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Related papers: The Fractal Distribution of HII Regions in Disk Ga…

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In this work we quantify the degree to which star-forming events are clumped. We apply a precise and accurate technique to calculate the correlation dimension Dc of the distribution of HII regions in a sample of disk galaxies. Our reliable…

Astrophysics · Physics 2010-11-08 Nestor Sanchez , Emilio J. Alfaro

We study the distribution of stars, HII regions, molecular gas, and individual giant molecular clouds in M33 over a wide range of spatial scales. The clustering strength of these components is systematically estimated through the fractal…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-08 Nestor Sanchez , Neyda Anez , Emilio J. Alfaro , Mary Crone Odekon

Several two-dimensional studies in spiral galaxies show that HII star formation regions have a fractal distribution, with a fractal dimension of approximately 2.3. In this work, the fractal dimension is calculated through the box-counting…

Astrophysics of Galaxies · Physics 2020-08-04 Canavesi Tobias , Hurtado Santiago

The fractal structure of star formation on large scales in disk galaxies is studied using the size distribution function of stellar aggregates in kpc-scale star fields. Achival HST images of 10 galaxies are Gaussian smoothed to define the…

Astrophysics · Physics 2009-10-31 Bruce G. Elmegreen , Debra Meloy Elmegreen

We use fractal analysis to systematically study the clustering strength of the distribution of stars, HII regions, molecular gas, and individual giant molecular clouds in M33 over a wide range of spatial scales. We find a clear transition…

Astrophysics of Galaxies · Physics 2011-09-15 Nestor Sanchez , Neyda Anez , Emilio Alfaro , Mary Crone Odekon

Evidence is presented that the galaxy distribution can be described as a fractal system in the redshift range of the FDF galaxy survey. The fractal dimension $D$ was derived using the FDF galaxy volume number densities in the spatially…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 G. Conde-Saavedra , A. Iribarrem , Marcelo B. Ribeiro

As part of a large study to map the distribution of star formation across galactic disks, we have obtained deep Halpha images of the nearby Sculptor Group spirals NGC 247 and NGC 7793. These images are of sufficiently high quality that they…

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…

Astrophysics · Physics 2008-03-11 Nestor Sanchez , Emilio J. Alfaro , Enrique Perez

Infrared shells and bubbles are ubiquitous in the Galaxy and can generally be associated with HII regions formed around young, massive stars. In this paper, we use high-resolution 3D SPH simulations to explore the effect of a single O7 star…

Astrophysics of Galaxies · Physics 2015-06-16 S. Walch , A. P. Whitworth , T. G. Bisbas , R. Wunsch , D. A. Hubber

Aims: We derive the 3-D HI volume density distribution for the Galactic disk out to R = 60 kpc. Methods: Our analysis is based on parameters for the warp and rotation curve derived previously. The data are taken from the…

Astrophysics · Physics 2015-05-13 P. M. W. Kalberla , L. Dedes

Estimates of the fractal dimension $D$ of the set of galaxies in the universe, based on ever improving data sets, tend to settle on $D\approx 2$. This result raised a raging debate due to its glaring contradiction with astrophysical models…

The interstellar medium is structured as a hierachy of gas clouds, that looks self-similar over 6 orders of magnitude in scales and 9 in masses. This is one of the more extended fractal in the Universe. At even larger scales, the ensemble…

Astrophysics · Physics 2018-03-28 F. Combes

Using a sample of 133 991 galaxies distributed in the sky region $100^{\circ} <\alpha<270^{\circ}$ and $7^{\circ}<\delta<65^{\circ}$, extracted from the SDSS NASA/AMES Value Added Galaxy Catalog (AMES-VAGC), we estimate the fractal…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-07 T. Canavesi , T. E. Tapia

We investigate the relationship of the HII region luminosity function (HII LF) to the HII region size distribution and density wave triggering in grand-design spiral galaxies. We suggest that the differential nebular size distribution is…

Astrophysics · Physics 2009-11-10 M. S. Oey , J. S. Parker , V. J. Mikles , X. Zhang

Fractal dimensions can be used to characterize the clustering and lacunarities in density distributions. We use generalized fractal dimensions to study the neutral hydrogen distribution (HI) during the epoch of reionization. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Bidisha Bandyopadhyay , T. Roy Choudhury , T. R. Seshadri

The methods of determining the fractal dimension and irregularity scale in simulated galaxy catalogs and the application of these methods to the data of the 2dF and 6dF catalogs are analyzed. Correlation methods are shown to be correctly…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Nikita Yu. Lovyagin

This work tests if the large-scale galaxy distribution can be characterized as a fractal system. The $\Lambda$CDM cosmology with $H_0=(70\pm 5)$ km/s/Mpc is adopted to study the UltraVISTA DR1, COSMOS2015 and SPLASH surveys, alongside the…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-03 Sharon Teles

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.…

Astrophysics of Galaxies · Physics 2012-08-02 Nestor Sanchez , Emilio J. Alfaro

We present HST/WFC3 narrowband imaging of the H-alpha emission in a sample of eight gravitationally-lensed galaxies at z = 1 - 1.5. The magnification caused by the foreground clusters enables us to obtain a median source plane spatial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 R. C. Livermore , T. Jones , J. Richard , R. G. Bower , R. S. Ellis , A. M. Swinbank , J. R. Rigby , Ian Smail , H. Ebeling , R. A. Crain

A sample of 69 galaxies with radial velocities less than 2500 km/s was selected from the HI Parkes All Sky Survey (HIPASS) to deduce details about star formation in nearby disk galaxies selected with no bias to optical surface brightness…

Astrophysics · Physics 2009-11-11 J. F. Helmboldt , R. A. M. Walterbos , G. D. Bothun , K. O'Neil
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