TY - JOUR
T1 - IRTS observation of the mid-infrared spectrum of the zodiacal emission
AU - Ootsubo, T.
AU - Onaka, T.
AU - Yamamura, I.
AU - Tanabé, T.
AU - Roellig, T. L.
AU - Chan, K. W.
AU - Matsumoto, T.
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1998
Y1 - 1998
N2 - We present the mid-infrared spectrum (3-12 μm) of the zodiacal emission obtained by the Infrared Telescope in Space (IRTS), the first Japanese cryogenically cooled orbital infrared telescope. The Near-Infrared Spectrometer (NIRS) on board IRTS provided the spectrum of 3-4 μm, while that of 4.5-11.7 μm has been observed by the Mid-Infrared Spectrometer (MIRS). In this paper we present the data reduction and results of the observations by MIRS. Spectra of the background emission at high galactic latitudes (ζbζ > 30°) have been extracted from the MIRS observations by excluding point sources. The observed sky brightness has a clear dependence on the ecliptic latitude, indicating that the zodiacal emission dominates in the mid-infrared sky brightness. On the other hand, the spectral shape does not show any appreciable dependence on the ecliptic latitude for β = 0°-75°. The spectrum combining the NIRS and MIRS observations can be fitted by a grey body radiation at 250 K, but excess emission is seen in the 3-6 μm range. Alternatively, the spectrum of the zodiacal emission can be reproduced fairly well by a grey body at 280 K with an excess around 10 μm. In this case the excess may be attributed to a silicate emission band. Other than these excesses, no spectral features above the 10% level are seen in the MIRS spectrum.
AB - We present the mid-infrared spectrum (3-12 μm) of the zodiacal emission obtained by the Infrared Telescope in Space (IRTS), the first Japanese cryogenically cooled orbital infrared telescope. The Near-Infrared Spectrometer (NIRS) on board IRTS provided the spectrum of 3-4 μm, while that of 4.5-11.7 μm has been observed by the Mid-Infrared Spectrometer (MIRS). In this paper we present the data reduction and results of the observations by MIRS. Spectra of the background emission at high galactic latitudes (ζbζ > 30°) have been extracted from the MIRS observations by excluding point sources. The observed sky brightness has a clear dependence on the ecliptic latitude, indicating that the zodiacal emission dominates in the mid-infrared sky brightness. On the other hand, the spectral shape does not show any appreciable dependence on the ecliptic latitude for β = 0°-75°. The spectrum combining the NIRS and MIRS observations can be fitted by a grey body radiation at 250 K, but excess emission is seen in the 3-6 μm range. Alternatively, the spectrum of the zodiacal emission can be reproduced fairly well by a grey body at 280 K with an excess around 10 μm. In this case the excess may be attributed to a silicate emission band. Other than these excesses, no spectral features above the 10% level are seen in the MIRS spectrum.
UR - http://www.scopus.com/inward/record.url?scp=0032449794&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032449794&partnerID=8YFLogxK
U2 - 10.1186/BF03352142
DO - 10.1186/BF03352142
M3 - Article
AN - SCOPUS:0032449794
VL - 50
SP - 507
EP - 511
JO - Earth, Planets and Space
JF - Earth, Planets and Space
SN - 1343-8832
IS - 6-7
ER -