ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 272 (2000), S. 3-13 
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The development of galactic fountain theories is reviewed with special emphasis on the different approaches and concepts that have been used in the past. In particular the outstanding contribution of Franz Kahn to our physical understanding is appreciated. It is argued that galactic outflows represent an essential phase during galaxy evolution. The dynamics of the outflow imprints its signature on the emission spectra of soft X-rays, which may well be observable with AXAF and XMM. Finally, some remarks about winds in starburst galaxies and AGN are made.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 272 (2000), S. 299-302 
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Warm absorbers are an important new probe of the central region of active galaxies (AGN).Observing and modeling this component provides a wealth of information on the nature of the warm absorber itself, its relation to other components of the active nucleus, and the intrinsic AGN X-ray spectral shape. We briefly review the general properties of dusty warm gas. For the first time, we then apply such a model to the IR loud quasar. IRAS 13349+2438. It was the first to be suggested to host a dusty warm absorber (Brandt et al. 1996), but has not yet been modeled as such.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 272 (2000), S. 303-306 
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Narrow-line Seyfert 1 galaxy RX J0134.3-4258 was detected during the ROSAT all-sky survey with an ultrasoft spectrum (Greiner, 1996).Our later pointed observation led to the discovery of drastic spectral variability. Here, we present the first detailed analysis of the soft X-ray properties of this peculiar source.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 371 (1994), S. 774-777 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Observations show that associations of young massive stars (OB associations) produce superbubbles which are bound by outward propagating shock waves, compressing and heating swept-up interstellar gas (supershells). Although there is some disagreement whether a supershell ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 216 (1994), S. 297-301 
    ISSN: 1572-946X
    Keywords: stellar winds ; HII regions ; turbulence ; bipolar outflows
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We describe the process of turbulent mixing, occuring at the interface between the stellar wind bubble and the overlying, compressed HII layer. It is shown that hot electrons from the bubble can penetrate into the mixing region, where they deposit some fraction of their thermal energy. This first leads to an expansion of the gas at constant pressure, which soon becomes too inefficient to carry away the additional energy. Therefore pressure can build up in the mixing layer, forcing the gas to expand into the bubble. We also discuss the effect of the over-pressure on the HII shell and find that it is possible to punch a hole at the polar caps, where mixing is most efficient. This may lead to the formation of bipolar outflows. We apply our model to the wind-blown HII region NGC 6334(A), and show that it can explain the observed distortion of the bubble and the bipolar ionization cones.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Space science reviews 78 (1996), S. 183-198 
    ISSN: 1572-9672
    Keywords: Local Interstellar Medium ; EUV emission ; Soft X-ray Background ; Local Bubble models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A summary of the lively discussions in working group 2 (WG2) on the origin and evolution of the LB is given below. The debate focussed mainly on the problem of how to pin down the physical properties of the LB. As a first step, we had to critically assess the observational constraints that are put on any model, predominantly from the SXR and EUV data. Next we were discussing models on the origin and evolution of the LB, which are able to explain the observations and which would allow to infer basic LB properties. A simple model, emphasizing the self-consistent dynamical and thermal evolution of a non-equilibrium plasma is presented. We also found, that picturing the LB as an isolated phenomenon is not supported by the data. Instead, the LB environment and its influence on the evolution of the LB have to be taken into consideration. Two different views are presented here. Either the LB and the Loop I superbubble are two physically separate phenomena, which are currently interacting, or star formation epochs in the Scorpius-Centaurus Association interacting with the molecular gas in the Aquila Rift and the interarm region around the Sun may have sculpted the configuration of interstellar matter within 200 parsecs, including the Local Bubble. However, so far observational constraints are insufficient to establish a canonical model of the evolution and the origin of the LB.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Astrophysics and space science 272 (2000), S. 295-298 
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present here an analysis of the X-ray properties of a sample of LINER galaxies observed with the ROSAT PSPC and HRI instruments. A spatial analysis shows that the bulk of the X-ray emission is consistent with arising from a point source; some extended emission appears at weak emission levels. The X-ray spectra are formally best described by a power law with photon indexΓx ≈ −2 or thermal emission from a Raymond-Smith plasma with highly subsolar abundances (Z ≤ 0.1).Several emission mechanisms that might contribute to the observed X-ray spectra are discussed. In particular, we take the very subsolar abundances derived from Raymond-Smith fits as an indication of a more complex emission mechanism, like the presence of a second hard component or plasma out of equilibrium.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Space science reviews 75 (1996), S. 279-297 
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The nonthermal particle production in contemporary starburst galaxies and in galaxy clusters is estimated from the Supernova rate, the iron content, and an evaluation of the dynamical processes which characterize these objects. The primary energy derives from SN explosions of massive stars. The nonthermal energy is transformed by various secondary processes, like acceleration of particles by Supernova Remnants as well as diffusion and/or convection in galactic winds. If convection dominates, the energy spectrum of nonthermal particles will remain hard. At greater distances from the galaxy almost the entire enthalpy of thermal gas and Cosmic Rays will be converted into wind kinetic energy, implying a fatal adiabatic energy loss for the nonthermal component. If this wind is strong enough then it will end in a strong termination shock, producing a new generation of nonthermal particles which are subsequently released without significant adiabatic losses into the external medium. In clusters of galaxies this should only be the case for early type galaxies, in agreement with observations. Clusters should also accumulate their nonthermal component over their entire history and energize it by gravitational contraction. The pion decay γ-ray fluxes of nearby contemporary starburst galaxies is quite small. However rich clusters should be extended sources of very high energy γ-rays, detectable by the next generation of systems of air Cherenkov telescopes. Such observations will provide an independent empirical method to investigate these objects and their cosmological history.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2006-02-17
    Print ISSN: 0004-6361
    Electronic ISSN: 1432-0746
    Topics: Physics
    Published by EDP Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2017-08-01
    Print ISSN: 0004-6361
    Electronic ISSN: 1432-0746
    Topics: Physics
    Published by EDP Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...