sumspec is an
IRAF task in the
rvsao package which
combines spectra, shifting them to a common redshift. The
VELOCITY header parameter of each of these spectra is assumed to be
a solar-system-barycenter-corrected velocity, and a barycentric
correction (computed by sumtemp or extracted from the BCV or HCV
header parameter) is subracted to get the redshift of the spectrum.
Each spectrum is shifted and rebinned to the desired wavelength range and
bin size, which may be linear in wavelength or in log-wavelength, then added
to the summed template. Input may be multispec or twodspec format,
but output is always a one-dimensional file. Continuum may be removed
from input spectra or the resulting spectrum using the parameters set
by contsum.
The resulting spectrum can then be used as a template by
xcsao to find redshifts from
spectra by cross-correlating them against it following the method of
Tonry and Davis 1979, A.J., 84, 1511).
Last updated September 20, 2019 by Jessica Mink
[rvsao]
[xcsao]
[emsao]
[sumspec]
[contsum]
[linespec]