The Infrared Camera onboard the AKARI satellite carried out spectroscopic observations with a grism mode named NG, whose wavelength coverage was 2.5{5.0 m. We reinvestigate the current ux calibration for the NG grism mode, with which calculated ux density implausibly decreases at 4.9 m especially for red objects due to the second-order light contamination. We perform a new spectral response calibration using blue and red standard objects simultaneously. New response curves which contain both the rst- and second-order light are able to separate each contribution consistently and useful for studies of red objects such as CO ro-vibrational absorption in active galactic nuclei.

ABSTRACT
1. INTRODUCTION
2. METHOD
    2.1. Treatment of the 2nd Order Light Contamination
    2.2. Standard Objects
    2.3. Pixel-to-Wavelength Relation
3. RESULTS
4. CONCLUSIONS
REFERENCES

• Chihiro Kochi(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency/Department of Physics, Graduate School of Science, The University of Tokyo)
• Kenichi Yano(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency/Department of Physics, Graduate School of Science, The University of Tokyo)
• Youichi Ohyama(Institute of Astronomy and Astrophysics, Academia Sinica)
• Mai Shirahata(National Astronomical Observatory of Japan)
• Naoki Isobe(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)
• Takao Nakagawa(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)
• Shunsuke Baba(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency/Department of Physics, Graduate School of Science, The University of Tokyo)