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Related papers: 2n-Stream Thermal Emissions from Clouds

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Scattering of light at a distribution of scatterers is an intrinsically cooperative process, which means that the scattering rate and the angular distribution of the scattered light are essentially governed by bulk properties of the…

Atomic Physics · Physics 2015-05-18 H. Bender , C. Stehle , S. Slama , R. Kaiser , N. Piovella , C. Zimmermann , Ph. W. Courteille

We have developed a new retrieval approach to modelling near-infrared spectra of Uranus that represents a significant improvement over previous modelling methods. We reanalysed IRTF/SpeX observations of Uranus observed in 2009 covering the…

Earth and Planetary Astrophysics · Physics 2016-01-13 P. G. J. Irwin , D. S. Tice , L. N. Fletcher , J. K. Barstow , N. A. Teanby , G. S. Orton , G. R. Davis

Our aim is to compare the infrared properties of big, ``classical'' dust grains with visual extinction in the cloud L1642. In particular, we study the differences of grain emissivity between diffuse and dense regions in the cloud. The…

Astrophysics · Physics 2009-11-13 K. Lehtinen , M. Juvela , K. Mattila , D. Lemke , D. Russeil

By radiation transfer models with a realistic power spectra of the projected density distributions, we show that the optical properties of grains are poorly constrained by observations of reflection nebulae. The ISM is known to be…

Astrophysics · Physics 2009-11-07 John S. Mathis , Barbara A. Whitney , Kenneth Wood

As the 3D spatial properties of exoplanet atmospheres are being observed in increasing detail by current and new generations of telescopes, the modelling of the 3D scattering effects of cloud forming atmospheres with inhomogeneous opacity…

Earth and Planetary Astrophysics · Physics 2021-06-04 Elspeth Lee , Kenneth Wood , Ian Dobbs-Dixon , Anna Rice , Christiane Helling

Within the project Galactic Cold Cores we are carrying out Herschel photometric observations of cold interstellar clouds detected with the Planck satellite. The three fields observed as part of the Herschel science demonstration phase (SDP)…

A transport theory for atomic matter waves in low-dimensional waveguides is outlined. The thermal fluctuation spectrum of magnetic near fields leaking out of metallic microstructures is estimated. The corresponding scattering rate for…

Quantum Physics · Physics 2015-06-26 C. Henkel , S. Potting

We have used a numerical simulation of a turbulent cloud to synthesize maps of the thermal emission from dust at a variety of far-IR and sub-mm wavelengths. The average column density and external radiation field in the simulation is well…

Astrophysics · Physics 2009-11-11 S. Schnee , T. Bethell , A. Goodman

Thermal emission is the process by which all objects at non-zero temperatures emit light, and is well-described by the classic Planck, Kirchhoff, and Stefan-Boltzmann laws. For most solids, the thermally emitted power increases…

Several radio-wave scintillation phenomena exhibit properties which are difficult to accommodate within the standard propagation model based on distributed Kolmogorov turbulence in the ionised ISM; here we discuss one such phenomenon,…

Astrophysics · Physics 2007-05-23 Mark A. Walker

Since in situ studies and interplanetary dust collections only provide a spatially limited amount of information about the interplanetary dust properties, it is of major importance to complete these studies with properties inferred from…

Earth and Planetary Astrophysics · Physics 2016-09-20 Jeremie Lasue , Anny-Chantal Levasseur-Regourd , Nicolas Fray , Hervé Cottin

Collective X-ray Thomson scattering has become a versatile tool for the diagnostics of dense plasmas. Assuming homogeneous density and temperature throughout the target sample, these parameters can be determined directly from the plasmon…

Owing to their wavelengths dependent absorption and scattering properties, clouds have a strong impact on the climate of planetary atmospheres. Especially, the potential greenhouse effect of CO2 ice clouds in the atmospheres of terrestrial…

Earth and Planetary Astrophysics · Physics 2015-06-16 D. Kitzmann , A. B. C. Patzer , H. Rauer

Telescopes are now able to resolve dust polarization across circumstellar disks at multiple wavelengths, allowing the study of the polarization spectrum. Most disks show clear evidence of dust scattering through their unidirectional…

Solar and Stellar Astrophysics · Physics 2022-04-27 Zhe-Yu Daniel Lin , Zhi-Yun Li , Haifeng Yang , Ian Stephens , Leslie Looney , Rachel Harrison , Manuel Fernández-López

We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external FUV (6 eV < E < 13.6 eV) flux G_0 (scaling factor in multiples of…

Astrophysics · Physics 2011-02-11 David Hollenbach , Michael J. Kaufman , Edwin A. Bergin , Gary J. Melnick

3D convective cloud images form via two intertwined radiative diffusion processes. Sunlight starts in the anti-solar direction and ends in toward-sensor ones, but repeated forward-peaked scattering smears the well-collimated beams…

Atmospheric and Oceanic Physics · Physics 2021-07-28 Anthony B. Davis , Linda Forster , David J. Diner , Bernhard Mayer

We present spectrophotometric ISO imaging with the LWS and the CAM-CVF of the Serpens molecular cloud core. The LWS map is centred on the far infrared and submillimetre source SMM1 and its size is 8' x 8'. The fine structure line emission…

Astrophysics · Physics 2009-11-07 B. Larsson , R. Liseau , A. B. Men'shchikov

We study how different opacity-temperature scalings affect the dynamical evolution of irradiated gas clouds using time-dependent, radiation-hydrodynamics (rad-HD) simulations. When clouds are optically thick, the bright side heats up and…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Sergei Dyda , Daniel Proga , Christopher S Reynolds

Context: Observations of scattered light in the 1-5 $\mu$m range have revealed dust grains in molecular cores with sizes larger than commonly inferred for the diffuse interstellar medium. It is currently unclear whether these grains are…

Astrophysics of Galaxies · Physics 2014-09-05 M. Andersen , W-F. Thi , J. Steinacker , N. Tothill

We present new observations of [CII] fine structure line emission from an isolated molecular cloud using the upGREAT instrument onboard SOFIA. These data are analyzed together with archival CO=1-0 and HI 21 cm emission spectra to…

Astrophysics of Galaxies · Physics 2022-12-21 Mark Heyer , Paul F. Goldsmith , Robert Simon , Rebeca Aladro , Oliver Ricken