English
Related papers

Related papers: Variable accretion and emission from the stellar w…

200 papers

(ABRIDGED) We present in detail our new 3D numerical models for the accretion of stellar winds on to Sgr A*. In our most sophisticated models, we put stars on realistic orbits around Sgr A*, include `slow' winds (300 km/s), and account for…

Astrophysics · Physics 2007-05-23 J. Cuadra , S. Nayakshin , V. Springel , T. Di Matteo

Sgr A* is currently being fed by winds from a cluster of gravitationally bound young mass-loosing stars. Using observational constraints on the orbits, mass loss rates and wind velocities of these stars, we numerically model the…

Astrophysics · Physics 2007-05-23 J. Cuadra , S. Nayakshin , V. Springel , T. Di Matteo

An attempt is made to reconcile the large wind-loss rates of stars in the Galactic Centre (GC) with the predicted low accretion rate for Sgr A*, the putative blackhole at the heart of the Milky Way. It is found that, independent of the…

Astrophysics · Physics 2016-08-30 R. F. Coker

Spectral and kinematic studies suggest that the nonthermal radio source Sgr A*, located at the center of the Milky Way, is a supermassive compact object with a mass 2-3 million solar masses. Winds from nearby stars, located approximately…

Astrophysics · Physics 2009-10-30 Robert F. Coker , F. Melia

The Galactic center provides a unique laboratory to study the interaction of a supermassive black hole (SMBH) with its gaseous and stellar environment. Simulations to determine the accretion of stellar winds from the surrounding O-stars…

Astrophysics of Galaxies · Physics 2016-01-20 Nora Lützgendorf , Edwin van der Helm , Inti Pelupessy , Simon Portegies Zwart

Gas clouds are present in the Galactic centre, where they orbit around the supermassive black hole. Collisions between these clumps reduce their angular momentum, and as a result some of the clumps are set on a plunging trajectory.…

High Energy Astrophysical Phenomena · Physics 2013-07-09 Bozena Czerny , Devaky Kunneriath , Vladimir Karas , Tapas K. Das

The central super-massive black hole of the Milky Way, Sgr A*, accretes at a very low rate making it a very underluminous galactic nucleus. Despite the tens of Wolf-Rayet stars present within the inner parsec supplying ${\sim}10^{-3}\rm\…

Astrophysics of Galaxies · Physics 2020-01-08 Diego Calderón , Jorge Cuadra , Marc Schartmann , Andreas Burkert , Christopher M. P. Russell

Sgr A* is an ideal target to study low-luminosity accreting systems. It has been recently proposed that properties of the accretion flow around Sgr A* can be probed through its interactions with the stellar wind of nearby massive stars…

High Energy Astrophysical Phenomena · Physics 2016-05-04 I. M. Christie , M. Petropoulou , P. Mimica , D. Giannios

The Milky Way's Galactic Center hosts the black hole Sagittarius A* (Sgr A*), which provides us with a close-up view into supermassive black hole accretion and feedback. Recent works have shown that the winds from $\sim 30$ Wolf-Rayet (WR)…

High Energy Astrophysical Phenomena · Physics 2026-01-16 Edward Skrabacz , Lena Murchikova , Sean M. Ressler , Asad Ukani , Siddhant Solanki

The observed rotation measures (RMs) towards the galactic centre magnetar and towards Sagittarius A* provide a strong constraint on MHD models of the galactic centre accretion flow, probing distances from the black hole separated by many…

High Energy Astrophysical Phenomena · Physics 2018-11-26 Sean M. Ressler , Eliot Quataert , James M. Stone

It is thought that many characteristics of the gaseous features within the central parsec of our Galaxy, are associated with the accretion of ambient plasma by a central concentration of mass. Using a 3D hydrodynamical code, we have been…

Astrophysics · Physics 2007-05-23 R. Coker , F. Melia

The massive black hole in our galactic center, Sgr A*, accretes only a small fraction of the gas available at its Bondi radius. The physical processes determining this accretion rate remain unknown, partly due to a lack of observational…

High Energy Astrophysical Phenomena · Physics 2015-03-18 Michael McCourt , Ann-Marie Madigan

The gas cloud G2 is currently being tidally disrupted by the Galactic Centre super-massive black hole, Sgr A*. The region around the black hole is populated by $\sim 30$ Wolf-Rayet stars, which produce strong outflows. We explore the…

Astrophysics of Galaxies · Physics 2015-12-16 D. Calderón , A. Ballone , J. Cuadra , M. Schartmann , A. Burkert , S. Gillessen

At the center of the Milky Way lurks a unique compact nonthermal radio source, Sgr A*. It is thought to be powered by a 2.6 million solar mass black hole that is accreting the stellar winds from the numerous early-type stars that exist in…

Astrophysics · Physics 2007-05-23 R. F. Coker , S. Markoff

How accretion proceeds around the massive black hole in the Galactic center and other highly sub-Eddington accretors remains poorly understood. The orbit of the S2 star in the Galactic center passes through the accretion disk of the massive…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Dimitrios Giannios , Lorenzo Sironi

The radio source Sgr A* at the center of our Galaxy is believed to be a 2.6 x 10^6 solar mass black hole which accretes gas from the winds of nearby stars. We show that limits on the X-ray and infrared emission from the Galactic Center…

Astrophysics · Physics 2009-10-31 Eliot Quataert , Ramesh Narayan , Mark Reid

We propose a 2-temperature radial dynamical model of plasma flow near Sgr A* and fit the bremsstrahlung emission to extensive quiescent X-Ray Chandra data. The model extends from several arcseconds to black hole (BH) gravitational radius,…

High Energy Astrophysical Phenomena · Physics 2009-12-18 Roman V. Shcherbakov , Frederick K. Baganoff

Winds from massive stars supply ~ 10^{-3} solar masss/year of gas to the central parsec of the Galactic Center. Spherically symmetric hydrodynamic calculations show that ~ 1 % of this gas, or ~ 10^{-5} solar masses/year, flows in towards…

Astrophysics · Physics 2009-11-10 Eliot Quataert

We present Athena++ grid-based, hydrodynamic simulations of accretion onto Sagittarius A* via the stellar winds of the $\sim 30$ Wolf-Rayet stars within the central parsec of the galactic center. These simulations span $\sim$ 4 orders of…

High Energy Astrophysical Phenomena · Physics 2018-06-26 Sean M. Ressler , Eliot Quataert , James M. Stone

The evidence for the presence of a concentration of dark matter at the Galactic center is now very compelling. There is no question that the stellar and gas kinematics within 0.01 pc is dominated by under-luminous matter in the form of…

Astrophysics · Physics 2009-10-30 Fulvio Melia , Robert Coker
‹ Prev 1 2 3 10 Next ›