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Related papers: A cool disk in the Galactic Center?

200 papers

The vertical structure of optically thick accretion disks is investigated in the two-zone approximation. The disk is divided into an underlying disk and a corona, where the latter is defined as the upper surface layers for which the…

Astrophysics · Physics 2009-11-07 Ranjeev Misra , R. E. Taam

Observations of massive stars within the central parsec of the Galaxy show that, while most stars orbit within a well-defined disc, a significant fraction have large eccentricities and / or inclinations with respect to the disc plane. Here,…

Astrophysics · Physics 2009-03-08 Jorge Cuadra , Philip J. Armitage , Richard D. Alexander

The soft excess in active galactic nuclei (AGNs) may arise through a combination of relativistic reflection and the effects of a warm corona at the surface of the accretion disc. Detailed examination of the soft excess can therefore…

High Energy Astrophysical Phenomena · Physics 2024-04-05 D. R. Ballantyne , V. Sudhakar , D. Fairfax , S. Bianchi , B. Czerny , A. De Rosa , B. De Marco , R. Middei , B. Palit , P. -O. Petrucci , A. Rozanska , F. Ursini

This study investigates the thermal stability of thin accretion disks in high-energy astrophysical systems, incorporating the effects of magnetic fields, winds, and coronae. We analyze how these factors influence disk stability, focusing on…

High Energy Astrophysical Phenomena · Physics 2025-01-28 Arezoo Tajmohamadi , Shahram Abbassi

For most of their lives, galaxies are surrounded by large and massive coronae of hot gas, which constitute vast reservoirs for gas accretion. This Chapter describes a mechanism that allows star-forming disc galaxies to extract gas from…

Astrophysics of Galaxies · Physics 2017-05-31 Filippo Fraternali

Disc galaxies like the Milky Way are expected to be surrounded by massive coronae of hot plasma that may contain a significant fraction of the so-called missing baryons. We investigate whether the local (|vLSR|<400 km/s) warm-hot absorption…

Astrophysics of Galaxies · Physics 2015-06-15 A. Marasco , F. Marinacci , F. Fraternali

We study the accretion flow of a hot gas captured by the black hole gravity in the presence of a thin cold accretion disk. Such geometrical arrangement is expected in Active Galactic Nuclei (AGN) and in galactic X-ray binary systems because…

Astrophysics · Physics 2007-05-23 Sergei Nayakshin

If a supermassive black hole resides in the centers of galaxies, there are several effects expected to be observed. It is likely that accretion disks are around the supermassive black hole. Stellar interactions with the accretion flows…

Astrophysics · Physics 2009-10-31 Heon-Young Chang

We construct a disk-corona model which accounts for the optical-to-X-ray spectral properties of Seyfert nuclei and QSOs. We study emission spectrum emerging from a vertical disk-corona structure composed of two-temperature plasma by solving…

Astrophysics · Physics 2009-10-31 Toshihiro Kawaguchi , Toshiya Shimura , Shin Mineshige

The hot plasma permeating clusters of galaxies often shows a central peak in the X-ray surface brightness that is coincident with a drop in entropy. This is taken as evidence for a cooling flow where the radiative cooling in the central…

Astrophysics · Physics 2015-06-24 Marcus Brueggen , Christian R. Kaiser

We study a model of an accretion disc surrounded by an extended corona of the temperature 10^7 - 10^8 K. This corona modifies the disk spectrum since it redirects a significant fraction of the emission from the central parts towards the…

Astrophysics · Physics 2015-06-24 A. Kurpiewski , J. Kuraszkiewicz , B. Czerny

We discuss the structure of a central stellar cluster whose dynamics is influenced by gravitation of a supermassive black hole and by the dissipative interaction of orbiting stars with an accretion disc. We also take the effect of disc…

Astrophysics · Physics 2007-05-23 V. Karas , L. Subr

We apply the disk-corona evaporation model (Meyer & Meyer-Hofmeister) originally derived for dwarf novae to black hole systems. This model describes the transition of a thin cool outer disk to a hot coronal flow. The mass accretion rate…

Astrophysics · Physics 2009-10-31 B. F. Liu , W. Yuan , F. Meyer , E. Meyer-Hofmeister , G. Z. Xie

Circumplanetary disks can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary disks for…

Earth and Planetary Astrophysics · Physics 2016-12-07 J. Szulágyi , L. Mayer , T. Quinn

We show that the ultraviolet absorption features, newly discovered in HST spectra, are consistent with being formed in a layer that extends a few kpc above the disk of the Milky Way. In this interface between the disk and the Galactic…

Astrophysics of Galaxies · Physics 2015-06-12 Filippo Fraternali , Antonino Marasco , Federico Marinacci , James Binney

We study the influence of fuzzy-dark-matter cores on the orbits of stars at the Galactic centre. This dark matter candidate condenses into dense, solitonic cores, and, if a super-massive black hole is present at the centre of such a core,…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Yonadav Barry Ginat , Bence Kocsis

Gravitationally unstable disks can fragment and form bound objects provided that their cooling time is short. In protoplanetary disks radiative cooling is likely to be too slow to permit formation of planets by fragmentation within several…

Astrophysics · Physics 2011-02-11 Roman R. Rafikov

We examine heating and cooling in protostellar disks using 3-D radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized…

Earth and Planetary Astrophysics · Physics 2015-05-27 S. Hirose , N. J. Turner

New X-ray observations with XMM-Newton show a lack of spectral evidence for large amounts of cooling and condensing gas in the centers of galaxy clusters believed to harbour strong cooling flows. The paper reexplores the cooling flow…

Astrophysics · Physics 2009-11-07 H. Boehringer , K. Matsushita , E. Churazov , Y. Ikebe , Y. Chen

Massive and diffuse haloes of hot gas (coronae) are important intermediaries between cosmology and galaxy evolution, storing mass and angular momentum acquired from the cosmic web until eventual accretion on to star-forming discs. We…

Astrophysics of Galaxies · Physics 2017-01-20 Gabriele Pezzulli , Filippo Fraternali , James Binney