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Related papers: Inverse Hubble Flows in Molecular Clouds

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We investigate the formation and evolution of giant molecular clouds (GMCs) by the collision of convergent warm neutral medium (WNM) streams in the interstellar medium, in the presence of magnetic fields and ambipolar diffusion (AD),…

Unified dark matter cosmologies economically combine missing matter and energy in a single fluid. Of these models, the standard Chaplygin gas is theoretically motivated, but faces problems in explaining large scale structure if linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Abdelrahman Abdullah , Amr El-Zant , Ali Ellithi

We present a systematic analysis of the velocity structure functions (VSFs) of 167 molecular clouds with angular sizes greater than $\sim$176 arcmin$^2$ in three sectors of the Galactic mid-plane. We calculated the 1st- to 3rd-order VSFs…

After cosmic inflation and before the transition to radiation domination, the cosmic energy density may have been dominated during an extended period by an oscillating massive scalar condensate. We show that during this period, sub-Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Karsten Jedamzik , Martin Lemoine , Jerome Martin

In the past two decades, secular evolution has emerged as an important new paradigm for the formation and evolution of the Hubble sequence of galaxies. A new dynamical mechanism was identified through which density waves in galaxies, in the…

Astrophysics of Galaxies · Physics 2012-03-08 Xiaolei Zhang , Ronald J. Buta

A significant tension has become manifest between the current expansion rate of our Universe measured from the cosmic microwave background by the Planck satellite and from local distance probes, which has prompted for interpretations of…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-27 Lucas Lombriser

We present semi-analytic dynamical models for giant molecular clouds evolving under the influence of HII regions launched by newborn star clusters. In contrast to previous work, we neither assume that clouds are in virial or energetic…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Christopher D. Matzner , Christopher F. McKee

We develop a model for the growth of dark matter halos and use it to study their evolved density profiles. In this model, halos are spherical and form by quiescent accretion of matter in clumps, called satellites. The halo mass as a…

Astrophysics · Physics 2009-10-30 Adi Nusser , Ravi Sheth

We use simulations of LSS formation to study the build-up of magnetic fields (MFs) in the ICM. Our basic assumption is that cosmological MFs grow in a MHD amplification process driven by structure formation out of a seed MF present at high…

Astrophysics · Physics 2010-12-09 Klaus Dolag , Dario Grasso , Volker Springel , Igor Tkachev

We consider the linear kinematics of large-scale peculiar motions in a perturbed Friedmann universe. In so doing, we take the viewpoint of the "real" observers that move along with the peculiar flow, relative to the smooth Hubble expansion.…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Eleni Tsaprazi , Christos G. Tsagas

A class of inflationary scenarios for primordial black hole (PBH) formation include a small barrier in the slope of the potential. There, the inflaton slows down, generating an enhancement of primordial perturbations. Moreover, the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-29 Albert Escrivà , Vicente Atal , Jaume Garriga

This study shows the connection between three previously observed but seemingly unrelated phenomena in hydrodynamic (HD) and magnetohydrodynamic (MHD) turbulent flows, involving the emergence of fluctuations occurring on very long time…

Fluid Dynamics · Physics 2015-05-28 P. Dmitruk , P. D. Mininni , A. Pouquet , S. Servidio , W. H. Matthaeus

The evolution of a prolate cloud at an Hii boundary is investigated using Smoothed Particle Hydrodynamics (SPH). The prolate molecular clouds in our investigation are set with their semi-major axis perpendicular to the radiative direction…

Solar and Stellar Astrophysics · Physics 2015-06-22 Timothy M. Kinnear , Jingqi Miao , Glenn J. White , Simon Goodwin

The formation of stars is governed by the intricate interplay of nonideal magnetohydrodynamic (MHD) effects, gravity, and turbulence. Computational challenges have hindered a comprehensive 3D exploration of this interplay, posing a…

Astrophysics of Galaxies · Physics 2025-07-15 Aris Tritsis

Here we examine the evolution of irradiated clouds using the Smoothed Particle Hydrodynamics ({\small SPH}) algorithm coupled with a ray-tracing scheme that calculates the position of the ionisation-front at each timestep. We present…

Astrophysics of Galaxies · Physics 2015-06-11 S. Anathpindika , H. C. Bhatt

The physical nature of the very local (<3 Mpc) Hubble flow is studied on the basis of the recent high precision observations in the Local Volume. A model including both analytical treatment and computer simulations describes the flow…

We re-examine the decoherence rate of primordial fluctuations within minimal inflationary models, using only the gravitational interactions required for the underlying fluctuation-generation mechanism itself. Since gravity provides the…

General Relativity and Quantum Cosmology · Physics 2025-09-10 C. P. Burgess , R. Holman , Greg Kaplanek

We investigate to what extent future microwave background experiments might be able to detect a suppression of fluctuation power on large scales in flat and open universe models. Such suppression would arise if fluctuations are generated by…

Astrophysics · Physics 2008-11-26 Arjun Berera , Alan F. Heavens

Formation of interstellar clouds as a consequence of thermal instability is studied using two-dimensional two-fluid magnetohydrodynamic simulations. We consider the situation of converging, supersonic flows of warm neutral medium in the…

Astrophysics of Galaxies · Physics 2015-05-14 Tsuyoshi Inoue , Shu-ichiro Inutsuka

A formalism that simultaneously searches for the monopolar and dipolar peculiar velocities is presented. The formalism is applied to (1) the Mark III catalogue, (2) Lauer and Postman's Abell cluster catalogue, and (3) Riess et al.'s Type Ia…

Astrophysics · Physics 2009-10-28 Xiangdong Shi