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In this paper we investigate the influence of the substrate material and film thickness on the Peierls transition temperature in tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) thin films, grown by physical vapor deposition. Our…

Materials Science · Physics 2010-09-14 Vita Solovyeva , Michael Huth

Since the chemical evolution of galaxies seems to differ between morphological types and deviates in many details from the standard scenario the question has to be addressed when, how and to what amount metal-enriched ejecta from Supernovae…

Astrophysics · Physics 2007-05-23 Andreas Rieschick , Gerhard Hensler

Thermal transport is a fundamental mechanism of energy transfer process quite distinct from wave propagation phenomena. It can be manipulated well beyond the possibilities offered by natural materials with a new generation of artificial…

Applied Physics · Physics 2024-09-04 Zhoufei Liu , Peng Jin , Min Lei , Chengmeng Wang , Fabio Marchesoni , Jian-Hua Jiang , Jiping Huang

A non negligible fraction of white dwarf stars show the presence of heavy elements in their atmospheres. The most accepted explanation for this contamination is the accretion of material coming from tidally disrupted planetesimals, which…

Solar and Stellar Astrophysics · Physics 2022-04-13 F. C. Wachlin , G. Vauclair , S. Vauclair , L. G. Althaus

Rotating convective turbulence is ubiquitously found across geophysical settings, such as surface and subsurface oceans, planetary atmospheres, molten metal planetary cores, magma chambers, and magma oceans. Depending on the thermal and…

Fluid Dynamics · Physics 2023-11-08 Jewel A. Abbate , Jonathan M. Aurnou

The turbulent burning of nuclei is a common phenomenon in the evolution of stars. Here we examine a challenging case: the merging of the neon and oxygen burning shells in a 23 M$_{\odot}$ star. A previously unknown quasi-steady state is…

Solar and Stellar Astrophysics · Physics 2018-09-12 Miroslav Mocák , Casey Meakin , Simon Wattana Campbell , David Arnett

We present an analysis of the 0.95-14.5 micron spectral energy distributions of nine field ultracool dwarfs with spectral types ranging from L1 to T4.5. Effective temperatures, gravities, and condensate cloud sedimentation efficiencies are…

We review five mechanisms for forming brown dwarfs: (i) turbulent fragmentation of molecular clouds, producing very low-mass prestellar cores by shock compression; (ii) collapse and fragmentation of more massive prestellar cores; (iii) disc…

Astrophysics · Physics 2007-05-23 Anthony Whitworth , Matthew R. Bate , Aake Nordlund , Bo Reipurth , Hans Zinnecker

Although transit spectroscopy is a powerful method for studying the composition, thermal properties and dynamics of exoplanet atmospheres, only a few transiting terrestrial exoplanets will be close enough to allow significant transit…

Earth and Planetary Astrophysics · Physics 2015-05-28 Franck Selsis , Robin Wordsworth , François Forget

Based on a simple thermodynamical argument, we proposed a unified cloudy model (UCM) with a warm dust cloud deep in the photosphere. We showed, for the first time, that a single grid of model photospheres (Teff between 800 and 2600K) offers…

Astrophysics · Physics 2007-05-23 Takashi Tsuji

The gap caused by a strong electric field between the quark surface and nuclear crust of a strange star is studied in an improved model including gravity and pressure as well as electrostatic forces. The transition from gap to crust is…

Astrophysics · Physics 2009-11-13 Morten Stejner , Jes Madsen

Iron-rich layers are known to form in the stellar subsurface through a combination of gravitational settling and radiative levitation. Their presence, nature and detailed structure can affect the excitation process of various stellar…

Solar and Stellar Astrophysics · Physics 2015-06-22 Varvara Zemskova , Pascale Garaud , Morgan Deal , Sylvie Vauclair

The abundances of the chemical elements observed at the surface of metal-poor stars are not always representative of their initial values. During stellar evolution, various physical processes modify their internal composition. In this short…

Solar and Stellar Astrophysics · Physics 2011-08-26 Sylvie Vauclair

Since the discovery of the first L dwarf 19 years ago and the discovery of the first T dwarf 7 years after that, we have amassed a large list of these objects, now numbering almost six hundred. Despite making headway in understanding the…

Astrophysics · Physics 2007-05-23 J. Davy Kirkpatrick

We aim at understanding the formation of cloud layers in quasi-static substellar atmospheres. The time-dependent description presented in (Helling & Woitke 2006) is a kinetic model describing nucleation, growth and evaporation. It is…

Astrophysics · Physics 2009-11-13 Ch. Helling , P. Woitke , W. -F. Thi

The impact of unocculted stellar surface heterogeneities in the form of cool spots and hot faculae on the spectrum of a transiting planet has been a daunting problem for the characterization of exoplanet atmospheres. The…

Earth and Planetary Astrophysics · Physics 2020-02-12 Aishwarya R. Iyer , Michael R. Line

The low luminosity of Uranus is a long-standing challenge in planetary science. Simple adiabatic models are inconsistent with the measured luminosity, which indicates that Uranus is non-adiabatic because it has thermal boundary layers…

Earth and Planetary Astrophysics · Physics 2020-01-15 A. Vazan , R. Helled

The modeling of stellar spectra is pervasive in astronomy. Conventionally, the shapes of absorption lines are modeled by convolving thermal profiles (computed given some model stellar atmosphere and line list) with broadening kernels…

Solar and Stellar Astrophysics · Physics 2025-12-11 Michael L. Palumbo

This work presents numerical results on the transport of heat and chemical species by shear-induced turbulence in strongly stratified but thermally diffusive environments. The shear instabilities driven in this regime are sometimes called…

Solar and Stellar Astrophysics · Physics 2016-04-20 Pascale Garaud , Logithan Kulenthirarajah