English
Related papers

Related papers: Probabilistic Interpolation of Sagittarius A*'s Mu…

200 papers

The supermassive black hole, Sagittarius A* (Sgr A*), at the centre of the Milky Way undergoes regular flaring activity which is thought to arise from the innermost region of the accretion flow. We performed the monitoring observations of…

Observations of Sagittarius A* (Sgr A*) in near-infrared (NIR) show irregular flaring activity. Flares coincide with astrometric rotation of brightness centroid and with looping patterns in fractional linear polarization. These signatures…

High Energy Astrophysical Phenomena · Physics 2024-11-27 A. I. Yfantis , M. Wielgus , M. A. Mościbrodzka

We present the first detection from the Spitzer Space Telescope of 4.5 micron variability from Sgr A*, the emitting source associated with the Milky Way's central black hole. The >23 hour continuous light curve was obtained with the IRAC…

High Energy Astrophysical Phenomena · Physics 2015-06-22 J. L. Hora , G. Witzel , M. L. N. Ashby , E. E. Becklin , S. Carey , G. G. Fazio , A. Ghez , J. Ingalls , L. Meyer , M. R. Morris , H. A. Smith , S. P. Willner

In this paper, we provide a first physical interpretation for the Event Horizon Telescope (EHT)'s 2017 observations of Sgr A*. Our main approach is to compare resolved EHT data at 230 GHz and unresolved non-EHT observations from radio to…

High Energy Astrophysical Phenomena · Physics 2023-11-17 The Event Horizon Telescope Collaboration

An initial three-station version of the Event Horizon Telescope, a millimeter-wavelength very-long baseline interferometer, has observed Sagittarius A* (Sgr A*) repeatedly from 2007 to 2013, resulting in the measurement of a variety of…

Stellar dynamics indicate the presence of a super massive 3-4x10^6 Msun solm black hole at the Galactic Center. It is associated with the variable radio, near-infrared, and X-ray counterpart Sagittarius A* (SgrA*). The goal is the…

Using a combination of general-relativistic magnetohydrodynamics simulations and ray tracing of synchrotron emission, we study the effect of modest (24 degrees) misalignment between the black hole spin and plasma angular momentum, focusing…

High Energy Astrophysical Phenomena · Physics 2022-03-02 Christopher J. White , Eliot Quataert

The recent detection of a 3-hr X-ray flare by the Chandra Observatory has raised the possibility of enhanced emission over a broad range of wavelengths from Sgr A*, the suspected 2.6 x 10^6 solar mass black hole at the Galactic Center,…

Astrophysics · Physics 2009-11-07 S. D. Hornstein , A. M. Ghez , A. Tanner , M. Morris , E. E. Becklin , P. Wizinowich

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

We report the detection of the two-dimensional structure of the radio source associated with the Galactic Center black hole, Sagittarius A*, obtained from Very Long Baseline Array (VLBA) observations at a wavelength of 7mm. The intrinsic…

Sgr A* at the Galactic Center is a puzzling source. It has a mass M=(2.5+/-0.4) x 10^6 solar masses which makes it an excellent black hole candidate. Observations of stellar winds and other gas flows in its vicinity suggest a mass accretion…

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

At radio wavelengths, images of the compact radio source Sagittarius A* (Sgr A*) in the Galactic Center are scatter broadened with a lambda^2 dependence due to an intervening ionized medium. We present VLBI observations of Sgr A* at 86 GHz…

We present the first Chandra results of the giant molecular cloud Sagittarius B2 (Sgr B2), located about 100 pc away from the Galactic center. Diffuse X-rays are clearly separated from one-and-a-half dozen resolved point sources. The X-ray…

Astrophysics · Physics 2009-11-06 H. Murakami , K. Koyama , Y. Maeda

We present the longest, by a factor of two, near-infrared lightcurve from Sgr A* - the supermassive black hole in the Galactic center. Achieved by combining Keck and VLT data from one common night, which fortuitously had simultaneous…

Astrophysics · Physics 2009-11-13 L. Meyer , T. Do , A. Ghez , M. R. Morris , G. Witzel , A. Eckart , G. Belanger , R. Schoedel

Context. The properties of the accretion flow surrounding the supermassive central black hole of the Galaxy, Sgr A*, will be scrutinized by the new-generation instrument GRAVITY and the Event Horizon Telescope (EHT). Developing fast,…

High Energy Astrophysical Phenomena · Physics 2019-04-17 F. H. Vincent , M. A. Abramowicz , A. A. Zdziarski , M. Wielgus , T. Paumard , G. Perrin , O. Straub

In recent years, near-IR and X-ray flares have been detected from the Galaxy's central radio point source, Sagittarius A* (Sgr A*), believed to be a \~3.10^6 solar masses supermassive black hole. In some cases, the transient emission…

Astrophysics · Physics 2009-11-13 Michel Tagger , Fulvio Melia

We have performed monitoring observations of the flux density toward the Galactic center compact radio source, Sagittarius A* (Sgr A*), which is a supermassive black hole, from 1996 to 2005 using the Nobeyama Millimeter Array of the…

The gas cloud G2 falling toward Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, is supposed to provide valuable information on the physics of accretion flows and the environment of the black hole. We…

High Energy Astrophysical Phenomena · Physics 2015-04-22 J. -H. Park , S. Trippe , T. P. Krichbaum , J. -Y. Kim , M. Kino , A. Bertarini , M. Bremer , P. de Vicente
‹ Prev 1 3 4 5 6 7 10 Next ›