Excitation temperature of C2 and broadening of the 6196A diffuse
  interstellar band
  This paper presents a finding of the correlation between the width of a
strong diffuse interstellar band at 6196A and the excitation temperature of C2
based on high resolution and high signal-to-noise ratio spectra. The excitation
temperature was determined from absorption lines of the Phillips A-X and
Mulliken D-X systems. The width and shape of the narrow 6196A DIB profile
apparently depend on the C2 temperature, being broader for higher values.
