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We combine observed properties of galaxies as the core density and radius with the theoretical linear evolution of density fluctuations computed from first principles since the end of inflation till today. The halo radius r_0 is computed in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 H. J. de Vega , P. Salucci , N. G. Sanchez

We demonstrate the existence of distribution functions that can be used to represent spherical massless cored stellar systems embedded in cuspy dark matter halos with constant mildly tangential velocity anisotropy. In particular, we derive…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Maarten A. Breddels , Amina Helmi

We introduce a class of eccentric discs with "strong" density cusps whose potentials are of St\"ackel form in elliptic coordinates. Our models exhibit some striking features: sufficiently close to the location of the cusp, the potential and…

Astrophysics · Physics 2007-05-23 M. A. Jalali , A. R. Rafiee

This paper introduces a new two-parameter family of dwarf spheroidal (dSph) galaxy models. The density distribution has a Plummer profile and falls like the inverse fourth power of distance in projection, in agreement with the star-count…

Astrophysics · Physics 2009-11-07 M. I. Wilkinson , J. Kleyna , N. W. Evans , G. Gilmore

We consider a special family of Gaussian hypergeometric functions whose entries are cubic and trivial characters over finite fields. The special values of these functions are known to give the Frobenius traces of families of Hessian…

Number Theory · Mathematics 2025-02-14 Ken Ono , Sudhir Pujahari , Hasan Saad , Neelam Saikia

We present a new model for galactic bars with exponentially falling major axis luminosity profiles and Gaussian cross-sections. This is based on the linear superposition of Gaussian potential-density pairs with an exponential weight…

Astrophysics of Galaxies · Physics 2020-02-26 D. P. McGough , N. W. Evans , J. L. Sanders

We constrain an interacting, holographic dark energy model, first proposed by two of us in [1], with observational data from supernovae, CMB shift, baryon acoustic oscillations, x-rays, and the Hubble rate. The growth function for this…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Iván Durán , Diego Pavón , Winfried Zimdahl

Modified matter power spectra with approximately Gaussian bump on sub-Mpc scales can be a result of a complex inflation. We consider five spectra with different Gaussian amplitudes $A$ and locations $k_0$ and run N-body simulations in a…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-15 M. V. Tkachev , S. V. Pilipenko , E. V. Mikheeva , V. N. Lukash

[Abridged] We unveil the complex shape of a proto-supercluster at z~2.45 in the COSMOS field using the spectroscopic redshifts of the VIMOS Ultra-Deep Survey (VUDS), complemented by the zCOSMOS-Deep sample and high-quality photometric…

We develop and present the Descriptive Parametric Model (DPM), a tool for generating profiles of gaseous halos (pressure, electron density, and metallicity) as functions of radius, halo mass, and redshift. The model assumes single-phase,…

We present a model for the UV to submillimeter emission from stars embedded in the general interstellar dust in galaxies (the 'infrared cirrus' component). Such emission is characterized by relatively low optical depths of dust and by cool…

Astrophysics · Physics 2009-11-07 Andreas Efstathiou , Michael Rowan-Robinson

Relativistic thick ring models are constructed using previously found analytical Newtonian potential-density pairs for flat rings and toroidal structures obtained from Kuzmin-Toomre family of discs. In particular, we present systems with…

General Relativity and Quantum Cosmology · Physics 2014-01-31 M. Ujevic , P. S. Letelier , D. Vogt

Winds arising from galaxies, star clusters, and active galactic nuclei are crucial players in star and galaxy formation, but it has proven remarkably difficult to use observations of them to determine physical properties of interest,…

Astrophysics of Galaxies · Physics 2017-08-30 Mark R. Krumholz , Todd A. Thompson , Eve C. Ostriker , Crystal L. Martin

We introduce a very simple model of a dark halo. It is a close relative of Hernquist's model, being generated by the same transformation but this time applied to the logarithmic potential rather than the point mass. The density is…

Astrophysics of Galaxies · Physics 2015-06-22 N. W. Evans , A. A. Williams

We use the combined GALFORM semi-analytical model of galaxy formation and GRASIL spectrophotometric code to investigate the properties of galaxies selected via their sub-mm emission. Our fiducial model has previously been shown to fit the…

We calculate the density profiles of virialized halos in the case of structure evolving hierarchically from a scale-free Gaussian delta-field having a power spectrum $P(k)\propto k^n$ in a Omega=1 Universe; we suppose that the initial…

Astrophysics · Physics 2007-05-23 A. Del Popolo , M. Gambera

The CuO-planes of high-T_c superconductors were found to consist of geometric stripes with alternating superconducting and antiferromagnetic areas. Here we will investigate the repulsive Hubbard model of striped clusters as a possible…

Superconductivity · Physics 2007-05-23 Werner Fettes , Thomas Husslein , Ingo Morgenstern

Various analytic expressions have been proposed for the density profile of dark matter halos. We consider six of these expressions for which the density profile has a power-law fall-off rho proportional to r^{-3} at large radii and a…

Astrophysics · Physics 2007-05-23 Lawrence M. Widrow

In this paper, we present two simple approaches for deriving anisotropic distribution functions for a wide range of spherical models. The first method involves multiplying and dividing a basic augmented density with polynomials in $r$ and…

Astrophysics of Galaxies · Physics 2014-04-11 Manasvi Lingam , Phuc H. Nguyen

The probability distribution function (PDF) of the mass surface density is an essential characteristic of the structure of molecular clouds or the interstellar medium in general. Observations of the PDF of molecular clouds indicate a…

Astrophysics of Galaxies · Physics 2015-06-18 Joerg Fischera