中文
相关论文

相关论文: Interstellar extinction by fractal polycrystalline…

200 篇论文

For more than 5000 stars with accurate parallaxes from the Hipparcos and Gaia DR1 Tycho-Gaia astrometric solution (TGAS), Tycho-2 photometry, interstellar polarization from eight catalogues and interstellar extinction from eight 3D maps the…

星系天体物理 · 物理学 2017-07-26 George Gontcharov

The Interstellar Medium has a fractal structure, in the sense that gas and dust distribute in a hierarchical and self-similar manner. Stars in new-born cluster probably follow the same fractal patterns of their parent molecular clouds.…

星系天体物理 · 物理学 2012-08-02 Nestor Sanchez , Emilio J. Alfaro

In many models of dusty objects in space the grains are assumed to be composite or fluffy. However, the computation of the optical properties of such particles is still a very difficult problem. We analyze how the increase of grain porosity…

天体物理学 · 物理学 2009-11-11 N. V. Voshchinnikov , V. B. Il'in , Th. Henning , D. N. Dubkova

The proper motions of stars in the outskirts of globular clusters are used to estimate cluster velocity dispersion profiles as far as possible within their tidal radii. We use individual color-magnitude diagrams to select high probability…

星系天体物理 · 物理学 2021-12-08 Raymond G. Carlberg , Carl J. Grillmair

The joint use of accurate near- and mid-infrared photometry from the 2MASS and WISE catalogues has allowed the variations of the extinction law and the dust grain size distribution in high Galactic latitudes (|b|>50) at distances up to 3…

星系天体物理 · 物理学 2019-10-25 George Gontcharov

We present a study to estimate the dust content in galaxy clusters by using one the most complete existing catalogues of galaxy clusters based on SDSS data and following two methods: the first one compares the colours of samples of galaxies…

宇宙学与河外天体物理 · 物理学 2014-11-11 C. M. Gutierrez , M. Lopez-Corredoira

The internal dust extinction in spiral galaxies can affect our understanding of their structure and morphology, as well as our perception of the distant universe in the background. The intrinsic properties of the stellar and dust components…

天体物理学 · 物理学 2007-05-23 Simone Bianchi

We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5--25$\rm \mu m$. We study the variation in absorption profiles with volume fractions of inclusions.…

星系天体物理 · 物理学 2016-07-22 Ranjan Gupta , Dipak B. Vaidya , Rajeshwari Dutta

Existing observations are consistent with rich clusters of galaxies having no dust on $\simgt$ Mpc scales, while galaxy groups most probably do have dust distributed over $\lesssim$ Mpc scales. Dust in groups accounts for the observed…

天体物理学 · 物理学 2009-11-07 Joshua G. Nollenberg , Liliya L. R. Williams , Steve J. Maddox

In order to study the effect of dust extinction on the afterglow of gamma-ray bursts (GRBs), we carry out numerical calculations with high precision based on rigorous Mie theory and latest optical properties of interstellar dust grains, and…

高能天体物理现象 · 物理学 2011-08-26 Gu-Jing Lv , Lang Shao , Zhi-Ping Jin , Da-Ming Wei

The extinction curve of interstellar dust in the dense molecular cloud cores is crucial for understanding dust properties, particularly size distribution and composition. We investigate the infrared extinction law in four nearby isolated…

星系天体物理 · 物理学 2024-11-04 Jun Li , Bingqiu Chen , Biwei Jiang , He Zhao , Botao Jiang , Xi Chen

The Interstellar Medium seems to have an underlying fractal structure, which can be characterized through its fractal dimension (Df). However, several factors may affect the determination of Df, such as distortions due to projection, low…

天体物理学 · 物理学 2008-03-11 Nestor Sanchez , Emilio J. Alfaro , Enrique Perez

We present three dimensional maps in monochromatic extinction $A_{\rm 0}$ and the extinction parameter $R_0$ within a few degrees of the Galactic plane. These are inferred using photometry from the Pan-STARRS1 and Spitzer Glimpse surveys of…

Identification by the Ulysses spacecraft of interstellar grains inside the planetary system provides a new window for the study of diffuse interstellar matter. Dust particles observed by Ulysses and confirmed by Galileo are more massive…

天体物理学 · 物理学 2015-06-24 E. Grün , M. Landgraf

Photometry from the Tycho-2, 2MASS, and WISE catalogues for clump and branch giants at a distance up to 25 kpc toward the Galactic poles has allowed the variations of various characteristics of the infrared interstellar extinction law with…

星系天体物理 · 物理学 2019-10-25 George Gontcharov

An analysis is made on the morphology of the sequences, formed by stars distributed along the line of sight in (V,V--I) colour-magnitude diagrams from Baade's Window (l=1.0,b=-3.9). The extinction is due to an absorbing layer with an…

天体物理学 · 物理学 2007-05-23 Y. K. Ng , G. Bertelli

We use observations from the CASTLES survey of gravitational lenses to study extinction in 23 lens galaxies with $0 < z_l < 1$. The median differential extinction between lensed images is $\Delta E(\bv) = 0.05$ mag, and the directly…

天体物理学 · 物理学 2007-05-23 B. A. McLeod , E. E. Falco , C. S. Kochanek , J. Lehar , J. A. Munoz , C. D. Impey , C. Keeton , C. Y. Peng , H. -W. Rix

We predict the survival time of initially bound star clusters in the solar neighbourhood taking into account: (1) stellar evolution, (2) tidal stripping, (3) shocking by spiral arms and (4) encounters with giant molecular clouds. We find…

天体物理学 · 物理学 2016-08-30 Henny J. G. L. M. Lamers , Mark Gieles

Scattering and absorption of X-rays by interstellar dust is calculated for a model consisting of carbonaceous grains and amorphous silicate grains. The calculations employ realistic dielectric functions with structure near X-ray absorption…

天体物理学 · 物理学 2009-11-10 B. T. Draine

3D maps of interstellar dust are crucial for understanding the structure of the Milky Way interstellar medium to apply correction to astrophysical observations affected by dust. We aim at providing new extinction estimates in the Gaia BP/RP…

星系天体物理 · 物理学 2025-11-18 M. Barbillon , A. Recio-Blanco , P. de Laverny , P. A. Palicio