相关论文: The Circular Polarization of Sagittarius A* at Sub…

We summarize the current state of polarization observations of Sagittarius A*, the compact radio source and supermassive black hole candidate in the Galactic Center. These observations are providing new tools for understanding accretion…

We report here the detection of circular polarization in the Galactic Center black hole candidate, Sagittarius A*. The detection was made at 4.8 GHz and 8.4 GHz with the Very Large Array. We find that the fractional circular polarization at…

We report on the submillimeter properties of Sagittarius A* derived from observations with the Submillimeter Array and its polarimeter. We find that the spectrum of Sgr A* between 230 and 690 GHz is slightly decreasing when measured…

Sgr A* exhibits a persistent negative circular polarization (CP) at 230\,GHz, offering a powerful probe of the magnetic field geometry in its accretion flow. Using a stationary semi-analytic radiatively inefficient accretion flow (RIAF)…

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on…

The linearly polarized millimeter and sub-millimeter emission in Sagittarius A* is produced within 10 Schwarzschild radii of the supermassive black hole at the Galactic Center and may originate from a hot magnetized accretion disk, where…

We report here multi-epoch, multi-frequency observations of the circular polarization in Sagittarius A*, the compact radio source in the Galactic Center. Data taken from the VLA archive indicate that the fractional circular polarization at…

Many radio sources like quasars, blazars, radio galaxies, and micro-quasars exhibit circular polarisation (CP) with surprising temporal persistent handedness. As a possible explanation we propose that the CP is due to Faraday conversion…

We describe recent results for Sgr A*, M81* and other low luminosity active galactic nuclei. We have conducted linear and circular polarimetry over a frequency range of 1.4 to 230 GHz and detected a variety of phenomena. The polarization…

Using the Submillimeter Array, we have made the first high angular resolution measurements of the linear polarization of Sagittarius A* at submillimeter wavelengths, and the first detection of intra-day variability in its linear…

We present a search for linear polarization at 22 GHz, 43 GHz and 86 GHz from the nearest super massive black hole candidate, Sagittarius A*. We find upper limits to the linear polarization of 0.2%, 0.4% and 1%, respectively. These results…

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…

We report on 85-101 GHz light curves of the Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), observed in April 2017 with the Atacama Large Millimeter/submillimeter Array (ALMA). This study of high-cadence full-Stokes data…

The recent detection of significant linear polarization at mm and sub-mm wavelengths in the spectrum of Sgr A* (if confirmed) will be a useful probe of the conditions within several Schwarzschild radii ($r_S$) of the event horizon at the…

We report here BIMA array observations of linear polarization in Sagittarius A*, the compact radio source in the Galactic Center. These observations had a resolution of 20 arcsec x 5 arcsec oriented North-South. We do not detect linear or…

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…

We obtain estimates of Sgr A* accretion flow and black hole parameters by fitting polarized sub-mm observations with spectra computed using three-dimensional (3D) general relativistic (GR) magnetohydrodynamical (MHD) (GRMHD) simulations.…

The millimeter/submillimeter wavelength polarization of Sgr A* is known to be variable in both magnitude and position angle on time scales down to a few hours. The unstable polarization has prevented measurements made at different…

Sagittarius A* (Srg A*), the supermassive black hole at the center of the Milky Way, provides a unique laboratory to study accretion dynamics and plasma processes near the event horizon. We investigated the variability and polarization…

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…