Search Publications
Diffuse interstellar bands carriers and cometary organic material★
Bertaux, Jean-Loup; Lallement, Rosine
We suggest that the large organic molecules found in the dust of comet 67P/CG originated from the interstellar medium (ISM), and that this material is the source of absorption features in stellar spectra known as diffuse interstellar bands (DIBs). These large organic molecules were present in the ISM prior to the emergence of the pre-solar nebula …
Suzaku analysis of the supernova remnant G306.3-0.9 and the gamma-ray view of its neighbourhood
Sezer, A.; Yamazaki, R.; Ergin, T.
We present an investigation of the supernova remnant (SNR) G306.3-0.9, using archival multiwavelength data. The Suzaku spectra are well described by two-component thermal plasma models: the soft component is in ionization equilibrium and has a temperature ∼0.59 keV, while the hard component has temperature ∼3.2 keV and ionization time-scale ∼2.6 ×…
Stability of Sulphur Dimers (S2) in Cometary Ices
Lunine, J. I.; Mousis, O.; Ronnet, T. +5 more
S2 has been observed for decades in comets, including comet 67P/Churyumov-Gerasimenko. Despite the fact that this molecule appears ubiquitous in these bodies, the nature of its source remains unknown. In this study, we assume that S2 is formed by irradiation (photolysis and/or radiolysis) of S-bearing molecules embedded in th…
The Magnetic Future of the Sun
Metcalfe, Travis S.; Judge, Philip G.; Guinan, Edward +2 more
We analyze space- and ground-based data for the old (7.0 ± 0.3 Gyr) solar analogs 16 Cyg A and B. The stars were observed with the Cosmic Origins UV Spectrographs on the Hubble Space Telescope (HST) on 2015 October 23 and 2016 February 3, respectively, and with the Chandra X-ray Observatory on 2016 February 7. Time-series data in Ca II data are us…
The Polarization Signature of Photospheric Magnetic Fields in 3D MHD Simulations and Observations at Disk Center
Rezaei, R.; Puschmann, K. G.; Beck, C. +1 more
Before using three-dimensional (3D) magnetohydrodynamical (MHD) simulations of the solar photosphere in the determination of elemental abundances, one has to ensure that the correct amount of magnetic flux is present in the simulations. The presence of magnetic flux modifies the thermal structure of the solar photosphere, which affects abundance d…
Integrated cosmological probes: concordance quantified
Amara, Adam; Refregier, Alexandre; Nicola, Andrina
Assessing the consistency of parameter constraints derived from different cosmological probes is an important way to test the validity of the underlying cosmological model. In an earlier work [1], we computed constraints on cosmological parameters for ΛCDM from an integrated analysis of CMB temperature anisotropies and CMB lensing from Planck, gal…
Wind shear and turbulence on Titan: Huygens analysis
Lorenz, Ralph D.
Wind shear measured by Doppler tracking of the Huygens probe is evaluated, and found to be within the range anticipated by pre-flight assessments (namely less than two times the Brunt-Väisälä frequency). The strongest large-scale shear encountered was ∼5 m/s/km, a level associated with 'Light' turbulence in terrestrial aviation. Near-surface winds…
Schumann resonances at Mars: Effects of the day-night asymmetry and the dust-loaded ionosphere
Montmessin, F.; Toledo-Redondo, S.; Molina-Cuberos, G. J. +6 more
Schumann resonances are standing waves that oscillate in the electromagnetic cavity formed between the conducting lower ionosphere and the surface of the planet. They have been measured in situ only on Earth and Titan, although they are believed to exist on other planets like Mars. We report numerical simulations of the Martian electromagnetic cav…
AGNs with discordant optical and X-ray classification are not a physical family: diverse origin in two AGNs
Barcons, X.; Carrera, F. J.; Braito, V. +7 more
Approximately 3-17 per cent of active galactic nuclei (AGNs) without detected rest-frame UV/optical broad emission lines (type-2 AGN) do not show absorption in X-rays. The physical origin behind the apparently discordant optical/X-ray properties is not fully understood. Our study aims at providing insight into this issue by conducting a detailed a…
AKARI near-infrared background fluctuations arise from normal galaxy populations
Komatsu, E.; Helgason, K.
We show that measurements of the fluctuations in the near-infrared background (NIRB) from the AKARI satellite can be explained by faint galaxy populations at low redshifts. We demonstrate this using reconstructed images from deep galaxy catalogues (Hawk-I UDS/GOODS Survey and S-Cosmic Assembly Deep Near-Infrared Extragalactic Legacy Survey) and tw…