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Related papers: Grain Physics and Rosseland Mean Opacities

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Previous computations of low temperature Rosseland and Planck mean opacities from Alexander & Ferguson (1994) are updated and expanded. The new computations include a more complete equation of state with more grain species and updated…

As small solid grains grow into larger ones in protoplanetary nebulae, or in the cloudy atmospheres of exoplanets, they generally form porous aggregates rather than solid spheres. A number of previous studies have used highly sophisticated…

Earth and Planetary Astrophysics · Physics 2015-06-18 Jeffrey N. Cuzzi , Paul R. Estrada , Sanford S. Davis

We attempt to produce low temperature opacity data incorporating the effects of varied abundances of the elements carbon and nitrogen. For our temperature range of interest, molecules represent the dominant opacity source. Our dataset…

Astrophysics · Physics 2009-11-13 Michael T. Lederer , Bernhard Aringer

We have computed the size distribution of silicate grains in the outer radiative region of the envelope of a protoplanet evolving according to the scenario of Pollack et al. (1996). Our computation includes grain growth due to Brownian…

Astrophysics · Physics 2009-11-13 Naor Movshovitz , Morris Podolak

We present a method to include the evolution of the grain size and grain opacity $\kappa_\mathrm{gr}$ in the equations describing the structure of protoplanetary atmospheres. The key assumption of this method is that a single grain size…

Earth and Planetary Astrophysics · Physics 2015-06-22 Chris W. Ormel

We present new Rosseland and Planck mean opacity tables relevant to the shallow interiors and atmospheres of giant planets. The tables span metallicities from 0.31 to 50 times solar, temperatures from 100 - 6000 K, and pressures from 1e-6 -…

Earth and Planetary Astrophysics · Physics 2026-01-07 Louis Siebenaler , Yamila Miguel

Rosseland mean opacity plays an important role in theories of stellar evolution and X-ray burst models. In the high-temperature regime, when most of the gas is completely ionized, the opacity is dominated by Compton scattering. Our aim here…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Juri Poutanen

We present a set of gas-phase Planck mean and Rosseland mean opacity tables applicable for simulations of star and planet formation, stellar evolution, disk modelling at various metallicities in hydrogen-rich environments. The tables are…

Solar and Stellar Astrophysics · Physics 2015-05-13 Ch. Helling , W. Lucas

In this study we compute the equation of state and Rosseland mean opacity from temperatures of T~30000 K down to T~400 K, pushing the capabilities of the AESOPUS code (Marigo et al., 2022; Marigo & Aringer, 2009) into the regime where solid…

Solar and Stellar Astrophysics · Physics 2023-10-24 P. Marigo , P. Woitke , E. Tognelli , L. Girardi , B. Aringer , A. Bressan

The building of a stellar structure requires knowing the Rosseland mean opacity at each layer of the model. This mean opacity is very often interpolated in pre-computed tables due to the overwhelming time to compute it from monochromatic…

Solar and Stellar Astrophysics · Physics 2021-02-10 Alain Hui-Bon-Hoa

Context. We investigate the grain opacity k_gr in the atmosphere of protoplanets. This is important for the planetary mass-radius relation since k_gr affects the H/He envelope mass of low-mass planets and the critical core mass of giant…

Earth and Planetary Astrophysics · Physics 2014-12-10 C. Mordasini

We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of…

Earth and Planetary Astrophysics · Physics 2021-06-28 Richard S. Freedman , Jacob Lustig-Yaeger , Jonathan J. Fortney , Roxana E. Lupu , Mark S. Marley , Katharina Lodders

Grain size is an important control on mantle viscosity and permeability, but is difficult or impossible to measure in situ. We construct a two-dimensional, single phase model for the steady-state mean grain size beneath a mid-ocean ridge.…

Geophysics · Physics 2015-06-23 Andrew J. Turner , Richard F. Katz , Mark D. Behn

Dust grains play a major role in many astrophysical contexts. They affect the chemical, magnetic, dynamical, and optical properties of their environment, from galaxies down to the interstellar medium, star-forming regions, and…

Astrophysics of Galaxies · Physics 2021-05-18 Pierre Marchand , Vincent Guillet , Ugo Lebreuilly , Mordecai-Mark Mac Low

The Rosseland mean opacity of dust in protoplanetary disks is often calculated assuming the interstellar medium (ISM) size distribution and a constant dust-to-gas ratio. However, the dust size distribution and the dust-to-gas ratio in…

Earth and Planetary Astrophysics · Physics 2021-09-28 Yayaati Chachan , Eve J. Lee , Heather A. Knutson

We have computed wind models with time-dependent dust formation and grain-size dependent opacities, where (1) the problem is simplified by assuming a fixed dust-grain size, and where (2) the radiation pressure efficiency is approximated…

Solar and Stellar Astrophysics · Physics 2010-10-04 Lars Mattsson , Susanne Höfner

In this paper, we present mean gas and dust opacities relevant to the physical conditions typical of protoplanetary discs. As the principal absorber for temperatures below ~1,500 K, we consider spherical and aggregate dust particles of…

Astrophysics · Physics 2009-11-10 D. Semenov , Th. Henning , Ch. Helling , M. Ilgner , E. Sedlmayr

Recently, Bailey et al. (2015) made a direct measurement of the Iron opacity at the physical conditions of the solar tachocline. They found that the wavelength-integrated Iron opacity is roughly 75% higher that what the OP and OPAL models…

Solar and Stellar Astrophysics · Physics 2015-11-11 Ehsan Moravveji

We address the critical need for accurate Rosseland mean gas opacities in high-pressure environments, spanning temperatures from 100 K to 32000 K. Current opacity tables from Wichita State University and AESOPUS 2.0 are limited to $\log(R)…

Intending to solve the decade old problem of solar opacity, we report substantial photoabsorption uncertainty due to the effect of ion-ion correlations. By performing detailed opacity calculations of the solar mixture, we find that taking…

Solar and Stellar Astrophysics · Physics 2018-03-01 Menahem Krief , Yair Kurzweil , Alexander Feigel , Doron Gazit
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