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Related papers: Fractal Structure of Molecular Clouds

200 papers

Molecular clouds often exhibit filamentary or sheet-like shapes. We compute the free-fall time ($\tff$) for finite, uniform, self-gravitating circular sheets and filamentary clouds of small but finite thickness, so that their volume density…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jesús A. Toalá , Enrique Vázquez-Semadeni , Gilberto C. Gómez

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…

Astrophysics · Physics 2007-05-23 Ralf Klessen

The star-forming ability of a molecular cloud depends on the fraction of gas it can cycle into the dense-phase. Consequently, one of the crucial questions in reconciling star-formation in clouds is to understand the factors that control…

Astrophysics of Galaxies · Physics 2017-12-20 S. Anathpindika , A. Burkert , R. Kuiper

We exhibit a characteristic structure of the class of all regular graphs of degree d that stems from the spectra of their adjacency matrices. The structure has a fractal threadlike appearance. Points with coordinates given by the mean and…

Combinatorics · Mathematics 2007-08-30 V. Ejov , J. A. Filar , S. K. Lucas , P. Zograf

We have built a new kind of manifolds which leads to an alternative new geometrical space. The study of the nowhere differentiable functions via a family of mean functions leads to a new characterization of this category of functions. A…

General Physics · Physics 2008-11-26 Faycal Ben Adda

In the last years there has been a growing interest in the understanding a vast variety of scale invariant and critical phenomena occurring in nature. Experiments and observations indeed suggest that many physical systems develop…

Astrophysics · Physics 2019-08-17 L. Pietronero , F. Sylos Labini , M. Montuori

The shape of the cold interstellar molecular gas is determined by several processes, including self-gravity, tidal force, turbulence, magnetic field, and galactic shear. Based on the 3D dust extinction map derived by Vergely et al., we…

Astrophysics of Galaxies · Physics 2024-08-27 Yi-Heng Xie , Guang-Xing Li , Bing-Qiu Chen

The paper deals with the fundamental problem of a modeling of the physical, in particular, thermal hydraulic processes, in various media of fractal structure of the natural, technological and technical systems and devices. The examples of a…

Computational Physics · Physics 2018-02-27 Ivan V. Kazachkov

Active fluids, composed of individual self-propelled agents, can generate complex large-scale coherent flows. A particularly important laboratory realization of such an active fluid is a system composed of microtubules, aligned in a…

Soft Condensed Matter · Physics 2021-07-28 Kevin A. Mitchell , Amanda J. Tan , Jorge Arteaga , Linda S. Hirst

While the universe becomes more and more homogeneous at large scales, statistical analysis of galaxy catalogs have revealed a fractal structure at small-scales (\lambda < 100 h^{-1} Mpc), with a fractal dimension D=1.5-2 (Sylos Labini et al…

Astrophysics · Physics 2010-11-30 H. J. de Vega , N. Sánchez , F. Combes

Many young star clusters appear to be fractal, i.e. they appear to be concentrated in a nested hierarchy of clusters within clusters. We present a new algorithm for statistically analysing the distribution of stars to quantify the level of…

Astrophysics of Galaxies · Physics 2017-01-20 S. E. Jaffa , A. P. Whitworth , O. Lomax

We find that clouds of optically-thin, pressure-confined gas are prone to fragmentation as they cool below $\sim10^6$ K. This fragmentation follows the lengthscale $\sim{c}_{\text{s}}\,t_{\text{cool}}$, ultimately reaching very small scales…

Astrophysics of Galaxies · Physics 2018-05-10 Michael McCourt , S. Peng Oh , Ryan M. O'Leary , Ann-Marie Madigan

There exists observational evidence that the interstellar medium has a fractal structure in a wide range of spatial scales. The measurement of the fractal dimension (Df) of interstellar clouds is a simple way to characterize this fractal…

Astrophysics · Physics 2011-02-11 Nestor Sanchez , Emilio J. Alfaro , Enrique Perez

The model of the universe is considered in which background of the universe is not defined by the matter but is a priori specified as a homogenous and isotropic flat space. The scale factor of the universe follows the linear law. The scale…

Astrophysics · Physics 2007-05-23 D. L. Khokhlov

In this Letter we investigate the shape of the probability distribution of column densities (PDF) in molecular clouds. Through the use of low-noise, extinction-calibrated \textit{Herschel}/\textit{Planck} emission data for eight molecular…

Solar and Stellar Astrophysics · Physics 2015-06-23 Marco Lombardi , João Alves , Charles J. Lada

To what extent magnetic fields affect how molecular clouds (MCs) fragment and create dense structures is an open question. We present a numerical study of cloud fragmentation using the SILCC-Zoom simulations. These simulations follow the…

Astrophysics of Galaxies · Physics 2023-07-26 S. Ganguly , S. Walch , D. Seifried , S. D. Clarke , M. Weis

The emission spectra and the ionization structure of the low ionization stages of iron, Fe I--IV, in gaseous nebulae are studied. This work includes: (i) new atomic data: photoionization cross sections, total e-ion recombination rates,…

Astrophysics · Physics 2009-10-30 Manuel A. Bautista , Anil K. Pradhan

Fractals are defined as geometric shapes that exhibit symmetry of scale. This simply implies that fractal is a shape that it would still look the same even if somebody could zoom in on one of its parts an infinite number of times. This…

Space Physics · Physics 2015-05-29 Ioannis Haranas , Ioannis Gkigkitzis , Athanasios Alexiou

The "Nessie" Nebula is a filamentary infrared dark cloud (IRDC) with a large aspect ratio of over 150:1 (1.5 degrees x 0.01 degrees, or 80 pc x 0.5 pc at a kinematic distance of 3.1 kpc). Maps of HNC (1-0) emission, a tracer of dense…

Astrophysics of Galaxies · Physics 2015-05-19 James M. Jackson , Susanna C. Finn , Edward T. Chambers , Jill M. Rathborne , Robert Simon

In this article, we have employed fractal formalism to calculate the Fracture Functions of the Leading neutron produced in \textit{ep} collisions. The fractal concept describes the self-similar behavior of the proton structure at Leading…

High Energy Physics - Phenomenology · Physics 2021-12-08 Samira Shoeibi Mohsenabadi , F. Taghavi-Shahri