サガワ ヒデオ   SAGAWA HIDEO
  佐川 英夫
   所属   京都産業大学  理学部 宇宙物理・気象学科
   職種   教授
言語種別 英語
発行・発表の年月 2018/04
形態種別 研究論文
査読 査読あり
標題 New measurements of D/H on Mars using EXES aboard SOFIA
執筆形態 その他
掲載誌名 Astronomy & Astrophysics
出版社・発行元 EDP Sciences
巻・号・頁 612,pp.A112
著者・共著者 Encrenaz, T.,DeWitt, C.,Richter, M. J.,Greathouse, T. K.,Fouchet, T.,Montmessin, F.,Lefèvre, F.,Bézard, B.,Atreya, S. K.,Aoki, S.,Sagawa, H.
概要 The global D/H ratio on Mars is an important measurement for understanding the past history of water on Mars
locally, through condensation and sublimation processes, it is a possible tracer of the sources and sinks of water vapor on Mars. Measuring D/H as a function of longitude, latitude and season is necessary for determining the present averaged value of D/H on Mars. Following an earlier measurement in April 2014, we used the Echelon Cross Echelle Spectrograph (EXES) instrument on board the Stratospheric Observatory for Infrared Astronomy (SOFIA) facility to map D/H on Mars on two occasions, on March 24, 2016 (Ls = 127°), and January 24, 2017 (Ls = 304°), by measuring simultaneously the abundances of H2O and HDO in the 1383-1391 cm-1 range (7.2 μm). The D/H disk-integrated values are 4.0 (+0.8, -0.6) × Vienna Standard Mean Ocean Water (VSMOW) and 4.5 (+0.7, -0.6) × VSMOW, respectively, in agreement with our earlier result. The main result of this study is that there is no evidence of strong local variations in the D/H ratio nor for seasonal variations in the global D/H ratio between northern summer and southern summer.
DOI 10.1051/0004-6361/201732367
ISSN 1432-0746