Herschel/HIFI observations of Mars: first detection of O_2 at submillimetre wavelengths and upper limits on HCl and H_2O_2

P. Hartogh (1) , C. Jarchow , E. Lellouch (2) , M. de Val-Borro , M. Rengel , R. Moreno (2) , A. S. Medvedev , H. Sagawa (3) , B. M. Swinyard , T. Cavalié (4, 5, 6, 7) , D. C. Lis (8) , M. I. Błęcka , M. Banaszkiewicz (9) , D. Bockelée-Morvan (2) , J. Crovisier (2) , T. Encrenaz (2) , M. Küppers (1) , L. -M. Lara , S. Szutowicz , B. Vandenbussche , F. Bensch , E. A. Bergin (10) , F. Billebaud (4, 5, 6, 7) , N. Biver (2) , G. A. Blake (11) , J. A. D. L. Blommaert , J. Cernicharo (12) , L. Decin (13) , P. Encrenaz (14) , H. Feuchtgruber , T. Fulton , T. de Graauw , E. Jehin (15) , M. Kidger , R. Lorente , D. A. Naylor , G. Portyankina , M. Sánchez-Portal , R. Schieder , S. Sidher , N Thomas (16) , E. Verdugo , C. Waelkens , N. Whyborn , D. Teyssier (17) , F. Helmich (18) , P. Roelfsema , J. Stutzki (18) , H. G. Leduc , J. A. Stern

1 MPS - Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research
2 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
3 Center for Mathematics and Physics
4 OASU - Observatoire aquitain des sciences de l'univers
5 LAB - Laboratoire d'Astrophysique de Bordeaux [Pessac]
6 UB - Université Sciences et Technologies - Bordeaux 1
7 L3AB - Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux
8 CALTECH - California Institute of Technology
9 CBK - Space Research Centre of Polish Academy of Sciences
10 CfA - Harvard-Smithsonian Center for Astrophysics
11 LOCIE - LabOratoire proCédés énergIe bâtimEnt
12 CSIC - Centro de Investigaciones Biológicas
13 Instituut voor Sterrenkunde [Leuven]
14 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique
15 ESO - European Southern Observatory
16 UNIBE - Universität Bern / University of Bern
17 Herschel Science Center [Madrid]
18 LAOG - Laboratoire d'Astrophysique de Grenoble

We report on an initial analysis of Herschel/HIFI observations of hydrogen chloride (HCl), hydrogen peroxide (H_2O_2), and molecular oxygen (O_2) in the Martian atmosphere performed on 13 and 16 April 2010 (L_s ~ 77{\deg}). We derived a constant volume mixing ratio of 1400 +/- 120 ppm for O_2 and determined upper limits of 200 ppt for HCl and 2 ppb for H_2O_2. Radiative transfer model calculations indicate that the vertical profile of O_2 may not be constant. Photochemical models determine the lowest values of H_2O_2 to be around L_s ~ 75{\deg} but overestimate the volume mixing ratio compared to our measurements.

Mots clés: Astrophysics; Earth and Planetary Astrophysics

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]; Planétologie et astrophysique de la terre [astro-ph.EP]

P. Hartogh, C. Jarchow, E. Lellouch, M. de Val-Borro, M. Rengel, et al.. Herschel/HIFI observations of Mars: first detection of O_2 at submillimetre wavelengths and upper limits on HCl and H_2O_2. Astronomy and Astrophysics - A&A, 2010, 521, pp.id.L49. ⟨10.1051/0004-6361/201015160⟩. ⟨hal-00520822⟩