Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-06-27
Mon.Not.Roy.Astron.Soc.362:626-648,2005
Astronomy and Astrophysics
Astrophysics
27 pages, 12 figures (4 in color), MNRAS accepted
Scientific paper
10.1111/j.1365-2966.2005.09343.x
In this paper we present high-resolution hydrodynamical models of warm ionized clouds embedded in a superwind, and compare the OVI and soft X-ray properties to the existing observational data. These models include thermal conduction, which we show plays an important role in shaping both the dynamics and radiative properties of the resulting wind/cloud interaction. Heat conduction stabilizes the cloud by inhibiting the growth of K-H and R-T instabilities, and also generates a shock wave at the cloud's surface that compresses the cloud. This dynamical behaviour influences the observable properties. We find that while OVI emission and absorption always arises in cloud material at the periphery of the cloud, most of the soft X-ray arises in the region between the wind bow shock and the cloud surface, and probes either wind or cloud material depending on the strength of conduction and the relative abundances of the wind with respect to the cloud. In general only a small fraction (<1%) of the wind mechanical energy intersecting a cloud is radiated away at UV and X-ray wavelengths, with more wind energy going into accelerating the cloud. Models with heat conduction at Spitzer-levels are found to produce observational properties closer to those observed in superwinds than models with no thermal conduction, in particular in terms of the OVI-to-X-ray luminosity ratio, but cloud life times are uncomfortably short (<1Myr) compared to the dynamical ages of real winds. We experimented with reducing the thermal conductivity and found that even when we reduced conduction by a factor of 25 that the simulations retained the beneficial hydrodynamical stability and low O{\sc vi}-to-X-ray luminosity ratio found in the Spitzer-level conductive models, while also having reduced evaporation rates.
D'Ercole Annibale
Heckman Timothy M.
Hoopes Charles G.
Marcolini Andrea
Strickland David K.
No associations
LandOfFree
The dynamics and high-energy emission of conductive gas clouds in supernova-driven galactic superwinds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The dynamics and high-energy emission of conductive gas clouds in supernova-driven galactic superwinds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The dynamics and high-energy emission of conductive gas clouds in supernova-driven galactic superwinds will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-646994