suitably scaled version of a continuum image from the H-alpha image.


'An Imaging Survey of Northern Galactic Hα Emission with Arcminute Resolution' by Dennison, B., Simonetti, J. H., and Topasna, G. A., 1998, PASA, 15, 147

VTSS Halpha VTSS Continuum corrected Halpha

Maps (New version on March 12th 2018)

  • H-alpha: VTSS_1_4096.fits
  • Continuum Corrected H-alpha: VTSS_CONT_1_4096.fits

Original WCS Data

Project Website