Large angular scale fluctuations of near infrared extragalactic
  background light based on the IRTS observations
  We measure the spatial fluctuations of the Near-Infrared Extragalactic
Background Light (NIREBL) from 2$^{\circ}$ to 20$^{\circ}$ in angular scale at
the 1.6 and 2.2 $\mu$m using data obtained with Near-Infrared Spectrometer
(NIRS) on board the Infrared Telescope in Space (IRTS). The brightness of the
NIREBL is estimated by subtracting foreground components such as zodiacal
light, diffuse Galactic light, and integrated star light from the observed sky.
The foreground components are estimated using well-established models and
archive data. The NIREBL fluctuations for the 1.6 and 2.2 $\mu$m connect well
toward the sub-degree scale measurements from previous studies. Overall, the
fluctuations show a wide bump with a center at around 1$^{\circ}$ and the power
decreases toward larger angular scales with nearly a single power-law spectrum
(i.e. \textit{F($\sqrt{l(l+1)C_l/2\pi}$)} $\sim$ $\theta^{-1}$) indicating that
the large scale power is dominated by the random spatial distribution of the
sources. After examining several known sources, contributors such as normal
galaxies, high redshift objects, intra-halo light, and far-IR cosmic
background, we conclude that the excess fluctuation at around the 1$^{\circ}$
scale cannot be explained by any of them.
