Near-infrared diffuse interstellar bands in 0.91-1.32 micron
  We present a comprehensive survey of diffuse interstellar bands (DIBs) in
$0.91-1.32\mu$m with a newly-developed near-infrared (NIR) spectrograph,
WINERED, mounted on the Araki 1.3 m Telescope in Japan. We obtained
high-resolution ($R=28,300$) spectra of 25 early-type stars with color excesses
of $0.07<E(B-V)<3.4$. In addition to the five DIBs previously detected in this
wavelength range, we identified 15 new DIBs, 7 of which were reported as DIB
"candidates" by Cox. We analyze the correlations among NIR DIBs, strong optical
DIBs, and the reddening of the stars. Consequently, we found that all NIR DIBs
show weaker correlations with the reddening rather than the optical DIBs,
suggesting that the equivalent widths of NIR DIBs depend on some physical
conditions of the interstellar clouds, such as UV flux. Three NIR DIBs,
$\lambda\lambda$10780, 10792, and 11797, are found to be classifiable as a
"family," in which the DIBs are well correlated with each other, suggesting
that the carriers of these DIBs are connected with some chemical reactions
and/or have similar physical properties such as ionization potential. We also
found that three strongest NIR DIBs $\lambda\lambda10780, 11797, 13175$ are
well correlated with the optical DIB $\lambda 5780.5$, whose carrier is
proposed to be a cation molecule with high ionization potential, indicating
that the carriers of the NIR DIBs could be cation molecules.
