Zobrazeno 1 - 10
of 56
pro vyhledávání: '"Jappsen, A. K."'
Autor:
Kitsionas, S., Federrath, C., Klessen, R., Schmidt, W., Price, D., Dursi, J., Gritschneder, M., Walch, S., Piontek, R., Kim, J., Jappsen, A. -K., Ciecielag, P., Mac Low, M. -M.
Contradicting results have been reported in the literature with respect to the performance of the numerical techniques employed for the study of supersonic turbulence. We aim at characterising the performance of different particle-based and grid-base
Externí odkaz:
http://arxiv.org/abs/0810.4599
Publikováno v:
Astrophys.J.694:1161-1170,2009
The formation of the first stars out of metal-free gas appears to result in stars at least an order of magnitude more massive than in the present-day case. We here consider what controls the transition from a primordial to a modern initial mass funct
Externí odkaz:
http://arxiv.org/abs/0810.1867
Publikováno v:
AIPConf.Proc.990:76-78,2008
In cold dark matter cosmological models, the first stars to form are believed to do so within small protogalaxies. We wish to understand how the evolution of these early protogalaxies changes once the gas forming them has been enriched with small qua
Externí odkaz:
http://arxiv.org/abs/0708.4363
Autor:
Glover, S. C. O., Jappsen, A. -K.
Publikováno v:
Astrophys.J.666:1-19,2007
We present a simplified chemical and thermal model designed to allow computationally efficient study of the thermal evolution of metal-poor gas within large numerical simulations. Our main simplification is the neglect of the molecular chemistry of t
Externí odkaz:
http://arxiv.org/abs/0705.0182
Autor:
Vazquez-Semadeni, E., Gomez, G. C., Jappsen, A. K., Ballesteros-Paredes, J., Gonzalez, R. F., Klessen, R. S.
Publikováno v:
Astrophys.J.657:870-883,2007
We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting compressions cause co
Externí odkaz:
http://arxiv.org/abs/astro-ph/0608375
Publikováno v:
Astrophys.J.660:1332-1343,2007
We study the influence of low levels of metal enrichment on the cooling and collapse of ionized gas in small protogalactic halos using three-dimensional, smoothed particle hydrodynamics simulations. Our initial conditions represent protogalaxies form
Externí odkaz:
http://arxiv.org/abs/astro-ph/0511400
Stars form by gravoturbulent fragmentation of interstellar gas clouds. The supersonic turbulence ubiquitously observed in Galactic molecular gas generates strong density fluctuations with gravity taking over in the densest and most massive regions. C
Externí odkaz:
http://arxiv.org/abs/astro-ph/0506349
(abridged version) Identifying the processes that determine the initial mass function of stars (IMF) is a fundamental problem in star formation theory. One of the major uncertainties is the exact chemical state of the star forming gas and its influen
Externí odkaz:
http://arxiv.org/abs/astro-ph/0410371
Autor:
Jappsen, A. -K., Klessen, R. S.
Publikováno v:
Astron.Astrophys. 423 (2004) 1-12
Using hydrodynamic simulations we investigate the rotational properties and angular momentum evolution of prestellar and protostellar cores formed from gravoturbulent fragmentation of interstellar gas clouds. We find the specific angular momentum j o
Externí odkaz:
http://arxiv.org/abs/astro-ph/0402361
Publikováno v:
J. Appl. Phys. 92, 3137 (2002)
The complex impedance of a semiconductor superlattice biased into the regime of negative differential conductivity and driven by an additional GHz ac voltage is computed. From a simulation of the nonlinear spatio-temporal dynamics of traveling field
Externí odkaz:
http://arxiv.org/abs/cond-mat/0112471