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We infer the absolute time dependence of kinematic gas temperature along a proposed orbit of molecular clouds in the Central Molecular Zone (CMZ) of the Galactic Center (GC). Ammonia gas temperature maps are one of the results of the…

Astrophysics of Galaxies · Physics 2017-02-22 Nico Krieger , Jürgen Ott , Fabian Walter , J. M. Diederik Kruijssen , Henrik Beuther , the SWAG team

We have calculated the radiation field, dust grain temperatures, and far infrared emissivity of numerical models of turbulent molecular clouds. When compared to a uniform cloud of the same mean optical depth, most of the volume inside the…

Astrophysics · Physics 2009-11-10 Thomas Bethell , Ellen Zweibel , Fabian Heitsch , J. S. Mathis

Detailed studies of the shape of dust emission spectra are possible thanks to the current instruments capable of observations in several sub-millimetre bands (e.g., Herschel and Planck). However, some controversy remains even on the basic…

Astrophysics of Galaxies · Physics 2015-06-03 M. Juvela , N. Ysard

We are interested in the influence of cloudy atmospheres on the thermal radius evolution of warm exoplanets from an interior modelling perspective. By applying a physically motivated but simple parameterized cloud model, we obtain the…

Earth and Planetary Astrophysics · Physics 2024-04-10 Anna Julia Poser , Ronald Redmer

To examine the evolution of giant molecular clouds in the stream of a hot plasma we performed two-dimensional hydrodynamical simulations that take full account of self-gravity, heating and cooling effects and heat conduction by electrons.…

Astrophysics · Physics 2009-11-13 W. Vieser , G. Hensler

The primary radiation generated in the central continuum-forming region of Active Galactic Nuclei can be reprocessed by very dense, small-scale clouds that are optically-thin to Thomson scattering. In spite of the extreme conditions…

Astrophysics · Physics 2015-06-24 Z. Kuncic , A. Celotti , M. J. Rees

We demonstrate that the observationally inferred rapid onset of star formation after parental molecular clouds have assembled can be achieved by flow-driven cloud formation of atomic gas, using our previous three-dimensional numerical…

Astrophysics · Physics 2009-11-13 Fabian Heitsch , Lee Hartmann

{It has recently been proposed that giant molecular complexes form at the sites where streams of diffuse warm atomic gas collide at transonic velocities.} {We study the global statistics of molecular clouds formed by large scale colliding…

Astrophysics · Physics 2009-11-13 P. Hennebelle , R. Banerjee , E. Vazquez-Semadeni , R. Klessen , E. Audit

The thermal stability of accretion disk and the possibility to see a limit-cycle behaviour strongly depends on the ability of the disk plasma to cool down. Various processes connected with radiation-matter interaction appearing in hot…

High Energy Astrophysical Phenomena · Physics 2017-08-16 Mikolaj Grzedzielski , Agnieszka Janiuk , Bozena Czerny

Mixing by hydrodynamical instabilities plays a key role in cloud-wind interactions, causing cloud destruction in the adiabatic limit and facilitating cloud survival with efficient radiative cooling. However, the rate of mixing in numerical…

Astrophysics of Galaxies · Physics 2026-02-11 Hannah Leary , Helena M. Richie , Evan Schneider

Accumulating observational evidence for a number of radio galaxies suggests an association between their jets and regions of active star formation. The standard picture is that shocks generated by the jet propagate through an inhomogeneous…

Astrophysics · Physics 2009-11-10 P. Chris Fragile , Stephen D. Murray , Peter Anninos , Wil van Breugel

We performed high resolution hydrodynamical simulations of dense cool clouds embedded in supernova-driven galactic superwinds. Here we present preliminary results of our reference model in which the effect of heat conduction are taken into…

Astrophysics · Physics 2007-05-23 A. Marcolini , D. K. Strickland , A. D'Ercole , T. M. Heckman

Aerosol opacity has emerged as a critical factor controlling transmission and emission spectra. We provide a simple guideline for the effects of aerosol morphology on opacity and residence time in the atmosphere, as it pertains to transit…

Earth and Planetary Astrophysics · Physics 2024-08-22 Sanaz Vahidinia , Sarah E. Moran , Mark S. Marley , Jeff N. Cuzzi

Warm absorber spectra contain bound-bound and bound-free absorption features seen in the X-ray and UV spectra from many active galactic nuclei (AGN). The widths and centroid energies of these features indicate they occur in outflowing gas,…

High Energy Astrophysical Phenomena · Physics 2023-04-12 Dev R Sadaula , Manuel A Bautista , Javier A Garcia , Timothy R Kallman

Energy loss through optically thin radiative cooling plays an important part in the evolution of astrophysical gas dynamics and should therefore be considered a necessary element in any numerical simulation. Although the addition of this…

Instrumentation and Methods for Astrophysics · Physics 2010-11-12 Allard Jan van Marle , Rony Keppens

Cold clouds embedded in warm media are very common objects in astrophysics. Their disruption timescale depends strongly on the dynamical configuration. We discuss the evolution of an initially homogeneous cold cloud embedded in warm…

Astrophysics · Physics 2009-11-11 F. Heitsch , A. D. Slyz , J. E. G. Devriendt , A. Burkert

Recent modeling of the warm absorber in active galactic nuclei has proved the usefulness of constant total (gas plus radiation) pressure models, which are highly stratified in temperature and density. We explore the consistency of those…

Astrophysics · Physics 2009-11-13 L. Chevallier , B. Czerny , A. Rozanska , A. C. Goncalves

Both absorption and emission line studies show that cold gas around galaxies is commonly outflowing at speeds of several hundred km$\,\textrm{s}^{-1}$. This observational fact poses a severe challenge to our theoretical models of galaxy…

Astrophysics of Galaxies · Physics 2018-07-25 Max Gronke , S. Peng Oh

We investigate the frequency comb induced radiation pressure force acting on a cloud of cold $^{87}$Rb atoms. Reduction and spectral broadening of the frequency comb force are observed as the cloud's optical thickness is increased. Since…

Atomic Physics · Physics 2022-05-04 Mateo Kruljac , Danijel Buhin , Domagoj Kovacic , Vjekoslav Vulic , Damir Aumiler , Ticijana Ban

Cosmic-ray and X-ray ionisations in molecular gas produce a weak far-ultraviolet flux through the radiative decay of H2 molecules that have been excited by collisions with energetic electrons (the Prasad-Tarafdar mechanism). I consider the…

Astrophysics · Physics 2009-10-31 Mark Wardle