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

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…

PAPER WITHDRAWN. The recent detection of Sgr A* in the X-ray band, together with the radio polarization measurements conducted over the past few years, offer the best constraints yet for understanding the nature of the emitting gas within…

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 investigate radiatively inefficient accretion flow models for Sgr A*, the supermassive black hole in our Galactic Center, in light of new observational constraints. Confirmation of linear polarization in the submm emission argues for…

We report the detection of variable emission from Sgr A* in almost all wavelength bands (i.e. centimeter, millimeter, submillimeter, near-IR and X-rays) during a multi-wavelength observing campaign. Three new moderate flares are detected…

The mm to sub-mm spectrum of Sgr A* at the Galactic center, as well as its polarization characteristics, are consistent with the inner 10 Schwarzschild radii of a tight Keplerian emitting region of hot, magnetized, orbiting gas. This plasma…

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…

Millimeter polarimetry of Sgr A* probes the linearly polarized emission region on a scale of $\sim 10$ Schwarzschild radii ($R_S$) as well as the dense, magnetized accretion flow on scales out to the Bondi radius ($\sim 10^5 R_S$) through…

The detection of a mm/Sub-mm ``bump'' in Sgr A*'s radio spectrum suggests that at least a portion of its overall emission is produced within a compact accretion torus. This inference is strengthened by observations of strong linear…

Lensed gravitational waves will offer new means to probe the distribution of matter in the universe, complementary to electromagnetic signals. Lensed continuous gravitational waves provide new challenges and opportunities beyond those of…

In this study, we demonstrate some of the caveats in common statistical methods used for analysing astronomical variability timescales. We consider these issues specifically in the context of active galactic nuclei (AGNs) and use a more…

Context: Recent near-infrared polarization measurements of SgrA* show that its emission is significantly polarized during flares and consists of a non- or weakly polarized main flare with highly polarized sub-flares. The flare activity…

Very Long Baseline Interferometry (VLBI) at sub-millimeter waves has the potential to image the shadow of the black hole in the Galactic Center, Sagittarius A* (Sgr A*), and thereby test basic predictions of the theory of general…

Context. VX Sgr is a cool, evolved, and luminous red star whose stellar parameters are difficult to determine, which affects its classification. Aims. We aim to spatially resolve the photospheric extent as well as the circumstellar…

We report the time-resolved spectral analysis of a bright near-infrared and moderate X-ray flare of Sgr A*. We obtained light curves in the $M$-, $K$-, and $H$-bands in the mid- and near-infrared and in the $2-8~\mathrm{keV}$ and…

We measured the linear polarization of Sagittarius A* to be 7.2 +/- 0.6 % at 230 GHzusing the BIMA array with a resolution of 3.6 x 0.9 arcsec. This confirms the previously reported detection with the JCMT 14-m antenna. Our high resolution…

General relativistic magnetohydrodynamic (GRMHD) simulations of accretion disks and jets associated with supermassive black holes show variability on a wide range of timescales. On timescales comparable to or longer than the gravitational…

We explore the variability properties of long, high cadence GRMHD simulations across the electromagnetic spectrum using an efficient, GPU-based radiative transfer algorithm. We focus on both disk- and jet-dominated simulations with…

The Spitzer Space Telescope provides a unique view of the Universe at infrared wavelengths. Improved sensitivity and angular resolution over previous missions enable detailed studies of astrophysical objects, both in imaging and…

The radio emission from Sgr A$^\ast$ is thought to be powered by accretion onto a supermassive black hole of $\sim\! 4\times10^6~ \rm{M}_\odot$ at the Galactic Center. At millimeter wavelengths, Very Long Baseline Interferometry (VLBI)…