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Related papers: Star formation in accretion discs : from the Galac…

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Studies of the Galactic Centre suggest that in-situ star formation may have given rise to the observed stellar population near the central supermassive black hole (SMBH). Direct evidence for a recent starburst is provided by the currently…

A star acquires much of its mass by accreting material from a disc. Accretion is probably not continuous but episodic. We have developed a method to include the effects of episodic accretion in simulations of star formation. Episodic…

Astrophysics of Galaxies · Physics 2015-05-27 Dimitris Stamatellos , Anthony Whitworth , David Hubber

Stars are likely to form or to be captured in AGN disks. Their mass reaches an equilibrium when their rate of accretion is balanced by that of wind. If the exchanged gas is well mixed with the stellar core, this metabolic process would…

Astrophysics of Galaxies · Physics 2023-09-19 Mohamad Ali-Dib , Douglas N. C. Lin

Compact objects are expected to exist in the accretion disks of supermassive black holes (SMBHs) in active galactic nuclei (AGNs), and in the presence of such a dense environment ($\sim 10^{14}\,{\rm cm^{-3}}$), they will form a new kind of…

High Energy Astrophysical Phenomena · Physics 2021-04-21 Jian-Min Wang , Jun-Rong Liu , Luis C. Ho , Pu Du

It is well established that Solar-mass stars gain mass via disk accretion, until the mass reservoir of the disk is exhausted and dispersed, or condenses into planetesimals. Accretion disks are intimately coupled with mass ejection via polar…

We propose that the accretion disks fueling active galactic nuclei are supported vertically against gravity by a strong toroidal ($\phi-$direction) magnetic field that develops naturally as the result of an accretion disk dynamo. The…

High Energy Astrophysical Phenomena · Physics 2016-10-12 Mitchell C. Begelman , Joseph Silk

(Abridged) The Galactic Center (GC) hosts a population of young stars some of which seem to form mutually inclined discs of clockwise and counter clockwise rotating stars. We present a warped disc origin scenario for these stars assuming…

Astrophysics of Galaxies · Physics 2015-06-11 A. Ulubay-Siddiki , H. Bartko , O. Gerhard

Pebble accretion has become a popular component to core accretion models of planet formation, and is especially relevant to the formation of compact, resonant terrestrial planetary systems. Pebbles initially form in the inner protoplanetary…

Earth and Planetary Astrophysics · Physics 2019-03-06 Duncan H Forgan

Many disc-type post-asymptotic giant branch (post-AGB) stars are chemically peculiar, showing underabundances of refractory elements in their photospheres that correlate with condensation temperature. The aim of this paper is to investigate…

Solar and Stellar Astrophysics · Physics 2019-09-04 Glenn-Michael Oomen , Hans Van Winckel , Onno Pols , Gijs Nelemans

The collapse of massive molecular clumps can produce high mass stars, but the evolution is not simply a scaled-up version of low mass star formation. Outflows and radiative effects strongly hinder the formation of massive stars via…

Astrophysics · Physics 2007-05-23 Harold W. Yorke

The processes driving gas accretion on to supermassive black holes (SMBHs) are still poorly understood. Angular momentum conservation prevents gas within $\sim10\,$pc of the black hole from reaching radii $\sim10^{-3}\,$pc where viscous…

Astrophysics of Galaxies · Physics 2018-05-16 Christian Faber , Walter Dehnen

We consider the structure of self-gravitating marginally stable accretion disks in galactic centers in which a small fraction of the disk mass has been converted into proto-stars. We find that proto-stars accrete gaseous disk matter at…

Astrophysics · Physics 2009-11-11 Sergei Nayakshin

The disks of active galactic nuclei (AGNs) have emerged as a rich environment for the evolution of stars and their compact remnants. The very dense medium favors rapid accretion, while torques and migration traps enhance binary formation…

High Energy Astrophysical Phenomena · Physics 2021-07-07 Rosalba Perna , Hiromichi Tagawa , Zoltan Haiman , Imre Bartos

We investigate the properties of stars born via gravitational instability in accretion discs around supermassive black holes (SMBHs) in active galactic nuclei (AGN), and how this varies with the SMBH mass, accretion rate, or viscosity. We…

Astrophysics of Galaxies · Physics 2023-04-13 Andrea Derdzinski , Lucio Mayer

Stellar black holes (sBHs) are widely believed to exist in the accretion disks of active galactic nuclei (AGNs). Previous studies often focus on the transient emission produced by embedded sBHs. Here, we explore the possible observational…

High Energy Astrophysical Phenomena · Physics 2024-04-12 Shuying Zhou , Mouyuan Sun , Tong Liu , Jian-Min Wang , Jun-Xian Wang , Yongquan Xue

Supermassive stars born from pristine gas in atomically-cooled haloes are thought to be the progenitors of supermassive black holes at high redshifts. However, the way they accrete their mass is still an unsolved problem. In particular, for…

Solar and Stellar Astrophysics · Physics 2018-01-31 Lionel Haemmerlé , Tyrone E. Woods , Ralf S. Klessen , Alexander Heger , Daniel J. Whalen

Pebble accretion refers to the assembly of rocky planet cores from particles whose velocity dispersions are damped by drag from circumstellar disc gas. Accretion cross-sections can approach maximal Hill-sphere scales for particles whose…

Earth and Planetary Astrophysics · Physics 2018-08-15 Jonathan W. Lin , Eve J. Lee , Eugene Chiang

An accreting massive black hole (MBH) in a galactic nucleus is surrounded by a dense stellar cluster. We analyze and simulate numerically the evolution of a thin accretion disk due to its internal viscous torques, due to the frame-dragging…

Astrophysics of Galaxies · Physics 2015-05-30 Michal Bregman , Tal Alexander

Star formation occurs within dense regions of giant molecular clouds (GMCs), however, exactly how gas collects and evolves to form individual stars and what role dense cores play remains unclear. We use the Lagrangian cell information in…

Astrophysics of Galaxies · Physics 2026-04-09 Ananya Kaalva , Stella S. R. Offner , Nina Filippova , Michael Y. Grudic

In recent years, it has been demonstrated that massive stars see their infant circumstellar medium shaped into a large, irradiated, gravitationally unstable accretion disc during their early formation phase. Such discs constitute the gas…

Solar and Stellar Astrophysics · Physics 2024-05-31 D. M. -A. Meyer , E. Vorobyov