Zobrazeno 1 - 10
of 64
pro vyhledávání: '"Dursi, L. J."'
In this paper we discuss the effect of recombinations to highly excited states (n > 100) in hydrogen during the cosmological recombination epoch. For this purpose, we developed a new ODE solver for the recombination problem, based on an implicit Gear
Externí odkaz:
http://arxiv.org/abs/1003.4928
Autor:
Dursi, L. J., Pfrommer, C.
High-resolution X-ray observations have revealed cavities and `cold fronts' with sharp edges in temperature, density, and metallicity within galaxy clusters. Their presence poses a puzzle since these features are not expected to be hydrodynamically s
Externí odkaz:
http://arxiv.org/abs/0711.0213
Autor:
Dursi, L. J.
Publikováno v:
ApJ 670:221, Nov 20, 2007
There has been significant recent work which examines a situation where a thin magnetic layer is `draped' over a core merging into a larger cluster; the same process also appears to be at work at a bubble rising from the cluster centre. Such a thin m
Externí odkaz:
http://arxiv.org/abs/0706.3216
Autor:
Zingale, M., Dursi, L. J.
Publikováno v:
Astrophys.J.656:333-346,2007
We consider the competition of the different physical processes that can affect the evolution of a flame bubble in a Type Ia supernovae -- burning, turbulence and buoyancy. Even in the vigorously turbulent conditions of a convecting white dwarf, ther
Externí odkaz:
http://arxiv.org/abs/astro-ph/0610297
Autor:
Dursi, L. J.
Publikováno v:
Astrophys.J. 606 (2004) 1039-1056
Supernovae of Type Ia are used as standard candles for cosmological observations despite the as yet incomplete understanding of their explosion mechanism. In one model, these events are thought to result from subsonic burning in the core of an accret
Externí odkaz:
http://arxiv.org/abs/astro-ph/0312135
Autor:
Dursi, L. J., Zingale, M.
Block-structured AMR meshes are often used in astrophysical fluid simulations, where the geometry of the domain is simple. We consider potential efficiency gains for time sub-cycling, or time refinement (TR), on Berger-Collela and oct-tree AMR meshes
Externí odkaz:
http://arxiv.org/abs/astro-ph/0310891
Autor:
Robinson, K., Dursi, L. J., Ricker, P. M., Rosner, R., Calder, A. C., Zingale, M., Truran, J. W., Linde, T., Caceres, A., Fryxell, B., Olson, K., Riley, K., Siegel, A., Vladimirova, N.
Publikováno v:
Astrophys.J. 601 (2004) 621-643
Recent Chandra and XMM-Newton observations of galaxy cluster cooling flows have revealed X-ray emission voids of up to 30 kpc in size that have been identified with buoyant, magnetized bubbles. Motivated by these observations, we have investigated th
Externí odkaz:
http://arxiv.org/abs/astro-ph/0310517
Autor:
Alexakis, A., Calder, A. C., Heger, A., Brown, E. F., Dursi, L. J., Truran, J. W., Rosner, R., Lamb, D. Q., Timmes, F. X., Fryxell, B., Zingale, M., Ricker, P. M., Olson, K.
Publikováno v:
Astrophys.J.602:931-937,2004
Many classical nova ejecta are enriched in CNO and Ne. Rosner et al. recently suggested that the enrichment might originate in the resonant interaction between large-scale shear flows in the accreted H/He envelope and gravity waves at the interface b
Externí odkaz:
http://arxiv.org/abs/astro-ph/0307126
Autor:
Dursi, L. J., Zingale, M., Calder, A. C., Fryxell, B., Timmes, F. X., Vladimirova, N., Rosner, R., Caceres, A., Lamb, D. Q., Olson, K., Ricker, P. M., Riley, K., Siegel, A., Truran, J. W.
Publikováno v:
Astrophys.J. 595 (2003) 955-979
Critically understanding the `standard candle'-like behavior of Type Ia supernovae requires understanding their explosion mechanism. One family of models for Type Ia Supernovae begins with a deflagration in a Carbon-Oxygen white dwarf which greatly a
Externí odkaz:
http://arxiv.org/abs/astro-ph/0306176
Autor:
Zingale, M., Woosley, S. E., Cumming, A., Calder, A., Dursi, L. J., Fryxell, B., Olson, K., Ricker, P., Rosner, R., Timmes, F. X.
We look at the spreading of localized temperature perturbations in the accreted fuel layer of a non-rotating neutron star. The pressure at the base of the accreted fuel layer is large and the material is only partially degenerate. Any temperature per
Externí odkaz:
http://arxiv.org/abs/astro-ph/0211336