Transient Faraday-complex spectropolarimetric structure detected during radio flaring of Swift J1727 implies internal Faraday rotation from electron-proton jet plasma with rotating mass ~10^21 g, a small fraction of accreted mass.
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WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
11 Pith papers cite this work. Polarity classification is still indexing.
abstract
Astronomical widefield imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays. We present a new widefield interferometric imager that uses the w-stacking algorithm and can make use of the w-snapshot algorithm. The performance dependencies of CASA's w-projection and our new imager are analysed and analytical functions are derived that describe the required computing cost for both imagers. On data from the Murchison Widefield Array, we find our new method to be an order of magnitude faster than w-projection, as well as being capable of full-sky imaging at full resolution and with correct polarisation correction. We predict the computing costs for several other arrays and estimate that our imager is a factor of 2-12 faster, depending on the array configuration. We estimate the computing cost for imaging the low-frequency Square-Kilometre Array observations to be 60 PetaFLOPS with current techniques. We find that combining w-stacking with the w-snapshot algorithm does not significantly improve computing requirements over pure w-stacking. The source code of our new imager is publicly released.
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2026 11roles
background 1polarities
background 1representative citing papers
A calibration strategy using full-Jones corrections with an in-field unpolarised calibrator and visibility-based multi-epoch alignment enables sub-arcsecond polarimetric imaging with LOFAR at metre wavelengths.
VAPOLA releases multi-epoch multi-band ALMA full-Stokes products and polarimetric fits for AGN and Sgr A* via an automated pipeline and web portal.
MACSJ0417’s giant radio halo shows spectral steepening and radio–X-ray correlation consistent with turbulence from a 6:1 off-axis merger that preserved the cool core; pure hadronic models are energetically excluded.
EP250905a is best explained as a mildly off-axis structured-jet afterglow at z=2.714, possibly weakly magnified by a foreground galaxy at z=0.374.
Presents ultra-low frequency spectral index maps for 22 bright extended radio galaxies showing indices of ~0.5 near cores rising to >1.0 in lobes for FR I sources and 0.5-0.9 in FR II hotspots.
EP250304a/SN 2025fhm is presented as a member of an emerging subclass of shocked cocoon-dominated low-luminosity GRB-SNe based on spectral, photometric, and light-curve modeling comparisons to prior events.
Deep 3 GHz polarised source counts detect 65 sources (51 deg^{-2}), consistent with 1.4 GHz literature due to spectral index and depolarisation, with a 2σ upper limit of <2.0 deg^{-2} on polarised SFG density.
Multi-scale radio observations of 15 local U/LIRGs decompose emission to show nuclear components contribute ~50% on average while diffuse SF-related emission dominates ~80% of total power, with radio excess linked to AGN rather than boosted star formation.
Presents a non-negativity constrained iterative deconvolution method for SKA radio images that is fast and performs well on simulated point and extended sources in noise-free conditions.
Summarizes observational lessons on simulation pipelines and systematic mitigation from SKAO precursors for Cosmic Dawn and EoR studies.
citing papers explorer
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Spectropolarimetric detection of baryonic mass loading in a transient relativistic jet: application to the black hole X-ray binary Swift J1727.8$-$1613
Transient Faraday-complex spectropolarimetric structure detected during radio flaring of Swift J1727 implies internal Faraday rotation from electron-proton jet plasma with rotating mass ~10^21 g, a small fraction of accreted mass.
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Polarisation and Faraday rotation measure imaging at metre wavelengths with sub-arcsecond resolution: a foundational calibration strategy
A calibration strategy using full-Jones corrections with an in-field unpolarised calibrator and visibility-based multi-epoch alignment enables sub-arcsecond polarimetric imaging with LOFAR at metre wavelengths.
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VAPOLA -- A multi-year, multi-band polarization survey of AGN and Sgr A* at mm wavelengths with ALMA I. Survey Overview and Science-Ready Archival Products
VAPOLA releases multi-epoch multi-band ALMA full-Stokes products and polarimetric fits for AGN and Sgr A* via an automated pipeline and web portal.
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Multi-Wavelength Signatures of a Giant Cometary Radio Halo in MACSJ0417-1154
MACSJ0417’s giant radio halo shows spectral steepening and radio–X-ray correlation consistent with turbulence from a 6:1 off-axis merger that preserved the cool core; pure hadronic models are energetically excluded.
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Multi-wavelength Constraints on the Transient EP250905a
EP250905a is best explained as a mildly off-axis structured-jet afterglow at z=2.714, possibly weakly magnified by a foreground galaxy at z=0.374.
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The ultra low-frequency spectral properties of bright extended radio galaxies in the 3CRR catalogue
Presents ultra-low frequency spectral index maps for 22 bright extended radio galaxies showing indices of ~0.5 near cores rising to >1.0 in lobes for FR I sources and 0.5-0.9 in FR II hotspots.
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Probing a new subclass of llGRB-SN transients: Insights from EP250304a and its associated supernova
EP250304a/SN 2025fhm is presented as a member of an emerging subclass of shocked cocoon-dominated low-luminosity GRB-SNe based on spectral, photometric, and light-curve modeling comparisons to prior events.
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The VLA-COSMOS 3 GHz Large Project: Polarised source counts and catalogue
Deep 3 GHz polarised source counts detect 65 sources (51 deg^{-2}), consistent with 1.4 GHz literature due to spectral index and depolarisation, with a 2σ upper limit of <2.0 deg^{-2} on polarised SFG density.
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The PARADIGM Project II: Characterising Nuclear and Diffuse Radio Components in Local U/LIRGs
Multi-scale radio observations of 15 local U/LIRGs decompose emission to show nuclear components contribute ~50% on average while diffuse SF-related emission dominates ~80% of total power, with radio excess linked to AGN rather than boosted star formation.
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A Non-Negativity Iterative Approach to Image Deconvolution for SKA
Presents a non-negativity constrained iterative deconvolution method for SKA radio images that is fast and performs well on simulated point and extended sources in noise-free conditions.
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Observations of the Cosmic Dawn and Epoch of Reionization with the SKAO: Observational Lessons Learned from Precursors and Pathfinder Instruments
Summarizes observational lessons on simulation pipelines and systematic mitigation from SKAO precursors for Cosmic Dawn and EoR studies.