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The JWST has been collecting scientific data for over two years now. Scientists are now looking deeper into the data, which introduces the need to correct known systematic effects. Important limiting factors for the MIRI/MRS are the…

Instrumentation and Methods for Astrophysics · Physics 2024-06-18 Danny Gasman , Ioannis Argyriou , Jane E. Morrison , David R. Law , Alistair Glasse , Karl D. Gordon , Patrick J. Kavanagh , Craig Lage , Polychronis Patapis , G. C. Sloan

Preliminary VLBA polarisation results on 6 ``blazars'' from 6.5-cm to 7-mm are presented here. Observing at several different wavelengths, separated by short and long intervals, enabled reliable information about the magnetic (B) field…

Astrophysics · Physics 2007-10-02 Shane P. O'Sullivan , Denise C. Gabuzda

We present a diagnostic test of possible Galactic contamination of cosmic microwave background sky maps designed to provide an independent check on the methods used to compile these maps. The method involves a non-parametric measurement of…

Astrophysics · Physics 2009-11-10 Patrick Dineen , Peter Coles

We investigate the capability of ongoing radio telescopes for probing Faraday rotation measure (RM) due to the intergalactic magnetic field (IGMF) in the large-scale structure of the universe which is expected to be of order $O(1) {\rm…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Shinsuke Ideguchi , Keitaro Takahashi , Takuya Akahori , Kohei Kumazaki , Dongsu Ryu

We construct a simple and robust approach for deriving constraints on magnetic fields in galaxy clusters from rotation measure (RM) maps. Relaxing the commonly used assumptions of a correlation between the magnetic field strength and the…

High Energy Astrophysical Phenomena · Physics 2013-09-19 Gilad Rave , Doron Kushnir , Eli Waxman

Magnetic fields play an important role in plasma dynamics, yet it is a quantity difficult to measure accurately with physical probes, whose presence disturbs the very field they measure. The Faraday rotation of a polarized beam of light…

Calibration of instrumental polarization is critical for measuring polarized radio emissions from astrophysical sources to extract the magnetic field information in astrophysical, heliospheric, and terrestrial plasmas. At meter wavelengths,…

Instrumentation and Methods for Astrophysics · Physics 2025-05-08 Devojyoti Kansabanik , Angelos Vourlidas , Soham Dey , Surajit Mondal , Divya Oberoi

A transmitted, unknown radar signal is observed at the receiver through more than one path in additive noise. The aim is to recover the waveform of the intercepted signal and to simultaneously estimate the direction of arrival (DOA). We…

Statistics Theory · Mathematics 2011-03-30 Tabea Rebafka , Céline Lévy-Leduc , Maurice Charbit

Using a set of compilations of measurements for extragalactic radio sources we construct all-sky maps of the Faraday Rotation produced by the Galactic magnetic field. In order to generate the maps we treat the radio source positions as a…

Astrophysics · Physics 2009-11-10 Patrick Dineen , Peter Coles

The parsec-scale Faraday rotation measure (RM) distribution of six "blazars" is investigated using multi-frequency (4.6--43 GHz) polarization observations taken on 2006 July 2 with the VLBA. Analysis of the RM provides the direction of the…

Astrophysics · Physics 2009-02-11 Shane P. O'Sullivan , Denise C. Gabuzda

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

These Faraday rotation calculations of hot, thick accretion flows are motivated by the measured steady rotation measure (RM) of $\approx -6 \times 10^5$ rad m$^{-2}$ from Sgr A*. In our numerical simulations, the quasi-steady state…

Astrophysics · Physics 2011-02-11 Prateek Sharma , Eliot Quataert , James M. Stone

Multi-frequency polarimetry with the Very Long Baseline Array (VLBA) telescope has revealed absolute Faraday Rotation Measures (RMs) in excess of 1000 rad/m/m in the central regions of 7 out of 8 strong quasars studied (e.g., 3C 273, 3C…

Astrophysics · Physics 2009-10-31 G. B. Taylor

Radio map estimation (RME) is the problem of inferring the value of a certain metric (e.g. signal power) across an area of interest given a collection of measurements. While most works tackle this problem from a purely non-Bayesian…

Signal Processing · Electrical Eng. & Systems 2025-08-11 Tien Ngoc Ha , Daniel Romero

We aim to study the polarization and magnetic field properties of the SNR HB 9 using new 21-cm continuum cube data from the Five-hundred-meter Aperture Spherical radio telescope (FAST). We computed the Faraday depth at 21 cm, and…

Astrophysics of Galaxies · Physics 2025-05-21 Li Xiao , Ming Zhu , Xiao-Hui Sun , Wolfgang Reich , Patricia Reich , Peng Jiang , Chun Sun

The increased sensitivity of future radio telescopes will result in requirements for higher dynamic range within the image as well as better resolution and immunity to interference. In this paper we propose a new matrix formulation of the…

Astrophysics · Physics 2014-11-18 Chen Ben-David , Amir Leshem

We studied the polarization behavior of the quasar 3C 273 over the 1 mm wavelength band at ALMA with a total bandwidth of 7.5GHz across 223 to 243 GHz at 0.8 arcsec resolution, corresponding to 2.1 kpc at the distance of 3C 273. With these…

Astrophysics of Galaxies · Physics 2019-03-13 T. Hovatta , S. O'Sullivan , I. Martí-Vidal , T. Savolainen , A. Tchekhovskoy

Magnetic Particle Imaging (MPI) is a promising imaging modality that tracks magnetic nanoparticles (MNPs) to generate real time, high-resolution images. However, achieving an optimal balance between strong signal strength and sharp image…

Medical Physics · Physics 2025-12-18 Abuobaida M. khair , Wenjing Jiang , Moritz Wildgruber , Wenjun Xi , Xiaopeng Ma

We report on multi-frequency polarimetry Very Long Baseline Interferometry observations of active galactic nuclei using the VLBA. These observations are used to construct images of the Faraday Rotation Measure (RM) in J1613+342, Mrk 501, 3C…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 G. B. Taylor , R. Zavala

In the context of track fitting problems by a Kalman filter, the appropriate functional forms of the elements of the random process noise matrix are derived for tracking through thick layers of dense materials and magnetic field. This work…

Instrumentation and Detectors · Physics 2016-07-21 Kolahal Bhattacharya , Sudeshna Banerjee , Naba K Mondal
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