English
Related papers

Related papers: Some improvements to the spherical collapse model

200 papers

The efficiency of star formation, defined as the ratio of the stellar to total (gas and stellar) mass, is observed to vary from a few percent in regions of dispersed star formation to about a third in cluster-forming cores. This difference…

Astrophysics · Physics 2009-11-10 Fumitaka Nakamura , Zhi-Yun Li

Cosmological Perturbation Theory (PT) is a useful tool to study the cumulants of the density and velocity fields in the large scale structure of the Universe. In Papers I & II of this series we saw that the Spherical Collapse (SC) model…

Astrophysics · Physics 2009-10-30 P. Fosalba , E. Gaztanaga

Rotation curves constrain a galaxy's underlying mass density profile, under the assumption that the observed rotation produces a centripetal force that exactly balances the inward force of gravity. However, most rotation curves are measured…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. J. Dalcanton , A. Stilp

We investigate the properties of highly compressible turbulence, the compressibility arising from a small effective polytropic exponent $\gamma_e$ due to cooling. In the limit of small $\gamma_e$, the density jump at shocks is shown to be…

Astrophysics · Physics 2009-10-28 E. Vazquez-Semadeni , T. Passot , A. Pouquet

Spherical collapse predicts that a single value of the turnaround density (average matter density within the scale on which a structure detaches from the Hubble flow) characterizes all cosmic structures at the same redshift. It has been…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 Vasiliki Pavlidou , Giorgos Korkidis , Theodore Tomaras , Dimitrios Tanoglidis

Star clusters are subject to density irregularities in their host galaxy, such as giant molecular clouds (GMCs), the galactic disc and spiral arms, which are largely ignored in present day (N-body) simulations of cluster evolution. Time…

Astrophysics · Physics 2007-05-23 M. Gieles

In this article, our goal is to investigate the cosmological dynamics and structure formation in a modified cosmological framework inspired by a generalized mass-to-horizon entropy relation and consistent with the Clausius relation.…

General Relativity and Quantum Cosmology · Physics 2026-04-20 Subhra Mondal , Amitava Choudhuri

We review the properties of turbulent molecular clouds (MCs), focusing on the physical processes that influence star formation (SF). MC formation appears to occur during large-scale compression of the diffuse ISM driven by supernovae,…

Astrophysics · Physics 2007-05-23 J. Ballesteros-Paredes , R. S. Klessen , M. -M. Mac Low , E. Vazquez-Semadeni

Most massive galaxies are thought to contain a supermassive black hole in their centre surrounded by a tenuous gas environment, leading to no significant emission. In these quiescent galaxies, tidal disruption events represent a powerful…

High Energy Astrophysical Phenomena · Physics 2016-10-07 Clément Bonnerot , Elena M. Rossi , Giuseppe Lodato

Since 1995, numerous close-in planets have been discovered around low-mass stars (M to A-type stars). These systems are susceptible to be tidally evolving, in particular the dissipation of the kinetic energy of tidal flows in the host star…

Earth and Planetary Astrophysics · Physics 2016-11-28 Emeline Bolmont , Florian Gallet , Stéphane Mathis , Corinne Charbonnel , Louis Amard

We present 3D smoothed particle hydrodynamics simulations of the collapse of clumps formed through gravitational instability in the outer part of a protoplanetary disc. The initial conditions are taken directly from a global disc…

Earth and Planetary Astrophysics · Physics 2015-06-11 M. Galvagni , T. Hayfield , A. C. Boley , L. Mayer , R. Roskar , P. Saha

We present new Fokker-Planck models of the evolution of globular clusters, including gravitational tidal shocks. We extend our calculations beyond the core collapse by adopting three-body binary heating. Effects of the shocks are included…

Astrophysics · Physics 2009-10-30 Oleg Y. Gnedin , Hyung Mok Lee , Jeremiah P. Ostriker

A review of gravitational and hydrodynamical processes during formation of clusters and evolution of galaxies is given. Early, at the advent of N-body computer simulations, the importance of tidal fields in galaxy encounters has been…

Astrophysics · Physics 2015-06-24 Jan Palous

Dynamical friction leads to an orbital decay of massive objects like young compact star clusters or Massive Black Holes in central regions of galaxies. The dynamical friction force can be well approximated by Chandrasekhar's standard…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-01 A. Just , F. M. Khan , P. Berczik , A. Ernst , R. Spurzem

The Press-Schechter theory of the cosmological mass function and its modifications allow to constraint cosmological scenarios of the structure formation. Recently a few new models have been suggested that explored the influence of…

Astrophysics · Physics 2015-06-24 Sergei F. Shandarin

Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit {\black or overpredict} the development of observed large-scale structures. Traditional approaches to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-28 C. Prescod-Weinstein , N. Afshordi

We present an analytical model for the non-spherical collapse of overdense regions out of a Gaussian random field of initial cosmological perturbations. The collapsing region is treated as an ellipsoid of constant density, acted upon by the…

Astrophysics · Physics 2009-10-22 Daniel J. Eisenstein , Abraham Loeb

The dynamical evolution of short-period low-mass binary stars (with mass $M < 1.5M_{\odot}$, from formation to the late main-sequence, and with orbital periods less than $\sim$10 days) is strongly influenced by tidal dissipation. This…

Solar and Stellar Astrophysics · Physics 2025-07-18 Jessica Birky , Rory K. Barnes , James R. A. Davenport

We study the effect of stellar mass segregation driven by collisional relaxation within the potential well of a smooth dark matter halo. This effect is of particular relevance for old stellar systems with short crossing times, where small…

Astrophysics of Galaxies · Physics 2025-11-03 Raphaël Errani , Jorge Peñarrubia , Matthew G. Walker

We explore the effects of tidal interactions on star formation (SF) by analysing a sample of CALIFA survey galaxies. The sample consists of tidally and non-tidally perturbed galaxies, paired at the closest stellar mass densities for the…

‹ Prev 1 4 5 6 7 8 10 Next ›