English
Related papers

Related papers: Resolving Horizon-Scale Dynamics of Sagittarius A*

200 papers

The super-massive 4 million solar mass black hole Sagittarius~A* (SgrA*) shows flare emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a…

We report measurements with the Very Long Baseline Array of the proper motion of Sgr A* relative to two extragalactic radio sources spanning 18 years. The apparent motion of Sgr A* is -6.411 +/- 0.008 mas/yr along the Galactic plane and…

Astrophysics of Galaxies · Physics 2020-04-01 M. J. Reid , A. Brunthaler

(abridged) The black hole Sagittarius A* (Sgr A*) is a prime target for next-generation Earth-space very-long-baseline interferometry missions such as the Black Hole Explorer (BHEX), which aims to probe baselines of the order of 20…

High Energy Astrophysical Phenomena · Physics 2025-07-16 Aditya Tamar , Ben Hudson , Daniel C. M. Palumbo

Polarimetric light curves of Sagittarius A* (Sgr A*) sometimes exhibit loops in the Stokes $Q$ and $U$ plane over time, often interpreted as orbiting hotspot motion. In this work, we apply the differential geometry of planar curves to…

High Energy Astrophysical Phenomena · Physics 2025-07-15 Angelo Ricarte , Nicholas S. Conroy , Maciek Wielgus , Daniel Palumbo , Razieh Emami , Chi-kwan Chan

This paper presents the Suzaku results obtained for the Sagittarius (Sgr) C region using the concept of X-ray reflection nebulae (XRNe) as the echo of past flares from the super massive black hole, Sgr A*. The Sgr C complex is composed of…

Astrophysics of Galaxies · Physics 2016-03-02 Syukyo Gando Ryu , Masayoshi Nobukawa , Shinya Nakashima , Takeshi Go Tsuru , Katsuji Koyama , Hideki Uchiyama

Sagittarius A* (SgrA*) lying in the Galactic Centre $8$ kpc from Earth, hosts the closest supermassive black hole known to us. It is now inactive, but there is evidence indicating that about six million years ago it underwent a powerful…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Pau Amaro-Seoane , Xian Chen

Sagittarius A*, the supermassive black hole at the center of our galaxy, exhibits episodic near-infrared flares. The recent monitoring of three such events by the GRAVITY instrument has shown that some flares are associated with orbital…

High Energy Astrophysical Phenomena · Physics 2023-04-05 N. Aimar , A. Dmytriiev , F. H. Vincent , I. El Mellah , T. Paumard , G. Perrin , A. Zech

Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, undergoes large-amplitude near-infrared (NIR) flares that can coincide with the continuous rotation of the NIR emission region. One promising explanation…

High Energy Astrophysical Phenomena · Physics 2024-04-18 Arpiar Avetis Grigorian , Jason Dexter

Upcoming VLBI observations will resolve nearby supermassive black holes, most notably Sagittarius A* and M87, on event horizon-scales. Recent observations of Sagittarius A* with the Event Horizon Telescope have revealed horizon-scale…

High Energy Astrophysical Phenomena · Physics 2020-04-15 Ziri Younsi , Oliver Porth , Yosuke Mizuno , Christian M. Fromm , Hector Olivares

It has been suggested that there is possibly a class of stellar-mass black holes (BHs) residing near (distance $\le 10^3 M$) the galactic center massive black hole, Sgr A*. Possible formation scenarios include the mass segregation of…

High Energy Astrophysical Phenomena · Physics 2022-09-20 Shammi Tahura , Zhen Pan , Huan Yang

The centre of the Milky Way hosts a supermassive black hole of 4 million solar masses called Sagittarius A*. This object has been observed for more than 20 years in the near infrared. This has confirmed some effects of General Relativity.…

High Energy Astrophysical Phenomena · Physics 2024-01-02 Aimar Nicolas

Sagittarius A* (Sgr A*) exhibits frequent flaring activity across the electromagnetic spectrum, often associated with a localized region of strong emission, known as a hot spot. We aim to establish an empirical relationship linking key…

High Energy Astrophysical Phenomena · Physics 2026-02-25 A. I. Yfantis , D. C. M. Palumbo , M. Mościbrodzka

Sagittarius A* is a compact radio source at the Galactic center, powered by accretion of fully ionized plasmas into a supermassive black hole. However, the radio emission cannot be produced through the thermal synchrotron process by a…

High Energy Astrophysical Phenomena · Physics 2009-04-02 Kyle W. Martin , Siming Liu , Chris Fragile , Cong Yu , Chris L. Fryer

A radiatively inefficient accretion flow (RIAF), which is commonly characterized by its sub-Keplerian nature, is a favored accretion model for the supermassive black hole at Galactic center, Sagittarius A$^{*}$. To investigate the…

High Energy Astrophysical Phenomena · Physics 2016-10-26 Hung-Yi Pu , Kazunori Akiyama , Keiichi Asada

Sagittarius A* (Sgr A*) is a compact radio source at the Galactic center. Observations have confirmed that its mass is approximately (4.1)*10$^{6}$ M$_{\odot}$, and Sgr A* is generally believed to be powered by gas accretion onto a…

High Energy Astrophysical Phenomena · Physics 2026-03-05 Shenyue Yin , Siming Liu

The recent detection of variable infrared emission from Sagittarius A*, combined with its previously observed flare activity in X-rays, provides compelling evidence that at least a portion of this object's emission is produced by nonthermal…

Astrophysics · Physics 2009-11-10 Siming Liu , Vahe' Petrosian , Fulvio Melia

Observational data of the Sagittarius A* (Sgr A*) shadow released by the Event Horizon Telescope (EHT) are used to investigate eventual deviations in the black hole shadow radius, aiming to seek physics beyond the Standard Model (SM) coming…

General Relativity and Quantum Cosmology · Physics 2024-09-26 A. S. Lemos , J. A. V. Campos , F. A. Brito

The accretion flow around the Galactic Center black hole Sagittarius A* (Sgr A*) is expected to have an electron temperature that is distinct from the ion temperature, due to weak Coulomb coupling in the low-density plasma. We present four…

High Energy Astrophysical Phenomena · Physics 2018-05-31 Andrew Chael , Michael E. Rowan , Ramesh Narayan , Michael D. Johnson , Lorenzo Sironi

Sagittarius A* (Sgr A*) is the supermassive black hole residing at the center of the Milky Way. It has been the main target of an extensive multiwavelength campaign we carried out in April 2007. Herein, we report the detection of a bright…

High Energy Astrophysical Phenomena · Physics 2014-11-20 G. Trap , A. Goldwurm , R. Terrier , K. Dodds-Eden , S. Gillessen , R. Genzel , E. Pantin , P. O. Lagage , P. Ferrando , G. Belanger , D. Porquet , N. Grosso , F. Yusef-Zadeh , F. Melia
‹ Prev 1 4 5 6 7 8 10 Next ›