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Related papers: Performance test of RM CLEAN and its evaluation wi…

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Recovering low-rank and sparse matrices from incomplete or corrupted observations is an important problem in machine learning, statistics, bioinformatics, computer vision, as well as signal and image processing. In theory, this problem can…

Machine Learning · Computer Science 2014-09-04 Fanhua Shang , Yuanyuan Liu , Hanghang Tong , James Cheng , Hong Cheng

We present a broadband polarization analysis of 36 discrete polarized radio sources over a very broad, densely-sampled frequency band. Our sample was selected on the basis of polarization behaviour apparent in narrowband archival data at…

High Energy Astrophysical Phenomena · Physics 2016-07-06 C. S. Anderson , B. M. Gaensler , I. J. Feain

Flux calibration of spectra in reverberation mapping (RM) is most often performed by assuming the flux constancy of some specified narrow emission lines, which stem from an extended region that is sometimes partially spatially resolved, in…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Yan-Rong Li , Jian-Min Wang , Chen Hu , Pu Du , Jin-Ming Bai

We present a catalog of Faraday rotation measures (RMs) and redshifts for 4003 extragalactic radio sources detected at 1.4 GHz, derived by identifying optical counterparts and spectroscopic redshifts for linearly polarized radio sources…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-02 Alison M. Hammond , Timothy Robishaw , B. M. Gaensler

The standard formula for the rotation measure, RM, which determines the position angle, $\psi={\rm RM}\lambda^2$, due to Faraday rotation, includes contributions only from the portions of the ray path where the natural modes of the plasma…

Solar and Stellar Astrophysics · Physics 2015-05-20 D. B. Melrose

We investigate the Faraday rotation measure (RM) due to the intergalactic magnetic field (IGMF) through the cosmic web up to cosmological distances, using a model IGMF based on turbulence dynamo in the large-scale structure of the universe.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Takuya Akahori , Dongsu Ryu

We investigate the effect of radio-frequency interference (RFI) excision in estimating the cosmological \hi\ 21 cm power spectrum. Flagging of RFI-contaminated channels results in a non-uniform sampling of the instrumental bandpass…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 Arnab Chakraborty , Abhirup Datta , Aishrila Mazumder

We consider the effectiveness of foreground cleaning in the recovery of Cosmic Microwave Background (CMB) polarization sourced by gravitational waves for tensor-to-scalar ratios in the range $0<r<0.1$. Using the planned survey area,…

Magnetic fields are an energetically important component of star-formation galaxies, but it is often difficult to measure their properties from observations. One of the complexities stems from the fact that the magnetic fields, especially…

Astrophysics of Galaxies · Physics 2024-08-09 Amit Seta , Christoph Federrath

In this article we derive an unbiased expression for the expected mean-squared error associated with continuously differentiable estimators of the noncentrality parameter of a chi-square random variable. We then consider the task of…

Applications · Statistics 2012-10-15 Florian Luisier , Thierry Blu , Patrick J. Wolfe

Polarisation measurements of solar flares at millimetre-waves were used to investigate the magnetic field configuration of the emitting sources. We analyse two solar flares (SOL2013-02-17 and SOL2013-11-05) observed by the POlarisation…

Solar and Stellar Astrophysics · Physics 2020-05-05 Douglas F. da Silva , Paulo J. A. Simões , R. F. Hidalgo Ramírez , Adriana Válio

We present a harmonic model for the data analysis of an all-sky cosmic microwave background survey, such as Planck, where the survey is obtained through ring-scans of the sky. In this model, resampling and pixelisation of the data are…

We present an updated version of POLARIS, a well established code designated for dust polarisation and line radiative transfer (RT) in arbitrary astrophysical environments. We extend the already available capabilities with a synchrotron…

Astrophysics of Galaxies · Physics 2019-11-06 Stefan Reissl , Robert Brauer , Ralf S. Klessen , Eric W. Pellegrini

We investigate whether the method of wavelet-based Faraday rotation measure (RM) Synthesis can help us to identify structures of regular and turbulent magnetic fields in extended magnetized objects, such as galaxies and galaxy clusters.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 R. Beck , P. Frick , R. Stepanov , D. Sokoloff

Rotation measure synthesis allows the estimation of Faraday dispersion via a Fourier transform and is the primary tool to probe cosmic magnetic fields. We show this can be considered mathematically equivalent to the one dimensional…

Instrumentation and Methods for Astrophysics · Physics 2020-05-13 Luke Pratley , Melanie Johnston-Hollitt

This paper addresses the general problem of blind echo retrieval, i.e., given M sensors measuring in the discrete-time domain M mixtures of K delayed and attenuated copies of an unknown source signal, can the echo locations and weights be…

Sound · Computer Science 2018-11-01 Helena Peic Tukuljac , Antoine Deleforge , Rémi Gribonval

One of the main computational drawbacks in the application of 3-D iterative inversion techniques is the requirement of solving the field quantities for the updated contrast in every iteration. In this paper, the 3-D electromagnetic inverse…

Signal Processing · Electrical Eng. & Systems 2019-06-27 Shilong Sun , Bert Jan Kooij , Alexander G. Yarovoy

High-redshift 21-cm observations will provide crucial insights into the physical processes of the Epoch of Reionization. Next-generation interferometers such as the Square Kilometer Array will have enough sensitivity to directly image the…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-27 Simon Gazagnes , Léon V. E. Koopmans , Michael H. F. Wilkinson

Reverberation mapping (RM) is a powerful approach for determining the nature of the broad-line region (BLR) in active galactic nuclei. However, inferring physical BLR properties from an observed spectroscopic time series is a difficult…

Astrophysics of Galaxies · Physics 2019-06-28 S. W. Mangham , C. Knigge , P. Williams , Keith Horne , A. Pancoast , J. H. Matthews , K. S. Long , S. A. Sim , N. Higginbottom

Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum, with applications ranging from laser technology to self-referencing of frequency combs. However, accessing the nonlinear response of a medium…