相关论文: Radio Linear and Circular Polarization from M81*

The Dominion Radio Astrophysical Observatory Deep Field polarization study has been matched with the Spitzer Wide-Area Infrared Extragalactic survey of the European Large Area Infrared Space Observatory Survey North 1 field. We have used…

New observations of Sgr A have been carried out with the VLA using the broadband (2 GHz) continuum mode at 5.5 GHz, covering the central 30 pc region of the RBZ at the Galactic center. Using the MS-MFS algorithms in CASA, we have imaged Sgr…

We present the peculiar case of PSZ2G091.83+26.11 at z=0.822. This cluster hosts a Mpc-scale radio halo and an elongated radio source, whose location with the respect to the intracluster medium (ICM) distribution and to the cluster centre…

We present a theoretical study of the emission from a superluminal polarization current whose distribution pattern rotates (with an angular frequency $\omega$) and oscillates (with a frequency $\Omega $) at the same time, and which…

Based on archival Chandra observations, we present a systematic timing survey of several hundred X-ray sources in M31, M81, and Centaurus A, mostly low-mass X-ray binaries (LXMBs), focusing on searching and characterizing aperiodic and…

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…

The central region of the Galaxy has been observed at 580, 620 and 1010 MHz with the Giant Metrewave Radio Telescope (GMRT). We detect emission from Sgr-A*, the compact object at the dynamical centre of the Galaxy, and estimate its flux…

Although the continua of radio-loud Active Galactic Nuclei (AGN) are typically dominated by synchrotron radiation over virtually the entire spectrum, it is not clear whether the radio and higher-frequency emission originate in the same or…

We present a series of new high-sensitivity and high-resolution radio-continuum images of M31 at \lambda=20 cm (\nu=1.4 GHz). These new images were produced by merging archived 20 cm radio-continuum observations from the Very Large Array…

We analyzed data in polarized intensity obtained with the Very Long Baseline Array (VLBA) at twelve epochs (one observation per month from January to December 2011) at 15, 24, and 43 GHz. For the absolute orientation of the electric vector…

The compact radio source at the center of our Galaxy, Sagittarius A* (Sgr A*), is the subject of intensive study as it provides a close-up view of an accreting supermassive black hole. Sgr A* provides us with a prototype of a low-luminosity…

With the Westerbork Synthesis Radio Telescope (WSRT), multi-frequency polarimetric images were taken of the diffuse radio synchrotron background in a region centered on (l,b) = (161,16). The observations were done simultaneously in 5…

I describe an observational program aimed at understanding the radio emission from distant, rapidly evolving galaxy populations. These observations were carried out at 1.4 and 8.5 GHz with the VLA centered on the Hubble Deep Field. Further…

We review recent observations of circularly polarized radiation from AGN made with the VLBA and with the ATCA. We also discuss briefly the detections of the Galactic sources Sag A* and SS433. The origin of the circular polarization is still…

We present the results of parsec-scale circular polarization (CP) measurements based on VLBA data for a number of radio-bright, core-dominated AGN obtained simultaneously at 15, 22 and 43 GHz. The degrees of CP $m_c$ for the VLBI core…

We present measurements with the VLBA of the variability in the centroid position of Sgr A* relative to a background quasar at 7-mm wavelength. We find an average centroid wander of 71 +/- 45 micro-arcsec for time scales between 50 and 100…

We present a radio polarization study of SN 1006, based on combined VLA and ATCA observations at 20 cm that resulted in sensitive images with an angular resolution of 10 arcsec. The fractional polarization in the two bright radio and X-ray…

The repeating FRB source, FRB 20201124A, was found to be highly active in March and April 2021. We observed the source with the Effelsberg 100-m radio telescope at 1.36 GHz on 9 April 2021 and detected 20 bursts. A downward drift in…

We conducted millimeter continuum observations for samples of nearby early-type galaxies (21 sources) and nearby low-luminosity active galactic nuclei (LLAGN; 16 sources) at 100 GHz (3 mm) using the Nobeyama Millimeter Array (NMA). In…

We present 1420 MHz (lambda=21cm) observations of polarized emission from an area of 117 degree square in the Galactic plane in Cygnus, covering 82 < l < 95, -3.5 < b < +5.5, a complex region where the line of sight is directed nearly along…