We report a search for fluctuations of the sky brightness toward the North Ecliptic Pole with AKARI, at 2.4, 3.2, and 4.1 μm . The stacked images with a diameter of 10 arcminutes of the AKARI-Monitor Field show a spatial structure on the scale of a few hundred arcseconds. A power spectrum analysis shows that there is a significant excess fluctuation at angular scales larger than 100 arcseconds that cannot be explained by zodiacal light, diffuse Galactic light, shot noise of faint galaxies, or clustering of low-redshift galaxies. These findings indicate that the detected fluctuation could be attributed to the first stars of the universe, i.e., Population III stars.

ABSTRACT
1. INTRODUCTION
2. OBSERVATION AND DATA REDUCTION
    2.1. Observation
    2.2. Data Reduction
3. RESULTS
4. SUMMARY
REFERENCES

• T. MATSUMOTO(Department of Physics and Astronomy, Seoul National University, Department of Infrared Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA))
• H. J. SEO(Department of Physics and Astronomy, Seoul National University)
• W. -S. JEONG(Korea Astronomy and Space Science Institute (KASI))
• H. M. LEE(Department of Physics and Astronomy, Seoul National University)
• S. MATSUURA(Department of Infrared Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA))
• H. MATSUHARA(Department of Infrared Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA))
• S. OYABU(Department of Infrared Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Department of Physics, Nagoya University)
• J. PYO(Korea Astronomy and Space Science Institute (KASI))
• T. WADA(Department of Infrared Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA))