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Related papers: Modeling Grain Alignment by Radiative Torques and …

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Paramagnetic alignment of thermally rotating oblate dust grains is studied analytically for finite ratios of grain to gas temperatures. For such ratios, the alignment of angular momentum J in respect to the grain axis of maximal inertia is…

Astrophysics · Physics 2015-06-24 A. Lazarian

Many of the general-relativity-tests such as bending of light near a star and gravitational red/blue shift are explained without general-relativity and without Newtonian-approach. The author first casts doubts on both, the Newtonian and the…

General Physics · Physics 2007-05-23 Dr. R. C. Gupta

We present the results of numerical experiments to assess degeneracies in lightcurve models of starspots. Using synthetic lightcurves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Lucianne M. Walkowicz , Gibor S. Basri , Jeff A. Valenti

Dust is an essential component of the interstellar medium (ISM) and plays an important role in many different astrophysical processes and phenomena. Traditionally, dust grains are known to be destroyed by thermal sublimation, Coulomb…

Astrophysics of Galaxies · Physics 2020-07-07 Thiem Hoang

Aligned non-spherical dust particles polarize starlight passing through the dust cloud. They also emit polarized far infrared and sub-mm radiation. Substantial progress in understanding of grain alignment theory makes the interpretation of…

Astrophysics · Physics 2007-05-23 A. Lazarian

We have obtained the first time-resolved, disc-integrated observations of Earth's poles with the Deep Impact spacecraft as part of the EPOXI Mission of Opportunity. These data mimic what we will see when we point next-generation space…

We have extended the analytical model proposed earlier to estimate the inner disk radius of accreting neutron stars in the strong-propeller (SP) phase, and the conditions for the transitions between the strong and weak propeller (WP) phases…

High Energy Astrophysical Phenomena · Physics 2020-11-11 Unal Ertan

We present a new set of analytic models for the expansion of HII regions powered by UV photoionisation from massive stars and compare them to a new suite of radiative magnetohydrodynamic simulations of turbulent, self-gravitating molecular…

Astrophysics of Galaxies · Physics 2016-06-08 Sam Geen , Patrick Hennebelle , Pascal Tremblin , Joakim Rosdahl

Based on three years of deep observations of the Galactic center with the Chandra X-ray Observatory, we report the discovery of changes in the intensities and morphologies of two hard X-ray nebulosities. The nebulosities are dominated by…

Astrophysics · Physics 2009-11-11 M. P. Muno , F. K. Baganoff , W. N. Brandt , S. Park , M. R. Morris

We report successful fitting of a Roche model, with a surface temperature gradient following the von Zeipel gravity darkening law, to observations of Altair made with the Navy Prototype Optical Interferometer. We confirm the claim by…

Many Ground Penetrating Radar (GPR) profiles acquired in dry aeolian environment have shown good reflectivity inside present-day dunes. We show that the origin of this reflectivity is related to changes in grain size distribution, packing…

Geophysics · Physics 2012-08-21 Julien Guillemoteau , Maksim Bano , Jean-Rémi Dujardin

We present a survey for extended 2.2 $\mu$m emission in 20 new visual reflection nebulae, illuminated by stars with temperatures of 3,600 --- 33,000 K. We detect extended 2.2 $\mu$m emission in 13 new nebulae, illuminated by stars with…

Astrophysics · Physics 2009-10-28 K. Sellgren , M. W. Werner , L. J. Allamandola

A model was developed for the excitation of the UIBs by H atom impacts in the Interstellar Medium. It builds upon the fact that, in the presence of far UV radiation and hydrocarbon grains, the hydrogen gas will be partially dissociated and…

Astrophysics of Galaxies · Physics 2015-05-30 Renaud Papoular

We present a novel method to measure the strength of interstellar magnetic fields based on ultraviolet (UV) polarization of starlight, which is in part produced by weakly aligned, small interstellar grains. We begin with calculating degrees…

Astrophysics of Galaxies · Physics 2016-05-10 Thiem Hoang , A. Lazarian , P. G. Martin

Based on the background of the 2021 Higher Education Club Cup National College Students Mathematical Contest in Modeling A, according to the relevant data of the China Sky Eye (FAST) radio telescope, the main cable nodes and actuators are…

Optimization and Control · Mathematics 2022-04-13 Tongyue Shi , Siyu Tao , Haining Wang

The $\gamma$-ray observation of interstellar gas provides a unique way to probe the cosmic rays (CRs) outside the solar system. In this work, we use an updated version of Fermi-LAT data and recent multi-wavelength tracers of interstellar…

High Energy Astrophysical Phenomena · Physics 2019-06-19 Zhao-Qiang Shen , Xiaoyuan Huang , Qiang Yuan , Yi-Zhong Fan , Da-Ming Wei

Production of resonances is considered in the framework of the single-freeze-out model of ultra-relativistic heavy ion collisions. The formalism involves the virial expansion, where the probability to form a resonance in a two-body channel…

Nuclear Theory · Physics 2009-11-10 Wojciech Broniowski , Wojciech Florkowski , Brigitte Hiller

We carried out high-sensitivity spectropolarimetric observations of the central star of the Red Rectangle proto-planetary nebula with the aim of constraining the mechanism that gives its biconical shape. The stellar light of the central…

Solar and Stellar Astrophysics · Physics 2015-06-23 M. J. Martinez Gonzalez , A. Asensio Ramos , R. Manso Sainz , R. L. M. Corradi , F. Leone

If aspherical dust grains are immersed in an anisotropic radiation field, their temperature depends on the cross-sections projected in the direction of the anisotropy.It was shown that the temperature difference produces polarized thermal…

Astrophysics · Physics 2009-10-31 Takashi Onaka

The composition of Solar System surfaces can be inferred through reflectance and emission spectroscopy, by comparing these observations to laboratory measurements and radiative transfer models. While several populations of objects appear to…

Earth and Planetary Astrophysics · Physics 2020-11-02 Robin Sultana , Olivier Poch , Pierre Beck , Bernard Schmitt , Eric Quirico