Now showing items 1-20 of 24

  • The 3D thermal, dynamical and chemical structure of the atmosphere of HD 189733b: implications of wind-driven chemistry for the emission phase curve (article) 

    Drummond, B; Mayne, NJ; Manners, J; Baraffe, I; Goyal, J; Tremblin, P; Sing, DK; Kohary, K (American Astronomical Society / IOP Publishing, 2018)
    In this paper we present three-dimensional atmospheric simulations of the hot Jupiter HD~189733b under two different scenarios: local chemical equilibrium and including advection of the chemistry by the resolved wind. Our ...
  • Advection of potential temperature in the atmosphere of irradiated exoplanets: a robust mechanism to explain radius inflation 

    Tremblin, P; Chabrier, G; Mayne, NJ; Amundsen, DS; Baraffe, I; Debras, F; Drummond, B; Manners, J; Fromang, S (American Astronomical Society / IOP Publishing, 2017)
    The anomalously large radii of strongly irradiated exoplanets have remained a major puzzle in astronomy. Based on a 2D steady state atmospheric circulation model, the validity of which is assessed by comparison to 3D ...
  • Benchmarking the Multi-dimensional Stellar Implicit Code MUSIC 

    Goffrey, T; Pratt, J; Viallet, M; Baraffe, I; Popov, MV; Walder, R; Folini, D; Geroux, C; Constantino, T (arXiv.org, 2016-10-31)
    We present the results of a numerical benchmark study for the MUlti-dimensional Stellar Implicit Code (MUSIC) based on widely applicable two- and three-dimensional compressible hydrodynamics problems relevant to stellar ...
  • Cloudless atmospheres for young low-gravity substellar objects 

    Tremblin, P; Chabrier, G; Baraffe, I; Liu, MC; Magnier, EA; Lagage, P-O; Oliveira, CAD; Burgasser, AJ; Amundsen, DS; Drummond, B (American Astronomical Society / IOP Publishing, 2017-11-15)
    Atmospheric modeling of low-gravity (VL-G) young brown dwarfs remains a challenge. The presence of very thick clouds has been suggested because of their extremely red near-infrared (NIR) spectra, but no cloud models provide ...
  • The effect of metallicity on the atmospheres of exoplanets with fully coupled 3D hydrodynamics, equilibrium chemistry, and radiative transfer (article) 

    Drummond, B; Mayne, NJ; Baraffe, I; Tremblin, P; Manners, J; Amundsen, D; Goyal, J; Acreman, D (EDP Sciences for European Southern Observatory (ESO), 2018-01-03)
    In this work we have performed a series of simulations of the atmosphere of GJ 1214b assuming different metallicities using the Met Office Unified Model (UM). The UM is a general circulation model (GCM) that solves the ...
  • The effects of consistent chemical kinetics calculations on the pressure-temperature profiles and emission spectra of hot Jupiters 

    Drummond, B; Tremblin, P; Baraffe, I; Amundsen, DS; Mayne, N; Venot, O; Goyal, J (EDP Sciences, 2016-10-16)
    In this work we investigate the impact of calculating non-equilibrium chemical abundances consistently with the temperature structure for the atmospheres of highly-irradiated, close-in gas giant exoplanets. Chemical kinetics ...
  • The effects of consistent chemical kinetics calculations on the pressure-temperature profiles and emission spectra of hot Jupiters 

    Drummond, B; Tremblin, P; Baraffe, I; Amundsen, DS; Mayne, N; Venot, O; Goyal, J (EDP Sciences, 2016-10-16)
    In this work we investigate the impact of calculating non-equilibrium chemical abundances consistently with the temperature structure for the atmospheres of highly-irradiated, close-in gas giant exoplanets. Chemical kinetics ...
  • Extreme value statistics for two-dimensional convective penetration in a pre-Main Sequence star 

    Pratt, J; Baraffe, I; Goffrey, T; Constantino, T; Viallet, M; Popov, MV; Walder, R; Folini, D (EDP Sciences for European Southern Observatory (ESO), 2017-07-15)
    We examine a penetration layer formed between a central radiative zone and a large convection zone in the deep interior of a young low-mass star. Using the Multidimensional Stellar Implicit Code (MUSIC) to simulate ...
  • HARPS3 for a roboticized Isaac Newton telescope 

    Thompson, SJ; Queloz, D; Baraffe, I; Brake, M; Dolgopolov, A; Fisher, M; Fleury, M; Geelhoed, J; Hall, R; Hernandez, JIG; Horst, RT; Kragt, J; Navarro, R; Naylor, T; Pepe, F; Piskunov, N; Rebolo, R; Sander, L; Segransan, D; Seneta, E; Sing, D; Snellen, I; Snik, F; Spronck, J; Stempels, E; Sun, X; Tschudi, SS; Young, J (Society of Photo-optical Instrumentation Engineers (SPIE), 2016)
    We present a description of a new instrument development, HARPS3, planned to be installed on an upgraded and roboticized Isaac Newton Telescope by end-2018. HARPS3 will be a high resolution (R = 115,000) echelle spectrograph ...
  • A Jacobian-free Newton-Krylov method for time-implicit multidimensional hydrodynamics 

    Viallet, M; Goffrey, T; Baraffe, I; Folini, D; Geroux, C; Popov, M; Pratt, J; Walder, R (arXiv.org, 2015-12-14)
    This work is a continuation of our efforts to develop an efficient implicit solver for multidimensional hydrodynamics for the purpose of studying important physical processes in stellar interiors, such as turbulent convection ...
  • A library of ATMO forward model transmission spectra for hot Jupiter exoplanets 

    Goyal, JM; Mayne, N; Sing, DK; Drummond, B; Tremblin, P; Amundsen, DS; Evans, T; Carter, AL; Spake, J; Baraffe, I; Nikolov, N; Manners, J; Chabrier, G; Hebrard, E (Oxford University Press (OUP) / Royal Astronomical Society, 2017-11-23)
    We present a grid of forward model transmission spectra, adopting an isothermal temperature-pressure profile, alongside corresponding equilibrium chemical abundances for 117 observationally significant hot exoplanets ...
  • Lithium depletion in solar-like stars: effect of overshooting based on realistic multi-dimensional simulations 

    Baraffe, I; Pratt, J; Goffrey, T; Constantino, T; Folini, D; Popov, MV; Walder, R; Viallet, M (American Astronomical Society / IOP Publishing, 2017-08-09)
    We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated ...
  • An M-dwarf star in the transition disk of Herbig HD 142527 

    Lacour, S; Biller, B; Cheetham, A; Greenbaum, A; Pearce, T; Marino, S; Tuthill, P; Pueyo, L; Mamajek, EE; Girard, JH; Sivaramakrishnan, A; Bonnefoy, M; Baraffe, I; Chauvin, G; Olofsson, J; Juhasz, A; Benisty, M; Pott, J-U; Sicilia-Aguilar, A; Henning, T; Cardwell, A; Goodsell, S; Graham, JR; Hibon, P; Ingraham, P; Konopacky, Q; Macintosh, B; Oppenheimer, R; Perrin, M; Rantakyrö, F; Sadakuni, N; Thomas, S (EDP Sciences, 2016-06)
    Aims. HD 142527A is one of the most studied Herbig Ae/Be stars with a transitional disk, as it has the largest imaged gap in any protoplanetary disk: the gas is cleared from 30 to 90 AU. The HD 142527 system is also unique ...
  • Multi-dimensional structure of accreting young stars 

    Geroux, C; Baraffe, I; Viallet, M; Goffrey, T; Pratt, J; Constantino, T; Folini, D; Popov, MV; Walder, R (EDP Sciences for European Southern Observatory (ESO), 2016-02-11)
    This work is the first attempt to describe the multi-dimensional structure of accreting young stars based on fully compressible time implicit multi-dimensional hydrodynamics simulations. One major motivation is to analyse ...
  • Near-Infrared Spectroscopy of the Y0 WISEP J173835.52+273258.9 and the Y1 WISE J035000.32-565830.2: the Importance of Non-Equilibrium Chemistry 

    Leggett, SK; Tremblin, P; Saumon, D; Marley, MS; Morley, CV; Amundsen, DS; Baraffe, I; Chabrier, G (American Astronomical Society, 2016-06-03)
    We present new near-infrared spectra, obtained at Gemini Observatory, for two Y dwarfs: WISE J035000.32-565830.2 (W0350) and WISEP J173835.52+273258.9 (W1738). A FLAMINGOS-2 R=540 spectrum was obtained for W0350, covering ...
  • Observable signatures of wind-driven chemistry with a fully consistent three dimensional radiative hydrodynamics model of HD 209458b (article) 

    Drummond, B; Mayne, NJ; Manners, J; Carter, A; Boutle, I; Baraffe, I; Hebrard, E; Tremblin, P; Sing, D; Amundsen, D; Acreman, D (American Astronomical Society / IOP Publishing, 2018-03-15)
    We present a study of the effect of wind-driven advection on the chemical composition of hot Jupiter atmospheres using a fully-consistent 3D hydrodynamics, chemistry and radiative transfer code, the Met Office Unified ...
  • Planetary internal structures 

    Baraffe, I; Chabrier, G; Fortney, J; Sotin, C (University of Arizona Press, 2014)
    This chapter reviews the most recent advancements on the topic of terrestrial and giant planet interiors, including Solar System and extrasolar objects. Starting from an observed mass-radius diagram for known planets in ...
  • Results from a set of three-dimensional numerical experiments of a hot Jupiter atmosphere. 

    Mayne, NJ; Debras, F; Baraffe, I; Thuburn, J; Amundsen; Acreman, D; Smith, C; Browning, MK; Manners, J; Wood, N (EDP Sciences, 2017-04-05)
    We present highlights from a large set of simulations of a hot Jupiter atmosphere, nominally based on HD 209458b, aimed at exploring both the evolution of the deep atmosphere, and the acceleration of the zonal flow or ...
  • Self-consistent evolution of accreting low-mass stars and brown dwarfs 

    Baraffe, I; Elbakyan, VG; Vorobyov, EI; Chabrier, G (arXiv.org, 2016-08-26)
    We present self-consistent calculations coupling numerical hydrodynamics simulations of collapsing pre-stellar cores and stellar evolution models of accreting objects. We analyse the main impact of consistent accretion ...
  • Spherical-shell boundaries for two-dimensional compressible convection in a star 

    Pratt, J; Baraffe, I; Goffrey, T; Geroux, C; Viallet, M; Folini, D; Constantino, T; Popov, M; Walder, R (EDP Sciences, 2016)
    Context: We study the impact of two-dimensional spherical shells on compressible convection. Realistic profiles for density and temperature from a one-dimensional stellar evolution code are used to produce a model of a ...