排序方式: 共有16条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Sergiy Silich Guillermo Tenorio-Tagle Casiana Muñoz-Tuñón 《Astrophysics and Space Science》2009,324(2-4):215-217
The existence of compact H?ii regions around massive stellar clusters with ages exceeding several Myr challenges our understanding of the physical processes occurring inside such clusters, and their impact on the interstellar medium of the host galaxy. Here, we summarize our recent results dealing with the hydrodynamics of matter ejected by massive stars inside the cluster and show that compact H?ii regions found around some massive clusters may indicate that these are evolving in a bimodal hydrodynamic regime. The latter is characterized by the accumulation of the injected matter in the central, thermally unstable zone, and by the ejection of mass supplied by massive stars in the outer regions of the cluster. 相似文献
5.
R. Wünsch J. Palouš G. Tenorio-Tagle S. Silich 《Astrophysics and Space Science》2009,324(2-4):219-223
It is shown that the winds of very massive and compact clusters evolve in a special bimodal way, such that in which the material deposited by stars into the inner cluster region becomes thermally unstable, forms cold dense clumps, and eventually feeds further episodes of star formation, while the material deposited into the outer region creates a quasi-stationary wind. We perform 2D numerical simulations of such winds using the finite difference hydrodynamic code ZEUS for which the cooling routine has been modified to make it suitable for modelling extremely fast cooling regions. We explore how the fraction of the deposited mass which is accumulated inside the cluster depends on the cluster parameters. 相似文献
6.
G. A. Añorve-Zeferino G. Tenorio-Tagle S. Silich 《Monthly notices of the Royal Astronomical Society》2009,394(3):1284-1306
In this work, we present a comprehensive X-ray picture of the interaction between a super star cluster and the interstellar medium. In order to do that, we compare and combine the X-ray emission from the superwind driven by the cluster with the emission from the wind-blown bubble. Detailed analytical models for the hydrodynamics and X-ray luminosity of fast polytropic superwinds are presented. The superwind X-ray luminosity models are an extension of the results obtained in Paper I. Here, the superwind polytropic character allows us to parametrize a wide variety of effects, for instance, radiative cooling. Additionally, X-ray properties that are valid for all bubble models taking thermal evaporation into account are derived. The final X-ray picture is obtained by calculating analytically the expected surface brightness and weighted temperature of each component. All of our X-ray models have an explicit dependence on metallicity and admit general emissivities as functions of the hydrodynamical variables. We consider a realistic X-ray emissivity that separates the contributions from hydrogen and metals. The paper ends with a comparison of the models with observational data. 相似文献
7.
G. S. Bisnovatyi-Kogan S. I. Blinnikov S. A. Silich 《Astrophysics and Space Science》1989,154(2):229-246
We present the results of calculations of blast waves propagation in plane-stratified medium, taking into account gravitational forces, pre-explosion gas motion and different laws of energy input into the cavity. The numerical hydrodynamic scheme based on infinitely thin-layer approximation is described. The results are compared with two-dimensional axisymmetric numerical calculations. The evolution of a superbubble in plane-stratified galactic disk is discussed. It is shown that late SNR structure is highly dependent on pre-supernova-interstellar gas relative motion. 相似文献
8.
Sergey A. Silich & Guillermo Tenorio-Tagle 《Monthly notices of the Royal Astronomical Society》1998,299(1):249-266
Two-dimensional calculations of the evolution of remnants generated by the strong mechanical energy deposited by stellar clusters in dwarf galaxies ( M ∼ 109 –1010 M⊙) are presented. The evolution is followed for times longer than both the blowout time and the presumed span of energy injection generated by a coeval massive stellar cluster. The remnants are shown to end up wrapping around the central region of the host galaxy, while growing to kiloparsec-scale dimensions. Properties of the remnants such as luminosity, size, swept-up mass and expansion speed are given as functions of time for all calculated cases. The final fate of the swept-up galactic gas and of the matter processed by the central starburst is shown to be highly dependent on the properties of the low-density galactic halo. Superbubbles powered by star clusters, with properties similar to those inferred from the observations, slow down in the presence of an extended halo to expansion speeds smaller than the host galaxy escape velocity. Values of the critical luminosity required for the superbubbles to reach the edge of the galaxies with a speed comparable to the escape speed are derived analytically and numerically. The critical luminosities are larger than those in the detected sources, and thus the superbubbles in amorphous dwarf galaxies must have already undergone blowout and are presently evolving into an extended low-density halo. This will inhibit the loss of the swept-up and processed matter from the galaxy. 相似文献
9.
Guillermo Tenorio-Tagle Sergey A. Silich Daniel Kunth Elena Terlevich Roberto Terlevich † 《Monthly notices of the Royal Astronomical Society》1999,309(2):332-342
The detection of Ly α emission in star-forming galaxies in different shapes and intensities (always smaller than predicted for case B recombination) has puzzled the astronomical community for more than a decade. Here we use two-dimensional calculations to follow the evolution of superbubbles and of the H ii regions generated by the output of UV photons from massive stars. We show the impact caused by massive star formation in the ISM of different galaxies and we look at the conditions required to detect Ly α emission from a nuclear H ii region, and the variety of profiles that may be expected as a function of time. 相似文献
10.
Daniel Kunth Françcois Legrand Guillermo Tenorio-Tagle Sergey Silich J. Miguel Mas-Hesse Miguel Cerviño 《Astrophysics and Space Science》2002,281(1-2):261-266
We show evidences that gas outflows occur in starburst galaxies as superbubbles evolve. We then question whether hot gas will
be expelled and enrich the IGM with metals or be retained within the host galaxy. For this purpose we construct three extreme
scenarios of the star formation histories for a sample of dwarf galaxies using either their present metallicity or their luminosity.
The three scenarios imply different mechanical energy input rates, those are compared with theoretical lower limits for the
ejection of processed matter out of host galaxies. The comparison strongly points at the existence of extended gaseous haloes
acting as a barrier that allows these galaxies to retain their metals and enhance their abundance. Our findings strongly point
that continuous star-forming processes, rather than coeval bursts, must contribute to the overall metallicity in our galaxy
sample.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献