TY - JOUR
T1 - MODELING of the ZODIACAL EMISSION for the AKARI/IRC MID-INFRARED ALL-SKY DIFFUSE MAPS
AU - Kondo, Toru
AU - Ishihara, Daisuke
AU - Kaneda, Hidehiro
AU - Nakamichi, Keichiro
AU - Takaba, Sachi
AU - Kobayashi, Hiroshi
AU - Ootsubo, Takafumi
AU - Pyo, Jeonghyun
AU - Onaka, Takashi
N1 - Publisher Copyright:
© 2016. The American Astronomical Society. All rights reserved..
PY - 2016/3
Y1 - 2016/3
N2 - The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.
AB - The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.
KW - interplanetary medium
KW - zodiacal dust
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U2 - 10.3847/0004-6256/151/3/71
DO - 10.3847/0004-6256/151/3/71
M3 - Article
AN - SCOPUS:84961199301
VL - 151
JO - Astronomical Journal
JF - Astronomical Journal
SN - 0004-6256
IS - 3
M1 - 71
ER -