English
Related papers

Related papers: A radiation driven implosion model for the enhance…

200 papers

We present astrochemical photo-dissociation region models in which cosmic ray attenuation has been fully coupled to the chemical evolution of the gas. We model the astrochemical impact of cosmic rays, including those accelerated by…

Astrophysics of Galaxies · Physics 2019-06-26 Brandt A. L. Gaches , Stella S. R. Offner , Thomas G. Bisbas

Molecular clouds interacting with supernova remnants may be subject to a greatly enhanced irradiation by cosmic rays produced at the shocked interface between the ejecta and the molecular gas. Over the past decade, broad-band observations…

Astrophysics · Physics 2009-11-11 M. Fatuzzo , F. C. Adams , F. Melia

Diffuse interstellar clouds show large abundances of H_3^+ which can be maintained only by a high ionization rate of H_2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Nick Indriolo , Brian D. Fields , Benjamin J. McCall

We present radiation-magnetohydrodynamic simulations aimed at studying evolutionary properties of H\,{\normalsize II} regions in turbulent, magnetised, and collapsing molecular clouds formed by converging flows in the warm neutral medium.…

The main signature of the interaction between cosmic rays and molecular clouds is the high ionisation degree. This decreases towards the densest parts of a cloud, where star formation is expected, because of energy losses and magnetic…

Solar and Stellar Astrophysics · Physics 2015-10-21 Marco Padovani , Patrick Hennebelle , Alexandre Marcowith , Katia Ferrière

The value of the accretion luminosity during the early phases of star formation is a crucial information which helps us understand how stars form, yet it is still very difficult to obtain. We develop a new methodology to measure accretion…

Solar and Stellar Astrophysics · Physics 2025-11-26 L. Testi , A. Natta , S. Gozzi , C. F. Manara , J. P. Williams , R. Claes , U. Lebreuilly , P. Hennebelle , R. Klessen , S. Molinari

Gas metallicity $Z$ and the related dust-to-gas ratio $f_\textrm{d}$ can influence the growth of HII regions via metal line cooling and UV absorption. We model these effects in star-forming regions containing massive stars. We compute…

Astrophysics of Galaxies · Physics 2021-01-06 Ahmad A. Ali

Accretion-driven luminosity outbursts are a vivid manifestation of variable mass accretion onto protostars. They are known as the so-called FU Orionis phenomenon in the context of low-mass protostars. More recently, this process has been…

Solar and Stellar Astrophysics · Physics 2016-10-26 D. M. -A. Meyer , E. I. Vorobyov , R. Kuiper , W. Kley

Recent studies have suggested that low-energy cosmic rays (CRs) may be accelerated inside molecular clouds by the shocks associated with star formation. We use a Monte Carlo transport code to model the propagation of CRs accelerated by…

The evolution of radiation emitted during the dynamical collapse of metal-free protostellar clouds is investigated within a spherically symmetric hydrodynamical scheme that includes the transfer of radiation and the chemistry of the…

Astrophysics · Physics 2009-11-06 Emanuele Ripamonti , Francesco Haardt , Andrea Ferrara , Monica Colpi

The formation of massive stars may take place at relatively low accretion rates over a long period of time if the accretion can continue past the onset of core hydrogen ignition. The accretion may continue despite the formation of an…

Astrophysics · Physics 2009-11-10 Eric Keto

Massive star formation requires the accretion of gas at high rate while the star is already bright. Its actual luminosity depends sensitively on the stellar structure. We compute pre-main-sequence tracks for massive and intermediate-mass…

Solar and Stellar Astrophysics · Physics 2016-03-23 Lionel Haemmerlé , Thomas Peters

Massive protostars launch accretion-powered, magnetically-collimated outflows, which play crucial roles in the dynamics and diagnostics of the star formation process. Here we calculate the shock heating and resulting free-free radio…

Astrophysics of Galaxies · Physics 2023-09-08 Emiko C. Gardiner , Jonathan C. Tan , Jan E. Staff , Jon P. Ramsey , Yichen Zhang , Kei E. Tanaka

We present the first three-dimensional calculations of Radiation Driven Implosion of Molecular Clouds including self-gravity and ionization. We discuss the effects of initial density perturbations on the dynamics of ionizing globules and…

Astrophysics · Physics 2009-11-07 Olaf Kessel-Deynet , Andreas Burkert

Class I protostars in three high-mass star-forming regions are found to have correlations among the local projected density of other Class I protostars, the summed flux from these other protostars, and the protostellar luminosity in the…

Astrophysics of Galaxies · Physics 2015-06-18 Bruce G. Elmegreen , Rachel Hurst , Xavier Koenig

We explore to what extent simple algebraic models can be used to describe H II regions when winds, radiation pressure, gravity and photon breakout are included. We a) develop algebraic models to describe the expansion of photoionised H II…

Astrophysics of Galaxies · Physics 2020-01-08 Sam Geen , Eric Pellegrini , Rebekka Bieri , Ralf Klessen

We present an evolutionary sequence of models of the photoionized disk-wind outflow around forming massive stars based on the Core Accretion model. The outflow is expected to be the first structure to be ionized by the protostar and can…

Solar and Stellar Astrophysics · Physics 2016-02-17 Kei E. I. Tanaka , Jonathan C. Tan , Yichen Zhang

We construct a model for cosmic ray acceleration from protostellar accretion shocks and calculate the resulting cosmic ray ionization rate within star-forming molecular clouds. We couple a protostar cluster model with an analytic accretion…

Astrophysics of Galaxies · Physics 2018-07-25 Brandt A. L. Gaches , Stella S. R. Offner
‹ Prev 1 2 3 10 Next ›