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Related papers: Stellar Orbits Near Sagittarius A*

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The inner ~200 pc region of the Milky Way contains a nuclear stellar disc and a nuclear star cluster that are embedded in the larger Galactic bar. These stellar systems overlap spatially, which makes it challenging to separate stars that…

Astrophysics of Galaxies · Physics 2025-07-16 A. Feldmeier-Krause , T. Veršič , G. van de Ven , E. Gallego-Cano , N. Neumayer

We successfully measured the trigonometric parallax of Sagittarius A* (Sgr A*) to be $117\pm17$ micro-arcseconds ($\mu$as) using the VLBI Exploration of Radio Astrometry (VERA) with the newly developed broad-band signal-processing system…

We present a determination of the mass of the supermassive black hole (BH) and the nuclear stellar orbital distribution of the elliptical galaxy Centaurus A (NGC5128) using high-resolution integral-field observations of the stellar…

Stars orbiting within 1$\arcsec$ of the supermassive black hole in the Galactic Centre, Sgr A*, are notoriously difficult to detect due to obscuration by gas and dust. We show that some stars orbiting this region may be detectable via…

Astrophysics of Galaxies · Physics 2015-10-28 Idan Ginsburg , Xiawei Wang , Abraham Loeb , Ofer Cohen

Sagittarius A* (Sgr A*) is the variable radio, near-infrared (NIR), and X-ray source associated with accretion onto the Galactic center black hole. We present an analysis of the most comprehensive NIR variability dataset of Sgr A* to date:…

We present a new geometrical method for measuring the distance to the Galactic center (R_0) by solving for the Keplerian orbit of individual stars bound to the black hole associated with the Sgr A* from radial velocity and proper motion…

Astrophysics · Physics 2009-10-31 Samir Salim , Andrew Gould

High-velocity stars and peculiar G objects orbit the central supermassive black hole (SMBH) Sagittarius A* (Sgr A*). Together, the G objects and high-velocity stars constitute the S cluster. In contrast with theoretical predictions, no…

Astrophysics of Galaxies · Physics 2024-12-18 Florian Peißker , Michal Zajacek , Lucas Labadie , Emma Bordier , Andreas Eckart , Maria Melamed , Vladimir Karas

Recent broad-band 34 and 44 GHz radio continuum observations of the Galactic center have revealed 41 massive stars identified with near-IR counterparts, as well as 44 proplyd candidates within 30" of Sgr A*. Radio observations obtained in…

Astrophysics of Galaxies · Physics 2015-08-19 F. Yusef-Zadeh , H. Bushouse , R. Schödel , M. Wardle , W. Cotton , D. A. Roberts , F. Nogueras-Lara , E. Gallego-Cano

Empirically determining the averaged variations of the orbital parameters of the stars orbiting the Supermassive Black Hole (SBH) hosted by the Galactic Centre (GC) in Sgr A* is, in principle, a valuable tool to put on the test the General…

General Relativity and Quantum Cosmology · Physics 2017-10-06 Lorenzo Iorio

The angular momentum evolution of stars close to massive black holes (MBHs) is driven by secular torques. In contrast to two-body relaxation, where interactions between stars are incoherent, the resulting resonant relaxation (RR) process is…

Astrophysics of Galaxies · Physics 2015-05-20 Ann-Marie Madigan , Clovis Hopman , Yuri Levin

Aims. We aim to characterize the properties of the inner companion of the S-type AGB star pi1 Gru and to identify plausible future evolutionary scenarios for this triple system. Methods. We observed pi1 Gru with ALMA and VLT/SPHERE. In…

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

The IRS 13E complex is an unusual concentration of massive, early-type stars at a projected distance of ~0.13 pc from the Milky Way's central supermassive black hole Sagittarius A* (Sgr A*). Because of their similar proper motion and their…

Astrophysics · Physics 2009-11-11 R. Schoedel , A. Eckart , C. Iserlohe , R. Genzel , T. Ott

The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation (ref 1). Sagittarius A*, the compact source of radio, infrared…

We analyze the nuclear stellar dynamics of the SB0 galaxy NGC 1023, utilizing observational data both from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope and from the ground. The stellar kinematics measured from…

Radio images of the Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), are dominated by interstellar scattering. Previous studies of Sgr A* have adopted an anisotropic Gaussian model for both the intrinsic source and the…

The near-infrared emission from the black hole at the Galactic center (Sgr A*) has unique properties. The most striking feature is a suggestive periodic sub-structure that has been observed in a couple of flares so far. Using near-infrared…

Astrophysics · Physics 2009-11-13 L. Meyer , R. Schoedel , A. Eckart , W. J. Duschl , V. Karas , M. Dovciak

The supermassive black hole Sagittarius A* (Sgr A*) is located at the dynamical center of the Milky Way. In a recent study of the X-ray flaring activity from Sgr A* using Chandra, XMM-Newton and Swift data from 1999 to 2015, it has been…

High Energy Astrophysical Phenomena · Physics 2020-04-15 E. Mossoux , B. Finociety , J. -M. Beckers , F. H. Vincent

Sagittarius A* (Sgr A*) is the variable radio, near-infrared (NIR), and X-ray source associated with accretion onto the Galactic center black hole. We have analyzed a comprehensive submillimeter (including new observations simultaneous with…

We present a new constraint on the mass of the black hole in the active S0 galaxy NGC 5273. Due to the proximity of the galaxy at $16.6 \pm 2.1$ Mpc, we were able to resolve and extract the bulk motions of stars near the central black hole…

Astrophysics of Galaxies · Physics 2023-05-31 Katie A. Merrell , Eugene Vasiliev , Misty C. Bentz , Monica Valluri , Christopher A. Onken